Finicky Red Pear Scale Insect

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The red pear scale insect is an inhabitant of the southern regions of Russia and a big pear lover. However, it harms not only the pear - from time to time cherries with plums, almonds, as well as apricots, cherries, apple trees, walnuts and peaches suffer from its attacks. In the case of mass reproduction of red pear scale insects, multilayer colonies are formed on shoots, branches and trunks. In those places where pests intensively suck out tree juices, sap flow is disrupted and the bast becomes mortified, which is accompanied by curvature of the branches with their subsequent death, as well as the formation of unpleasant growths. Also, the volume of the harvest and its quality are sharply reduced, moreover, the trees themselves often die

Meet the pest

Females of the red pear scale are up to 1 mm in length, differ in a pear-like shape and are colored black or pink. The size of their gray round shields is approximately 1.5 mm. The larval peels are usually reddish-brownish and located in the centers of the scutes or near their edges.

Wingless males, growing up to 0.7 mm, are characterized by a brown-orange color and a clear division of the body into abdomens, breasts and heads. Their antennae are endowed with eight to nine segments, and the scutes of the male nymphs are gray and oblong.

The egg size of red pear scale insects is approximately 0.25 mm. They are distinguished by their oval shape and white color immediately after laying. And after some time, the eggs of the pests acquire a pink color. The length of the first instar black-red larvae reaches about 0.33 mm. And the larvae of the second instar resemble the structure of the bodies of females and grow to 0.6 mm in length.

The overwintering of fertilized females and larvae of the second instar takes place on the bark of tree trunks and branches. In April, the larvae turn into females, having previously shed. When the pears have bloomed, the females begin to lay eggs. The egg-laying process lasts for about two months, and the total fertility is from forty to fifty eggs. As for the duration of embryonic development, it usually fits into seven to twenty days.

Approximately at the end of May or at the beginning of June, the revival of gluttonous larvae occurs. For several hours, they are distinguished by pronounced mobility, and then stick to the tree bark in the immediate vicinity of the mother's shields, or directly under them. In this form, they develop for about a couple of months. In this case, the larvae of females are characterized by a double molt, and for the larvae of males - three times. Males, like females, appear around the end of July or at the very beginning of August. It is noteworthy that the ratio of females to males is 3: 1. After mating, all males die, and the fertilized females remain to winter. In addition, some of the larvae that have reached the second instar, which did not have time to complete their development, also go for wintering. During the year, only one generation of red pear scale insects develops.

The habitat of harmful parasites is the southern regions of the European part of the CIS, South and North America, North Africa, as well as Western Europe and the Caucasus.

How to fight

In the event that a couple of hundreds of red pear scale larvae are found on each square meter of branches, they are sprayed with ovicides. As a rule, such treatments are carried out on dormant buds in early spring. And when the migration of harmful larvae begins, they switch to insecticide treatments. They cultivate only the areas inhabited by these fastidious scoundrels.

The red pear scale insect also has natural enemies - some of these voracious pests infect endoparasites, and ticks with spiders and a huge number of other predatory insects are not averse to eating their larvae.