Effects of Ephestia Elutella(Hübner) on Foraging Behavior of Habrobracon Hebetor(Say) under Different Temperatures and Host Density

The effects of density of Ephestia elutella (Hübner) (Lepidoptera:Pyralidae) on foraging behaviors of Habrobracon hebetor (Say) (Hymenoptera:Braconidae) under various temperatures were examined in this study by measuring functional responses, the number of parasitized hosts, and the number of eggs laid of H. hebetor under five constant temperatures (15, 20, 25, 30 and 35℃) at different host larval densitiesof the 5^th instar E. elutella. The results revealed that the number of hosts paralyzed by H. hebetor increased with the increase of host density and temperature, it exhibited a Holling's II disc equation under various temperatures. The instantaneous attack rate (a) increased and then decreased with the increase of temperature, and the handling times (T_h) decreased with the increase of temperature. However, the maximum control efficiency (a/T_h) and theoretical maximum attack rate (T/T_h) of H. hebetor on E. elutella were found at 30-35℃. In addition, the number of parasitized hosts, the number of eggs laid, and the efficiency of conversion (ECI) of H. hebetor decreased with the increase of host density, although they increased with the increase of temperature. Namely, the number of parasitized hosts, the number of eggs laid, and the ECI were relatively higher at temperatures 30-35℃ and low host densities (5 and 10), which were favorable to the mass-rearing of the wasp. In conclusion, the results of this study provide a theoretical basis for the control of storage pests including E. elutella by mass rearing and utilization of this parasitoid.