Influence of natal host on southern pine beetle host acceptance

The southern pine beetle, Dendroctonus frontalis Zimmerman (SPB) (Coleoptera: Curculionidae), is a major pest capable of attacking all pine species in its native range. Although longleaf pines are susceptible to SPB attack, outbreaks are less common in longleaf pine forests than in loblolly pine forests. We investigated whether the natal host (the tree where an immature beetle develops) influenced SPB host selection preference by rearing beetles on either loblolly or longleaf pine logs in the lab and testing their host acceptance via no-choice and choice trials. While the natal host did not influence female beetle acceptance of either loblolly or longleaf hosts, a significantly higher proportion of longleaf-reared females did not accept either host. The natal host hypothesis does not adequately explain the relative rarity of SPB outbreaks in longleaf versus loblolly pine forests. Remaining hypotheses for this phenomenon, which require further research, are explored in this study.