VARIATION IN BIOTIC POTENTIALITIES OF ENC ARSIA-FORMOSA AFTER BLACK PUPAE COLD-STORAGE .2. VARIATION IN DAILY FECUNDITY AND LONGEVITY

Variation in biotic potentialities of Encarsia formosa after black pup ae cold storage 2. Variation in daily fecundity and longevity. Once th e rates of hatching after cold storage had been tested, it was necessa ry to consider biotic potentialities of Encarsia formosa born from bla ck pupae stored at low temperature. In spite of good rates of hatching , black pupae stored for 15 and 20 days at 9 degrees C exhibited a red uction in the insects' biotic potentialities (daily fecundity and long evity). The addition of sugar providing energy during the hatching of the parasite palliates the injurious effect of the cold but the length of storage is still limited. The study shows that, on the one hand, m inor variations in biotic potentialities exist due to differences in, for example, photoperiod, but that on the other hand, the stress due t o the cold storage removes this variation.