Natural Insecticide: 6-inch banana spider

Tags

banana spider, gardening, natural insecticide, natural pest control, Nephila clavipes

By Rady Ananda

This six-inch female weaved a web support line so strong that it impeded my opening the patio door – not by much, of course, but enough that I could feel it. The silk of Nephila clavipes surpasses the strength of Kevlar, a fiber used in bulletproof vests. And she layers it.

Nephila clavipes (banana spider) by Rady Ananda Sept.2009, Ft. Lauderdale

Nephila clavipes is commonly known as golden silk orb-weaver, golden silk spider, calico spider, giant wood spider, writing spider, and banana spider.

Nephila clavipes (banana spider) Josh Hillman, 2002, Tallahassee

Webs can be up to six feet in diameter (usually 3 feet), and are very sticky. In the sun, the bright gold strands glow, attracting bees to their doom. As with most spiders, the female ingests damaged parts of the web. Unlike most spiders, N. clavipes adapts to disruption and will not likely repair frequently damaged areas. Thus, the web is rarely symmetrical.

That also means I can open the patio door without bothering her again. In this photo, the webbing can be faintly seen against the black screen:

Nephila clavipes (banana spider) Rady Ananda Sept.2009 So FLA

Banana spiders live in warm regions, from North Carolina and across the Gulf States through Central America, as far south as Argentina, and into the West Indies. Larger relatives occur in the South Pacific, Southeast Asia and Madagascar. The males emerge in July and the females much later, between August and October. (Hawkinson 2006) Ours arrived the end of August, here in South Florida. She’ll live one year, barring disaster.

This is Josh Hillman’s close-up dorsal view, which is much sharper than I could get on my zoom, but the pattern and texture differ on my banana spider (where the spots are bumps):

Nephila clavipes (dorsal view) Josh Hillman 2002 Tallahassee FL

The ventral surface on our spider bears a colorful bright pattern:

Nephila clavipes (ventral view) Rady Ananda Sept.2009 So FLA

The males are much smaller, as this Hillman photo shows:

Nephila clavipes (with male) Josh Hillman 2002 Tallahassee FL

But that size difference can be extreme. In our pair, the female is about 6 inches long and the male is about 1.5″.

Nephila clavipes (with male) by Rady Ananda Sept.2009 South FLA

The next photo lets you see her size against the patio eaves. The male appears as a tiny pale clump just above the top left leg. (She’s hanging upside down, so it’s her right rear leg.)

Nephila clavipes (with male). The camera is 5 feet above ground. The bottom of the eave is 9 feet above ground. (Rady Ananda Sept.2009 South FLA)

“Banana spiders prey on a wide variety of small to medium sized flying insects, including mosquitoes, grasshoppers, stinkbugs, leaf-footed bugs, bees, butterflies, flies, small moths and wasps. Banana spiders have even been seen feeding on beetles and dragonflies.” (Hawkinson 2006)

That makes them beneficial to gardens, garden parties, and the environment (using no toxic chemicals). Altho that size is a little freaky for this transplanted Ohio gal, she’ll spend her short life with us and help with insect clean-up in this year’s garden.

After my first barely successful garden attempt down here, I learned that Florida’s growing season is September thru June. That’s the opposite of Ohio’s growing season of May thru October. Another difference in this garden will be the seeds. This time, we got ahold of heirloom seeds from South Florida, that have been passed on for generations. We’ll be trying:

Parsley, sage and basil;
Celery, broccoli, carrots, and sweet banana peppers;
A mesclun mix lettuce and spinach; and
Three kinds of tomatoes: Roma, beefsteak and Juliett grape tomato.

I’ll let you know how my garden grows.