Galerucella beetles on purple loosestrife

Description:

Galerucella beetles - about .5cm, tan with black marginal stripes - being used as a biological control for the loosestrife. Purple loosestrife (emerging) shoot approximately 6 - 8 inches high, showing clear beetle damage.

Habitat:

Loosestrife found in open wetlands and stream edges - extremely invasive. Larval and adult beetles damage the plant by eating the leaves. Eggs are laid on the leaves in early June, larva emerge and feed until midsummer, then go to ground to molt. Adults emerge in early May to begin feeding and mating. The insects do not kill the plants outright, but the damage inflicted stunts plants growth, keeping the plants to a height of only about 3 feet (vs. 6 ft on uninfested plants) and a single short flower stalk (vs. 5 or 6 tall stalks). A single loosestrife stalk can produce up to 50,000 seeds.

Notes:

These beetles are 3rd generation offspring of beetles raised at South Windsor High School for release at Donnelly Nature Preserve for control of invasive purple loosestrife. All the emerging plants spotted today showed some beetle damage and about every third shoot had at least one pair of beetles mating.