PROC. ENTOMOL. SOC. WASH. 88(4), 1986, pp. 748-759 INSECTS ASSOCIATED WITH PURPLE LOOSESTRIFE {LYTHRUM SALIC ARIA L.) IN EUROPE S. W. T. Batra, D. Schroeder, P. E. Boldt and W. Mendl (SWTB) Beneficial Insect Laboratory, BBII, Agricultural Research Service, USDA, Beltsville, Maryland 20705, presently with Systematic Entomology Lab-oratory, same address; (DS, WM) European Station, Commonwealth Institute of Biological Control, CH-2800 Delemont, Switzerland; (PEB) Biological Control of Weeds Laboratory-Europe, Agricultural Research Service-International Activi-ties, Via Gastone Monaldi 34, 00128 ..orne, Italy (Present address: Grassland, Soil and Water Research Laboratory, ARS, USDA, Temple, Texas 76503). Abstract. — In Europe, 120 species of phytophagous insects, including 14 species apparently restricted to Lythrum, and 64 species of floral visitors were found associated with purple loosestrife, L. salicaria L. Of potential value for the bio-logical control of this aggressive alien weed in North American wetlands are: Dasineura salicariae (Cecidomyiidae); Hylobius transversovittatus, Nanophyes marmoratus, N. brevis (Curculionidae); Pyrrhalta calmariensis, P. pusilla, Aphthona lutescens, Altica lythri (Chrysomelidae); and Acleris lorquiniana (Tortricidae). Ecological, bionomic, and host-specificity investigations of these natural enemies are needed. Purple loosestrife, Lythrum salicaria L. (Lythraceae), is considered by some ecologists to be a menace to our North American wetlands because it displaces native wildlife foods such as cattails (Typha spp.). Control by chemical or me-chanical methods is difficult and usually not practical for large, well-established stands (Stuckey, 1980). For these reasons, and because biological control is com-patible with wildlife conservation and management in wetlands, a search for natural enemies of purple loosestrife in Europe was undertaken. However, because ornamental purple loosestrife is widely cultivated, garden escapes are common (Stuckey, 1 980), and beekeepers may propagate it as a nectar source (Pellett, 1 966). These uses pose conflicts of interest regarding the feasibility of biological control. This tall, vigorous, herbaceous perennial is native to Eurasia and usually found in freshwater wetland habitats (Hulten, 1971; Stuckey, 1980). In mid-to late summer, it bears three types of self-incompatible, insect-pollinated, vivid magenta flowers that are densely packed throughout conspicuous vertical verticillate spikes (Levin and Kerster, 1973; Teale, 1982). Each plant may bear as many as 3000 flowers, yielding 300,000 seeds; a pure stand of purple loosestrife may thus produce up to 59 billion seeds per hectare (24 billion/acre; Teale, 1982). In Europe, purple loosestrife may occasionally form dense monospecific stands, on calcareous or acid soils (Shamsi and Whitehead, 1974), but it usually occurs as a minor component (1-4% of cover) of mixed wetland vegetation (Bodrogkozy
BioStor
