Leek Moth Acrolepiopsis assectella
The larva of the Leek Moth (also known as Onion Moth) mines leaves. It concentrates on leek leaves, if available, but will also feed on onions, including the ones in gardens bred for their flowers. It regularly turns out to be a pest in both leeks and onions. About to pupate the caterpillar will often move to the top of the plant. The pupa is spun into a dark web, looking like the ones used for attaching cargo to a ships deck. The adult Leek Moth is just some 15 mm long and differs from similar species by the location and size of the white spot in the wings. Usually their are two generations, of which the second overwinters as adult. The Leek Moth has conquered a vast area: all of Europe, Asia (including Japan), much of Africa and in 1997 it turned up in Canada as well. It belongs to a small moth family called Plutellidae, even though some autors think it belongs to its own family, even smaller still, the Acrolepiidae. Many others believe however that these two families are just subfamilies to the Ermine Moths (Yponomeutidae). Perhaps some day the scientists will all agree?