Our Top Feltiella acarisuga - Spider mite Control
Feltiella acarisuga - Spider mite Control
A predatory midge that hunts two-spotted spider mite hot spots — Feltiella acarisuga.
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What it targets
FELTIELLAforce™ is the vendor name for Feltiella acarisuga, a small predatory midge whose larvae are voracious feeders on the eggs, larvae, and adults of spider mites. The primary host is the two-spotted spider mite (Tetranychus urticae); the carmine mite (T. cinnabarinus) and other Tetranychus spp. are within range. UF/IFAS calls F. acarisuga “one of the most effective and widespread natural enemies of spider mites,” particularly in greenhouse cropping systems where it can find hot spots faster than scouts often do.
One thing makes Feltiella distinctive in a spider-mite IPM program: the adults fly. They locate spider-mite colonies the grower hasn’t found yet and lay eggs right in them. Where leaf hairs slow phytoseiid mites — on tomato in particular — the predatory midge works around the obstacle that limits Phytoseiulus persimilis. Use Feltiella for greenhouse tomato and crops with continuous low-to-moderate pressure; pair with persimilis when an outbreak is already running.
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How it works
The larva is the only predacious stage. Females hunt for spider-mite colonies and lay ~30 eggs over a five-day adult life, depositing them next to the prey. Eggs hatch in less than two days, and the larvae begin feeding immediately. Daily intake per larva is high: roughly 80 spider-mite eggs, or 30 mixed-stage prey, or 15 adults. Per UF/IFAS, the larvae consume about five times as many spider mites as Phytoseiulus persimilis. Larvae forage on the leaf underside through four instars over about a week, then spin a cocoon attached to the leaf — often against a vein — and pupate. One adult emerges from each cocoon.
Adults are short-lived (2–3 days), more active at night, and rest on the leaf underside during the day. Egg-to-adult development takes about 10 days at 80°F and stretches to 34 days at 59°F, with relative humidity between 60–95%. The full cycle covers two to four weeks depending on temperature. That cycle means the colony you release today is feeding for weeks: new adults find new colonies, new larvae feed, new cocoons pupate, and the population layers in instead of arriving as one drop.
Why Feltiella works on tomato
Tomato cultivars carry trichomes — the leaf hairs that physically slow phytoseiid mites. Feltiella avoids the problem because the adult flies in and lays the eggs, and the larvae work on the leaf underside where colonies cluster. That puts Feltiella in the rare category of spider-mite predators that perform well in a tomato house.
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Crops, environments, and climate
Crops it supports
Vegetable crops
Tomato
Soft fruits
Ornamentals
Tree nurseries
Hemp / Cannabis
Environments
Greenhouses
Indoor facilities
Fields & row crops
Gardens
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Storage
Use immediately on receipt whenever possible. If a brief hold is unavoidable, keep the container at 42–50°F (6–10°C) and always release before the use-by date on the package.
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Instructions of use
When to release
Release as soon as spider mites are first detected on the crop — don’t wait for webbing. Feltiella is a curative predator that builds in over weeks rather than a one-day knock-down, so getting it in early lets the larvae establish before the spider-mite population doubles.
How to release
Pierce or open the top of the container and place the tray in a shaded spot near plants showing spider-mite pressure. Adults exit on their own — no tapping or distributing required. Choose a shaded location: full sun on the container slows emergence and reduces survival. Run weekly releases for at least six weeks, or until you start finding Feltiella eggs and larvae on the leaf underside.
Setting up for success
Remove yellow sticky cards for the first few days after release — the adult midges are attracted to yellow and will end up on the card instead of in the canopy. Blue sticky cards can stay up for thrips monitoring, but avoid placing them right next to the release tray. On food crops, plan for pupation on the leaf underside; if a harvest is coming up in days, time the release accordingly.
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Monitoring & advisories
Monitor for
- Yellow or red legless larvae on the leaf underside, in or next to spider-mite colonies. Easy to mistake for fly maggots at first glance.
- Cocoons attached to the leaf underside, often pressed against a leaf vein. Each cocoon yields one adult.
- Falling spider-mite counts on scouting routes within a few days of release — the most reliable sign that Feltiella is working.
- Adults are small and short-lived; you’ll see them more often resting on leaf undersides at night than in the canopy by day.
Advisories
- Yellow sticky cards within range of the release tray will catch adults. Pull them for the first few days; blue cards are fine.
- Adult lifespan is only 2–3 days. Establishment depends on getting females to lay eggs in colonies before they die, so positioning the tray inside the pest hot spot matters more than for a longer-lived predator.
- Cold conditions stretch the cycle dramatically — egg-to-adult goes from ~10 days at 80°F to ~34 days at 59°F. Use Feltiella in heated houses through cool months, or expect slower buildup.
- Spider mites don’t fly; they crawl and ride air currents and clothing. Restrict movement through hot spots while the predator establishes.
- Heavy outbreaks with visible webbing benefit from a Phytoseiulus persimilis knock-down first; layer Feltiella behind it for residual control.
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Release rates — for conventional crops
| Classification | Rate | Interval |
|---|---|---|
| Preventive / first detection preventive | 0.03–0.1 per sq. ft. | Weekly for ≥ 6 weeks |
| Continuing release active | Same rate, layered over weeks | Until Feltiella eggs/larvae are spotted in canopy |
| FELTIELLAforce™ ships as pupae in a 250-count container (vendor SKU FA25). One container covers ~2,500–8,300 sq. ft. at the preventive rate. | ||
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Cannabis Alert
Conventional release rates are usually not sufficient for cannabis growers. We recommend you double the rate or contact us for personalized help.
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Life cycle
The Feltiella acarisuga life cycle runs egg → larva (four instars) → pupa (cocoon on leaf underside) → adult. Total development takes about 10 days at 80°F and stretches to roughly 34 days at 59°F.
1
Egg
2
Larva
3
Pupa
4
Adult
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See it in action
Disclosures
Live-product policy. Beneficial Insectary works to guarantee the live delivery of fresh organisms. Replacements or credits are offered for compromised shipments when customers report issues or concerns within 24 hours — before any organisms suspected of viability issues are released. Don’t discard the product; you may be asked to return the shipment for analysis.
Establishment of biocontrol agents. Many variables — pesticide applications, watering practices, storage methods, and other cultural, physical, or mechanical controls — can shift biocontrol-agent and pest populations. Some beneficials need a steady pest presence to build their numbers; others require pollen or nectar as alternate food; others have specific photoperiod requirements. Long- or short-term establishment after release can’t be guaranteed, and refunds, discounts, or credits are not offered on products that have already been released.