Navel orangeworm

Myelois venipars, widely known as the navel orangeworm, is a destructive insect pest belonging to the order Lepidoptera and the family Pyralidae. Originally identified as a threat to citrus crops, it has become a primary economic pest for many tree nut industries, significantly impacting quality and yield.

The host range of this pest is extensive, primarily including almonds, walnuts, pistachios, and various citrus fruits. The insect demonstrates a strong preference for damaged or splitting fruit, where the larvae can easily bore into the interior to feed on the kernel or fruit flesh.

The biology of the species is characterized by multiple generations per year, depending on environmental temperatures. Adult moths are nocturnal, and females lay their eggs on the surface of fruit. Larvae undergo several developmental stages before pupating, often remaining within the protective environment of the host fruit or nut.

Damage caused by the larvae is severe. Beyond direct consumption of the product, the larvae introduce contaminants such as frass and webbing, which facilitate the colonization of molds and fungi. This secondary infection often renders the entire crop unsuitable for commercial use or human consumption.

Effective management requires an integrated approach focusing on orchard sanitation. Removing and destroying mummies—the overwintering fruit left on trees—is the most critical step to reducing the population for the next season. Additionally, growers utilize pheromone monitoring traps and targeted insecticide applications based on biofix dates to minimize economic loss.