Cut pine bolts were exposed to allow a field population of Sipalinus gigas to oviposit and the colonized insects in the bolts were examined periodically up to 29 mo after oviposition. The estimated survival rate of the immatures in the bolts decreased throughout the first and second season, and reached almost zero before the second overwintering. Predation was thought to be one of the major mortality factors of immature S. gigas. The increase of larval size and formation of a pupal chamber indicated that larval growth of S. gigas was completed within 4-5 mo after oviposition. The occurrence of pupae, callow adults and emerged adults suggested that S. gigas have bimodal adult emergence, namely they emerge in autumn of the year when they were laid as eggs as well as in the autumn of the following year. Although a small number of live larvae were found just before the second overwintering, they were less likely to grow into adults in the third season because of the high mortality of immatures in the second and third seasons.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.