Life history studies of the old house borer, Hylotrupes bajulus (L.) (Coleoptera: Cerambycidae)

Abstract

The old house borer has been present in the u.s. for over 200 years. During this time limited biological studies have been conducted. The biological data contained in these studies are based on casual field observations and reports from Europe and South Africa. The data presented here represent the first attempt in the U.S. to colonize and study the ORB under field and laboratory conditions. It is evident from this research that the ORB exhibits an extreme amount of biological plasticity. A North American biotype of the ORB was established through comparisons among populations on each continent. Laboratory and field observations compiled over several years form the foundation of the N. A. biotype. The delineation of the N. A. biotype is based on female fecundity and variation in the developmental rates of all life stages. The apparent differences noted in fecundity and developmental rates among biotypes prompted further laboratory investigations. Attempts were made to measure the degree of genetic divergence between the N. A. and European biotype. When these biotypes were reared under identical conditions the biological variation reported under field conditions was not seen. Results indicate that this species has undergone little genetic divergence and that differences between biotypes have originated from interactions of the genotype and environment. This high degree of biological flexibility allows the ORB to inhabit marginal habitats and explains its present world-wide distribution. An oligidic diet was developed for laboratory rearing of the ORB. This diet was concocted in an attempt to reduce larval mortality.