Icerya purchasi

Colony of Australian mealy bugs ( Icerya puchasi )

The Australian mealy bugs ( Icerya purchasi ) is a scale insect in the family cave scale insects ( Margarodidae ) (Greek Margarodes = pearly ) and the end of the 19th century in Australia and New Zealand has been known as a pest of citrus.

Features

The wingless females, which have a bright orange-red, yellow or brown body color, have first instar a body length of 5 millimeters, after the third larval stage they reach the adult imagines a body length of up to 15 millimeters. Here is the Eisack, they carry with them much crucial for the length, since it is 2 to 2.5 times longer than the female. The body is round to oval and convex. Young adult females cover the body, legs and antennae very soon with wax which is laterally produced by the body in the form of long threads. The Eisack is then formed from thick white layers of different waxy glandular secretions and is attached to the abdomen. He is always längsgerillt (14-16 grooves). The elongated oval-shaped, reddish -colored eggs are deposited in it. They have a smooth surface. The number of eggs in the Eisack may be between 100 and 1500.

The very infrequent males are about 3 to 5 millimeters long and have a dark red body. You own a pair of functional, metallic blue colored wings. The sensor, the thorax and the legs are brown.

Occurrence

The originally occurring in Australia animals are occurring by means of the people that has spread their food plants worldwide, as well as globally in the warmer areas. Especially in California occur, the animals plentiful on the citrus plantations.

Way of life

The scale insects suck plant juice, preferably from plants of the genera of the citrus plants (Citrus ) and the Pittosporum ( Pittosporum ). In their native range they are found on acacia (Acacia ), with which they were introduced also in 1868 or 1869 in California. But they are also found on other derblaubigen, evergreen or woody plants. They causing discoloration, deformities up to the drying up of the plants. The secondary damage is the secretion of honeydew, as this can easily colonize molds. The animals are devastating pests and frequently everywhere, especially where citrus plants are cultivated, as their natural enemies were missing.

Development

The females are hermaphrodites having the ability to self-fertilization. But you mate with the rarely occurring male. Just out of such incurred eggs can hatch males. There are an average of three generations into existence in the year.

Natural enemies

Among the natural enemies especially among the ladybug Rodolia cardinalis, who also hails from Australia and the fly Cryptochaetum iceryae. In winter 1888, the ladybug was taken to the biological control of Charles Valentine Riley to California to become the Schildlausplage Lord. The success was already in the following autumn. This was the first success for biological control. To date, about 500 million ladybugs of this type were bred and released in California.

Swell

Biology, harmful effects and biological and chemical control options for Australian mealy bugs ( cpm ) by Dipl. -Ing. ( FH) Marina Smerkol