Sunday, September 21, 2014

Bola Spider and Imperial Moth

It's always a challenge to see all nature has to offer when we're out hiking in the great outdoors but occasionally we run across things that we've never seen before and we are compelled to further research in order to satisfy our curiosity.  Renee Bentz, Allen County Parks employee, was at Metea County Park recently checking milkweed plants for caterpillars when she noticed a bird dropping on the underside of a leaf.  On closer inspection she realized it was actually a spider clinging to the leaf. Renee took a photograph, and headed for her insect and spiders field guide.
 What Renee saw was a Bola Spider (Mastophora bisaccata).  This spider does not spin a web in order to catch it's lunch but instead produces a single high strength thread adorned with sticky beads of scented liquid which attracts its prey.  The spider is capable of producing pheromones which are species specific in order to attract a wide range  of insects. As an insect approaches it the spider spins the thread, like a bola, using it's legs.  When the prey hits the thread it is trapped in the sticky liquid and promptly wrapped in a cocoon to keep it fresh for later consumption.
Photo by Renee Bentz

Another oddity seen recently at Fox Island County Park is this Imperial Moth caterpillar (Eacles imperialis).  This caterpillar was crawling slowly across the mulch when I saw it. This caterpillar's host plants are sassafras, elm, hackberry and several other trees.
The caterpillar will hatch and eat tree leaves until it is ready to pupate then crawl to the ground, find some soft soil, dig itself into the ground and stay there for the winter.  This caterpillar was 3 3/4" long and about the size of my index finger. The white dots along the side of the caterpillar are the spiracles or respiration openings.  The wingspan of an adult Imperial Moth can be nearly 6".  This caterpillar was returned to the ground after the pictures were taken.
Photo by J. Ormiston