Effect of temperature, relative humidity, and free water on the number and normalcy sic of Trichogramma pretiosum Riley Hymenoptera Trichogrammatidae emerging from eggs of Heliothis zea; Boddie Lepidoptera Noctuidae
Environmental Entomology 17.3: 470-475
ISSN/ISBN: 0046-225X Accession: 037242580
The effect of selected temperatures, relative humidities, and levels of free water at time of eclosion, and the effect of selected temperatures and relative humidity during development, were measured on the number of adult Trichogramma pretiosum Riley emerging from parasitized eggs of Heliothis zea (Boddie), and on the frequency of abnormal (brachypterous) wings among emerged adults. At time of eclosion, highest mean rates of emergence occurred at 32 plus or minus 1 degree C and 60 and 80% RH. Significant declines in adult emergence occurred above 80% and below 40% RH at all temperatures evaluated. Temperatures of 38 and 43 plus or minus 1 degree C lowered mean rates of adult eclosion by > 70% under optimum relative humidity. T. pretiosum adults that emerged at 27 and 32 plus or minus 1 degree C and 40, 60, and 80% RH generally had fully developed wings, whereas adults that emerged at higher and lower relative humidity and adults that emerged at 35, 38, and 43 plus or minus 1 degree C (all RH) had significantly higher mean frequencies of brachypterous wings than did the control.