Acrolepiopsis assectella

The leek moth or onion leaf miner (Acrolepiopsis assectella) is a species of moth of family Acrolepiidae and the genus Acrolepiopsis. The species is native to Europe and Siberia, but is also found in North America, where it is an invasive species. While it was initially recorded in Hawaii, this was actually a misidentification of Acrolepiopsis sapporensis. The leek moth is similar in appearance to other members of the genus Acrolepiopsis, with mottled brown and white wings. Its wing span is approximately 12 mm across. It is a pest of leek crops, as the larvae feed on several species of Allium by mining into the leaves or bulbs. The shape of the leaf mine is variable, ranging from a corridor to a blotch, and can be with or without frass. This leaf mining can occur in the tubular leaves or in the stem. In the case of onions and shallots, the larvae mine into the bulb. In North America, where the moth is an invasive species and has few known natural predators, the species threatens the production and biodiversity of Allium, and it has the potential to destroy entire crops. The parasitoid Diadromus pulchellus is used to control the spread of and damage caused by the leek moth in Europe and North America. The wings are brown mottled with white spots and measure about 12 mm across. High individual variation in wing pattern can make the leek moth difficult to distinguish from other Acrolepiopsis species at first, but its distinct genitalia make it easily identifiable. Males of this species can be identified by their long saccus, a portion of the male genitalia used for grasping females, and females by their long and flat ductus bursae, a portion of the female reproductive tract. The leek moth is native to Europe, where it is present throughout the entire continent. Scandinavia and Russia mark the northwestern and northeastern bounds of its range, respectively, and its presence extends to Algeria in the south. It is an invasive species in North America, where it was first discovered in Canada in 1993. It has since expanded its North American range to include parts of Ontario, Quebec, Prince Edward Island, and New York. Climate models suggest that the leek moth's range could continue to expand to encompass a larger portion of eastern North America. The female leek moth selects the host plant for oviposition. She is drawn to the plant through thiosulphinates, chemical attractants released by the plant. Egg-laying does not take place immediately, however; it occurs only after longer contact with the leaf, during which time another chemical signal cues oviposition. Propyl-cysteine-sulfoxide has been shown to induce egg-laying in the leek moth and could be involved in host plant selection as a characteristic signal of Allium. Larvae feed on plants of the genus Allium, including: The leek moth prefers A. sativum, garlic, A. porrum, leek, and A. cepa, onion, to other species of Allium.