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Insect Survey for the James River Park

Article by Arthur V. Evans, D.Sc.

Regional insect surveys are essential for our understanding of natural areas.  Whether measured in terms of diversity or biomass, insects are the dominate organisms in most terrestrial and freshwater ecosystems. They are excellent indicators of local biodiversity because their fine-grained response to environmental conditions and relatively rapid responses to environmental change. Inventories of insects, both short- and long-term, provide important information about natural systems by offering critical insights into faunal patterns, community ecology, and ecosystem integrity. Thus, an understanding of the insect fauna is key to conservation planning and natural resource management of the James River Park System.

In fall of 2019, I was approached by Anne Wright of the Center for Environmental Studies-Virginia Commonwealth University (CES-VCU) to develop a proposal for conducting an insect survey of the James River Park System (JRPS). Although photographs of live insects may be useful for documenting some species that inhabit the JRPS, images seldom have the detail necessary to positively identify most species, and voucher specimens must be collected. Voucher specimens are critical to insect surveys because they serve as verifiable and permanent records of the insect species encountered.

Working with Park Superintendent Bryce Wilk, I established trap sites at Ancarrow’s Landing, 42nd Street Parking Area, Reedy Creek Park Headquarters, The Wetlands, and Pony Pasture Rapids. Each trap site consists of a Malaise trap and a baited Lindgren funnel trap ( Marshall insert Figure 1).

Tent-like Malaise traps are designed to capture primarily flying insects, especially flies, bees, and wasps. Lindgren funnel traps resemble tree trunks and capture mostly wood-boring beetles and other insects.  Starting in April, the trap samples from each site were collected every two weeks. The traps will remain in service through to the end of September.

For the duration of the survey, I am also visiting various sites in the JRPS once a month to engage in additional insect collecting methods, including hand picking, aerial and dip netting, sweeping, beating, and night lighting. Each insect sample ( Marshall insert Figure 2) is carefully sorted, and select voucher specimens are prepared ( Marshall insert Figures 3a, b) and labeled (Marshall insert Figure 4) as museum-quality specimens.

In November, a display case of specially prepared insect specimens will be presented to the JRPS. A synoptic set of identified voucher specimens will be placed in the reference and teaching collection at the CES-VCU. The bulk of the specimens collected will be deposited in the Department of Recent Invertebrates, Virginia Museum of Natural History in Martinsville, where it will be available to researchers around the world. Vouchers identified to species will be listed on an Excel spreadsheet that will also include various collection data (locality, coordinates, date of collection, collector, method of collection, and specimen deposition) and submitted to the JRPS, CES-VCU, and VMNH at the end of 2020. The spreadsheet will continue to be updated as additional species identifications become available.

FIGURE CAPTIONS

Figure 1. The Malaise and Lindgren funnel traps near the 42nd Street Parking Area.

Figure 2. A black light trap sample collected in July near the 42nd Street Parking Area.

Figure 3. a. Insect specimens are pinned, placed on a spreading board with legs set in place, and left to dry.

Figure 3. b. For some winged insects, such as these dobsonflies and cicadas, it is desirable to spread their wings.

Figure 4. Once dry, insect specimens are removed from the spreading board and each is affixed with a locality label.

 

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