Effects of dietary moisture content and cut wood of different species on survival and weight of Asian longhorned beetle larvae: Anoplophora glabripennis (Coleoptera: Cerambycidae)

The wood-boring cerambycid Anoplophora glabripennis (Motschulsky), Asian longhorned beetle, is a highly destructive invasive pest that feeds on healthy hardwoods by tunneling under the bark and then within the sapwood as the larva matures. Larval growth and survival can be affected by the nutritional content, moisture content, and physical traits of the available food source. In this study, we experimentally manipulated the larval resource quality by controlling the moisture content of artificial diet (70 and 40% moisture) and by inserting larvae into cut wood of two different hosts [sugar maple (Acer saccharum Marshall) and grey birch (Betula populifolia Marshall)]. First and/or fifth instar larvae from a Chicago, Illinois laboratory colony were used to follow larval survival, weight, and pupation. Artificial diet moisture content did not affect larvae survival; however, larvae reared on wet diet weighed more on average than those reared on the dry diet for all times frames weights were taken. First-instar larvae reared in cut grey birch had higher survival, grew larger and molted while only one on cut sugar maple survived and molted once (all other larvae died without molting). The species of cut wood did not have a significant impact on fifth instar survival, growth, or emergence as an adult. Our findings suggest that this insect’s tolerance of highly variable host quality provides it with ample capacity to survive, disperse, and reproduce even when dietary moisture content is low or declining as might be expected in trees in the late stages of infestation.