Behavior and characterization of Moneilema variolare (Coleoptera: Cerambycidae), a new pest to Pachycereus marginatus

This study was conducted to elucidate the identification of Moneilema variolare Thomson, 1867, as a new pest to Pachycereus marginatus (DC.) Britton & Rose. Behavior, identification, and damages were investigated for 3 years. Adults emerged from pupal chamber in late winter, and fed on Pachycereus stems. Females laid eggs in the damaged plant tissue. Larvae fed inside the stems during the summer to mid-autumn. In late autumn, the larvae formed pupal chambers and pupated. Adults eclosed from pupae in late winter, and fed on P. marginatus, increasing the damage. During their larval and adult stage was possible to establish that this beetle causes at least three types of damage to the host plant: a) external chewing disfiguration by adults; b) consumption of the pith by larvae may lead to the death of the plant; and c) hollowing out of stems by boring larvae. These types of injury cause decreased vigor, and eventual death soon after or during the subsequent years. This is the first report of M. variolare infesting and development on P. marginatus, and represents a threat to its native populations.