IPM insects and mites: which pests Py-Bo can hit — and which it cannot

Plants grow. Insects find them. In a couple of generations you have a population problem. That part of the old “IPM, insects and mites… the short version” article still holds. What does not hold is treating every pest the same, or treating mites as a Py-Bo job.

This page is for commercial Australian growers and anyone searching IPM insects and mites, contact spray vs systemic, pyrethrum mites, which pests does pyrethrum kill or Py-Bo label pests. It rewrites that Tree Crop piece as an on-label explainer: surface insects a foliar contact spray can hit, versus internal, soil and mite pests it cannot. Product discussed: Py-Bo Natural Pyrethrum Insecticidal Concentrate (APVMA 53738; 80 g/L pyrethrins + 320 g/L piperonyl butoxide, EC). Always read the current APVMA-approved label. The label is the law.

The current public Py-Bo horticultural pest list (APVMA 53738) is: aphids, ants, cabbage moth and other caterpillars, earwigs, leafhoppers, thrips, whiteflies, on fruit and vegetable crops, cut flowers and ornamental plants. Confirm your crop and pest on the pack in the shed before you mix. This page does not authorise off-label use.

Know the pest before you mix

Pests differ in what they eat, where they eat and when they eat. A contact insecticide only kills the animal a droplet hits. It does not move in sap. It does not treat soil. It does not reach a larva inside fruit, a mine, a gall or a stem. Same physics — a small animal on a plant — is not a registration.

Integrated pest management (IPM) is still a choice of tools over the season: do nothing and hope native predators and parasitoids hold; buy in beneficials; use a registered systemic where the label and the crop allow; or use a contact knockdown when labelled surface pests threaten yield or quality. Combining two or more of those is IPM. Timing is still your call. The contact option on this page is only for pests named on the Py-Bo label.

Taxonomy: contact vs not

Read this table against the pack, not against the old magazine copy. The old article bundled scales, mealybugs, “various bugs”, beetles and mites with the surface suckers. Only the named horticultural pests below are a Py-Bo claim.

Pest / group	Where they live	On Py-Bo horticultural list (APVMA 53738)?	Hit by a foliar contact spray?
Aphids	Surface: growing tips, flowers, young leaves; inside curled flush	Yes	Yes, nymphs and adults the droplets wet. Inside a tight curl: much harder. Roots / dense wool: no
Thrips	Surface: flowers, new growth, undersides, calyx	Yes	Yes, larvae and adults contacted. Eggs in tissue: no. Pupae in soil or litter: no
Whiteflies	Undersides of leaves	Yes	Yes, adults and young nymphs if the underside is wet. Eggs and pupae: much harder
Cabbage moth and other caterpillars	Surface: leaves, buds, florets; exposed larvae	Yes (that named group)	Yes, exposed larvae. Once inside a head, cob, nut or fruit: no
Earwigs	Bunches, bark, litter; out at night	Yes	Yes, if spray reaches the hide or they are moving at dusk / night. Outside of a tight bunch only: miss
Leafhoppers	Surface: foliage	Yes	Yes, if contacted. Disturbed adults jump or fly
Ants	Canopy, honeydew trails; nest in soil or structure	Yes	Yes, workers the spray hits. Nest: not a foliar job
Mites (spider mites, rust mites, bud mites, any mite)	Leaves, buds, fruit russet	No — not named	Not a registered claim. The old title said “insects and mites”. Mites are not on this list
Scales, mealybugs	Surface but waxy / sheltered	No	Not named. Wax sheds water-based droplets
“Various bugs”, Rutherglen bug, fruit-spotting bugs, bronze orange bug	Surface / fly-in swarms	No	Not named. A swarm on flowers is a real problem; it is not a Py-Bo claim
Beetles, Monolepta (red-shouldered leaf beetle)	Flowers, foliage; larvae often in soil / pasture	No	Not named. Adult flower-feeders are not a licence to spray
Queensland fruit fly, nut borers, codling moth (in fruit), leaf miners, gall wasps, stem weevils	Inside fruit, mines, galls, stems	No	Cannot reach. Contact spray is not a systemic. These need a different registered product
Soil / root larvae (pasture scarabs and similar)	Soil, roots, inter-row	No	A foliar pass does not treat soil. Not named

On pome and stone fruit the internal pests — fruit fly, codling moth larvae in fruit, and other tissue-feeders — are not controlled by a contact spray. Beneficials generally do not either. That is a different label. Do not reach for Py-Bo because harvest is close and you wish it worked inside the fruit.

Earwigs in cherry, grape and other bunches are a labelled pest. So are leafhoppers on tropical fruit foliage, and exposed caterpillars on leaves and buds. “Bugs” on custard apple, giant fruit moths, and mites anywhere, are not. Keep the product in the shed for the pests on the pack — not for every animal that walks onto ripening fruit.

How to spray Py-Bo (1 mL/L, 1-day WHP)

Product: Py-Bo Natural Pyrethrum Insecticidal Concentrate (APVMA 53738)
Actives: 80 g/L pyrethrins + 320 g/L piperonyl butoxide (PBO), emulsifiable concentrate
Mode: contact only. Knockdown of insects the spray actually hits. Not systemic. Not residual in the plant. Pyrethrins break down rapidly in sunlight.
Labelled horticultural situation: fruit and vegetable crops, cut flowers and ornamental plants. Confirm your crop on the current pack.
Labelled horticultural pests: aphids, ants, cabbage moth and other caterpillars, earwigs, leafhoppers, thrips, whiteflies.
Rate on that labelled horticultural use: 1 mL Py-Bo per 1 L water, or 100 mL per 100 L water (1 L per 1,000 L). Do not invent another rate.
Withholding period: 1 day on labelled edible plants (do not harvest for 1 day after application). Spray today, pick tomorrow where the label allows. Confirm crop listing and WHP on the current label.
Re-entry: once the last droplet has settled, workers can re-enter. That is not a bee-safe claim.

Mix 1 mL/L (100 mL/100 L) in clean water only if that is the rate on the label for your situation.
Apply so droplets contact the named pests: tips and the inside of curled flush for aphids; flower insides, undersides and calyx for thrips; undersides for whiteflies; exposed larvae for cabbage moth and other caterpillars; bunch interiors and night-active insects for earwigs; foliage for leafhoppers; canopy workers for ants. Thorough coverage of all foliage, including undersurfaces, is what the horticultural use requires.
Prefer dusk / after dark. Do not spray plants in flower while bees are foraging.
If live labelled pests remain after the spray has dried, they were not contacted — or they flew or jumped off. Change volume, droplet size or nozzle angle on a test run, then treat the rest of the block. Do not raise the rate above 1 mL/L to make up for a dry underside or a missed bunch.
Follow up when the next hatch or fresh insects are visible. That is a hatch interval, not a calendar residual. UV breaks pyrethrins down in a few hours of sunlight — that is why WHP is one day.

Py-Bo knocks labelled contact pests in minutes. Dead insects mean droplets hit them. Live ones mean they were missed. You cannot kill them any deader than dead. Py-Bo is APVMA-approved for listed uses. Use only on crops, pests and situations named on the label. This page does not authorise off-label use.

Dusk versus bees (flowers)

Pyrethrins are dangerous to bees. The Py-Bo label says do not spray any plants in flower while bees are foraging. Bloom is when many fruit crops need pollination. It is also when aphids and flower thrips — both named pests — are in the same blossoms. That overlap is why dusk matters more than a daytime “quick knock” during flowering.

Honey bees forage in daylight. From sunset to sunrise they are in the hive — in southern and northern Australia. Apply after dark, when bees are in the hive. A dusk application also gives the spray the night before sunlight breaks it down.

Residues continue to keep bees off treated surfaces into the next morning until UV degrades the pyrethrins (often around mid-morning). In the first hour after sunrise you can see bees hover a hand-span off treated blossom and not land. Somewhere before lunch, depending on UV, they are usually back on the flowers and unaffected. Do not treat that as bee-safe in daylight on open flowers. The legal instruction is still: do not spray plants in flower while bees are foraging.

Contact spray will also knock beneficials it hits (ladybirds, lacewings, hoverfly larvae, Orius, parasitoids). Because residues degrade in a few hours of UV, you can re-introduce beneficials onto a lower pest population once the pyrethrins are gone. That is a regular IPM sequence: knock labelled surface pests that have overwhelmed the beneficials, then restock. Use Py-Bo as a knockdown or harvest-close flush, not as a weekly cover spray over an IPM program. Wait until there are enough labelled pests to justify the pass; do not spray “just in case” on empty flush.

What Py-Bo will not do

Will not make mites legal. Mites are not named on the Py-Bo horticultural list. The old article’s title and summary treated “insects and mites” as one contact job. They are not. Use a product registered for mites.
Will not kill pests inside plant tissue. Fruit fly, codling moth larvae in fruit, nut borers, leaf miners, gall wasps and stem weevils are out of reach. Contact is not systemic.
Will not treat soil or root larvae. A foliar pass does not drench pasture scarabs or other soil insects. Monolepta larvae in the inter-row are not a Py-Bo claim; nor are the adult beetles.
Will not make unlabelled surface pests legal. Scales, mealybugs, Rutherglen bug, fruit-spotting bugs and unnamed “bugs” are not named. Same leaf as an aphid is not a registration.
Will not kill thrips eggs in tissue, thrips pupae off-crop, or caterpillars already inside a head, cob or fruit.
Will not give a season-long residual. UV degrades pyrethrins; that is why WHP is one day and why you re-treat on hatch.
Will not spare bees or beneficials it hits. Dusk, not daylight bloom.
Will not replace coverage. Contact product, contact required. Live pests after a spray were missed, not “resistant to pyrethrum rate”.
Will not make an unlabelled crop legal. Named crops and named pests only. The label is the law.

FAQ

Which pests can Py-Bo hit?

On the current public horticultural list (APVMA 53738): aphids, ants, cabbage moth and other caterpillars, earwigs, leafhoppers, thrips and whiteflies, on fruit and vegetable crops, cut flowers and ornamental plants. Exposed stages the spray can wet. Confirm the current pack. This page is not a claim for every insect that ever sat on a tree.

Does Py-Bo kill mites?

No — not as a labelled horticultural claim. Mites are not named on the Py-Bo horticultural list. The old “IPM, insects and mites… the short version” article put mites in the title and in the summary with insects. That copy is not the label. Spider mites, rust mites, bud mites and any other mite need a product registered for that pest. Named crops and named pests only.

Will Py-Bo control fruit fly or codling moth?

No. Queensland fruit fly and codling moth larvae live inside fruit. A foliar contact spray cannot reach them. Nut borers, leaf miners, gall wasps and stem weevils are the same problem: they eat inside the tissue. Those pests need a different registered product. Do not use Py-Bo as a harvest-close substitute for an internal pest.

What about scales, mealybugs, Rutherglen bug and beetles?

Not named on the horticultural list. The old Tree Crop copy listed scales and mealybugs with the sap-suckers, beetles with the chewers, and Rutherglen bug as a swarm to knock with Py-Bo. None of those are a Py-Bo claim. A waxy scale covering sheds water-based droplets anyway. Use a product registered for the pest you have.

Can I use Py-Bo in an IPM program with beneficials?

Yes, as a knockdown of labelled surface pests when numbers threaten the crop — then restock. Py-Bo will kill beneficials it contacts. Residues degrade in a few hours of UV, so there is no lingering deposit to stop beneficials establishing. They will not have much to eat for a few days unless insects keep flying in. Do not run it as a weekly cover spray over a living beneficial population. Monitor; spray only when labelled pests justify the pass.

What rate of Py-Bo, and what is the withholding period?

On the labelled horticultural use: 1 mL per 1 L of water (100 mL per 100 L, or 1 L per 1,000 L). The withholding period on labelled edible plants is 1 day. Always confirm the crop, pest and WHP on the current APVMA-approved label. Do not invent rates.

What about bees?

Dangerous to bees. Do not spray any plants in flower while bees are foraging. Spray after dark when bees are in the hive. Residues keep bees off treated surfaces into the next morning until UV degrades the pyrethrins. Do not treat it as bee-safe in daylight on open flowers.

Will one spray fix it for the season?

No. Py-Bo is a contact knockdown with no residual. Aphids produce live young and can rebuild in about a week. Thrips eggs in tissue and pupae off the crop survive the first pass. Whitefly adults fly; earwigs re-enter bunches from litter. Plan a follow-up when the next hatch is visible, and keep walking the surfaces that hide them.

Why keep Py-Bo in the shed near harvest?

Because the withholding period on labelled edible plants is one day, and UV breaks the pyrethrins down in a few hours of sunlight. If labelled surface pests — aphids, thrips, whiteflies, exposed caterpillars, earwigs, leafhoppers, ants — turn up too close to pick for a longer-WHP product, a contact pass can still be on-label. That is not permission to spray mites, fruit fly or anything else that is not named. It will cost you more to need it for a labelled pest and not have it than to have it and not need it. Confirm the crop, pest and WHP on the pack.

Quick reference

On-label surface pests (APVMA 53738): aphids; thrips; whiteflies; cabbage moth and other caterpillars (exposed larvae); earwigs; leafhoppers; ants
Not claimed: mites (not named); scales; mealybugs; Rutherglen bug and other unnamed bugs; beetles / Monolepta; fruit fly; codling moth in fruit; nut borers; leaf miners; gall wasps; stem weevils; soil / root larvae
Rule: contact spray kills what it hits on the surface. It does not move in sap, treat soil, or reach pests inside tissue
IPM: beneficials, a registered systemic where lawful, and Py-Bo as a knockdown of named surface pests — not a weekly cover; restock beneficials after UV has degraded residues
Spray: Py-Bo 1 mL/L or 100 mL/100 L; contact; 1-day WHP; tips, undersides, flower insides, bunch interiors; dusk vs bees; follow-up on hatch
Bees: dangerous; do not spray plants in flower while bees are foraging; apply after dark; residues repel into next morning until UV
Coverage check: dead labelled pests = hit; live ones = missed. Change droplet, angle, volume or speed. Do not raise the rate
Product: 80 g/L pyrethrins + 320 g/L PBO; APVMA 53738; fruit and vegetable crops, cut flowers and ornamental plants

Always read and follow the current APVMA-approved label. The label is the law. Named crops and named pests only. Py-Bo is available through Pestech Australia’s Ag resellers or direct.

IPM insects and mites: which pests Py-Bo can hit, and which it cannot