The Developmental Biology of Grain-Sucking Bug, Stenocoris elegans Blöte, on Upland Rice

The grain-sucking bug, Stenocoris elegans Blöte (Hemiptera: Alydidae), is an important rice pest in West Africa. Investigation on its developmental biology is important to provide the base and possibility to bring forth further research for the improvement of the pest management strategy. The developmental biology of S. elegans was investigated on upland rice variety IDSA 10 in the laboratory in Ibadan, Nigeria. The results showed that pre-oviposition and post-oviposition periods were 9.9 ± 0.49 and 6.1 ± 1.17 days, respectively, under ambient temperature and relative humidity. A mated female of S. elegans laid an average of 135.1 eggs during an oviposition period of 33.5 days. The average egg incubation period was 7.9 ± 0.3 days. There were five nymphal instars, and the total developmental period (first instar to adult) averaged 18.0 days. An over-all mean growth ratio of 1.29 was recorded for this species. A regular relationship existed between measurements of nymphal vertex and the duration of their developmental periods, and a significant correlation (0.98) was obtained.