Q:
My garden is filled with daddy longleg spiders. Are they beneficial, detrimental, or harmless?
Jamie Corwin, Chaska, MN
A:
Dr. Maxcy Nolan, professor of entomology and extension entomologist with the University of Georgia in Athens, replies: Daddy longlegs are basically a neutral-to-beneficial force in the garden. Food-wise, they are creatures of opportunity, mostly feeding at night on small living and dead insects of all kinds (including other spiders) and cleaning up the garden. They also feed on plant juices, but not to the point of being a pest. They are not reported to have bitten or harmed a person.
Because daddy longlegs can be found in almost every garden, it’s worth knowing more about these odd-looking insects. Daddy longlegs usually nest in carports or under leaf litter in areas that provide shelter. They deposit eggs in cracks and crevices in the soil. In the North, they overwinter in the egg stage. In the South, they can be seen year-round. A large colony can be a nuisance, but otherwise there is no reason to eliminate these beneficial creatures from your garden. They are very sensitive to virtually all insecticides, especially those containing pyrethroids.
As a point of interest, the name of the taxonomic order to which daddy longlegs belong, Phalangida, comes from a Greek word meaning “finger” or “toe,” maybe because its body looks like a toe, or perhaps because of the long extremities that are its namesake.