Whitefly Biocontrol
General predators used most are Delphastus and green lacewing. Delphastus is introduced early in hot spots (areas where there are lots of whitefly). Inoculative releases take 3 weeks to turn a generation that yields 100 times more beetles. Unlike lacewing, Delphastus don’t eat parasitized whitefly. Lacewing are more affordable in inundative numbers in regular releases or to maintain control of other pests besides whitefly. Encarsia formosa does best against Greenhouse whitefly (GHWF), Trialeurodes vaporariorum and will attack Bemesia (silverleaf or sweet potato whitefly).
Eretmocerus does best against Bemesia, woolly, citrus and bayberry whitefly, and will parasitize GHWF. GHWF adults are white, wings together parallel to leaf surface. Bemesia adults are yellow, wings slightly apart showing abdomen and at an angle to leaf surface. A fringe rings the edge of white GHWF nymphs and no eye spots are visible; Bemesia nymphs are yellow with no fringe, but eye spots are visible. GHWF lays eggs in circular patterns while Bemesia lays its eggs singly. High populations may need to be reduced with Beauveria (Naturalis), soap (Dr. Bronner’s), neem, or Hot Pepper Wax before introducing biocontrols.
Green Lacewing Products
Lacewing on cards are shipped with 2,500, 5,000 or 10,000 lacewing eggs glued on each card; cards are perforated to guide cutting or tearing into 30 of ¾ X 2 inch tabs with a hook on one end and containing about 86, 170 or 332 eggs. Cut and place tabs into vines, shrubs or trees when larvae begin to hatch. Tabs can also be placed inside small paper cups and either stapled to plants or hung by a knotted string (through bottom of cup). The cards can be further cut into smaller pieces for wider distribution.
Cardboard vertical honeycomb holds 400 larvae ready to feed on pests as soon as they hit the plant. Honeycomb unit has paper on one side, organdy mesh on the other, with one larva in each cell. Larvae can walk as far as 7 miles, ranging up to 100 feet while looking for pests. During 2-3 weeks of life, one lone lacewing larva can consume 250 leafhopper nymphs , 300-400 aphids, 11,200 spider mites, 3,780 coccid scale crawlers or 6,500 scale eggs. Interfering ants, waxy coatings or hard shells on pests and low temperatures deter lacewings from dining on and destroying pests. Remove organdy mesh from a few cells at a time, turn over, tap larvae onto plants near pest hotspots. Release ~20 larvae per plant.
Eggs packaged in cups or bags of 1,000, 5,000 or 10,000 eggs per unit. Cups contain only the eggs and bags contain rice hulls as a carrier. Tiny larvae eat mites, mite eggs and insect eggs. Within about a week they start eating aphids. Release 2,000-3,000 eggs per acre every 2 weeks, 2-4 times OR 1 per 20 pests OR 2 per sq ft in greenhouses. Release when hatching begins: incubate cups or bags (ideal conditions 80º F, 60% RH), check each morning until tiny larvae appear in 1-4 days, sprinkle on plants directly or into paper cups placed in foliage.
Delphastus catalinae (=D. pusillus) is a predatory beetle targeting GHWF, banded-winged, sweet potato, silverleaf, woolly, azalea, hibiscus, cloudywinged, citrus and rhododendron whiteflies, and citrus blackfly. Optimum conditions are temperatures of 61°-90° F. Delphastus does not fly at temperatures below 55° F. Delphastus controls whitefly in commercial vegetable and flower greenhouses and semitropical or tropical plantings. Delphastus is useful for high-density whitefly populations, while parasites (Encarsia and Eretmocerus), do better at lower densities. Delphastus avoids feeding on parasitized whiteflies and may be used as an inoculant or in combination with other biological controls at high whitefly densities. Delphastus does not survive in the absence of prey, therefore should be released only after whiteflies are detected. Delphastus does not diapause and will survive mild winters and medium frosts. Prolonged temperatures below freezing will kill them. Low light levels and low temperatures slow down their reproductive rate, but they will still grow. Both adults and larvae feed on whitefly eggs and immature stages. If food is scarce, they will also feed on other small arthropods, such as spider mite and aphid, and will even cannibalize its own species. 1-2 per 100 sq ft, one release for inoculation.
Shipped Wednesday, order by previous Friday
Encarsia formosa is a parasitic wasp that targets greenhouse whitefly (GHWF) and, to a limited extent, Bemesia tabaci and possibly other whitefly. Targets 2nd instar of GHWF (scale on underside of leaf). Parasitized scale turn black. Double Encarsia release rates to control Bemesia. Adult Encarsia will also feed on whitefly honeydew and kill whitefly scale through host feeding. Excessive honeydew hampers activity of the parasite, so avoid high whitefly populations. Bring populations down with a soft pesticide, such as Mycotrol O or soap and oil, then release biocontrols. Encarsia are good flyers and will seek out prey, but tend to remain in regions where whitefly are concentrated. Even distribution is important in greenhouses. No diapause but inactive < 54° F. Proactive weekly releases for 8 to 10 weeks recommended for susceptible crops such as poinsettia. Optimal conditions are > 64° F and > 60% RH with bright light. Sold as 1,000 parasitized scale glued on a perforated card (strip) with hooks. Each strip can be separated into 10 tabs with 100 wasps each.
Shipped Wednesday, order by previous Friday.
Eretmocerous californicus (= E. eremicus) is a parasitic wasp targeting Bemesia tabaci, silverleaf, woolly, citrus, bayberry, and to a lesser extent, GHWF. Eretmocerus should be introduced as soon the first whiteflies are observed or as a preventive. Minimum effective temperatures: 50° F night and 65° F day. Useful at higher temperatures with optimal conditions > 75° F. Female adult wasps parasitize the 2nd and 3rd instar larval stages of the whitefly (on underside of leaf) and also host feed. Parasitized whitefly scale will turn yellow, rather than black. Supplied as loose parasitized whitefly scale in a bran carrier.
0.5-20 wasps per 10 sq ft.
Shipped Tuesday, order by previous Wednesday.
Amblyseius swirskii is a predatory mite that feeds on various thrips species’ larvae and eggs, the larvae of whitefly (GHWF and Bemisia tabaci) and spider mites. Swirskii is tolerant of high temperatures and requires >70° F day temps for development. It does not diapause and can be used year round. Is advantageous on crops with 2nd and 3rd cultivation cycles, i.e., where infestations of whitefly and thrips may already be established from the start of the cultivation cycle. Avoid where aphid control depends on Aphidoletes: the two are not compatible. Packed in shaker bottles with corn grit. Apply Swirskii preventively on low prey populations only if pollen is also available as food source. 2 per sq ft proactively, 5 per sq ft if thrips or whitefly present OR 10 per sq ft on hot spots in combination with other beneficials
*Requires >70° for development
*Good for crops w/ 2nd & 3rd cultivation cycles
*Does not diapause
*Can use pollen as food source
*Avoids webbing & hot spots
Eats Aphidoletes and Persimilis eggs
Shipped Monday or Tuesday, order by previous Wednesday.
Eggs packaged in cups or bags of 1,000, 5,000 or 10,000 eggs per unit. Cups contain only the eggs. Tiny larvae eat mites, mite eggs and insect eggs. Within about a week they start eating aphids. Release 2,000-3,000 eggs per acre every 2 weeks, 2-4 times OR 1 per 20 pests OR 2 per sq ft in greenhouses. Release when hatching begins: incubate cups or bags (ideal conditions 80º F, 60% RH), check each morning until tiny larvae appear in 1-4 days, sprinkle on plants directly or into paper cups placed in foliage.