Canadian Journal of Arthropod Identification

Sciomyzidae of northeastern North America

CJAI 35 -- March 20, 2019

Sarah Schorno, Stephen A. Marshall, William L. Murphy, and Matthew J. Muzzatti

| Abstract | Introduction | Materials & Methods | Checklist | Similar Families | Glossary | Key to Genera | Acknowledgments | References | PDF | Cite |


Materials and Methods

Specimens were obtained from the University of Guelph Insect Collection (DEBU, Guelph, Ontario, Canada), the Canadian National Collection of Insects, Arachnids and Nematodes (CNC, Ottawa, Ontario, Canada), the Royal Ontario Museum (ROM, Toronto, Ontario, Canada), and the National Museum of Natural History, Smithsonian Institution (Washington, DC, USA).

Geographic Limits of Study
Records for species in this study included those from the Canadian provinces east of Manitoba (Manitoba, Ontario, Quebec, Nova Scotia, New Brunswick, Prince Edward Island, Newfoundland and Labrador), and the adjacent northeastern states of the United States (North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Minnesota, Iowa, Missouri, Arkansas, Wisconsin, Illinois, Michigan, Indiana, Kentucky, Tennessee, Ohio, Maine, Vermont, New York, Massachusetts, Rhode Island, New Jersey, Pennsylvania, Maryland, Virginia).

Specimens were dissected when necessary for identification. Females of some genera (e.g. Limnia, Sepedon, and Tetanocera) are as yet unidentifiable to species and thus were determined to genus only. Male and female terminalia were examined after clearing whole abdomens in hot 10% potassium hydroxide (KOH) solution for approximately 8 minutes and subsequent neutralization in glacial (2%) acetic acid. Cleared structures were preserved in glycerin and pinned below specimens in microvials. Alternatively, abdomens can be cleared in hot lactic acid (abdomens cleared in lactic acid are less susceptible to ongoing deterioration than those cleared in KOH) or by use of enzymatic clearing (Yau and Marshall, 2015). The latter technique is safe, effective and utilizes clearing agents available in most pharmacies in the form of contact lens cleaning tablets, which is readily available even to the amateur naturalist.

Wing Interference Patterns (WIPs) Methods
WIPs were examined in 84 species across 21 genera of Sciomyzidae occurring in eastern Canada and the adjacent northeastern U.S. states. All of the specimens used were from the University of Guelph Insect Collection. WIPs were first observed on the dorsal surface of the wing under a stereomicroscope in front of a black background to ensure they were visible for photography. Entire WIPs were difficult to observe in preserved specimens that did not have their wings oriented properly prior to drying. A piece of black velvet was used as a background for photography. Wings were dissected from dry, pinned specimens and placed onto slides with one to two drops of 100% ethanol. A glass cover slip was placed on top to flatten the wing. Slides were prepared 24h before the photos were taken, giving the wings adequate time to dry before shooting. Slides were elevated above a piece of black velvet to reduce background artifacts. Pictures were taken using a Canon EOS 70D digital camera, an Infinity lens fit with a ring light, and a ML1000 Microptics Fiberoptic Illumination System, while using the software Helicon Remote (2016) to control the camera. Combinations of shutter speed and ISO, ranging from 1/8 sec to 4 sec shutter speeds and 125 – 250 ISO were used to take photographs. The photo-stacking program Helicon Focus (2015) was used to develop WIP photos. Images were processed using GNU Image Manipulation Program (GIMP) (2015) for Mac OSX. Image processing in GIMP was restricted to cropping, shading the background black, using the healing brush tool to neutralize dust from the wing surface, and adding up to 20% contrast. The wing terminology presented by Knutson and Vala (2011) was used to describe WIPs. For more information on WIPs, please consult Shevtsova et al. (2011).

Photograph stacks of whole specimens and diagnostic characters were taken with a Visionary Digital imaging system using a Canon EOS-1Ds camera. Stacks of images were combined by use of CombineZP software, and when appropriate, touch-up of images was conducted by use of Adobe Photoshop. Later images were stacked in Helicon focus and take using a Canon EOS70 and Helicon Remote to run a Stackshot motorized rail. Wherever possible, images of live flies were used to illustrate species habitus.

Distribution maps of species were created by use of Simplemappr open-access software (Shorthouse, 2010). The maps show specific localities (shown by dots) from various data sources (indicated by dot colour).

Locality Data
Distributional data were obtained from records of the University of Guelph Insect Collection (red dots on maps), the Canadian National Collection of Insects, Arachnids and Nematodes (yellow dot on maps), the late Benjamin A. Foote (green dots on maps), and from William L. Murphy (other institutions; purple dots on maps). Data from Benjamin A. Foote were included separately on maps to pay homage to his extensive personal collection of locality data for the Sciomyzidae family. William L. Murphy captured label data from specimens in the following collections:
CANADA: Ontario: Canadian National Collection of Insects, Arachnids and Nematodes (CNC), Ottawa; Great Lakes Forestry Centre (GLFC), Sault Ste. Marie; University of Guelph (DEBU), Guelph.
UNITED STATES: California: California Academy of Sciences (CAS), San Francisco; Essig Museum of Entomology (EMEC), University of California, Berkeley; Natural History Museum of Los Angeles County (NHM), Los Angeles. Connecticut: Peabody Museum of Natural History (PMNH), Yale University, New Haven. Delaware: University of Delaware (UDCC), Newark. Florida: Florida State Collection of Arthropods (FSCA), Gainesville. Illinois: Field Museum of Natural History (FMNH), Chicago; Illinois Natural History Survey (INHS), Champaign. Indiana: Purdue University (PURC), West Lafayette. Iowa: Iowa State University (ISUI), Ames. New Hampshire: University of New Hampshire (UNHC), Durham. New York: Cornell University Insect Collection (CUIC), Ithaca. Ohio: C.A. Triplehorn Insect Collection (OSUC), The Ohio State University, Columbus. Pennsylvania: Carnegie Museum of Natural History (CMNH), Pittsburgh; Pennsylvania Department of Agriculture (PADA), Harrisburg. Utah: Monte L. Bean Life Science Museum (BYU), Brigham Young University, Provo. Virginia: Virginia Polytechnic Institute and State University (VTEC), Blacksburg. Washington, DC: U.S. National Museum of Natural History (USNM), Smithsonian Institution.