Melon fly, also known as needle bee, melon maggot, etc., belongs to the diptera fruit fly family, drill moth pest, melon fruit fly to the open air planting of bitter melon is quite serious, has become the "number one killer" of bitter melon. The direct harm to bitter melon is the larvae of the melon fruit fly, and its adults lay eggs in the bitter melon and develop into larvae, which is difficult to control even with the frequent use of systemic pesticides.
1. Harmful symptoms
The female adult of the melon fruit fly stabs the egg laying tube into the epidermis of the young melon to lay eggs, and the larvae hatch into the flesh of the melon to feed as a pest, and the affected melon first turns yellow locally, and then the whole melon rots and falls off, and there are maggots inside. Sometimes, even if it does not decay, the puncture wound condenses and flows, and the deformity sinks.
Adult melon fly on the leaves
Adult melon flies on melons
Melon fruit fly larvae
Second, the characteristics of occurrence
Female adults can occur in multiple generations a year, with overlapping generations. Adults overwinter on weeds and fruit trees. Adults are active during the day, and when the sun is hot, they lie still in melon sheds or on the back of leaves, and have a tendency to sugar, wine, vinegar and aromatic substances. Female insects lay eggs in the tender melon, each time to produce a few to more than 10 grains, each female can produce dozens to more than 100 grains, the larva hatched in the melon to eat, the melon moth into a honeycomb shape, so that rot, fall off. The old mature larvae bounce to the ground before or after the melon falls, burrowing into the topsoil to pupate.
3. Prevention and control methods
Because fruit flies are pests of laying eggs in melons, and adults do not eat melon fruits and leaves, so general spraying to protect young melons does not work. The main control measure is to trap adult flies.
1, strengthen cultivation management Select planting plots, choose fields far from the nectar source plant area; it is necessary to pick up and remove the melons and fruits that fall to the ground in time, concentrate on treatment, treat them with agents or flooding, and reduce the source of insects.
2, sexual pheromones booby-trap adults Hang 10 to 15 booby trap bottles per acre in the vegetable field, hang under the melon shed, avoid direct sunlight, about 1.5 meters from the ground, trap adult insects.
3, bait booby trap melon fruit fly has a tendency to sugar, wine, vinegar and aromatic substances, especially like to eat sweet food. Use sugar, sweet orange juice, rice wine and enemy insect crystals to form poisonous bait, and put 20 to 25 points per acre to trap adult insects.
Bait booby traps
Bait traps adults
4, yellow plate booby trap adult insects First, the yellow board is hung on the melon rack 1.2 meters high from the ground, about 20 sheets per 667 square meters, the board face is vertical to the east and west, the control effect is better, because the pest has the habit of flying things; the second is to wrap the yellow plate outside the water bottle, and then hang in the melon shed, because the shape of the water bottle is similar to the melon, the melon fly flies are stuck.
Adults of the sticky melon fly
5, bagging insect prevention in areas with serious occurrences, bagging when the melon fruit is completely flowered and the petals are shrinking, otherwise, the melon bag will hinder the female flower from being affected by the powder and affecting the growth of the melon, which is currently the most effective protective measure to prevent the melon fruit from the melon fly. It should be noted that the fruit must be sprayed once before bagging to control other diseases and insects, and to ensure the quality of the melon and fruit after bagging.
6, drug control can be used 20% cypermethrin emulsion 3000 times liquid, or 1.8% avermectin emulsion 2000 times liquid, or 5% chloranthrum benzamide suspension 1500 times liquid spray adult insects at noon or evening, in the spraying appropriate addition of some sugar (150 times) will achieve better control results, we must pay attention to strict compliance with the safe drug interval of bitter melon harvest, while rotating medication.
Author: Lin Changhe