Pest control guides

Two leaf beetles cause a disproportionate number of calls to gardening helplines because they are bright and easy to see. The red lily beetle attacks lilies and fritillaries, and the rosemary beetle feeds on rosemary, lavender, sage and thyme. This article summarises the Royal Horticultural Society (RHS) advice pages “Red lily beetle” and “Rosemary beetle”. It covers gardens in the UK, and the RHS says the rosemary beetle is now widespread in England and Wales, established in Scotland and present in Northern Ireland. This is general gardening information rather than a recommendation of any product.

Red lily beetle: recognising it

The RHS says adult lily beetles are 8mm long with bright red wing cases and thorax and a black head and legs. Clusters of orange-red, sausage-shaped eggs appear on the undersides of leaves, and the larvae reach 6 to 8mm, rotund and reddish brown with black heads, usually hidden under their own wet black excrement (frass). Young larvae graze the underside of leaves, leaving white or brown dried-up patches, and older larvae eat entire leaves from the tips. Adults make rounded holes in leaves and can also feed on petals and seed pods. The RHS says lilies and fritillaries are the only plants on which eggs are laid and the grubs develop. It warns that other red beetles, such as cardinal beetles and red soldier beetles, can be confused with the lily beetle, but these do not damage lilies.

Red lily beetle: season and impact

According to the RHS, lily beetles are active from late March to October. The adults overwinter as adults in soil, leaf litter and other sheltered places, not necessarily near lilies, and begin emerging on sunny days in late March and April. Eggs are laid in small batches from April to mid-summer, larvae go into the soil to pupate when fully fed, and the next generation of adults emerges from mid-summer onwards. There is only one generation a year, and the RHS says the late-summer adults will not mate and lay eggs until the following year. It says plants can still flower well despite leaf damage, but that heavy defoliation in early summer can result in undersized bulbs that may not flower the next year, and that lily beetle has become widespread in Britain and Ireland since the early 1990s.

Red lily beetle: what the RHS advises

The RHS advice is to tolerate populations of plant-feeding beetles where possible, since lilies and fritillaries can tolerate some damage, and to encourage wildlife such as birds, frogs, wasps and predatory ground beetles that eat the larvae and sometimes the adults. It advises removing beetles by hand where practical. It explains that beetles find lilies partly through volatile chemicals from the leaves and produce aggregation pheromones that draw more beetles, and concludes that there is no advantage in attempting to treat the soil below lily plants.

Rosemary beetle: recognising it

The RHS describes adults as shiny, 6 to 7mm long, with metallic purple and green stripes on the wing cases and thorax, and larvae as greyish-white with darker stripes, 8mm when fully grown. Both feed on foliage and flowers of rosemary, lavender, sage, thyme and some related plants, and leaves can be reduced to short stumps with greyish-brown discolouration. It says that in most cases the overall appearance and health of the plant remain unaffected.

Rosemary beetle: season and impact

The RHS says the beetle is most active from August to April, though adults are present throughout the year. In mid-summer adults are on host plants but usually do little or no feeding; in late summer they start feeding, mating and laying eggs, which hatch after about ten days. Adults and larvae then feed on the foliage from autumn to spring in mild weather. There is one generation a year, but because the adults are long-lived, old and new generations can overlap. The RHS says it was first found breeding in central London in the late 1990s and has since spread rapidly.

Rosemary beetle: what the RHS advises

The RHS says host plants often survive populations of this beetle without noticeable adverse effects, so control is not usually necessary and the beetle can be accepted as part of the biodiversity a healthy garden supports, or treated as a colourful addition. It recommends encouraging birds, frogs and predatory ground beetles and, where practical, removing beetles by hand, which can help keep numbers below the level at which serious damage occurs. For taller rosemary and lavender it suggests tapping or shaking branches over newspaper spread underneath to collect adults and larvae.

Where a pest controller fits in

Neither page recommends professional treatment. The legal position on pest products in Great Britain is set out in the site’s article on pest products as biocides.

Common questions

Should I treat the soil for lily beetle?

The RHS says there is no advantage in attempting to treat the soil below lily plants.

Is the rosemary beetle harmful to plants?

The RHS says the beetle does not eat enough to harm healthy plants and control is not usually necessary.

The bottom line

The RHS treats the red lily beetle as tolerable and manageable by hand, with natural enemies helping, and treats the rosemary beetle as something to accept or pick off, not to spray. For both, hand removal, patience and encouraging predators are the RHS’s recommended approach.

Sources

• Royal Horticultural Society, “Red lily beetle” (rhs.org.uk)
• Royal Horticultural Society, “Rosemary beetle” (rhs.org.uk)

Every autumn, householders report clusters of ladybirds on window frames or small grey creatures on a kitchen floor and ask whether a pest controller is needed. This article summarises the Royal Horticultural Society (RHS) advice pages “Harlequin ladybird” and “Woodlice”. It concerns Britain, where the RHS says the harlequin ladybird is now widespread in England and spreading in Wales, Scotland and Ireland. Not every pest question needs a treatment; these two are examples where the RHS advice is to tolerate or remove by hand. This is general information, not a substitute for professional identification.

What a harlequin ladybird is

The RHS says the harlequin ladybird is one of about 40 species of ladybird found in Britain and Ireland, is predatory and prefers aphids but will eat other insects. It originates from Japan and has been introduced around the world as a biological control agent against aphids. The RHS says it was not deliberately introduced to Britain or Ireland but became established in 2004. Adults are 8 to 10mm long and very variable in colour; the two most common forms are black with two red spots or orange with 18 black spots. Some native ladybirds also have many colour forms and can look similar, so identification is often not easy. The RHS notes that the native two-spot and ten-spot ladybirds are small, at 4 to 5mm. Sightings can be submitted to the UK Ladybird Survey.

Why they gather in buildings

According to the RHS, many ladybird species like to overwinter in groups inside buildings, and the harlequin is no exception. In autumn adults seek overwintering sites and can form large aggregations, which can become particularly evident on the south side of buildings and other structures. The RHS says the appearance of large groups indoors can cause some concern but that there is no danger associated with their presence, although they can exude a clear yellow liquid that may stain furnishings.

What can and cannot be done

The RHS states that it is not possible to discourage ladybirds from entering buildings, and that the ladybirds can be captured and removed or tolerated. For control, it says there are no means of controlling harlequin ladybirds, since any action would also harm native ladybirds, other aphid predators and other insects, and because they are now so well established and abundant that destroying a few in one area will not make any difference to overall numbers. For buildings, it advises that they can be tolerated or captured and released outdoors. The site’s article on cluster flies in lofts looks at another autumn insect that overwinters in buildings, and its guide to pest products as biocides covers what a product label means.

The ecology point

The RHS says a harlequin ladybird can be considered a useful addition to the garden because it feeds on aphids, but that it will also eat scale insects, the eggs and larvae of butterflies and moths, other small insects, other ladybirds and even its own kind. The RHS says there was a fear that it would out-compete native aphid predators, that evidence in Britain is so far mixed, and that research is ongoing.

Woodlice indoors

The RHS says there are 30 species of woodlice in Britain, five of which are often found in gardens. They are terrestrial crustaceans that shelter in dark, damp places, especially where decaying plant material accumulates, and feed largely on damp decomposing plant material, which makes them part of the garden’s nutrient recycling. They are up to 1cm long and often grey, and some species, known as pillbugs, can roll into a ball when threatened. During the day they hide under logs, stones and flower pots and at night they move around looking for food.

On damage, the RHS says woodlice do not usually damage healthy plants but can become associated with damage that has other causes, such as slug damage or plants that have died and begun to rot. It says they occasionally damage very soft tissues such as seedlings and sometimes strawberry fruits, and that holes in older, tougher plant material will have been caused by something else such as slugs or caterpillars. Its management advice is that they are a vital part of garden biodiversity and should be encouraged in a healthy garden, that they are naturally abundant, and that they are food for shrews, toads, centipedes, some spiders, ground beetles and parasitoid flies.

The RHS says that woodlice can come into houses from gardens but are unlikely to survive for long indoors unless they find a damp place to shelter. Repeated sightings inside can therefore be a clue to a damp area. The site’s article on silverfish and moisture indoors discusses a similar link between a damp home and insects.

Common questions

Are harlequin ladybirds dangerous?

The RHS says there is no danger associated with their presence indoors, although a clear yellow liquid they exude may stain furnishings.

Can I stop them coming in?

The RHS says it is not possible to discourage ladybirds from entering buildings; they can be captured and released outdoors or tolerated.

The bottom line

The RHS advises tolerating harlequin ladybirds indoors or releasing them outside, because they cannot be controlled without harming other insects, and treating woodlice as harmless garden recyclers that only linger indoors where it is damp. Neither, on the RHS’s account, calls for treatment.

Sources

• Royal Horticultural Society, “Harlequin ladybird” (rhs.org.uk)
• Royal Horticultural Society, “Woodlice” (rhs.org.uk)

Slugs and snails are the most common pest enquiry the Royal Horticultural Society (RHS) receives, according to its research project page. This article summarises the RHS advice page “Slugs and snails” and the RHS science page describing its “Gastropod barriers” experiment. It concerns gardens in the UK and reports a small trial as the RHS describes it. It is general gardening information, not a product recommendation. The related legal question of slug pellet products is covered in the site’s article on the metaldehyde slug pellet ban in Great Britain.

Why the RHS urges a lighter touch

The RHS says gardeners have long thought of slugs and snails as the bad guys, but they are valuable in the garden ecosystem. It says many species feed on decomposing organic matter such as dead leaves, dung and dead slugs and snails, helping the composting process, and that they are food for birds, frogs, toads, hedgehogs, slow-worms and ground beetles. It says only a few species feed on live plants, and that only young seedlings and particularly tasty plants such as hosta are severely eaten. The netted field slug, brown soil slug and common garden snail are named as the species most likely to be found feeding on garden plants. The RHS says there are over 44 species of slugs and 90 species of snails in the UK.

The RHS says slugs and snails are so abundant that some feeding is normal, that they cannot and should not be eradicated, and that targeted management to protect vulnerable plants such as seedlings and soft young shoots gives the best results.

Practical steps from the RHS

• Choose less palatable plants, such as woody plants, those with thick or waxy leaves and some herbaceous plants; the page lists examples such as lady’s mantle, geranium, foxglove and fuchsia.
• Transplant sturdier plantlets grown in pots rather than vulnerable seedlings, with cloches for protection.
• Encourage predators.
• Search by torchlight on mild, damp evenings and hand-pick into a container, moving them elsewhere in the garden, though the RHS warns that some species have homing instincts and may return.
• Water in the early morning rather than the evening, because evening watering provides ideal conditions for movement at night.

What the RHS barrier trial found

The RHS project page says barriers and repellents are often suggested in gardening publications, that copper had shown effects in laboratory studies, and that egg shells and bark mulch had not been scientifically studied. The trial ran from February to September 2018 at the Field Research Facility at RHS Wisley, using lettuce, a favourite of slugs and snails. It compared no treatment, copper tape around pots and collars in the ground, sharp horticultural grit, pine bark mulch, wool pellets and washed, dried and roughly crushed eggshells. Treatments were tested in pots on a small patio and in a raised vegetable bed, with nine replicated blocks, each with a paired patio and bed and randomised treatment order. Damage was scored weekly for six weeks, then measured with a leaf area meter and dry mass at harvest.

The RHS advice page reports that a recent RHS study in a garden-realistic scenario found no reduction in slug damage from barriers made of copper tape, bark mulch, eggshells, sharp grit or wool pellets. It adds that copper-based barriers have repelled slugs in some studies, and that many substances thought to repel slugs, including rough or strong-smelling ones, lack scientific evidence. The trial used one crop and one site over one season, so it shows these barriers did not work under those conditions and does not prove that no barrier works anywhere.

Traps and biological control

The RHS says gardeners who want to protect vulnerable borders or vegetable beds can manage numbers with traps or biological control. Traps include scooped-out half orange, grapefruit or melon skins laid cut side down, or jars part-filled with beer and sunk into the soil; they should be checked and emptied regularly, preferably every morning. It describes the nematode biological control sold as Nemaslug as specific to molluscs, with no adverse effect on other types of animals, and says the nematodes enter slugs’ bodies and cause a fatal disease. It warns that it should be used in a targeted way because it will affect all species of slug, including beneficial ones, and is unlikely to affect snails because they rarely contact soil-dwelling nematodes. For effectiveness the soil must be moist and warm, 5 to 20°C, so spring to early autumn is the best time; evening application to moist but well-drained soil is recommended, and heavy soils such as clay may give poorer results.

Slug pellets

To the question whether to use slug pellets, the RHS answers no: it says slug pellets, even organic ones, have been shown to have negative effects on wildlife in the garden, and that it is better to encourage natural predators and use cultural and biological controls. That is the RHS’s position as a gardening charity, not a legal statement.

Common questions

Do eggshells or copper tape keep slugs off?

In the RHS Wisley trial as summarised on its advice page, they did not reduce slug damage to lettuce in pots or a raised bed.

The bottom line

The RHS advises living with slugs and snails, protecting seedlings and vulnerable plants, choosing tougher plants, hand-picking and trapping, and using slug nematodes only where targeted. Its Wisley trial found no reduction in damage from several popular barriers, and it advises against slug pellets because of effects on wildlife.

Sources

• Royal Horticultural Society, “Slugs and snails” (rhs.org.uk)
• Royal Horticultural Society, “Gastropod barriers” (RHS science project) (rhs.org.uk)

Rat poison does not stay with the rat. Predators and scavengers that eat poisoned or weakened rodents can take up the poison as well, which is why professional rodenticide use in Great Britain sits within a stewardship scheme. This article summarises the UK Centre for Ecology & Hydrology (UKCEH) report “Second Generation Anticoagulant Rodenticides (SGARs) in Mammals and Predatory Birds: An interspecies comparison” (Predatory Bird Monitoring Scheme, dated 26 February 2025) and the Campaign for Responsible Rodenticide Use (CRRU UK) website, the industry body that runs the stewardship regime. It reports monitoring findings at the strength the report supports: the data are observational, and the report itself says its comparisons have gaps. This is general information, not advice on treating a rodent problem.

What the report is

The report compares residues of five second-generation anticoagulant rodenticides (SGARs) in the livers of predatory birds and mammals collected across the UK, and assesses how residues changed after the conditions for using SGARs were revised in 2015 and after the industry-led stewardship regime began. It says avian and mammalian predators and scavengers are widely exposed to SGARs, likely through feeding on contaminated prey, which can include non-target animals. Its data come largely from carcasses sent in by the public and from other monitoring programmes, so they describe animals that were found and submitted, not a random sample of wildlife.

Which animals showed the most residue

The authors report that residues were significantly higher in generalist and scavenger birds and mammals than in other groups. Among the mean liver concentrations they tabulate, peregrine falcons, which mainly eat birds, were lowest (about 13 ng/g wet weight), barn owls and tawny owls, which eat small mammals, were intermediate (means of roughly 63 to 96 and 86 to 109 ng/g), and red kites, which scavenge, were highest among the birds (about 190 to 200 ng/g). The red fox had a very high mean of 993 ng/g. The report says the differences reflect feeding strategy and habitat, and that species also differ in their sensitivity to the poisons.

For other mammals reported by the Wildlife Incident Investigation Scheme, the report says badgers, grey squirrels and hedgehogs had significantly lower residues than foxes. For hedgehogs it reports residues detected in 55% of samples (6 of 11), which is a very small sample. The report notes that most grey squirrels (9 of 16) were below the limit of quantification, but that a few had very high residues. Numbers this small cannot support conclusions about the population as a whole.

Trends over time and what they do not prove

The report says summed SGAR residues have significantly increased over time in most species examined, and that residues and their occurrence rose significantly after the regulation change. It notes that the increase is largely driven by brodifacoum residues, whereas difenacoum residues in barn owls have recently shown a decreasing trend. Exposure has continued to increase in some species, such as the red kite and buzzard.

The authors stress that these changes are concurrent with the regulation change and the stewardship regime, not proven to be caused by either. They say the contrasting patterns among the active ingredients could result from changes in how much and for what purpose the products are used, or from other environmental factors such as diet. They recommend further work to identify the ecological factors that drive uptake and to integrate them into monitoring, and say further analysis is needed to understand the effect of the regulation change and the effectiveness of stewardship. In other words, the report identifies a pattern of concern and does not settle its cause.

What stewardship is

CRRU UK says it was set up in response to concern from government agencies that wildlife such as barn owls, kestrels and red kites were being accidentally exposed to rodenticides, and that those agencies called for better stewardship. Under its “Think Wildlife” banner it promotes best practice. Its home page summarises the stewardship rules: they apply to the supply and use of rodenticides authorised for application by professionals outdoors and carrying labels with stewardship conditions; pest controllers, farmers and gamekeepers must be qualified to access professional products; the rule is “no proof, no supply” of competence; and users should use rodenticides only after careful consideration of all options, using first the methods expected to be fully effective but presenting lower risks to wildlife. It adds that rodenticide residues in wildlife are being monitored closely and that HSE and other government agencies oversee stewardship, wildlife residues and rodenticide availability.

The site’s article on why professional rat poison access differs from what you can buy explains the access rules, and the article on feeding garden birds without feeding rats covers a way of reducing the rat problem at source.

What this means for a householder

The report does not test any product or household method. A customer can reasonably ask a pest controller how they minimise risks to wildlife, given that CRRU’s own wording says lower-risk methods should be used first.

Common questions

Does the report say rat poison is killing barn owls?

No. It measures residues in livers, not the cause of death, and it notes that sensitivity to the poisons varies between species.

Has stewardship reduced exposure?

The report says residues generally rose over time in most species after the 2015 changes, and that it cannot separate the effects of the regulation change from stewardship.

The bottom line

UKCEH’s 2025 report shows that UK predators and scavengers are widely exposed to second-generation rodenticides, with the highest residues in generalists and scavengers such as foxes and red kites, and that residues generally rose over time. It does not prove why. CRRU UK’s stewardship scheme says professionals should use lower-risk methods first, and monitoring continues.

Sources

• UK Centre for Ecology & Hydrology, “Second Generation Anticoagulant Rodenticides (SGARs) in Mammals and Predatory Birds: An interspecies comparison” (26 February 2025) (pbms.ceh.ac.uk)
• CRRU UK, “Think Wildlife” (stewardship essentials) (thinkwildlife.org)
• CRRU UK, “About CRRU UK” (thinkwildlife.org)

Gardeners often notice notched leaves in summer and blame the wrong culprit, then lose a container plant in winter without knowing why. Vine weevil is the usual explanation. This article summarises the Royal Horticultural Society (RHS) advice pages “Vine weevil” and “Biological Control in the Garden”. It is aimed at gardeners in Britain, and the RHS describes vine weevil as very widespread and common there. This is general gardening information, not a recommendation of any product.

Two life stages, two kinds of damage

The RHS says vine weevils are broad-snouted beetles that can feed on a wide range of plants indoors and outdoors and can be especially damaging to plants in containers. The adults eat leaves in spring and summer, but it is the grubs that can cause the most damage over autumn and winter when they feed on plant roots, resulting in wilting and plant death. Most plant losses occur from September to March, when the grubs are becoming fully grown, according to the RHS biology notes.

Adults are about 9mm long, dull black with a dirty yellow mark on the wing cases, and are mainly active after dark, hiding by day in leaf litter beneath their host plants. They cannot fly but are excellent crawlers and climbers. The RHS says adults rarely cause enough damage to affect the vigour of plants; their notches around leaf margins are unsightly, especially on rhododendron, evergreen euonymus, hydrangea, epimedium, bergenia, primula and strawberry. The grubs are plump, white, C-shaped and legless, up to 10mm long, and are found among roots. They can also bore into tubers of cyclamen and begonia and the stem bases of cacti and succulents, and can kill woody plants by gnawing the outer tissues of larger roots and stem bases.

Where plants are most at risk

According to the RHS, plants in pots and containers, outdoors or under cover, are the most likely to be severely damaged by grubs, and plants in open ground are less likely to be harmed. It notes that heavy populations can occur on strawberries, primula, sedum, heuchera and young yew plants. A wilting pot in autumn or winter with no obvious pest above ground is worth tipping out to check the roots.

Why every adult is female

The RHS says all vine weevil adults are female and each can lay several hundred eggs during spring and summer, reproducing asexually. The eggs are brown, less than 1mm across and very difficult to see in soil. It adds that larger yellowish-brown spheres seen in potting compost are likely to be controlled-release fertiliser pellets. This pattern does not apply to every related species; the recently arrived Otiorhynchus armadillo, for example, is often found mating.

Non-chemical steps the RHS describes

• Tolerate adult leaf damage, as the RHS advises.
• Remove adults by hand. On mild spring or summer evenings, inspect plants and walls by torchlight and pick off adults; shake shrubs over an upturned umbrella or newspaper to collect more. In greenhouses, look under pots and on the underside of staging, where they hide by day.
• Encourage predators. Vine weevils and grubs are eaten by birds, frogs, toads, shrews, hedgehogs and predatory ground and rove beetles.
• Check susceptible plants frequently, looking for notched leaves on thick-leaved evergreens as a sign adults are present, and repot plants, removing as many larvae as possible from around roots and compost.

The RHS warns that after an apparent disappearance, numbers can build up again, so gardeners with vine weevil should keep up their guard.

Nematodes and their timing

The RHS says biological control of the larvae is available as microscopic insect-pathogenic nematodes, in several species and combinations sold by biological control suppliers and as sachets from some retail outlets. It says they are suitable for containers and open ground. For the best results they should be applied in August or early September, when the soil or potting medium is warm enough and before the grubs have grown large enough to cause serious damage. It gives temperature ranges of 5 to 20°C for Steinernema species and 12 to 20°C for Heterorhabditis species. It says the nematodes can give poor results in dry or heavy soils and work best in lighter soils and open potting composts.

The RHS guide to biological control adds general points that apply here. Nematodes are living organisms and should be used as soon as possible after purchase. Nematode biological controls are usually specific to insects or molluscs, but they have the potential to infect non-target animals, so they should be used in a targeted manner and only when there is a specific problem to treat.

The RHS position on pesticides

The RHS states that it does not support the use of pesticides and recommends non-chemical control options whenever needed. Its biological control page notes that predators and parasites are very susceptible to most pesticides, which can persist for weeks. Anyone considering a product should read the label and follow the rules that apply to it; the site’s article on pest products as biocides explains the legal position for pest control products in Great Britain, and its article on metaldehyde slug pellets covers a related garden pest product.

Common questions

Are the notched leaves a reason to treat?

The RHS says adults rarely cause enough damage to affect plant vigour, and advises tolerating leaf damage.

When are nematodes applied?

The RHS says August or early September gives the best results, when the compost is warm enough.

The bottom line

Vine weevil damage that matters happens below the compost, where grubs eat roots from autumn to spring, especially in containers. The RHS advises tolerating leaf notching, picking off adults, encouraging predators, repotting and checking roots, and using nematodes in August or early September if biological control is wanted. The RHS does not support pesticide use for this problem.

Sources

• Royal Horticultural Society, “Vine weevil” (rhs.org.uk)
• Royal Horticultural Society, “Biological Control in the Garden” (rhs.org.uk)

Bed bugs are hard to remove, and in Canada the advice from Health Canada is unusually direct about what to buy, what to avoid and when to call a professional. This article summarises two Health Canada pages on bedbugs, one on how to get rid of them and one listing where to go for more information. It concerns Canada only. For the United States see the site’s article on what the EPA says about registered pesticides, and for general signs and treatment see the bed bug signs and treatment guide. This is general information, not pest control advice for a particular home.

Professional treatment is the recommended route

Health Canada says it strongly advises hiring a licensed pest control operator, because bedbugs are extremely difficult to eliminate without expertise. It suggests contacting the Canadian Pest Management Association or the relevant provincial association for referrals. The pages describe the tools a professional may use: liquid and aerosol insecticide sprays, insecticidal dusts, diatomaceous earth, pressurised carbon dioxide snow, and steam or heat treatments.

If the home is rented

Health Canada tells renters to notify the landlord immediately when bedbugs are found. It says building management often asks residents to prepare a unit, which typically means emptying storage furniture, putting belongings into bags, laundering all clothes and bedding, moving furniture away from walls and following the operator’s pre-treatment instructions. Responsibility for local health issues sits with provincial and municipal public health officers, according to the contacts page, which lists provincial bodies from Alberta Health Services to Quebec’s health ministry and names the Tenant Resource and Advisory Centre (TRAC) in British Columbia as a landlord-tenant contact. Tenancy rules differ by province, and the pages read do not set out those rules.

Buying pesticides: registration and labels

The guidance says to use only pesticides registered by Health Canada and to check the label for a Pest Control Products (PCP) registration number. It states that unregistered products are illegal, and advises reading labels thoroughly before buying. The label also decides where a product can go: Health Canada says never to apply pesticides to mattresses, box springs, baby cribs or toys unless the label explicitly allows it, and never to use a treatment on people, pets or bedding unless the label says so. A product registered for bed frames is not necessarily suitable for a mattress. Homemade pesticide recipes should not be used.

Physical control matters as much as chemicals

Health Canada’s key principle is that chemical treatment will only be effective if physical control methods and preventive measures are used alongside it. The methods it describes include:

• Steam: bedbugs die at 50°C and steam cleaners deliver at least 100°C; dry or low-vapour steamers keep moisture down, and moving slowly improves penetration. Steam before vacuuming.
• Heat for fabrics: small items go in a hot dryer for at least 30 minutes, and bedding and clothes are washed in hot water and dried on the hottest setting. Whole-home heat treatment is left to professionals.
• Freezing: this requires four days at a steady -19°C and may not kill every bug.
• Vacuuming: use a bagless vacuum or one with disposable bags, a stiff brush attachment and scraping motions, targeting mattresses, box springs, bed frames, skirting boards, furniture, rugs, drawers and heating units. Seal and discard bags immediately in white plastic so escapees are visible, and tape a paper towel over the hose end.
• Disposal and storage: throw out items that cannot be washed, heated or steamed, and store cleaned items in sealed heavy-duty bags or lidded bins.

Daily vacuuming is suggested as an ongoing preventive step.

What not to do

Health Canada warns against ozone generators, saying they can cause respiratory problems such as coughing, chest pain, shortness of breath and irritation of the eyes, nose and throat, and that no ozone devices are approved for bedbugs in Canada. It also warns against unregistered products, homemade mixtures and applying pesticides to people, pets or bedding contrary to the label. An archived Health Canada note on indoor application methods, last updated in 2017, mentions hand-held sprayers and dust applicators for crack and crevice treatments in residential spaces, and says that re-entry intervals are not specified because restricting entry into homes is not considered feasible. Health Canada advises waiting until a product has dried before re-entering. That note is archived, so current label directions take priority.

Choosing an operator

A customer can ask a company which registered products it will use, whether it will provide preparation instructions, how many follow-up visits are included and what happens if bugs return. The site’s advice on pests returning after treatment explains what evidence to collect.

Common questions

How can I tell if a product is legal in Canada?

Health Canada says to look for a PCP registration number on the label; unregistered products are illegal.

Are foggers or ozone machines a good idea?

Health Canada specifically warns against ozone generators for bedbugs. The pages read do not recommend foggers.

Who do I contact besides the landlord?

Provincial and municipal public health officers, and in British Columbia the Tenant Resource and Advisory Centre for landlord-tenant issues.

The bottom line

Health Canada’s position is that bedbug control should be led by a licensed operator, use only registered products according to the label, and combine chemical treatment with steam, laundering, vacuuming and careful storage. Ozone generators and homemade or unregistered products are to be avoided. Renters should tell the landlord immediately and can turn to public health officers for local support.

Sources

• Health Canada, “Bedbugs: how do I get rid of them?” (canada.ca)
• Health Canada, “Bedbugs: where do I go for more information?” (canada.ca)
• Health Canada, “Information Note: Pesticide Application Methods and Areas of Use” (archived) (canada.ca)

A lawn that turns yellow in patches, or is ripped up overnight, often points to grubs feeding on the roots. In the UK the usual suspects are leatherjackets, the larvae of crane flies, and chafer grubs, the larvae of beetles. The two look different, follow different calendars and call for different timing if a biological treatment is used. This article summarises the Royal Horticultural Society (RHS) profiles for leatherjackets and chafer grubs in lawns, which are written for gardeners across the UK. It does not cover pesticides, which the pages read do not discuss. It is general information.

Telling the two apart

The RHS describes leatherjackets as elongated, tubular, greyish-brown larvae up to 30mm long, with no visible legs or distinct head. Chafer grubs, by contrast, have stout white bodies curved in a C shape, light brown heads and three pairs of legs at the head end, reaching up to 18mm when straightened. The RHS says the species that most often damage lawns are the garden chafer and the Welsh chafer, and that lawn chafers live in turf, unlike similar-looking grubs such as stag beetle larvae, which are associated with dead wood. Identification matters because a treatment timed for one grub will miss the other.

Life cycles and when damage shows

Leatherjackets

Adult crane flies emerge between August and October and lay eggs in turf. The eggs hatch weeks later and the larvae feed on roots through the winter. The RHS notes that mild winters allow faster growth, while cold winters can delay significant damage until mid-summer.

Chafer grubs

Adult beetles emerge from late May through June and lay eggs in turf. The larvae feed on roots through autumn and winter without initially causing much damage, and pupate in the soil in spring. The RHS says damage is most noticeable between autumn and spring, and that infestations tend to be localised and sporadic.

Signs to look for

• Yellowish-brown patches where roots have been eaten.
• Small round holes made by birds such as crows, magpies and starlings probing for leatherjackets, according to the RHS.
• For chafer grubs, turf torn up by crows, jays, magpies and rooks, and by badgers and foxes, which the RHS says do this to reach the grubs. In this case the animals cause most of the visible destruction.
• Seedlings collapsing when leatherjackets eat stems at soil level.
• Larvae in the surface layers of soil when a patch is lifted, which is direct confirmation.

Where badgers are responsible, legal protection limits what can be done. The site’s article on badgers damaging a garden or property explains the position in England, Wales and Scotland, and the piece on urban foxes covers the other digger.

Biological control and its timing

The RHS describes nematode treatments for both grubs, though the products differ. For leatherjackets, the RHS says pathogenic nematodes of the species Steinernema feltiae or S. carpocapsae are watered into turf or soil and infect the larvae with a bacterial disease. They need well-drained but moist soil and a minimum temperature of 12°C, and the RHS advises applying them preventively from September to early October. For chafer grubs, it describes nematodes of the species Heterorhabditis bacteriophora, applied when soil temperature is between 12°C and 20°C and kept moist, with July to September offering preventive benefit before damage becomes visible.

The timing point is crucial. The RHS’s general page on biological control explains that nematodes are living organisms, usually supplied by mail order, mixed with water and watered on, and should be used as soon as possible after they are received. It adds that they should be used with care, and only when there is a specific problem to treat, because they can infect non-target animals within the insect or mollusc groups. By the time lawn damage is obvious, cold soil may make treatment ineffective, which is why the advice centres on prevention in late summer and early autumn.

Repair and habits

For chafer damage, the RHS advises repairing lawn areas in mid to late spring, when the grubs have moved deeper into the soil to pupate, by re-seeding or re-turfing. It notes that lures and traps exist for adult chafer beetles but that their effectiveness is uncertain. It also points out that most crane fly species are beneficial, helping recycle nutrients, and that birds rely on leatherjackets as food.

Using a lawn-care company

Lawn treatment firms may offer grub control. A sensible customer asks which grub is present and how it was identified, which product and species of nematode will be used, when soil temperature suits it, and whether a return visit is included. Written scope and follow-up, as discussed in the site’s guide on costs, callouts and quote comparison, help avoid paying for a visit at the wrong time of year.

Common questions

Is a bird-damaged lawn always a grub problem?

Not necessarily, but the RHS lists bird probing and torn turf as classic signs, and finding grubs in the soil confirms it.

Is autumn or summer the right time for nematodes?

According to the RHS, September to early October for leatherjackets, and July to September for chafer grubs.

Does this apply outside England?

The RHS pages are UK gardening advice and are not limited to one nation, though wildlife protection rules for badgers differ and are covered separately.

The bottom line

Leatherjackets and chafer grubs both eat lawn roots, but they differ in appearance, calendar and nematode species. The RHS focuses on identification first, preventive nematode timing in late summer and early autumn, spring repairs for chafer damage and a tolerant view of wildlife feeding on the grubs. Any paid service should be able to explain which grub it is treating and why the timing suits it.

Sources

• Royal Horticultural Society, “Leatherjackets” (rhs.org.uk)
• Royal Horticultural Society, “Chafer grubs in lawns” (rhs.org.uk)
• Royal Horticultural Society, “Biological control in the garden” (rhs.org.uk)

Box hedges, balls and topiary are a fixture of British gardens, and the box tree caterpillar has become one of their most damaging problems. Unlike a household pest, it is a horticultural one, and the choices made by owners, gardeners and contractors are mostly about monitoring and timing. This article summarises the Royal Horticultural Society (RHS) profile of the pest. The RHS describes the situation across the whole UK, and this article does not cover pesticide approvals, which are not addressed in the profile. It is general information.

What it is and how widespread it has become

The box tree caterpillar is the larva of Cydalima perspectalis, a moth native to East Asia. The RHS says young caterpillars are greenish-yellow with black heads, and mature ones reach about 4cm, with a greenish-yellow body marked with thick black and thin white stripes. The RHS reports that the pest was first detected in Britain in 2007 to 2008 and appeared in private gardens in 2011. By the end of 2014 it had become established in parts of London and the surrounding area. It now describes the moth as widely distributed across England, especially the south-east, and present throughout Wales, Scotland, Ireland and Northern Ireland as a common resident.

The yearly cycle

According to the RHS, the moth completes at least two generations a year. It overwinters as small caterpillars sheltered between webbed leaves, and in warm spells feeding can begin as early as February. By June caterpillars pupate and adults emerge; a second generation appears in late July or early August, and life stages overlap through the summer. By late September or October, most of the population consists of early-stage caterpillars. Because overwintering caterpillars are small, damage can appear suddenly when they grow, which is why the RHS stresses regular checks.

Recognising damage

The caterpillars defoliate box by eating the leaves and produce webbing over the areas where they feed. Affected plants may show patches of dieback, especially on trimmed plants. The RHS adds that caterpillars can also strip bark, which may girdle sections of a plant. Because the feeding is often inside a clipped surface, the first sign can be webbing, brown patches or droppings rather than visible caterpillars.

What the RHS recommends

Monitor early and often

The RHS advises frequent checks from early spring, and particularly from May onwards, so that action can be taken before a damaging population develops.

Hand removal

Where practical, caterpillars can be removed by hand. This is realistic for a few plants but slow for a long hedge.

Pheromone traps

The RHS says pheromone traps can show whether moths are present in the area and how active they are. They are a monitoring tool, and the profile does not present them as a way of clearing an infestation, so they suit gardeners who grow box and have not yet been affected.

Biological control

The RHS says the mixed nematode product sold as Fruit and Vegetable Protection has some effect on the caterpillars, but adds that nematodes could infect non-target animals and should be used with care.

The RHS’s separate page on biological control adds that nematodes are living organisms supplied mainly by mail order, mixed with water and watered onto affected plants, and to be used as soon as possible after they are received. It says products containing Steinernema feltiae and S. carpocapsae, including one sold for box tree caterpillar, are available, and that nematodes should be used only when there is a specific problem to treat.

Alternatives to box

The RHS suggests considering other hedging or topiary plants in place of box, and links to guidance on alternative shrubs. For households with repeated losses this may be more sustainable than yearly treatment.

Buying help from a contractor

A garden contractor or pest control company offering treatment should be able to say what they will apply, how it fits the RHS steps above and when they will return to check. The site’s advice on quote comparison and follow-up visits applies here as well: a single visit is unlikely to suit a pest with overlapping generations. Note that legal conditions on products, including what an amateur may use, are covered in the site’s explanation of how pest products are regulated in Great Britain; they are outside the scope of the RHS profile, so no product is recommended here.

Common questions

Is it a notifiable pest that must be reported?

The RHS profile does not describe any reporting requirement. Pests that are reportable, such as those covered in the site’s TreeAlert guide, are a different category.

When should box be checked?

The RHS says from early spring, with attention from May onwards, since feeding can begin as early as February in warm spells.

Will pheromone traps solve an infestation?

The RHS describes them as a way of detecting moths and gauging activity, not as a control on their own.

Does it occur outside England?

Yes. The RHS reports it in Wales, Scotland, Ireland and Northern Ireland.

The bottom line

The box tree caterpillar is now a common resident across the UK, with at least two generations a year and small overwintering caterpillars that can go unnoticed until damage appears. The RHS emphasises early and frequent checking, hand removal where practical, pheromone traps for monitoring, cautious use of nematodes and considering alternative plants. Any paid treatment should be judged against that timing rather than a single visit.

Sources

• Royal Horticultural Society, “Box tree caterpillar” (rhs.org.uk)
• Royal Horticultural Society, “Biological control in the garden” (rhs.org.uk)

Most pest problems are private: a mouse in the kitchen or wasps in the eaves. Some pests of trees and plants are different, because government treats certain outbreaks as a matter of public interest and wants sightings reported rather than handled quietly. This article summarises GOV.UK guidance on reporting a tree pest or disease and the Forest Research description of its TreeAlert service. It covers Great Britain and refers briefly to Northern Ireland, and it is general information, not plant health advice.

Why reporting matters

GOV.UK explains that notifiable tree and plant pests and diseases have the potential to cause the greatest damage. Once a report is confirmed, the authorities plot the location so that it can inform local tree and woodland managers, take preventive action to limit spread and, where possible, pursue eradication before the organism becomes established. A garden owner who treats a suspicious problem without telling anyone may therefore lose the chance of early containment. A pest controller called to a garden tree should treat unusual symptoms as something to report as well as something to treat.

Where to report in each part of the UK

GOV.UK gives different routes depending on the location:

• Trees in England, Scotland and Wales: use the TreeAlert service run by Forest Research.
• Plants in England and Wales: use the online form on the GOV.UK submission service.
• Plants in Scotland: report to SASA (Science and Advice for Scottish Agriculture).
• Commercial locations: the guidance directs reports to the Animal and Plant Health Agency (APHA) through its online plant health form.
• Northern Ireland: the guidance directs enquiries to the Department of Agriculture, Environment and Rural Affairs (DAERA).

The guidance was last updated on 3 September 2026, when an out-of-date email address was replaced with the online reporting form.

What TreeAlert asks for

Forest Research describes TreeAlert as the online tool for reporting tree pests and diseases, managed by Forest Research with funding from Defra, the Forestry Commission, Scottish Forestry and the Welsh Government. A report is made through a series of screens. The reporter provides a name, email address and level of experience; the date and location, given as a grid reference, map point or postcode; the number of affected trees and the tree type; and a description of symptoms. Photographs are requested, ideally three: the whole tree in its setting, the symptoms in context showing how they are distributed on the tree, and a close-up of the fine detail.

The pictures need to be clear enough to show what the reporter intends, in natural light or with a flash so they are not blurry or dark. Reports are processed through Forest Research’s tree health diagnostic and advisory service, and staff may contact the reporter for more information. According to Forest Research, the information supports monitoring and surveillance work, contributes to scientific research and helps protect the nation’s trees.

What not to do

• Do not assume that a stripped, discoloured or unusually dying tree is a nuisance to be dealt with privately; photograph it and report it.
• Do not rely on a general pesticide as a substitute for identification; products have legal conditions of use, as the site’s article on pest products as biocides explains.

Who receives the information

Because TreeAlert is funded by Defra, the Forestry Commission, Scottish Forestry and the Welsh Government, reports feed a shared picture across Great Britain rather than staying with one local body. Forest Research states that the information supports tree health monitoring and surveillance, contributes to ongoing scientific research and ultimately supports efforts to protect trees. For a householder, that means one photograph-led report can serve England, Scotland and Wales alike, whichever part of Great Britain the tree stands in.

Relationship to other reporting matters

Tree pests are only one category of reportable organism. The site covers others individually, including the oak processionary moth, which the Forest Research TreeAlert page lists among its popular search topics alongside acute oak decline. Each has its own guidance, so the TreeAlert report is the general entry point, not a substitute for reading the pest-specific advice.

Common questions

Do I have to give a location precisely?

TreeAlert accepts a grid reference, a point on a map or a postcode, so an exact grid reference is not compulsory.

Can I report a pest on a garden plant, not a tree?

GOV.UK gives separate routes for plants: an online form in England and Wales and SASA in Scotland.

What happens after I report?

Forest Research staff may contact the reporter, and confirmed findings are plotted and used to guide preventive action, according to the sources above.

Is TreeAlert available in Northern Ireland?

The Forest Research page does not mention Northern Ireland, and GOV.UK directs enquiries there to DAERA.

The bottom line

Suspected pests and diseases of trees and plants are reported to public bodies, not just dealt with privately. In England, Scotland and Wales, trees go through TreeAlert with clear photographs, plants go through the routes GOV.UK lists for each nation, and Northern Ireland enquiries go to DAERA. Reporting early supports containment and monitoring across the country.

Sources

• GOV.UK, “Report a tree pest or disease: overview”
• Forest Research, “TreeAlert” (forestresearch.gov.uk)

Rats, mice, cockroaches or bed bugs in a rented flat raise an immediate question: who arranges and pays for treatment? In Scotland the answer depends on the cause of the infestation, and tenants have a formal route to the First-tier Tribunal if a private landlord does not deal with a repair problem. This article summarises Shelter Scotland’s advice on pests and the Scottish Government’s statutory guidance on the Repairing Standard for private landlords. It applies to Scotland only. Separate articles cover England and Wales. It is general information, not legal advice.

The starting point: cause of the problem

Shelter Scotland says a landlord must deal with pests caused by repair problems, and gives examples such as damp, loose tiles or structural holes that let pests in. It says the same principle applies to social tenants, whose landlord is a council or housing association, where the infestation stems from a maintenance failure. A gap under a door or a broken air brick that gives rodents access is therefore a repair matter, while a problem caused by how a household stores food or manages waste is treated differently.

Tenants, according to the same guidance, are responsible for keeping the home clean enough to avoid attracting pests, for reporting repair problems promptly and for following the reporting procedure that applies to their type of landlord. Prompt written reporting also creates a record, which matters if the case goes further.

The Repairing Standard for private rented homes

The Scottish Government’s statutory guidance for private landlords sets out the Repairing Standard. Among its core elements, the house must be wind and water tight and in all other respects reasonably fit for human habitation. The structure and exterior, including drains, gutters and external pipes, must be in a reasonable state of repair, and installations for water, gas, electricity, sanitation, heating and hot water must work properly. The guidance page read for this article does not mention pests or infestations by name, so nothing here should be taken as saying that the standard lists pest control as such. Its relevance is indirect: where a defect in the structure, drainage or fabric is letting pests in, the repair obligation is engaged, in line with the Shelter Scotland advice.

Neighbour-caused problems

Shelter Scotland notes that where neighbours cause an infestation in shared areas or in an adjoining property, they bear responsibility for dealing with it. The council’s environmental health team can investigate complaints, order neighbours to remedy the problem, carry out pest control work and bill the responsible parties, and provide guidance and help. For the England and Wales equivalent of these council powers, see the site’s article on filthy and verminous premises; the sources for this article do not describe the Scottish statutory basis, so no legislation is cited for it here.

What if the tenant caused it?

Where the infestation was not caused by a repair defect, Shelter Scotland lists the options for a tenant: council pest control, which may involve charges, or a private pest control firm, which it describes as higher cost. It also points to crisis grants for emergency financial help and charitable grants through Turn2Us. Cost and responsibility can be argued differently depending on who caused the problem, so it is sensible to gather evidence early. The site’s guide to reporting the problem and establishing responsibility explains what to record.

When the landlord does not act

Under the Scottish Government’s guidance, a tenant who believes the Repairing Standard is not being met can apply to the First-tier Tribunal for Scotland (Housing and Property Chamber) for a determination. Vulnerable tenants may ask their local authority to apply on their behalf. When appropriate, the Tribunal issues a Repairing Standard Enforcement Order requiring specific repairs, and failing to carry out repairs required by such an order without reasonable excuse is a criminal offence. If a landlord does not comply, the Tribunal will send a copy of its failure-to-comply decision to the local authority, which can decide to carry out the work and recover the costs from the landlord. The Tribunal may also issue a Rent Relief Order restricting the rent payable until the order is complied with.

Persistent infestations

Shelter Scotland says tenants who cannot get rid of persistent pests may consider a homelessness application if conditions become uninhabitable, but that proper procedures for ending a tenancy must be followed. Because leaving a tenancy has consequences, advice from Shelter Scotland or a local advice service is sensible before deciding.

Common questions

Does the Repairing Standard mention rats or mice?

The guidance page read does not name pests. It covers fitness for habitation and the state of the structure, exterior and installations, which is how repair-related infestations engage it.

Who pays if pests come from next door?

Shelter Scotland says neighbours who cause an infestation are responsible, and that environmental health can require them to act or do the work and bill them.

Does this apply in England or Wales?

No. The Tribunal, the Repairing Standard and the enforcement order described here are Scottish.

The bottom line

In Scotland, a landlord must deal with pests caused by repair problems, neighbours must deal with pests they cause, and tenants must keep the home clean and report problems promptly. Private tenants whose landlord fails to act on a repair issue can apply to the First-tier Tribunal, which can issue an enforcement order backed by criminal penalties and council default powers. Written reports and dated evidence give the strongest footing.

Sources

• Shelter Scotland, “Dealing with pests, vermin or infestations in your home” (scotland.shelter.org.uk)
• Scottish Government, “Repairing Standard: statutory guidance for private landlords, 6. Repairing Standard – enforcement” (gov.scot)
• Scottish Government, “Repairing Standard: statutory guidance for private landlords” (gov.scot)