Cabbage moth
The diamondback moth (Plutella xylostella), sometimes called the cabbage moth, is a moth species of the family Plutellidae and genus Plutella. The small, grayish-brown moth sometimes has a cream-colored band that forms a diamond along its back. The species may have originated in Europe, South Africa, or the Mediterranean region, but it has now spread worldwide.
The moth has a short life cycle (14 days at 25 °C), is highly fecund, and is capable of migrating long distances. Diamondback moths are considered pests as they feed on the leaves of cruciferous crops and plants that produce glucosinolates. However, not all of these plants are equally useful as hosts to the moth. Because of this, studies have suggested using wintercress as a trap crop around agricultural fields because diamondback moths are highly attracted to that plant but their larvae fail to survive when eggs are laid on it.
Originally, pesticides were used to kill the moths but diamondbacks have developed resistance to many of the common chemicals. For this reason, new biological and chemical controls, as well as different planting methods are being pursued to reduce the destruction caused by the moths.
This small moth is colored gray and brown. It can potentially identified by a cream-colored band that may be present in the shape of a diamond on its back. The diamondback moth has a wingspan of about 15 mm and a body length of 6 mm. The forewings are narrow, brownish gray and lighter along the anterior margin, with fine, dark speckles. A creamy-colored stripe with a wavy edge on the posterior margin is sometimes constricted to form one or more light-colored diamond shapes, which is the basis for the common name of this moth. The hindwings are narrow, pointed toward the apex, and light gray, with a wide fringe. The tips of the wings can be seen to turn upward slightly when viewed from the side. The antennae are pronounced.
The adults of this species are visually identical to the adults of the New Zealand endemic moth Plutella antiphona.
The diamondback moth has a global distribution and is found in Europe, Asia, Africa, the Americas, Australia, New Zealand, and the Hawaiian Islands. It is said by some experts to be the most widely distributed of all Lepidoptera, but despite tremendous interest in limiting the damage it causes, the actual available data is inadequate. It probably originated in Europe, South Africa, or the Mediterranean region, but the exact migration path is not known. However, in North America it was observed in Illinois in 1854, and then found in Florida and the Rocky Mountains by 1883. Although diamondback moths cannot overwinter effectively in cold climates, it was found in British Columbia by 1905 and is now present in several Canadian regions.
