Tip Top Bio-Control Technical Bulletin

Target Pests:
Amblyseius fallacis feeds on mites on berry and fruit crops, as well as a supplement to P. persimilis in greenhouse situations. A. fallacis can also survive on lower pest densities and feed on a variety of food sources such as two-spotted mites, European red mite and pollen.

Description:
Amblyseius fallacis is pear-shaped and about the same size as it’s prey and hairless. It is reddish in color when feeding on the European red mite, gold when feeding on the two-spotted spidermite in strawberries and blotchy green when feeding on the two-spotted spidermite in cane berries.

Product Information:
A. fallacis comes on bean leaves as adults and two spotted mites as a food source. They are very perishable and must be placed in the crop as soon as possible.

Release Rates:
Overnight storage is possible between 35° and 50° F or until release. Release when temperatures are between 55° and 80° F, preferably not in the middle of the day. Sprinkle cup contents over foliage with highest spidermite densities. If densities are low, then spread as evenly as possible. The predators spread themselves by crawling on plants and tumbling in air currents.

Application in strawberries:
Release in the spring when the temperatures consistently reach 55° F. Continue release into the Fall until the daytime temperatures drop below 55° F. Releases can be made after picking, and after renovation when the foliage has recovered. Because alternate foods, such as pollen, are less available in small fruit fields, some sampling may be needed to establish that there is a low population of prey before initiating an inoculation. Releases are usually successful if made after the first appearance of the two-spotted spidermite and before the pest mite density reaches 1 per leaf. In strawberry fields with a history of large overwintering population of two-spotted spidermites, late summer and early fall releases are advised otherwise spring problems will be difficult to remedy.

Application in greenhouses:
Wet the canopy foliage at release points after release, because the predators prefer humid conditions. If relative humidity drops below 40% at canopy level, such as during a winter cold front, a reinoculation is advised.

Life stages:
A. fallacis matures from egg to adult in 7 days at 80° F. A female lays as many as 100 eggs during its life which allows for the control of low to moderate infestations. A. fallacis performs extremely well at temperatures below 70° F and is known to over-winter. It is limited by dry and hot conditions and relative humidity below 60% which reduce egg hatching.

Strategic Considerations:
A. fallacis is selected for its resistance to many organophosphate and pyrethriod insecticides including Imidan and Guthion. It is resistant to the miticides Kelthane, Omite, Vendex, and to all but one of the available fungicides, including Capstan, Ronilan, Rubigan, Polyram and Thitram. It is susceptible to the fungicide Benlate which interferes with reproduction, carbamate, and both synthetic and natural pyrethroids which leave a long lasting residue. Overuse of mist applied sulfur can suppress predator reproduction and reduce effectiveness.