Invertebrates

Crayfish Study Coming This Fall

By Casanova, Melvin, Sierra, and Smart
We will be studying the crayfish population and water quality of the creek along the Museum Road section of the Greenway. Our main focuses will be the health of the crayfish population and the correlation between their population density and the levels of pollution in the creek.

We will capture and study samples of crayfish in four different areas along the creek. We will use contraptions that we have created so we can safely and efficiently capture the crayfish and observe them well. There are four spots we will study; one at the bridge at the beginning, one about a quarter of a mile down, another one at the second bridge, and one further down from that.

We will compare the data from the different plots along the creek and will also study dissolved oxygen levels and temperatures of the water.

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Common vs. Rare Butterflies

The recent explosion of butterflies on the greenway trail has sparked some interest into these insects. Bill Day has done an extraordinary job documenting some species in pictures. Two particular species, the Silvery checkerspot and the Hayhurst’s scallopwing, have both been recently observed on the trails, but have different natural histories.

Silvery Checkerspot- Chlosyne nycteis
The Silvery Checkerspot butterfly is a member of the Brush-footed family (Nyphalidae). It lives mainly in wet woodlands. Adults fly from May until early September in 3 broods with gaps between broods. According to the graph below from NC data, this species has been observed most from the middle of August to the beginning of September. This data makes sense considering that you can visit the trails now and spot them by the hundreds. This would seem to indicate that food here is most abundant during this time.

http://149.168.1.196/nbnc/


http://149.168.1.196/nbnc/


Photo by Bill Day

Hayhurst’s Scallopwing- Staphylus hayhurstii
This species, which is a member of the Skipper family (Hesperidae), prefers disturbed areas like trails. Unlike the Silvery Checkerspot, this species is categorized as rare to uncommon in most of the Piedmont region. However, when they are spotted it is during July and August. You can refer to the map to see how uncommon they really are. There are really no good explanations to why they are uncommon. Their larval host plant is Lambsquarters (Chenopodium album)), which is abundant in this region. It may be that people just overlook them because of their small size (wingspan- 1.375 – 1.875 in). The adults fly from late April until early September so if you are visiting the trails, keep an eye out.


http://149.168.1.196/nbnc/


http://149.168.1.196/nbnc/


Photo by Bill Day

Bugs everywhere

August is a good time to see the tremendous diversity of insects on the greenway trails. Whether feeding, flying, or mating, they were out in force.