Biology of Bemisia tabaci (Genn.) B-biotype and parasitism by Encarsia formosa (Gahan) on collard, soybean and tomato plants

the silverleaf whitefly bemisia tabaci (genn.) b-biotype (= b. argentifolii) (hemiptera: aleyrodidae) is a polyphagous insect attacking many plant species of economic importance. a comparison study was conducted on the duration of the egg-to-adult period, and the percentage of hatching eggs of bemisia tabaci (genn.) b-biotype on collard (brassica oleracea l. var. acephala d.c.), soybean(glycine max (l.) merr.) and tomato (lycopersicon esculentum mill.) plants, as well as the egg-to-adult period of encarsia formosa (gahan) on the 1st, 2nd, 3rd and 4th whitefly nymphal instars on these three plant species. the experiments were conducted in a laboratory (25oc, 70 ± 10% rh, 14-hour photophase). the duration of the egg-to-adult period of b. tabaci was 19.8 days on collard, 21.2 days on soybean and 22.0 days on tomato. the number of hatched eggs was higher on collard when compared to soybean and tomato plants. concerning e. formosa regardless of plant species, the duration for the egg-to-adult period was shorter for the 3rd and 4th instar nymphs as compared with the other instars.