Sunday, November 10, 2013

October Butterfly Monitoring

Our two groups headed out on October 18, 2013.   As usual, one group rides in an ATV to reach the transects B, C and D along the trails.  The other group surveys the Transect A  on foot (from the Environmental Education Center past the dam to the trailhead).  
As we walked along the marsh, we observed a truck towing an ATV and thought - could that be our group's vehicle, and are they stranded in the hammock somewhere?  
In Transect A, we counted a total of 91 butterflies including a White Peacock (Anartia jatrophae), eleven Common Buckeyes (Junonia coenia), four Painted Ladies, (Vanessa cardui) all in the family of Brush foots (Nymphalidae). We counted a variety of Skippers: Salt Marsh skipper, Long-tailed skipper and several smaller skippers that we had to document as “unknown”.  It was a breezy day, they were not landing for more than a few seconds at a time, and we were not able to catch up with them!     All skippers are Family Hesperiidae.
American Lady
Painted Lady

We took time to identify the Painted Ladies in comparison to the American Lady and the Red Admiral.
Red Admiral

Also in transect A we observed an Orange Sulphur (Colias eurythemeof the family Pieridae.  Although we have seen these in past years,  this species has not previously been discussed in this blog.  The subfamily for Sulphurs is Coliadinae.  Their wing span is 1 3/8 - 2 3/4 inches. The male upperside is yellow with orange overlay, yellow veins, wide black border, and a dark black cell spot. The female is yellow or white with an irregular black border surrounding light spots. There is a silver spot with 2 concentric dark rings, and a spot above it on the underside hindwing.
Orange Sulphur (Colias eurytheme)
Adults nectar from many kinds of flowers including dandelion, milkweeds, goldenrods, and asters.
Caterpillar hosts are plants in the pea family (Fabaceae) including alfalfa (Medicago sativa), white clover (Trifolium repens), and white sweet clover (Melilotus alba).
Wing scales located on the dorsal wing surfaces in males contain ridges with lamellae that produce iridescent ultraviolet reflectance.
Females preferentially mate with males whose wings reflect ultraviolet light. Studies have suggested that this trait was the strongest and most informative predictor of male courtship success. 

Ceraunus Blue
In August, we noted that a Ceraunus Blue (Hemiargus ceraunus, Lycaenidae family) was identified in comparison to Cassius Blue (Leptotes cassius) of the same family: the Ceraunus has a single eyespot on the submarginal hind wing, whereas the Cassius has two spots.  
Today we spotted another Ceraunus and were reminded that sometimes the single spot identification is not reliable (wings may be worn) The “Zebra stripes” on the Cassuis’ wings is a better indicator.
Cassius Blue 
As we headed back toward the Environmental Education Center we saw our Trail Transect group walking back along the dirt road.  Yes that was their ATV that was being towed earlier.  Thanks to all volunteers but especially to those who stayed to return to the trails to complete the survey in the afternoon!