Please check this
link. Check also the recommended physcial control,i.e., going out at night with a flashlight to pick up the weevils, using sticky barriers, etc..
from the same link:
Coffee grounds spread around the base of plants will deter weevils. The disadvantages of this control are the amount of coffee grounds required for large plants or many plants and repeated applications. The author has used this method on a single plant with some success, only to see the weevils return the following year. The coffee grounds are a good mulch but will add to the acidity of the soil. Some may not like the color of the grounds and a thick covering may become moldy.
Several nurseries have begun use of beneficial nematodes as an effective control measure for weevils.
Unlike chemicals, nematode applications do not require masks or other safety equipment to apply. Nematodes do require specific conditions to be effective. A specific temperature range (soil temperature must be above 55 F, 13°C) is required. Because the nematodes are free swimming, the ground must be moist. It is advisable to apply water before and after applying. Applications must be made in accordance with the date listed on the container and application rates must be strictly adhered to. Beneficial nematodes are not found naturally in the soils of most areas, so must be applied yearly. They are only effective against the larvae, and the most beneficial time for application is in the fall. Applications in late summer can only be effective if there are larvae present. Some of the commercially available brands are BioSafe, Exhibit, Biovector, Nemesis and Scanmask. These products can be found in many garden stores and through mail-order catalogues or on the World Wide Web.
