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Meconema thalassinum (Orthoptera: Tettigoniidae), a foreign katydid established in British Columbia

2007; Entomological Society of British Columbia; Volume: 104; Linguagem: Inglês

0071-0733

Robert A. Cannings, James W. Wiskelly, Catrien A. H. Schiffer, Kar Lun Alan Lau, Karen Wiedenfeld Needham,

Ecology and Vegetation Dynamics Studies

Meconema thalassinum (De Geer), a katydid in the tettigoniid subfamily Meconematinae, is a European native established in northeastern North America since 1957 (Capinera et al. 2004). In the published literature it is known as far west as Michigan and extreme southwestern Ontario (Marshall et al. 2004). Rather than stridulating by rubbing the forewings together, as most Ensifera do, males call at night by tapping their hind tarsi on leaf surfaces or other substrates, and thus M. thalassinum is known in North America as the Drumming Katydid. The drumming is quiet, but sometimes may be heard 3 to 4 m away (Capinera et al. 2004). The species is pale green with a dorsal yellow stripe on the head and prothorax. Adults range from 14 to 20 mm in length; both sexes are fully winged and have an exposed tympanum on each fore tibia. The female has a curved ovipositor as long as the abdomen (Fig. 1a); the male’s subgenital plate is bifid, long and strongly upcurved (Fig. 1b). Meconema thalassinum lives mainly in deciduous trees and is mostly nocturnal; it eats insects as well as leaves (Johnstone 1970). Although there are recent photographs posted on the Internet (BugGuide 2007) from southwestern British Columbia and one from King County, Washington, this paper documents the earliest western North American records of M. thalassinum and the subfamily Meconomatinae. They come from the Lower Mainland region of southwestern British Columbia (from the Greater Vancouver area east to Maple Ridge and Langley) between 1991 and 2007 (Collections deposited in RBCM – Royal British Columbia Museum, Victoria, BC; SFU – Simon Fraser University collection, Burnaby, BC; UBC – Spencer Entomological Museum, University of BC, Vancouver, BC). Most specimens (25 of 31) were collected by entomology students for class projects at Simon Fraser University and the University of British Columbia. The earliest records are from Surrey (16 September 1991, J. Mayer (SFU)) and Haney (22 September 1991, S. Chaabra (SFU)). David Holden (pers. comm.), trapping Gypsy Moths with pheromone-baited delta traps, has found numerous Meconema specimens in the Vancouver and Lower Fraser Valley areas; the insects are apparently entering the traps for shelter or to eat dead insects trapped there. At 133 Powell Street in downtown Vancouver, Bruce Triggs captured a male in his apartment on 9 August 2006 (RBCM). Catrien Schiffer has observed the species for three years at her home on Puget Drive in Vancouver, a locality dominated by large trees and gardens. On 29 July 2005 a female appeared above the front door and both a male and female were seen there intermittently over the next two weeks. A male perched at the same place from 20 July 2006 until midAugust, when it was found dead (Fig. 1b)