GWC Prior Butterfly Stories 2005 continued ( Page 11 )

Butterflying at Petersburg State Game Area in western Monroe County just south of Dundee, Michigan this past Saturday May 21 was excellent. The oak savannah prairie habitat was in much better condition than it has been the past couple of years because of the extensive brush-cutting done by the DNR last September. Quite large patches of Wild Lupine including an albino variant were in bloom.

Chris Rickards, Sue McMahon, and I found a total of 15 butterfly species for the day. Among this total were four species of Swallowtail--Tiger, Black, Spicebush, and Giant Swallowtails--and three or four species of Duskywing--Dreamy, Juvenal's , Wild Indigo Duskywing, and ?Sleepy. Another two butterfliers we met on the site (Owen Perkins and Mo Nielsen) may have found another Duskywing species--Perseus Duskywing (a state-threatened species). [Subsequent identification proved their specimens were also Wild Indigo Duskywings].

In general Eastern-tailed Blues, Pearl Crescents, and American Coppers were quite numerous. The Coppers probably totaled far in excess of 200 butterflies.

Just as exciting as seeing the butterflies flying, we saw two Wild Indigo Duskywings copulating. We also saw a female Wild Indigo Duskywing lay an egg on one of its native foodplants Yellow Baptisia (Baptisia tinctoria). In checking other Yellow Baptisia at the site, we found single eggs on a number of plants. What made these finds special is the fact that the butterfly was laying eggs on a native hostplant which is rare in southeast Michigan. Wild Indigo Duskywing when it is found in our region almost invariably chooses Crown Vetch--a non-native plant--to lay eggs on and have its caterpillars eat. Without Crown Vetch it is most likely that Wild Indigo Duskywing would have gone extinct in southeast Michigan.

Butterflies for the Day:
Tiger Swallowtail (Papilio glaucus)
Black Swallowtail (Papilio polyxenes)
Spicebush Swallowtail (Papilio Troilus)
Giant Swallowtail (Papilio cresphontes)
Dreamy Duskywing (Erynnis icelus)
Juvenal's Duskywing (Erynnis juvenalis)
Wild Indigo Duskywing (Erynnis baptisiae)
Silver-spotted Skipper (Epargyreus clarus)
Eastern-tailed Blue (Everes comyntas)
American Copper (Lycaena phlaeas)
American Painted Lady (Vanessa virginiensis)
Red Admiral (Vanessa atalanta)
Pearl Crescent (Pyciodes tharos)
Clouded Sulphur (Colias philodice)
Orange Sulphur (Colias eurytheme)
Cabbage White (Pieris rapae)
White Colias Female

Butterflying during the week of June 20 in the Ann Arbor area has been fairly decent. Nothing really rare has been found but several new species for the year have been sighted. In addition several locally uncommon butterflies whose populations are being monitored in Ann Arbor area parks were found.

June 20: At least seven Silvery Checkerspots (Chlosyne nycteis) were flying in the open patches of and along the trails in the forest at Marshall Park. This species which is generally uncommon in southeast Michigan has had a substantial breeding colony at Marshall Park since at least the mid-1990's. At Marshall its larva feed on False Sunflower (Heliopsis helianthoides). A check of this plant on Monday showed a lot of leaf damage so maybe more Silvery Checkerspots are yet to emerge. While I was at Marshall Park I saw Silvery Checkerspots nectaring on Black-eyed Susan, Yellow Hawkweed, and Yarrow.

A check of South Pond Natural area failed to turn up any Long Dashes (Polites mystic) in the wet meadow. A Brown which may have been Appalachian Eyed Brown (Satyrodes Appalachia) was seen briefly in the forested edge of the wetland but features distinguishing it from Eyed Brown (Satyrodes Eurydice) were not seen.

June 21: Three new species of Browns were definitely sighted at Matthei Botanical Gardens. An Appalachian Eyed Brown which I got pictures of both upper and undersides was found in the forested sedgy areas along Flemming Creek. A Northern Pearly Eye (Enodia anthedon) was sighted along a trail through the forested floodplain of the creek. A single Wood Nymph (Cercyonnis pegala) floated through a drier grassy area in amongst scattered brush.

Other species of note at the Botanical Gardens included Long Dash, Silvery Checkerspot, Least Skipper (Ancyloxypha numitor), Red-spotted Purple (Limenitis arthemis), Baltimore (Euphydryas phaeton), and Harvester (Feniseca tarquinius). The Long Dash and the Silvery Checkerspots were mainly in a small Sedge meadow in the northeast section of the preserve. One Long Dash was nectaring on a Dogbane species. The three Least Skippers which I found mark the return of the species to the site after an absence of a year. The two Harvesters also mark a return after an absence. They were both seen in a section of Black Alder trees that had hosted them in previous years.

June 23: I searched the managed Big Bluestem prairie in Nichol's Arboretum known as Dow Prairie and the nearby wet meadow of Gallup Park. Both habitats had good butterflies. At Dow Prairie I found good numbers of Southern Cloudywing (Thorybes bathyllus) [15+], Great Spangled Fritillary (Speyeria cybele) [30+], a single Northern Cloudywing (Thorybes pylades), and two male Crossline Skippers (Polites origenes).

The monitored species here were the Cloudywings and the Crossline Skippers. All have a spotty distribution in southeast Michigan. In the past Dow Prairie has been among the very best locations for both Southern Cloudywing and Crossline Skipper but there has been some concern that the prairie is being burned too frequently and extensively. Judging from what I saw, the impact at least this year looks good.

At Dow both Southern Cloudywing and Crossline Skipper were nectaring on Black-eyed Susan. Southern Cloudywing was also seen on Pink Clover.

In the wet prairie of Gallup Park good numbers of Eyed Browns and a single Long Dash [the monitored species] was found.

June 24: Both Barton Nature and Foster Park were checked for Harvester but none were found. Each park has a location where Harvester has been found consistently and in good numbers for many years running. These two spots are the only places in southeast Michigan where I have seen tens of Harvesters at a time. In each spot the Harvesters have been clustered in areas where Black Alder is the thickest and not too far from a body of water. Since Black Alder is a non-native tree that can be invasive, the City of Ann Arbor has sought to remove Black Alder from natural areas. Pretty obviously the removal of all Black Alder from city parks would be a disaster for Harvester in Ann Arbor.