Reproduction of Tetrastichus howardi (Hymenoptera: Eulophidae) in Diatraea saccharalis (Lepidoptera: Crambidae) Pupae at Different Temperatures

Abstract

Temperature is a major abiotic factor affecting insects. The aim of this study was to evaluate the development of Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae) on Diatraea saccharalis F., sensu Guenée (Lepidoptera: Crambidae) pupae at 6 constant temperatures (16, 19, 22, 25, 28, and 31°C). This parasitoid developed at all temperatures with the shortest development time and lowest survival at 31°C. Tetrastichus howardi females oviposited immediately after making contact with the host pupae. Parasitoids that were kept at 25°C had the greatest fecundity, and those kept at 16°C had the greatest longevity. The greatest net reproductive rate (R0) occurred at 25°C, and the intrinsic rates of increase (rm) at 25, 28, and 31°C were similar but significantly greater than at the lower temperatures. The generation time (T) of T. howardi was significantly the longest at 16°C, which resulted in the slowest development and greatest female longevity. The fecundity of Tetrastichus howardi was greater in the 19 to 28°C temperature range than at 16°C and at 31°C. These results are important for the multiplication of T. howardi in the laboratory, and for understanding its potential for the biological control of D. saccharalis.