By Robert Wrigley, Thilina Hettiarachchi and Reid Miller
On June 30, 2022, several friends headed out to two areas of southern Manitoba (Delta Marsh and Portage la Prairie) to enjoy a day of collecting and photographing insects. The group consisted of University of Manitoba Entomology students Reid Miller, Thilina Hettiarachchi (from Sri Lanka), and Massimo Martini (Italy), plus Tim Arendse and Robert Wrigley. Robert also wanted to photograph habitats at Delta to accompany a paper on an ecological survey of the mammalian fauna of the area (Wrigley et al. 2022), conducted on the property of Delta Waterfowl (50.192351, -98.280690).
Water levels in the Delta Marsh and Lake Manitoba were exceptionally high in the spring of 2022 due to the melting of over two metres of snow the past winter (one of the snowiest on record). The high lake level and powerful waves decimated the marsh/willow habitats and some trees along the shoreline. In spite of impressive numbers of midges and mosquitoes present, we still managed to enjoy a couple of hours collecting and studying insects (e.g., Stelis lateralis, Hylaeus illinoisensis, Lasioglossum spp, Bombus spp, Poecilonota cyanipes). An interesting discovery was a specimen of the Variegated Lady Beetle (Hippodamia variegata), a mainly Eurasian species first recorded in North America at Montreal, Quebec in 1984, and subsequently introduced into eastern North America to control crop pests (Gordon 1987). Continuing its dispersal westward, it was first recorded in Manitoba in 2014 at Winnipeg (Wrigley and Semmler 2015). The Delta specimen extends the range 90 km northwest.
We then drove to the sandhills south of Portage la Prairie (49.886805, -98.312370) where we collected and photographed insects until it was dark enough to set up a mercury vapour light. Tim had collected Goldsmith Beetles (Cotalpa lanigera) here previously (Wrigley and Arendse 2020). This evening we hoped to find both the Goldsmith Beetle and Hammond’s Lined June Beetle (Polyphylla hammondi). Robert had captured a specimen of the latter large scarab two years ago in these sandhills, and Dr. Andrew Smith, Curator of Entomology at the Canadian Museum of Nature, had expressed interest in a fresh specimen for his analysis of the Canadian species of Polyphylla.
While the group scattered in search of other interesting arthropods, Robert checked on the status of a tiny species of weevil abundant (100 specimens) last year (on July 8 and 9) on flowers of Narrowleaf Meadowsweet (Spiraea alba). Only several specimens were active at this earlier date on the few flower heads in bloom. Dr. Robert Anderson identified this species as Odontocorynus pulverulentus and noted that it is the first record for Canada. It has been described as a southern plains species, occurring from southern South Dakota to southern Texas (https://bugguide. net/node/view/1036087).
With the night turning cooler than anticipated, none of the two targeted beetles arrived at the light, but Tim, with his uncanny ability to spot Goldsmith Beetles hidden in the foliage, located a specimen under a folded leaf of an aspen sapling.
Figure 22. Enigmatic Scarab Beetle.
Numerous individuals of two species of June beetles (Phyllophaga) and a Dichelonyx kirbyi (melolonthine scarabs) were discovered feeding and mating on aspen leaves after dark. While insect activity at the light was less than anticipated, the highlight of the evening was the appearance of an Enigmatic Scarab Beetle, tentatively identified as Glaresis canadensis (Glaresidae), which has been rarely collected in Canada. This
species typically inhabits sandhill prairie.
Around 11:00 p.m., we decided to disassemble our equipment and head for home. We considered the day successful, with the capture of numerous specimens for museums, and the photographing of a variety of insects.
Acknowledgments
We thank Jim Fisher and Del Penner for arranging access to the Delta Waterfowl property. Drs. Patrice Bouchard (Canadian National Collection of Insects, Arachnids and Nematodes) and Robert Anderson (Canadian Museum of Nature) kindly provided weevil identifications. Dr. Richard Westwood (University of Winnipeg) identified the Obliquebanded Leafroller Moth. Arlene Dahl provided technical support with the images.
References
Gordon RD. 1987. The first North American records of Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae). Journal of the New York Entomological Society, 95(2):307–309
Wrigley, RE and Semmler S. 2015. First Manitoba records for the non-native beetles Cantharis rufa (Coleoptera: Cantharidae) and Hippodamia variegata (Coleoptera: Coccinellidae). Proceedings of the Entomological Society of Manitoba, 71:27–34.
Wrigley RE and Arendse T. 2020. Sandhill Gold: The Goldsmith Beetle in the sandhills of southwestern Manitoba. Newsletter of the Biological Survey of Canada, 39(2):19–24.
Wrigley RE, Dubois J and Copland HWR. 2022. Mammals of the Delta Marsh, Manitoba.
Blue Jay, 80(4):14–19.