Sly Wrinkled Sapwood

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

The wrinkled sapwood is very partial to any fruit crops. Especially unpleasant is the fact that these pests are capable of producing up to two generations per year. And they inhabit mainly weakened fruit trees, affected by frost breaks or sunburn, or having various mechanical damage to the bark. At the same time, cunning wrinkled sapwoods almost always inhabit only individual branches. And the small rounded holes that they gnaw in the bark vaguely resemble holes from the shooting

Meet the pest

The wrinkled sapwood is a harmful bug, characterized by a matte black color and growing up to 3 mm in length. The body of harmful parasites is pubescent with short adjoining and, at the same time, slightly protruding hairs. Their longitudinally wrinkled elytra are painted in reddish-brownish tones and are equipped with punctate and rather deep grooves. The flat-convex foreheads of pests are also always wrinkled, and their abdomens are usually strongly convex. As for the legs and antennae, they are always painted in yellowish-brownish tones.

Gluttonous larvae overwinter in numerous passages made under the tree bark. With the onset of spring, they pupate, and closer to mid-May, vicious bugs begin to appear, the summer duration of which often reaches one and a half months. The bugs that come out immediately begin to feed intensively, gnawing out miniature depressions in the forks of branches and near the bases of the buds. As a result of their similar activity, gum begins to be released from the wounds.

At the end of additional feeding, harmful females immediately bite into the bark and, at the border of sapwood with bast, grind longitudinal uterine passages, reaching a length of one to three centimeters. In these moves, they will subsequently be paired. Mating females gnaw tiny holes on both sides of the passages and place up to three dozen eggs there. Their total fertility reaches one hundred to one hundred and twenty eggs, and the duration of the laying period is from fifteen to twenty days. After this time, the females close the entrance holes with their little bodies and die, thus preventing the penetration of uninvited guests into the uterine passages made by them.

The incubation period is usually six to ten days. As soon as it is completed, curved legless white larvae are selected into the light. And their heads are usually dark brown. The length of adult larvae often reaches 2 - 2, 6 mm. All hatched larvae begin to grind numerous and rather long transverse corridors at the border of sapwood and bast, which are incredibly sinuous and often intersect with each other.

Approximately at the beginning of July, voracious larvae begin to pupate. The development of harmful pupae, as a rule, takes from ten to fifteen days. And closer to the end of July and at the beginning of August, you can notice the appearance of new generation bugs. The beetles, in turn, manage to lay eggs, and the larvae hatched from them, having eaten enough, remain for the winter.

How to fight

The most important preventive measures against wrinkled sapwoods are strict adherence to all agrotechnical rules and the selection of the most healthy seedlings. In no case should fattening of fruit crops be allowed, which often occurs with excessive application of nitrogen-containing fertilizers.

In early spring, before harmful bugs begin to fly out, you should cut out all damaged and dry branches and immediately burn them. And when cunning parasites begin to get out from under the bark, fruit trees begin to spray "Metaphos" or "Chlorophos". Twigs with trunks should be moistened especially abundantly with these means. And after a couple of weeks, you can carry out a second treatment - as a rule, it is carried out in the event of a massive spread of pests.