ABOUT BOM SPECIES LIST BUTTERFLY HISTORY PIONEER LEPIDOPTERISTS METHODS
The Butterflies of Massachusetts
84 Common Sootywing Pholisora catullus (Fabricius, 1793)
Jet-black with sparkling white dots, the handsome Common Sootywing may have been quite familiar to the earliest human agriculturalists in North America. This is because its host plants, amaranths and chenopodiums, naturally thrive in disturbed areas around human settlements. Chenopodium, in fact, was domesticated by Native Americans as a food crop.
This species was one of the first New World butterflies to be described and named; it was figured by John Abbot in Georgia in the late 1700s. Despite its name, Common Sootywing was not common in Massachusetts at the end of the 19th century: Scudder reports it from only two areas: Boston and Middleboro where it was scarce, and the lower Connecticut River valley, where it was more easily found. He mentions specimens from Springfield, Northampton, Mt. Tom and South Hadley, and Amherst (1899: 1523).
Photo: Northampton community gardens, F. Model, August 21, 2006
In 1874 Mr. H. W. Parker wrote an article in Psyche, the journal of the nascent Cambridge Entomological Society, entitled “Novelties in Amherst, Mass.” Among the “novelties” was Pholisora catullus; Parker collected a male in June, and also found the species “not rare” on and after July 30. F. H. Sprague collected it in Springfield on August 9, 1883. Scudder had collected it in Boston, Hambly in Middleboro. But neither Scudder nor Maynard (1886) nor Parker (1874) considered Common Sootywing to be at all common in Massachusetts.
Common Sootywing must have been lightly present along river banks and around Indian settlements prior to the arrival of Europeans, and very likely increased around colonial and post-colonial habitations and urbanizing areas 1600-1850 (Table 1). It also seems likely to have increased or held steady through the industrializing years of 1850-1950, but does not seem to have been widely collected or observed. By 1934 Farquhar can add only the town of Salem to Scudder’s list of Massachusetts locations.
Today Common Sootywing is more common south of Massachusetts, for example in Connecticut (“common” CBA Checklist; O’Donnell et al.), New York (“very common around New York City, less so upstate” Shapiro 1974), and New Jersey (“fairly common, occassionally abundant” Gochfeld and Burger 1997). Massachusetts is in Common Sootywing’s secondary range, not its primary (Opler and Krizek 1984). This species is rare in both Maine and Vermont (see below), and therefore Massachusetts is effectively the northern limit of its range in eastern North America.
Host Plants and Habitat
Common Sootywing’s host plants are annuals in the Chenopod and Amaranth families: primarily Chenopodium album, ambrosioides, berlandieri and others (lamb’s quarters; goosefoot), and Amaranthus caudatus, retroflexus, spinosus, hybridus, and albus (pigweed) (Scott 1986). Except for C. album, which is naturalized from Europe, most Amaranths and Chenopods are native to the New World. They were probably introduced into New England from further south (Sorrie and Somers 1999), probably by Native Americans. But today they are widespread (McGee and Ahles 1999).
The 1990-95 Connecticut Atlas found Common Sootywing eggs or larvae on two plants, one native Amaranthus retroflexus, and one introduced, Chenopodium album. Thus Common Sootywing is among those species which have adopted a non-native host in addition to its several native hosts (Table 3, Switchers). In Massachusetts photographer Sam Jaffe found Common Sootywing on either amaranth or chenopodium in 2009 in the Blue Hills in Milton; other MBC members report it using pigweed or lamb’s quarters in their gardens.
Common Sootywing is at home in open areas created by human disturbance, such as vacant lots, weedy backyards, landfills and edges of croplands and pastures. Today, it is not usually found in natural settings. A number of sources (Opler and Krizek 1984; Cech 2004) mention sandy river banks and sand plains as the original habitat, because chenopodium often colonizes river sandplains after floods. Interestingly, these were also the areas also favored by Native Americans for their encampments.
Native Americans in the Late Woodland period prior to European arrival in Massachusetts gathered various chenopodiums and ground the seeds into a meal. Charred remains of C. incanum and C. berlandieri have been found in small quantities in hearth excavations in New England in time periods prior to the advent of maize cultivation (1300-1600). Chenopodium was probably simply gathered here, judging from its morphology, rather than cultivated, although it was a domesticated cultigen among other Native American groups who lived to the south and west, in Pennslyvania and the Great Lakes area. Still, even the “conditional sedentism” of many New England coastal and riverine Native American groups disturbed the land somewhat, and chenopodium was clearly present around Indian encampments, along with amaranth and other open area “weedy” plants such as composites, ragweed, and nettles ( Bragdon 1996: 39; 55-71; Bernstein 1999; George and Dewar, 1999).
Relative Abundance Today
The 1986-90 MAS Atlas found this species in only 70 out of 723 blocs, which would place it firmly in the “Uncommon” category. MBC sight records 2000-2007 place it similarly at the bottom of the “Uncommon-to-Common” category, relative to other species (Table 5). It is most definitely not a “Common” species, like American Copper or Little Wood Satyr. As the joke goes, it is the “Not-so-Common Sootywing.”
MBC records per total trip reports 1992-2009 show a generally upward trend through 2005, and then a decline after that. This may be expected an population fluctuation.
Chart 84: MBC Sightings per Total Trip Reports, 1992-2009
The readings since 2001 are strongly affected by the results of the Northampton NABA Count, begun in that year. The high readings in 2003, 2004 and 2005 and 2007 reflect unadjusted totals of 77, 62, and 106 sootywings found on that count in those years. Northampton count totals were down to 41 in 2006, and have remained low in 2008 (46), 2009 (0), and 2010 (14). Common Sootywing populations in the Northampton count circle have apparently fluctuated greatly in these years; that may be characteristic of this species.
State Distribution and Locations
Map 84: MBC Sightings by Town, 1992-2009
Common Sootywing has been reported from 98 out of 351 towns in Massachusetts (Map 84). Three new towns for 2010, which should be added to the map, are Westport, Cambridge, and Milton.
This species is well-distributed across the state, including Cape Cod and Martha’s Vineyard. However, it is uncommon in these latter two areas. Mello and Hansen (2004: 58) report that it is “uncommon” on Cape Cod, and believe it has declined generally in southeastern Massachusetts, perhaps due to herbicides or pesticides. Falmouth and Brewster are the only two towns on the Cape from which MBC has reports, and these are few reports of few individuals. The 1986-90 MAS Atlas also found it uncommon on Cape Cod. There are likewise only a few MBC reports from Martha’s Vineyard, and the Vineyard checklist ranks it as “Uncommon” (Pelikan 2000). Neither the Atlas nor MBC has reports from Nantucket.
The 1986-90 Atlas had also reported Common Sootywing as uncommon on Cape Ann, but MBC has several reports from Gloucester, Marblehead and Saugus, and many from other north shore towns such as Ipswich, Topsfield and Newbury.
The Atlas also found the species uncommon in northern Worcester County, and in far western Massachusetts, and MBC data largely confirm these assessments. This species has been reported in small numbers from only two towns in Berkshire County, Sheffield and Williamstown. The species is strong in the Connecticut River valley, however, as might be expected from its river valley origins.
Common Sootywing is usually observed in small numbers of less than five at a site. Locations which have proved particularly productive 1991-2010 are Boston/Roxbury Millennium Park max 10 on 5/30/2009 E. Nielsen; Bolton Flats, max. 6 on 5/30/1999 B. Walker; Grafton Dauphinais Park max. 13 on 7/30/2003, W. Bosse, W. Miller and E. Barry; Northampton community gardens max. 26 on 8/22/2004, B. Benner; Springfield Forest Park max. 5 on 8/5/2000 T. Gagnon; Stow Delaney WMA max. 28 on 6/2/2000 B. Walker et al.; and Wayland community gardens max. 10 on 8/24/1999 B. Cassie.
Common Sootywing is found on many of the NABA Counts due to its flight time. The high numbers reported for several years from the Northampton NABA Count (max. 106 on 7/22/2007) far outstrip the numbers found on any other counts. But this species is also consistently reported on the Concord Count (max. 24 on 7/10/1999) and the Blackstone Valley Count (max 13 on 7/16/2005). A Boston NABA Count was held once, on 7/23/2006, and turned up 19 Common Sootywings. The infrequently-held Lower Pioneer Count, based in Springfield, reported 13 on 7/15/1995.
Broods and Flight Time
Common Sootywing has two to three broods throughout its large Canada-to-Florida-to-Mexico range, and also two or three in Massachusetts. According to MBC flight records (http://www.naba.org/chapters/nabambc/flight-dates-chart.asp), the first brood flies from about late April to mid-June, and the second peaks in mid- July, but continues flying into September. The long period covered by the second flight, and a cluster of sightings in late August/early September, suggest that there are three broods here in some locations.
Three broods were apparent at one continuously monitored vegetable garden in Newbury, Massachusetts in 2010. Fresh individuals were observed, after gaps, on 5/25/2010, 7/4/2010, and 8/26/2010 (S. Stichter). At Northampton community gardens, which is very frequently visited by MBC members, three broods were also suggested in at least one year, 2007. Common Sootywings were first seen on 5/3 that year (3, B. Volkle), then again from 7/24 through 8/11/2007, and again from 9/3 through 9/18/2007 (various observers).
The flight dates appear to be about the same as a century ago. Scudder wrote that the earliest brood of Common Sootywing “appears toward the middle of May,” citing May 12 for Connecticut. The second brood “appears very late in July and probably flies until September (1889: 1526).”
In the 20 years 1991-2010, two first sightings of Common Sootywing have been in the first week of May or earlier (4/30/1998 Florence, T. Gagnon; 5/1/2010 Ware, B. Klassanos). Seven first sightings have been in the second week of May (5/8-5/14), five have been in the third week, and six in the last week of May. The Atlas first sighting was 5/10/1987 Braintree, R. Abrams. There does not appear to be a tendency for the first sightings to be progressively earlier over the years, although data from a single site, or data on average first brood date, might show such a tendency.
Since 1999, the last sightings have all been in September. The species probably flew into September in earlier years as well, but not enough effort was made to search for it. The four latest dates in MBC records are 9/21/2002 Marblehead, K. Haviland; 9/20/2010 Stow Delaney S. Moore; 9/20/2003 Northampton community gardens, Nielsen/Gagnon/Murray; and 9/19/2006 Newbury, S. Stichter.
One might think we need not worry about this butterfly, because of its liking for disturbed habitats. Yet there are many areas of Massachusetts where this species is very scarce or not found at all, either because of lack of habitat, or cold intolerance. The butterfly overwinters as an unfed larva, and pupates in the spring.
NatureServe has assigned no rank to Common Sootywing in Massachusetts or other New England states outside of Connecticut. But it is not a common butterfly, and Massachusetts is at the northern edge of its range. The 1995-2010 Maine Butterfly Survey has found Common Sootywing in only one township in extreme southern Maine (MBS 3/2011). The 2002-2007 Vermont Butterfly Survey (VBS) found in “extremely rare” in Vermont and ranked it S1. It was found only in the southern part of that state.
If climate warming means milder winters, that might lead to an increase in Common Sootywing’s numbers. But if it means colder, snowier winters, that outcome is uncertain. More research needs to be done on the response of this species to temperature variations.
© Sharon Stichter , 2011
page updated 3-11-2011
ABOUT BOM SPECIES LIST BUTTERFLY HISTORY PIONEER LEPIDOPTERISTS METHODS