Young gourds on my plants are getting deformed, develop puncture marks, then rot and ooze, and inside I find small white maggots. Many fruits drop while still small. What pest is this and how do I stop it without heavy spraying?
4 Answers
The puncture marks, rotting fruit with white maggots inside and the dropping of young gourds are signs of fruit fly, the most damaging pest of cucurbits. The female lays eggs under the skin of young fruit and the maggots feed inside. Heavy spraying does not work well because the maggots are protected inside. The proven low spray approach is to collect and destroy all fallen and infested fruits daily so maggots do not complete their cycle in the soil, and to hang cue lure or methyl eugenol pheromone traps at the recommended rate to trap male flies. Bait splashes of a protein hydrolysate or jaggery mixed with a small dose of insecticide on a few spots attract and kill adults without spraying the whole crop. Bagging individual young fruits with paper or net also gives clean produce. Since gourds are eaten fresh, follow label and waiting period for any bait, and ask your KVK for the local lure source.
The pheromone traps with cue lure caught huge numbers of flies. Cheap and a big help. I refill the lure as the KVK advised.
Picking up the dropped fruits every single day is the key thing nobody wants to do. When I got lazy the problem came right back.
I bag my bitter gourds when they are tiny. More work but the fruit comes out clean and sells better in the market.