Knowledgebase
Rindworms in pumpkin and watermelons #881002
Asked August 11, 2024, 10:30 AM EDT
Ramsey County Minnesota
Expert Response
I believe rindworm is the correct term for the caterpillars that bore into squash and watermelon fruits.
Spinosad to prevent Squash Vine Borer damage. #757502
Asked June 21, 2021, 2:21 PM EDT
I apply Spinosad to the lower stems of my vine crops once a week through June and July to prevent Squash Vine Borer. But when it rains, does it wash off? Should it be applied again? The directions are not clear about this.Ramsey County Minnesota
Expert Response
In mid June, put a yellow color container filled with water in your garden. Squash vine borer (SVB) adults are attracted to the yellow traps. They fly to the container and will be trapped when they fall into it. Check your traps at least once a day. Place floating row covers over your plants when you first detect squash vine borer adults. Keep the barriers in place for about two weeks after the first adult borer has been seen. Secure the row covers in a way that prevents adults from moving underneath it. Don't use row covers if cucurbits were planted in the same area the previous year. SVB overwinters in the soil underneath its host plant at about a 2 inch depth. Promptly pull up spent and dying vines and discard or destroy. If you don’t, these vines will discharge SVB until all the larvae inside the plants have completed their development. After the garden is finished in the fall, either roto-till or turn over all the soil in the vicinity of the vines with a spade. This will expose many of the underground pupae to the elements and to hungry birds. If SVB have become a perennial problem in your garden, consider skipping a year of production to clear the soil of these pests.
You could stagger your squash planting dates, so that you have different aged plants through the summer. As you pull older vines succumbing to the borer, younger, still healthy, plants will take their places and continue producing.Spray your plant stems every five to seven days in the evening with spinosad for control of SVB. Bee activity ceases in the evening. Spinosad is toxic to bees when wet. Similar to Bt, spinosad breaks down in sunlight, so late-day applications will expose insects to the toxins. Spinosad has a longer period of residual effectiveness compared with Bt, often providing good protection from pests for five to seven days. Diamide and spinosyn-type insecticides (e.g., Spinosad) are also very rainfast.
https://extension.umn.edu/yard-and-garden-insects/squash-vine-borers
