North America. This species is widespread throughout North America. States/Provinces listed in the distribution map pertain only to documented intentional redistributions.
Eurasian watermilfoil (Myriophyllum spicatum), northern watermilfoil (M. sibiricum)
Euhrychiopsis lecontei is fully aquatic and spends the growing season submersed on watermilfoil plants. Adult weevils are 3 mm long and dark with black and yellowish mottled stripes. Adults feed on the leaves and stems of target plants. Females lay their yellow eggs singly on plant tips throughout the growing season. Larvae are whitish-tan turning purplish-gray as they mature. They feed on stem tips and mine plant stems before pupating in chambers within stems. Up to five generations can occur per year, though three is more common in the field. In late summer, adults move to shore to overwinter in leaf litter.
Redistributions are not recommended for water bodies where native milfoil species are present. When redistributions are deemed necessary in the USA, an APHIS 526 permit is required for transporting E. lecontei interstate.
Larval and adult feeding and larval mining reduce the growth, vigor, and bouyancy of attacked stems and leaves.
Andreas, J.E., W.J. Glisson, B. Muffley, and J.K. Parsons. 2024. Eurasian Watermilfoil Biocontrol Agents: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2024-3-EURASIAN WATERMILFOIL-A. https://bugwoodcloud.org/resource/files/33589.pdf