What are the control methods of carambola diseases and insect pests?

Lepidoptera is a pest that harms carambola, so how can we control it? What are the ecological habits of Lepidoptera and what are the harmful diseases?

Ecological habits: Huaji leaf moth is commonly known as carambola fruit borer in Lepidoptera, which is not only harmful to carambola, but also occasionally found in longan, litchi, peach, guava and Annona. It occurs in Taiwan all year round, and about eight generations can be completed in a year. The life span of adults is about 8 ~ 19 days and the pre-oviposition period is about 3 ~ 13 days. Adults mate in the early morning and females lay eggs in the evening. Eggs are laid on the surface of the fruit, and each fruit can produce one to more than ten eggs, with an average of 120 eggs per female moth. The first egg is white and turns red after 1 ~ 2 days, and the egg period is about 3 ~ 10 days. The larvae are red to dark red, and the larval stage is about 10 ~ 26 days. When the larvae mature, most of them will produce fruit and pupate on the cracks in the bark, sand under the tree, dead branches, fallen leaves or dried fruit, and the pupal period is about 9 ~ 24 days.

Harmful form: the hatched larvae immediately drill into the fruit from the pedicel, petal or tail end of the fruit and eat the flesh. Granular brown insect feces excreted by the larvae can be seen outside the wormhole, which can be obviously different from the harmful hole of Oriental fruit fly. Usually, there are only 1 or 2 larvae in each fruit, and the immature larvae in the fruit will crawl out and then drill into the adjacent fruit to continue the damage.

Prevention and control methods:

1. Sex pheromone is used to control Spodoptera litura, mainly because it can trap and kill a large number of male moths, reduce the chance of mating between male moths and females, reduce the production of offspring, achieve the purpose of reducing the population, and the fruit damage rate is naturally reduced. however, it must be used for a long time and in a large area in order to give full play to its control potential. At present, the promotion dosage is 4: 8 pheromone traps per minute, the distance between traps is about 15 meters, and the lasting effect of the bait can be up to 6 months. Sex pheromone attractant can also be used as a density monitoring index or as an index of control or not. when the average number of insects per week is less than 5: 10, the control can be reduced.

Second, fruit drop is often a neglected source of important pest fruits. From the change of population, it is not difficult to understand that fruit drop has created a considerable number of pests. These pests may harm other orchards and may also become an important source of pests in the next stage of their own orchards. The removal of fallen fruit or damaged fruit can most reduce the source of insects in the field, and the method is simple, easy, safe and effective.

Third, Huaji leaf moth and oriental fruit fly are the most important pests of carambola fruit. Bagging can be used to block their harm to carambola. Fruit bagging was carried out in cooperation with fruit thinning operation when carambola fruit grew to about 5cm (30 ~ 40 days after flowering). Pest control should be carried out thoroughly before bagging, and bagging should not be carried out until the solution is dry to avoid drug damage; the bagging method should be in line with the standard, and the mouth of the bag should be tightened and tightened to prevent small insects such as shell insects from invading the fruit through the gap at the mouth of the bag.

4. In the southern region, carambola was cultivated in a net room with 10-12 mesh to prevent the harm of Spodoptera litura and fruit fly. Attention should be paid to the adaptation of pollination insects in the net room, poor ventilation and sunshine in the net room, fruit trees are easy to grow branches, and it is easy to cause the harm of leaf mites, and the cost of cultivation in the net room is high, so the suitability of carambola cultivation in the net room needs to be further improved.