Please answer the following questions according to your biological knowledge (1). In the flowering period of maize, if there is more rain and less rain, it will often lead to maize yield reduction.

(1) Rain will knock off the pollen in stamen anthers, which will reduce the pollen quantity, pollination rate and maize yield.

(2) It is better before the 3rd instar, because at this time, locusts have no wings, a small range of activities, a high distribution density and are easy to be killed.

(1) Fruit trees pollinated by insects rarely come out in rainy weather, which leads to insufficient pollination, and the flowers that are not pollinated cannot bear fruit after fertilization, resulting in reduced fruit yield. Fruit trees with wind-pollinated flowers will also be under-pollinated because of wet pollen and insufficient wind.

(2) In the larval stage, locusts have a short development time and a small food intake, while adults mainly feed on gramineous crops, with a large food intake and strong digestive ability. Therefore, locusts mainly harm gramineous crops, and the most serious period is the adult stage. It is best to kill locusts in the larval stage, especially before the third instar, which is conducive to centralized eradication.