Lestes forcipatus (Sweetflag
Spreadwing)
BC conservation rank: S4. Yellow List. Ranked S3 when
first discovered in BC, L.
forcipatus is now known to be more widespread and common. The northern
surveys have greatly increased our knowledge of this species in
BC.
Description: The male is very similar to the Northern
Spreadwing, but mature specimens of L.
forcipatus can usually be identified by the lack of pruinosity on the
rear third of the top of abdominal segment 2 (Simaika and Cannings 2004).
Females are unmistakable; the large, distinctive ovipositor extends beyond the
end of the abdomen (fig. 2). Length: male, female 40 mm.
Global
Range: : British Columbia east to Nova Scotia, south to Alabama, Missouri,
Wyoming and Washington (Westfall and May 1996). Faunal element: Austral (see
Appendix 2).
BC Distribution: Scattered
localities south of 56°N, but known in the southern Yukon.
Biology: A common species of eastern North America, L. forcipatus was unknown in BC until
1998, when it was found in the Rocky Mountain trench. The species is so
similar to L. disjunctus that it
had been overlooked (Simaika and Cannings 2004, Ramsay and Cannings 2005,
Cannings et al. 2005). Since then, although it is uncommon, it has been
found in a variety of ponds, marshes and marshy lakes (Wm01-02, Wm04-06), but
is probably most common in sedge fens (Wf05-08) (Cannings and Simaika 2005).
Walker (1953) described L.
forcipatus habitat in eastern Canada as "ponds, both temporary and
permanent, marshy lakes, and slow, weedy streams. In eastern North America, at
least, this damselfly commonly lays eggs in the sweetflag, a kind of aquatic
iris, thus its English name.
BC flight period: mid June to mid
September; mostly collected between mid July and mid August.
Lestes
forcipatus female. Photograph: Rob Cannings, RBCM.
Lestes
forcipatus Map 1. Geographical distribution and seasonal abundance of
records in British Columbia.
Lestes
forcipatus Map 2. Geographical distribution of records in British Columbia
before and after organized surveys began in 1996.
Lestes
forcipatus Map 3. Frequency of records in British Columbia by NTS 1/50,000
mapsheet.
Lestes
forcipatus Map 4. Frequency of collection localities in British Columbia
by NTS 1/50,000 mapsheet. |
