Loading...
Please wait, while we are loading the content...
Discovery of an isolated population of Anax longipes in Michigan (Odonata: Aeshnidae)
| Content Provider | Semantic Scholar |
|---|---|
| Author | Kielb O'brien, Mark |
| Copyright Year | 1996 |
| Abstract | Anax longipes is a large aeshnid dragonfly previously unknown from Michigan. Adults and larvae were found in abundance at a series of experi mental ponds within the E.S. George Reserve in Livingston County, Michi gan. Anax longipes Hagen was previously undocumented from Michigan (Kor mondy 1958), and is rarely encountered in the Great Lakes Region (Glotzhober 1995, Kielb 1996, Tennessen 1992). The species is widely distrib uted throughout the eastern United States, from Massachusetts to Wisconsin and south to Florida, with scattered records from southern Ontario, Canada (Dunkle 1989). However, in 1996 we discovered a small, but apparently sta ble population ofAnax ongi es at the University of Michigan's E. S. George Reserve (referred to as ESGR in numerous publications and on many speci mens collected there) in southwestern Livingston County, Michigan. The species was serendipitously discovered during the course of experiments on prey response ofHyla versicolor tadpoles (Amphibia: Hylidae) to the presence of aquatic predators (Scott Peacor, pers. comm.). Anax nymphs for the above experiments were collected from a series of 22 eight-year old artificial ponds. Upon close inspection, it was discovered that two species of Odonata nymphs were being used in the experiments, Anax Junius Drury and Anax longipes. Over 400 late-instar nymphs of A. longipes had been used in various phases of the experiments (Josh Van Buskirk, pers. comm.). Both species of Anax were shown to occur sympatrically in the ponds. On 6 August 1996 we visited the ESGR site and were able to observe a minimum of four Anax longipes and several Anax Junius. Specimens of adult A. Junius were obtained, but unfortunately no A. longipes were collected at that time. Ten Anax exuviae were collected from cattail (Typha) stems and later, when compared to the exuviae resulting from the emergence of adults from captive nymphs (Table 1), w re determined to be A. longipes. Six final instar Anax nymphs were also collected. These had all ceased to eat and were nearing adult emergence. In the course of the next eight days four of the six adults successfully emerged (Table 1). At least two other man-made ponds (constructed around 1940) at the ESGR had populations ofA. Junius in 1966-67, but no records ofA. longipes. Warren Brockelman (1968) collected aquatic samples at George Pond and 1 Insect Division, Museum of Zoology, The University of Michigan, Ann Arbor, MI 48109-1079. 1 Kielb and O'Brien: Discovery of an Isolated Population of Anax Longipes in Mi Published by ValpoScholar, 1996 162 THE GREAT LAKES ENTOMOLOGIST Vol. 29, No.3 Table 1. Emergence of adults from ultimate instars collected 6 August 1996. Date species sex comments 7 Aug 1996 A longipes F Emerged before 0600 h 9 Aug 1996 none emerged 'I'wo died. 10 Aug 1996 A longipes F Emerged before 0600 h 13 Aug 1996 A. longipes M Emerged before 0730 h 14 Aug 1996 A longipes M Emerged before 0430 h Table 2. Sex and seasonal range of recently-emerged Anax junius collected at the E.S. George Reserve in 1967 by M.Y. Brockelman. |
| Starting Page | 6 |
| Ending Page | 6 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| Volume Number | 29 |
| Alternate Webpage(s) | https://scholar.valpo.edu/cgi/viewcontent.cgi?article=1913&context=tgle |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
