Chlorantraniliprole impact on survival and progeny quality of the pupa of the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae)

Abstract

The insecticide chlorantraniliprole is recommended for integrated pest management programmes of caterpillar (Lepidoptera) pest species. This insecticide is considered harmless to parasitoids, but its selectivity may vary with the species of natural enemy, few of which were subjected to testing. Furthermore, in addition to the active ingredient, formulation adjuvants may improve insecticide efficiency, but also its impact on nontargeted organisms. Here the chlorantraniliprole effect and its interaction with adjuvant on the survival and qualitative parameters of progeny of the nontarget parasitoid Palmistichus elaeisis (Delvare and LaSalle) (Hymenoptera: Eulophidae) were studied. The treatments used were: chrolantraniliprole (T1), chlorantraniliprole+surfactant (T2), and deionised water (T3, control). Pupae of Diaphania hyalinata Linnaeus (Lepidoptera: Crambidae) were subjected to these treatments for 24 hours and offered to the adult parasitoids. Chlorantraniliprole and chlorantraniliprole+surfactant did not elicit direct toxicity to female parasitoids. However, chlorantraniliprole and its combination with surfactant reduced the head capsule width of the female progeny. This insecticide alone also reduced emergence and the progeny metatibia length. Chlorantraniliprole did not induce mortality of P. elaeisis adults, but its negative impact on the emergence and progeny size of this parasitoid suggests an important sublethal effect to be considered.