HOST FEEDING, EGG MATURATION, RESORPTION, AND LONGEVITY IN THE PARASITOID APHYTIS-MELINUS (HYMENOPTERA, APHELINIDAE)

I investigated several physiological factors associated with host feed ing in the parasitoid, Aphytis melinus DeBach. Host feeding refers to the consumption of host tissues or fluids by the adult female wasp. Dy namic behavioral models developed for the decision of whether to host feed or oviposit in Aphytis highlighted the importance of parasitoid e gg load (number of mature eggs) and two physiological features: whethe r host feeding supplies nutrients to a metabolic requirement as well a s to egg maturation and the presence and length of an egg maturation d elay; i.e., the time required to convert a host-feeding meal to mature eggs. I therefore investigated these two features in Aphytis. Host fe eding appeared to supply a metabolic nutrient demand as well as egg ma turation in Aphytis; females that received honey ad libitum but no hos t meals resorbed eggs until they had few or no eggs left and then died . By contrast, female Aphytis given a host meal and honey ad libitum p roduced more eggs-with an almost-equal-to 12- to 18-h egg maturation d elay-and ultimately lived longer. Other parasitoids may have physiolog ies similar to Aphytis but too few data exist to make conclusions abou t broad patterns of the function of host feeding in parasitoids.