Whiteflies are tiny (about 1/32" long), four-winged, white-colored flies that are easily seen fluttering about disturbed vegetation. Whiteflies have four distinct stages: the egg, crawler, which settles down to become immobile scale, which goes through several states before maturing as the whitefly. After about three weeks, the adult whitefly emerges, ready to eat and start laying eggs. At all stages, whiteflies feed by sucking plant juices, which slows plant growth and attracts disease. Encarsia formosa is a tiny non-social wasp which feeds only on whiteflies. The adult female feeds on whitefly scales and lays hundreds of eggs, each one killing a whitefly scale. These wasps are very effective, but go into dormancy under a forcing regimen. Three to six weekly introductions are suggested at first sign of infection. $15 per 1,000 from 1PM Labs and Nature's Control. Deiphastus pusillus is a tiny (1/32" long) black ladybug that eats whiteflies at all stages of development. Each beetle eats 10 scales or 150 eggs daily, quickly controlling the whitefly population. Only one introduction should be required. Available from IPM Labs and Nature's Control. Nature's Control also sells two kinds of predatory nematodes, Steinernema fehiae and Heterorhabditis heliothedis, both species of tiny worms. They attack and kill almost all soil-dwelling insects. The company recommends reinoculation every 6 weeks, but they usually eliminate the problem so that no reintroductions are needed. One million of the worms, which are shipped on a sponge, treat up to 2,500 sq. ft. They are rinsed into water from the sponge and then sprayed, watered or irrigated into the medium. One million nematodes cost $16.
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