BIOLOGY OF SIPHONINUS-PHILLYREAE (HALIDAY) (HOMOPTERA, ALEYRODIDAE) AND ITS RELATIONSHIP TO TEMPERATURE

The effects of temperature on developmental rate (stage specific and t otal), survival, fecundity, longevity, sex ratio, and nymphal size of Siphoninus phillyreae (Haliday) were studied in environmental chambers at constant temperatures. Temperature had significant effects on deve lopmental rate, survival, fecundity, female longevity, and size of fem ale nymphs, but no effect on male longevity, sex ratio, and size of ma le nymphs. Lower developmental thresholds for each preimaginal stage a nd total development were approximate to 10. Upper developmental thres holds for eggs and first instars were approximate to 30 and 25 degrees C, respectively. There was no survival of eggs at 10 degrees C or cra wlers at 32.2 degrees C. Net reproductive rates were 31, 49, and 8 via ble females per female at 20, 25, and 30 degrees C, respectively. Opti mal temperature for development, survival, and reproduction, within th e range examined, was 25 degrees C. Sex ratio was 1:1 at all three tem peratures tested (20, 25, and 30 degrees C). Size of female third and fourth instars only were significantly affected by temperature.