Usually, there are two main types of scarab beetles that are harmed on sweet cherries, namely apple-haired scarab beetles and black-velvet scarab beetles. Scarab beetles are commonly known as copper shell mantises, blind bumpers, and old doves. It belongs to the order Coleoptera, gill turtle family. It can harm peach, plum, cherry, apple, pear and other fruit trees, but also harm field crops, vegetables, weeds, and trees.
First, the morphological characteristics of scarab beetles
1. Adult insects. The body is 7 to 8 mm long, ovoid, black or black brown, densely covered with short black hairs. The elytra are shorter than the abdomen , and each elytra has 9 longitudinal grooves consisting of notches.
2. Eggs. Oval, 1.5mm long, milky white.
3. Larvae. The mature larvae are about 15 mm long, with a yellowish-brown head and a milky white abdomen.
4. Pupae. Naked pupae, about 8mm long. It is yellowish-white at first, and later yellowish-brown.
Second, scarab beetle is harmful symptoms
Black-velvet scarab beetles are mainly harmful nursery seedlings, apple-haired scarab beetles are mainly harmful to flowers and leaves, and patina scarabs and gray-plated gills are mainly harmful to leaves.
Adults bite the young shoots, young leaves and buds of fruit trees, causing the petals and leaves to appear absent, sometimes eating all of them; the larvae are grubs, feeding on the young roots underground.
Third, the occurrence of scarab beetles
It occurs in one generation per year and overwinters in larvae and adults in soils 20 to 30 cm deep. From mid-April (cherry blossoming) to mid-May of the following year, the excavation activities are at their peak, and they are most abundant in the evening.
Adults overeat the buds, leaves, young leaves, and petals of fruit trees and intersect their tails on them. Adults have suspended death and a certain degree of phototropism. Spawning is peak from late May to early June, with the largest spawning occurring at a depth of 10 cm in lush, overgrown soils.
The hatching larvae feed on whisker roots and humus, and the larval stage averages about 75 days. The mature larvae pupate in the soil chamber 20 to 40 cm in the soil, the pupal period is 10 to 15 days, and it feathers into adult worms in mid-to-late September and overwinters in the soil chamber.
Fourth, scarab control technology
1. Artificial prevention and control. In autumn and winter, when fertilized and deeply turned over the soil, destroying the soil chamber can dry out the insect body or make it peck at by birds. Remove weeds from the orchard and surrounding areas and apply fully decomposed fertilizer. Adults have pseudo-death, chemotactic and phototrophotism, so the insect is controlled by means of pseudo-death artificial oscillation and trapped, and booby-trapped with sweet and sour liquid and black light. When black-velvet scarab beetles occur in the nursery, poplar branches about 60 cm long can also be scattered and placed in the nursery to trap adult insects.
2. Biological control. During the larval stage, the soil is watered with insect pathogen nematodes or white zombie liquid, causing them to infect the larvae and cause disease and death.
3. Chemical control. Serious orchards occur, and during the flowering period, the soil under the canopy can be medicated. Generally, the ground is sprinkled with 5% octyl thiophos granules, 50 kg per hectare, and the ground is shallow after sprinkling. When adult insects are severely infested, the tree is sprayed with 50% octylthion emulsion 800 times liquid, or 5% high-efficiency cypermethrin emulsion 2000 times liquid, or 40.7% chlorpyrifos emulsion 500 times liquid sprayed on the soil surface under the tree, and then raked the surface of the loose soil.