Parasitism of Tetrastichus howardi (Ollif, 1893) (Hymenoptera: Eulophidae) on Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae) pupae at different ages

Abstract

Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) is an adult parasitoid of lepidopteran pests, and the age of the host has a strong influence on its reproduction. This study aimed to evaluate the biological characteristics of T. howardi reared on different aged pupae of Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae). For that, pupae with 24, 48, 72, 96, 120, 144 or 168 h of age were exposed to parasitism. The experimental design was completely randomized, with seven treatments (pupal age) and ten replications, with each replication consisting of five pupae individualized with one female parasitoid at the respective ages. Tetrastichus howardi parasitized and emerged in pupae of all the evaluated ages. The duration of the cycle (egg-adult) in days, number of parasitoids that emerged per pupa (progeny), progeny per female, sex ratio of the parasitoid and longevity of adults were similar. This is the first record of T. howardi reproducing in C. includens pupae under laboratory conditions. The highest parasitism and development of T. howardi was obtained in 24-to 96-hour-old pupae of C. includens, indicating that this age range is more favorable to rear this parasitoid under laboratory conditions.