This period of emergence occurs typically from July to September. The total maturation time from egg to adult is approximately 40-60 days. A second generation has been observed in some years and locations. Recommendations for use For sites with fewer than 100 plants, hand removal or spot treatment with registered herbicides is recommended. For larger infestations, release of loosestrife beetles is recommended.
Releases are typically of pupae and adult beetles.
The larger the numbers released, the better the chance for establishment. A minimum of 2,000 to 3,000 beetles per site are recommended. Releases in successive years will improve the chance for establishment. Beetles may be released at any time after purple loosestrife emerges in the spring until late August. Beetles released after the summer solstice are likely to feed and overwinter without reproducing.