Lm. Hanks et al., BIOLOGICAL CONSTRAINTS ON HOST-RANGE EXPANSION BY THE WOOD-BORING BEETLE PHORACANTHA-SEMIPUNCTATA (COLEOPTERA, CERAMBYCIDAE), Annals of the Entomological Society of America, 88(2), 1995, pp. 183-188
The eucalptus longhorned borer, Phoracantha semipunctata F., is a cosm
opolitan pest of Eucalyptus. The developing larvae damage trees by bor
ing through the outer bark and along the cambium layer. Although the b
orer has become established in many parts of the world where it has en
countered novel host-plant species, it has restricted its attacks to E
ucalyptus and a few closely related species. The goal of this study wa
s to investigate the behavioral and ecological barriers to host-range
expansion by P. semipunctata. In laboratory experiments, gravid female
P. semipunctata showed a low propensity to oviposit on logs of nine n
ovel host species even though they had been deprived of their natural
oviposition hosts. Survivorship of neonate larvae artificially introdu
ced into logs of some novel host species was similar to that of larvae
in Eucalyptus logs. However, larval development time in these novel h
osts was greatly prolonged and adult body size was reduced. These find
ings suggest that oviposition behaviors of the adult beetles could res
trict the host range of P. semipunctata to Eucalyptus species, and tha
t oviposition preferences correspond well with performance of the larv
ae.