Development rate and lower temperature threshold in the eggs of Eurygaster integriceps (Heteroptera : Scutelleridae)

Abstract

The sunn pest, Eurygaster integriceps Put. has a wide distribution in the Palearctic region. It is the most important pest problem of wheat in Turkey. The objective of this study was to attain better knowledge of the development of the sunn pest eggs. The lower temperature threshold and development rate of eggs were determined at 17, 20, 23, 26 and 32 degrees C +/- 1 degrees C in the laboratory. A linear model was used to describe the developmental rate and temperature. The egg development required 90.9 degree-days above the theoretical threshold of 11.7 degrees C. The development time was 17.6 +/- 0.1 days at 17 degrees C, and 4.5 +/- 0.01 days at 32 degrees C. Incubation time was inversely related to temperature. The study showed that the eggs of E. integriceps needed shorter periods of time to complete their development than immature stages of their parasitoids Trissolcus spp.