|
| |||||
|
|
| The Dragonflies
(Insecta: Odonata) of the Columbia Basin, British Columbia: Field Surveys, Collections Development and Public Education Table of Contents
Family Lestidae (Spreadwings) The Lestidae, or spreadwing damselflies, is one of two cosmopolitan families of Zygoptera. It is a small but widely distributed family in the Columbia Basin, where it contains only one genus, Lestes, with five species. Lestes Leach
Lestes adults are metallic green or bronze, with parts of the body, including the tip of the abdomen, often becoming pruinose white with age. They characteristically perch with wings half-spread. Females oviposit in tandem with males, and eggs are usually placed in plants above the surface of the water. The larvae are long and slender with banded gills and unusually elongated labia. Some species are adapted to temporary ponds (see Habitat section); in these situations larvae grow rapidly after overwintering as eggs. Cannings et al. (1980, 1987) described the
ecology of three of these species that inhabit a series of lakes
on the Chilcotin Plateau northwest of the Columbia Basin that range
greatly in salinity and alkalinity. Lestes dryas colonizes
only the freshest ponds, L. disjunctus occurs in lakes up
to medium salinities and L. congener inhabits the complete
range of salinities and occurs in very large numbers, even at the
highest concentrations (conductivity of 15,524 microSiemens). Emergence
and mating of the three species are also temporally separate: L.
dryas emerged about ten days before L. disjunctus, which
preceded L. congener by nine days. The main emergence of
L. disjunctus occurred 20 days before the peak of the Species:
|
 |
||
 |
Copyright © Royal
BC Museum |
|
