Herbivores on Phragmites in North America Lisa Tewksbury, Richard Casagrande, Bernd Blossey, and Geoff Balme

Introduction Over the past several decades, Phragmites australis populations in North America have dramatically increased in wetlands, particularly along the Atlantic Coast. All current control methods produce only partial or short-term control. Biological control has been proposed as a long-term control measure for P. australis. Prior to beginning a biological control program for P. australis it is important to document which insect herbivores are currently utilizing P. australis in the Northeast. Methods We initiated an extensive review of the literature, and conducted field surveys in Rhode Island and New York. In Rhode Island stem samples were collected from eight P. australis sites every two weeks from June to September, 1999. We dissected stems, recorded insects present and insect damage, and insects were reared to adults for identification.

Summary A table of insect herbivores known to feed on P. australis is provided as an important resource prior to serious consideration of biological control (Table 1). According to our literature review and field survey, there are 26 insect herbivore species known to feed on Phragmites australis in North America; 16 are recent introductions, five species are of unknown status, and only five are native. Only the Yuma skipper, Ochlodes yuma (Edwards), a species distributed throughout the western United States, and a gall midge, Calamomyia phragmites Felt, are considered native and monophagous on P. australis. The sixteen recent introductions include the moth Rhizedra lutosa (Hübner), chloropid gall-inducing flies in the genus Lipara, the gall midge Lasioptera hungarica (Möhn), a wasp, Tetramesa phragmitis (Erdös), and the rice grain gall midge Giraudiella inclusa (Frauenfeld).

Poanes viator (Edwards) Lepidoptera: Hesperiidae Adult and larva Common Name: broad-winged skipper Native to North America Host Plants: Zizania aquatica L., wild rice, and P. australis

Dicranoctetes saccharella (Busch) Lepidoptera: Elachistidae Lasioptera hungarica (Möhn) Diptera: Cecidomyiidae Larvae with fungal mycelium, and adult midge

Phytophagous Insects, Mites, and Pathogens Recorded on TABLE 1 Phytophagous Insects, Mites, and Pathogens Recorded on Phragmites australis in North America Species Larval feeding habit a Native Specificity b ACARI Tarsonemidae Steneotarsonemus phragmitidis (Schlechtendal) Leaf sheaths No M DIPTERA Agro myzidae Cerodontha incisa (Meigen) Leaf mines U P Cecidomyiidae Calamomyia phragmites Felt Stem galls Yes Giraudiella inclusa (Frauenfeld) Stems Lasioptera hungarica (Möhn) Chloropidae Oscinella frit (Linnaeus) Leave s Lipara similis Schiner Lipara rufitarsis Loew Lipara pullitarsis Doskocil&Chvála Lipara lucens Meigen Dolichopodidae Thrypticus sp. Loew HOMOPTERA Aphididae Hyal opterus pruni (Geoffr.) Leaves O Coccidae Eriopeltis festucae (Fonscolombe) Pseudococcidae

Table 1 Continued Chaetococcus phragmitis (Marchal) Stems, leaf sheaths No O HYMENOPTERA Eurytomidae Tetramesa phragmitis (Erdös) Stems M LEPIDOPTERA Elachistidae Dicranoctetes saccharella (Busch) Leaf blotch mines Yes P Hesperiidae Ochlodes yuma (Edwards) Leaves Poanes viator Crambidae Sclerocona acutellus (Eversmann) U Noctuidae Apamea oph iogramma (Esper) Apamea unanimis (Hübner) Rhizedra lutosa Stems, rhizomes Hydraecia micacea Leucania linita Guenée Simyra henrici Grote THYSANOPTERA Phlaeothripidae Uni dentified thrips Fungi Alternaria sp. Leaves, stems a U = unknown b Specificity as recorded in the literature (M = monophagous, O = oligophagous, P = polyphagous, U = unknown).

Giraudiella inclusa (Frauenfeld) Diptera: Cecidomyiidae Adult midge and galls on inside of shoot

Rhizedra lutosa (Hübner) (Lepidoptera: Noctuidae) Adult, eggs, larva, and larval feeding damage to rhizome First found in North America in 1988 in a blacklight trap in New Jersey Has also been found in Connecticut, Massachusetts, New York, and Ohio Larvae feed first on emerging shoots, and then mine rhizomes Infested shoots dry out, causing blanching of the leaves Larvae leave rhizomes to pupate in the soil, which limits R. lutosa to drier reed stands

Lipara similis Schiner Diptera: Chloropidae Larva and stem damage Lipara similis was first reported in 1958 as an import interception in North America (Sabrosky, 1958) There are three species of chloropid gall-inducing flies in the genus Lipara in North America: Lipara similis, Lipara rufitarsis, and Lipara lucens Lipara similis was found to be the most abundant of the three, during stem surveys in Rhode Island Larvae bore into the tip of the shoot in the spring, and kill the apical meristem. Lipara flies effectively stunt shoot growth of infected P. australis stems, and prevent them from flowering

Tetramesa phragmitis (Erdos) Hymenoptera: Eurytomidae Larvae and feeding marks on inside of shoot Reference:Tewksbury, L., Casagrande, R., Blossey, B., Häfliger, P., Schwarzländer, M. 2002. Potential for Biological Control of Phragmites australis in North America. Biological Control. 23(2):191-212.