Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba

87 Chapter 2 Click Beetles and Wireworms (Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba Willem G. van Herk and Robert S. Vernon Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, 6947 #7 Hwy, Agassiz, British Columbia Email: [email protected] Abstract. This chapter describes the Elateridae of Alberta (144 species), Saskatchewan (108 species), and Manitoba (109 species). It provides current names for species, as well as synonymized names that persist in the literature. Also discussed are the species that have been left out during recent changes to elaterid renaming and classification, although no new name combinations are given. The chapter outlines species distributions, biogeography where known, and the life histories of five common species: Aeolus mellillus (Say), Agriotes mancus (Say), Hypnoidus bicolor (Eschscholtz), Limonius californicus (Mannerheim), and Selatosomus aeripennis destructor (Brown). An examination of the seasonal movements and activity of larvae in response to soil temperature and moisture and moulting cycles is followed by an overview of past research on Prairie Province species. The chapter concludes with a discussion of current research needs and management issues. Résumé. Le présent chapitre décrit les Elateridae de l’Alberta (138 espèces), de la Saskatchewan (76 espèces) et du Manitoba (104 espèces). Il fournit les noms actuels de ces espèces, ainsi que les synonymes qui persistent dans la documentation spécialisée. Il se penche également sur les espèces qui ont été laissées de côté lors des récents changements apportés à la nomenclature et à la classification des élatéridés, sans toutefois s’attarder aux nouvelles combinaisons de noms. Le chapitre décrit la répartition des espèces, leur caractéristiques biogéographiques — lorsqu’elles sont connues — ainsi que le cycle de vie de cinq espèces communes : Aeolus mellillus (Say), Agriotes mancus (Say), Hypnoidus bicolor (Eschscholtz), Limonius californicus (Mannerheim), et Selatosomus aeripennis destructor (Brown). Il examine les déplacements saisonniers et l’activité des larves sous l’effet des variations de la température et de l’humidité du sol ainsi qu’au fil des cycles de la mue, et présente un aperçu des recherches effectuées par le passé sur les espèces des provinces des Prairies. Nous nous penchons en guise de conclusion sur les besoins actuels et les enjeux de la gestion de la recherche. Introduction The Elateridae are the largest family of the series Elateriformia and superfamily Elateroidea and the ninth most diverse family of beetles overall, with nearly 10,000 described species worldwide and nearly 1,000 described species in the Nearctic region (Johnson 2002). The family is well represented in Canada. Bousquet et al. (2013) lists 133 elaterid species for Alberta, 102 for Saskatchewan, and 100 for Manitoba (numbers adjusted in this chapter). The main feature distinguishing this family from other Coleoptera is the flexible union of the prothorax and mesothorax, a result of a prosternal intercoxal process fitting into a groove on the mesosternum, which the beetles can flex and snap to right themselves and possibly also to startle and evade predators. This snapping action propels the beetles into the air and produces an audible click, giving the family its common names click beetles van Herk, W. G. and R. S. Vernon. 2014. Click Beetles and Wireworms (Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba. In Arthropods of Canadian Grasslands (Volume 4): Biodiversity and Systematics Part 2. Edited by D. J. Giberson and H. A. Cárcamo. Biological Survey of Canada. pp. 87-117. © 2014 Biological Survey of Canada. ISBN 978-0-9689321-7-9 doi: http://dx.doi.org/10.3752/9780968932179.ch2 Species checklist available at http://dx.doi.org/10.5886/5drq7v8p 88 W. G. van Herk and R. S. Vernon and skipjacks and the reason for the Greek root of the family’s name, ελατηρ: to drive, hurl, or set in motion. Beetle families generally placed close taxonomically include the Cerophytidae (rare click beetles), Eucnemidae (false click beetles), and Throscidae, all of which have some members that share the clicking mechanism (Calder et al. 1993), though molecular data suggest that Lycidae, Lampyridae, and Cantharidae may be more closely related to the Elateridae (Kundrata and Bocak 2010). In recent years, the Lissomidae, Cebrionidae, and some tribes of the Eucnemidae and Cerophytidae have been included as new subfamilies in the Elateridae (Johnson 2002), and most Drilidae have been included in the elaterid subfamily Agrypninae (Kundrata and Bocak 2010). Research into the biodiversity, distribution, and ecology of elaterids in Canada has decreased in the last few decades relative to most of the 1900s. For example, Thomas (1940) reviewed >450 papers on wireworm biology and management that had been published since his similar-sized review a decade previous (Thomas 1930). Subklew (1938) reviewed >1,000 papers, Gaedike (1969) >1,500, and Keaster et al. (1988) ~2,500. This attention was driven primarily by economics. Although adult elaterids are rarely of economic importance, wireworms (the name given to the long-lived (1–5 year) larval form) cause damage to cereal and vegetable crops worldwide. Their economic importance resulted in copious and excellent research, particularly in the United Kingdom, Germany, Japan, and North America. In Canada, research was done on pest elaterids from the 1930s to the 1970s in British Columbia (Wilkinson 1963; Wilkinson et al. 1964, 1976), Ontario (Begg 1957, 1962), Quebec (Lafrance 1963, 1967, 1968; Lafrance and Cartier 1964), and Atlantic Canada (Morris 1951; Eidt 1953, 1954, 1958, 1959; Fox 1961), but especially in the Prairie Provinces (Strickland 1927, 1935, 1939, 1942; King 1928; Arnason 1931; King et al. 1933; Glen et al. 1943; Glen 1950; Davis 1957, 1958a, 1958b, 1958c, 1959a, 1959b, 1959c, 1959d, 1961; Zacharuk 1958a, 1958b, 1962a, 1962b, 1962c, 1970a, 1970b, 1971, 1972, 1973a, 1973b, 1974; Doane 1961, 1963, 1966, 1967, 1977a, 1977b, 1981; Burrage 1963, 1964; Doane et al. 1975). The basic research done during this time, although unfortunately often overlooked in recent publications on wireworm biology and management, remains invaluable. In Canada, for example, the work by Wilkinson (1963) and Glen et al. (1943) led to identification keys for larvae of pest species in British Columbia and Canada, respectively, that are still in use for identifying larvae collected both within and well outside their intended regions (Vernon and van Herk 2012), and Doane et al.’s (1975) work on wireworm movement in soil is the basis for our own observational work (van Herk and Vernon 2007; van Herk et al. 2008b). Nearly all the elaterid research in Canada during this time focused on the biology and management of wireworms, and comparatively little attention was given to adults—notable exceptions being Brooks’ (1960) treatment of adult elaterids for Alberta, Saskatchewan, and Manitoba; Becker’s revisions of Neartic Athous Eschscholtz (Becker 1974, 1979b) and Agriotes Eschscholtz (Becker 1956); and Brown’s descriptions of Canadian elaterids, which amounted to a sizeable part of The Canadian Entomologist in the 1930s (Brown 1930, 1933a, 1933b, 1934a, 1934b, 1934c, 1934d, 1935a, 1935b, 1935c, 1936a, 1936b, 1936c, 1936d, 1936e, 1939). Interest in elaterid research waned after the 1960s, when organophosphate and organochlorine insecticides effectively controlled wireworms. In British Columbia, for example, aldrin and heptachlor killed wireworms (Agriotes obscurus L.) for 13 years after a single application to soil (Wilkinson et al. 1964, 1976). The elimination of these chemicals (which also persisted in potato tubers harvested for human consumption; Begg et al. 1960) from registration, and their replacement with compounds that are generally ineffective in reducing populations (Vernon et al. 2009, 2013; Vernon and van Herk 2012), has caused a Click Beetles and Wireworms (Coleoptera: Elateridae) of Alberta, Saskatchewan, and Manitoba 89 recent resurgence of wireworm populations in the Canadian Prairie Provinces, and with it a resurgence of interest in wireworms (for producers and insecticide companies) (Vernon and van Herk 2012). This increase in wireworm presence and grower concern across the Canadian Prairie Provinces has allowed us to identify larvae collected from hundreds of fields in Alberta, Saskatchewan, and Manitoba where crop damage has occurred. These data, collected over the last decade, have allowed us to compare historical and current distributions of pest species, assess the degree of genetic variability among and within species, and correlate this variability with geographical distance. Virtually all that is known about elaterid biology and distributions in the Prairie Provinces resulted from past and present pest management work. For this reason, and because wireworms are re-emerging as one of the most important agricultural pests in Canada and elsewhere (Vernon and van Herk 2012), this chapter includes a discussion of the biology, behaviour, and distribution of select elaterid species of economic importance. Species and Distribution Names of Species Listed In this chapter, we list all species found in Alberta, Saskatchewan, and Manitoba, rather than only those known to occur in the grassland areas of these provinces. We have chosen this approach because little is known about the distribution of most species within these provinces (and the rest of Canada; Fuller 1992), and listing all species

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