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Root Weevils

Four species of root weevil are established in Colorado including strawberry root weevils, lilac root weevils, black vine weevils and rough strawberry root weevils.  Varying in size by species, root weevils are 1/4”-1/2” in length.  Eggs are laid around the base of plants and larvae develop by pruning roots.  Pupation also occurs within the soil and adults typically emerge in June.  Adults are flightless and climb the stalks of plants in order to reach leaves which are notched along the edges by their feeding habits.  Hot dry weather during June and July often sees increased populations of root weevils invading homes and structures.  Rarely are insecticides necessary for the control of root weevils as damage is not typically significant.  Adults feed at night and harborage at the base of plants in soil areas during the day.  Insecticidal applications should be applied in areas where activity is likely occurring during the time period in which the spray is being applied.  Home and structure invasions cause no damage to the home or its contents including any occupants; however, due to their often large numbers, these invasions may be alarming.  In these cases, insecticidal applications may assist in decreasing the populations, but exclusion work to seal the home is often the primary method of interior control and then vacuuming the weevils as they appear on the interior.