These little pests can cause serious damage. For instance, if the plant is small, their larvae may cause enough root loss to kill the plant. Also, the larvae could cut away the main stem, destroying your plants. Moreover, even the larger plants can be affected. In their case, root damage can lead to nutrient deficiencies. Thus, here you’ll get the most efficient ways to rid your plants of black vine weevil bugs.
1. Hand picking
With the aid of a flashlight, pick-off the adults in the evening as they come out to feed.
Simply placing a white drop cloth under your plant in the evening or early morning and shaking the leaves will help to catch many of the adults. During the day, place a board under the plant. Check the board for hiding adults and scrape them off into a bucket of soapy water. Place a wrapper around the trunk of the plant and coat it with a sticky substance such as Tanglefoot. The wrapper should be at least 6″ wide.
The eggs and larvae of the black vine weevil require moisture to survive. If your plants are heavily mulched, pull back this mulch to allow the surface of the soil to dry out and do not water plants unless necessary.
4. Beneficial Nematodes
Rather than attacking the adults, beneficial nematodes go after the larvae in the soil and are a safe & natural method of controlling black vine weevil. A few things are critical in order to get good control:
5. Timing & Temperature
The soil requires a temperature of at least 60 F to work. Gardeners often miss the critical period in the spring since the weevil larvae pupate fairly early before the soil warms. The late summer and early fall is the best time to apply the nematodes.
The root zone around the plant must be moist since nematodes don’t swim and require water to carry them through the soil. Water the area before and after application.