Eggs are about 0.5mm in diameter, yellowish and most typically are adhered to the meristem. The scurrying female right below has recently oviposited two eggs. If you spot damage or eggs in an area you can then search for adults. Adults can be positively identified to species and either adults or very advanced pupae are required for positive identification. As indicated in the above photos , adults are typically near the tops of submersed milfoil and are small.
All weevils have a characteristic snout , which in the milfoil weevil looks like an elephant trunk.
The specimens can then later be verified by an expert. The milfoil weevil undergoes a complete life cycle - egg, larva, pupa and adult, underwater during the summer. Populations seem to go in pulses - late June through early August seems to be the best time to locate adult weevils. Copyright 1997-2001 by the Ray Newman, University of Minnesota, Department of Fisheries and Wildlife. All rights reserved.