Yellow-legged clearwing

The yellow-legged clearwing (Synanthedon vespiformis) belongs to the order Lepidoptera and the family Sesiidae. These insects are notable for their mimicry, as their coloration and behavior closely resemble wasps, which serves as a defensive strategy against predators in their natural habitat.

This pest primarily attacks stone fruit trees, including cherry, sweet cherry, plum, peach, and apricot. While its impact varies depending on the region, it is considered a significant threat to orchard health, as larvae interfere with the tree's vascular system, causing long-term damage and stress.

The life cycle typically spans one to two years. Adult moths are active during the spring and summer months. Females lay eggs near wounds, bark crevices, or previous pruning sites. Once hatched, the larvae bore into the bark to feed on the cambium and phloem layers, effectively girdling the tree if the infestation is severe enough.

Damage caused by the larvae is often insidious. Signs of activity include:

• Gummosis or resin flow from the trunk or branches.
• Frass (larval excrement) accumulation at the entry points.
• Yellowing and premature wilting of leaves during the growing season.
• Dieback of branches or complete death of the tree in cases of high population density.

Management of the yellow-legged clearwing requires an integrated approach. Orchard sanitation is paramount: pruning damaged wood, sealing bark wounds, and maintaining tree vigor can reduce the risk of infestation. During the adult flight period, the use of pheromone traps for monitoring is recommended, followed by targeted insecticide applications if necessary.