LABORATORY AND FIELD-EVALUATION OF EXOTIC PARASITOIDS OF BEMISIA-TABACI (GENNADIUS) (BIOTYPE-B) (HOMOPTERA, ALEYRODIDAE) IN THE LOWER RIO-GRANDE VALLEY OF TEXAS
Ja. Goolsby et al., LABORATORY AND FIELD-EVALUATION OF EXOTIC PARASITOIDS OF BEMISIA-TABACI (GENNADIUS) (BIOTYPE-B) (HOMOPTERA, ALEYRODIDAE) IN THE LOWER RIO-GRANDE VALLEY OF TEXAS, Biological control, 12(2), 1998, pp. 127-135
We evaluated a total of 38 exotic and 2 native parasitoid populations
of the sweetpotato whitefly Bemisia tabaci (Gennadius) (Biotype ''B'')
(Homoptera: Aleyrodidae) (= silverleaf whitefly, Bemisia argentifolii
Bellows and Perring), using laboratory and held experiments. Numbers
of B. tabaci parasitized were counted in sleeve cages on cantaloupe me
lons (Cucumis melo L. cv ''Perlita''), cotton (Gossypium hirsutum L. c
v ''Delta Pine 51''), and broccoli (Brassica oleracea L. cv ''Patriot'
'). Highest attack rates were found for Encarsia nr. pergandiella (Hym
enoptera: Aphelinidae) (Brazil) and Eretmocerus mundus Mercet (Spain)
on melons; Eretmocerus sp. (Pakistan) on cotton; and Eretmocerus mundu
s (Spain) on broccoli. In the laboratory, these three exotic parasitoi
ds attacked significantly greater numbers of hosts than the native spe
cies of Encarsia pergandiella Howard and Eretmocerus tejanus Rose and
Zolnerowich. Selected exotic parasitoids were evaluated in the field u
sing sleeve cages on melons, cotton, and kale (Brassica oleracea L. cv
''Siberian kale''). Eretmocerus spp. from Spain and India performed w
ell, in all crop types. Encarsia nr. pergandiella (Brazil) performed w
ell on melons, but not on kale or cotton. Selected exotic parasitoids
were released at various sites throughout Hidalgo County in the Lower
Rio Grande Valley of Texas. Of 29 populations released in the held, el
even were later recovered. Two Eretmocerus species (Spain and Pakistan
) were commonly recovered throughout the evaluation period. This infor
mation will be used to prioritize the parasitoid cultures for mass rea
ring and release in biocontrol-based IPM programs against B. tabaci.