Poplar hornet moth

The Poplar hornet moth (Paranthrene asiliformis) is a member of the Sesiidae family within the order Lepidoptera. This clearwing moth is recognized as a significant stem borer that poses a threat to various deciduous trees, particularly in forestry and urban landscaping.

The primary host plants for this species include various species of Populus (poplar) and Salix (willow). It is also known to infest alder, birch, and oak. The moth shows a preference for trees that are already stressed, but it can successfully colonize healthy timber if the population density is high enough.

The biological cycle of this pest typically spans two years. Adults emerge from late May through July and exhibit Batesian mimicry, resembling hornets to deter predators. Females lay their eggs on the bark, specifically near wounds, cracks, or areas of decay where the larvae can easily penetrate the tree.

Upon hatching, the larvae burrow into the bark and cambium, creating extensive galleries that disrupt the vascular tissue of the tree. This activity leads to visible swellings, bark cracking, and weakened trunk structure. Such damage makes the trees susceptible to secondary pathogens, including wood-decay fungi and other insect pests.

Management strategies focus on preventive measures and reducing population levels through integrated pest management (IPM):

• Rigorous sanitation, including the removal and destruction of heavily infested trees.
• Proper care of trees to minimize mechanical injuries that attract egg-laying females.
• Use of pheromone traps to monitor adult flight patterns and time interventions accurately.
• Application of biological control agents such as nematodes or entomopathogenic bacteria during the larval hatching phase.