G.G.E. Scudder and Vickery, V.R. 1998. Orthopteroid Insects in Smith, I.M., and G.G.E. Scudder, eds. Assessment of species diversity in the Montane Cordillera Ecozone. Burlington: Ecological Monitoring and Assessment Network, 1998.

ORTHOPTEROID INSECTS

G.G.E. Scudder
Department of Zoology
University of British Columbia
Vancouver, B.C.
V6T 1Z4
and
V.R. Vickery
Lyman Entomological Museum and Research Laboratory
Macdonald College of McGill University
Ste-Anne-de-Bellevue, Quebec
H9C 3V9

ABSTRACT

The Montane Cordillera is the richest ecozone in western Canada for orthopteroid insects, and is the home for all the species native to British Columbia. To date 125 species or subspecies have been recognized as occurring in the ecozone. Of these, 2 belong to the Dermaptera (earwigs), 1 to the Notoptera (rock-crawlers), 9 to the Dictuoptera (termites, mantids and cockroaches), 33 to the Grylloptera (katydids and crickets), and 80 to the Orthoptera (grasshoppers). Both earwigs, all 4 cockroaches and the European mantid are alien introductions, the latter purposely introduced for biological control.

There has been insufficient study of the ecology and distribution of most of the species to allow for precise determination of niche and associations with particular biogeoclimatic zones, ecoregions, ecodistricts or ecosections. However, 11 species, including the ground-dwelling mantid (Litaneutria minor), are considered as potentially rare or endangered, all of these being confined to the Okanagan Valley. Most of these are threatened by loss and/or degradation of the shrub-steppe habitat in the South Okanogan Basin ecosection, and are likely to be the first that respond to climate change, being at the edge of their zoogeographic range. Most of the potentially rare or endangered species have a Cordilleran range, and it is this zoogeographic element that dominates the Montane Cordilleran orthopteroid fauna.

Populations of mesic species in this same South Okanogan Basin ecosection are also likely in danger owing to loss of the riparian habitat. However, forbivorous orthopteroids in the ecozone in general are not threatened, there being no old-growth forest specialists so far identified.

In the Montane Cordillera, livestock grazing no doubt has had an influence on grasshopper biodiversity, as most studies to date have found species-specific responses to grazing. However, it is clear that the effects of grazing vary according to the species of grasshopper, geographic region, plant community, grazing system, and yearly variation in weather. Additional studies are needed, with adequate experimental control, to determine the specific mechanisms underlying the observed responses to grazing.

Further research and monitoring of orthopteroids in the ecozone is needed, and will be facilitated by the excellent systematic handbook already available for these insects. Such research and monitoring in the future is highly desirable, because livestock grazing will be continued, and recent changes to range management guidelines will result in significant impact on range grassland communities and their structure.

Introduction

The orthopteroid insects include the grasshoppers, katydids, crickets and their relatives, as well as the cockroaches, mantids, termites, earwigs and rock-crawlers. They constitute the Subcohort Ulonata of the Cohort Polyneoptera or Polynephria of the Insecta, and characteristically are exopterygotes with chewing mouth parts, typically with leathery forewings or tegmina with usually a reticular venation or numerous crossveins. The hind wings usually have plicate folding and large anal lobes. Immature stages are terrestrial, and metamorphosis is incomplete.

Sources of Information

The major source for infomation on the Orthopteroids of Canada and adjacent regions is Vickery and Kevan (1985). Updated information on distribution, nomenclature and ecology is to be found in Vickery and Scudder (1987) and Vickery (1987, 1997a, 1997b).

 

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