Biological Quality of Tetrastichus Howardi (Hymenoptera: Eulophidae) Reared with Tenebrio molitor (Coleoptera: Tenebrionidae) Pupae after Cold Storage

Abstract

The endoparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) can be reared with the alternative host Tenebrio molitor (Linnaeus) (Coleoptera: Tenebrionidae). Host storage at low temperatures can regulate parasitoid production and demand in biological control programs. The life cycle (egg to adult), parasitism and emergence percentage, number of parasitoids emerged per host pupae, sex ratio, and longevity of the T. howardi offspring per T. molitor pupa were evaluated after low temperature storage of this host for different periods, and its immature (pupae) in T. molitor pupae for 5 periods at 10.3 °C. Tenebrio molitor pupae stored at 0.5 ± 0.09 °C and 2.7 ± 0.11 °C for 10 and 20 d, respectively, were adequate to produce T. howardi. The biological characteristics of this parasitoid were better with T. molitor pupae stored at 0.5 ± 0.09 °C and 2.7 ± 0.11 °C for 10 and 20 d. Tetrastichus howardi immature (pupae) can be stored in T. molitor pupae for 10, 20, 30, 60, and 90 d at 10.3 °C, preferably in pupae of this host for 10 d to produce the adults of this parasitoid for biological control programs. These results contribute to overcoming 1 of the difficulties encountered in the mass production of parasitoids. Therefore, the conservation of T. molitor pupae in low temperatures can be used to increment of population of T. howardi in mass production for pest control programs.