What are the characteristics of aphid hazards? How to prevent it?

Aphids, commonly known as borers, are important pests that harm strawberries, and they are harmful all year round in protected cultivation. Especially in early summer and autumn drought, the damage is the most serious. There are several aphids known to harm strawberries, but cotton aphid and peach aphid are more common (Figure 55). The body of cotton aphid is green and dull. It overwinters with eggs on many plants, which will be harmful to reproduction when the weather gets warmer next spring. The main harmful parts are leaves, heart leaves and flowers. Myzus persicae overwinters in the roots of grass and vegetables in winter. In strawberry protected cultivation, aphids are harmed by adults who overwinter or continue to reproduce on strawberry stems and old leaves. Aphids live in groups on the back of young leaves, sucking juice, which leads to weak plant growth. Aphids are sucking mouthparts. When feeding, they stick their mouthparts into plant tissues to suck, and the leaves curl and twist after sucking. Aphids are the disseminators of some viruses. As long as the infected plants are smoked and then moved to virus-free plants for smoking, the virus can spread to another plant, causing serious harm.

Fig. 55 Myzus persicae

1. winged viviparous female aphid 2. Wingless viviparous female aphid

Aphids have strong reproductive ability and fast reproductive speed, and can reproduce for more than 20 generations a year under protected conditions. Aphids reproduce in two ways, one is parthenogenesis and the other is hermaphroditism. A female insect can breed dozens of small aphids a year, and the reproductive rate is very high.

Prevention and cure method

(1) clear the old leaves and weeds in the field in time to reduce the source of insects; (2) Spraying pesticides to control aphids in the early stage can spray 40% dimethoate EC 1500 times or 50% dichlorvos 1800 times. The spraying frequency can be determined according to the occurrence degree of pests, and it is generally sprayed every 7 days or so 1 time. It must be noted that spraying should be stopped 15 days before fruit harvesting.