The Cherry Sawfly Is A Slippery Enemy

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

The cherry sawfly eagerly feasts on not only cherries - cherries, hawthorns and pears often come into his field of vision, and a little less often - irga, mountain ash and apple trees, as well as cotoneaster, quince and thorns with plums. Most of all, the cherry sawfly attacks the leaves from the southern sides of tree crowns. Compared to the first generation of these pests, the second is considered to be much more harmful. However, in any case, all generations of these cherry lovers need to be fought

Meet the pest

The length of males of the cherry sawfly is on average 4 - 5 mm, and the females of this pest are slightly larger - 5 - 6 mm. These enemies of cherries are endowed with a shiny black body and black legs, in the middle of which, upon closer examination, you can see areas of brownish shades. The wingspan of adults reaches 10 - 12 mm.

The size of the pale green oval eggs of cherry sawflies reaches 0.6 mm. And the size of the yellowish-greenish larvae ranges from 9 to 11 mm. All larvae are endowed with black or brown tiny heads, ten pairs of legs, and noticeably widened anterior parts of the body (in the region of the thoracic segments). Harmful larvae are densely covered with shiny black mucus, which is lost by them when they reach the last age. Funny white-yellow pupae of the pest, 6 mm in size, winter in small earthen oval and rather dense cocoons.

Wintering of harmful larvae takes place in the soil in cocoons at a depth of six to fifteen centimeters. Their pupation occurs in early May in the southern regions, and with the onset of late May or early June - in the forest-steppe. A fairly large part of the larvae (sometimes even half) remains for re-hibernation in the diapause phase. The adults are massively removed from the soil seven to ten days after the start of the pupation period.

Two or three days after emergence, the females begin to lay eggs one at a time, having previously made small cuts in the juicy pulp of the leaves with the ovipositor for the subsequent placement of these eggs. It is not difficult to spot cherry sawfly eggs on the leaves - they form small brownish tubercles. On one leaf, in the case of mass reproduction of these parasites, one can find from ten to thirty eggs laid by different females. For seven to eight days of their life, they manage to lay about 50 - 75 eggs.

The duration of embryonic development of cherry sawflies is from seven to thirteen days. And in the second half of June and early July, a massive revival of harmful larvae begins. The larvae crawling to the upper sides of the leaves are gradually covered with mucus - this substance perfectly protects them from possible drying out. And after six to seven centuries, after fifteen to twenty days, the larvae that have completed development are sent to the soil.

In the northern zone of the forest-steppe, as well as in the woodland, the cherry sawfly manages to develop only in one generation, and in the steppe and southern forest-steppe - often in two. Years of the second generation with subsequent laying of eggs fall on the second half of August. And the larvae of the second generation often develop until the end of September or even before the beginning of October. Malignant larvae of the younger centuries gnaw out the flesh of the leaves in small specks, and the older larvae skeletonize the leaves, of which only a small mesh of veins remains. The damage from the second generation of cherry sawflies is more significant than from the first.

How to fight

Eggs laid by voracious cherry sawflies are actively infected with trichograms, and riders - representatives of the eulophid families with ichneumonids, as well as tahina flies can infect larvae.

In the near-trunk circles and in the aisles in the spring, it is necessary to carefully loosen the soil. Autumn plowing will also be a good and necessary measure - it contributes to the death of wintering larvae. When harmful larvae begin to approach the pupation period en masse, the soil must also be loosened. Periodic spraying with infusions of bitter wormwood and tobacco will also help reduce the number of these slippery pests.

Treatment with biological products and insecticides will be justified if more than ten to fifteen percent of the leaves are populated by harmful cherry sawflies. A good effect can be achieved by using the preparations "Fufanon" and "Kemifos" (for ten liters of water they will need no more than 10 ml). And among biological products, the most popular are "Entobacterin", "Lepidocid", "Bitoxibacillin" and "Gaupsin".