Diamondback Moth – Plutella xylostella

Diamondback Moth – Plutellaxylostella Common Name: Diamondback Moth Latin Name: Plutellaxylostella Appearance:

• The adult is a little moth, about 10 to 12 mm in length. The back of the dark brown male moth has three white diamond-shaped markings. The diamond markings on the tan-colored female moth are less pronounced than on the male.
• Eggs are 0.5mm long and have a soft golden color.
• There are four phases of caterpillar development. Caterpillars are grey-green with a dark head in the first three phases. They are green with a green-brown head throughout their last growing stage. Caterpillars reach a maximum length of 12mm.

Host plant: Diamondback moth attacks only plants in the family Cruciferae. All cruciferous vegetables, including broccoli, Brussels sprouts, cabbage, Chinese cabbage, cauliflower, collard greens, kale, kohlrabi, mustard, radish, turnips, and watercress, are largely consumed. However, not all are equally liked, and ovipositing moths typically favor collard over cabbage. When cultivated crops are not yet accessible in the early part of the season, several cruciferous weeds play a vital role as hosts. Damages caused by Diamondback Moth: Caterpillars create a “feeding window” by eating several tiny holes in the leaves of their hosts, frequently leaving the leaf epidermis (the outermost layer of cells) unharmed. The caterpillars that burrow into the crowns of plants like cabbage and brussels sprouts are the ones that do the majority of the damage. By pupating inside broccoli florets and cauliflower curds, they also contaminate crops. This insect may kill the seedlings of cruciferous fodder crops and rapeseed, and severe defoliation or pod grazing may lower rapeseed output. Life history and Habits: The adults are active at dusk and during the night. Moths will leave their roosts throughout the day if plants are disturbed. Female moths lay their eggs on stems on the undersides of the leaves, either individually or in tiny groups. A female moth can lay over 150 eggs throughout her lifespan. Caterpillars in the first and some second development stages are leaf miners, burrowing deep into the leaf. Later development stages tunnel into the plant or feed on the undersides of leaves. Caterpillars will wiggle quickly backward across the leaf surface when disturbed while feeding and may fall to the ground on silken threads. Puberty takes place in an open-mesh cocoon. Temperature affects how long it takes for the life cycle to finish. The moth’s life cycle in Victoria will be finished in roughly a month throughout the summer. The bug grows considerably more slowly and does less harm in the winter. The moth completes its life cycle more quickly when the temperature rises in spring and summer, which increases pest populations. The moth will go through 6 to 7 cycles of life in a year. In the warmer months of the year, generations mix.