by Joseph DeSisto
I’m currently in Arizona, and don’t have much time for writing, but I’m just seeing too many cool things not to show you one of them. There are some amazing arachnids in the Southwest: so far I’ve seen tarantulas, scorpions, sun spiders, and black widows, all of which will appear on this site in some fashion. As a teaser, here’s a green lynx spider, common in much of the southern United States:
The prey above is a burnet moth in the family Zygaenidae. Its colors are a warning sign that this moth is extremely toxic, loaded with hydrogen cyanide, but this spider doesn’t seem to mind.
Most spiders fall into one of two categories based on hunting strategy: ambush predators (including web-builders) and wandering hunters. Lynx spiders are both. The one above waited patiently before grabbing a passing moth. Tomorrow, though, it might just as easily stride over the foliage, searching for less active preys such as caterpillars.
Aside from being an efficient hunter, green lynx spiders are very adaptable and do well in gardens and farms. Because they can be extremely abundant, biologists have studied their ecology to determine whether they might be useful to farmers. Whitcomb et al. (1963) recorded them as important predators of several important crop pests, notably the corn earworm, cotton leafworm, and cabbage looper, all three both as adult moths and as caterpillars.
The trouble is, lynx spiders don’t really care if the insects they eat are pests, and some of their favorite prey are beneficial insects. They are more than happy to eat wasps, which themselves are important caterpillar predators. The honey bee, an important pollinator, is one of their favorites (Whitcomb et al. 1966).
To determine just how useful lynx spiders actually were, Randall (1982) conducted a survey of prey items captured by lynx spiders throughout Florida. He then rated the spiders’ victims by importance to farmers: an insect cadaver could be either extremely harmful (e.g., cotton leaf worm), extremely beneficial (e.g., honey bee) or anywhere in between.
A total of 66 prey items were recorded, and in the end, data pointed to these spiders eating as many beneficial insects as harmful ones. So the green lynx spider might not be especially important to farmers. Or, more accurately, the green lynx is neither beneficial nor harmful. It is simply a spider trying to make a living however it can, irrespective of human interests.
Randall J.B. 1982. Prey records of the green lynx spider, Peucetia viridans (Hentz) (Araneae, Oxyopidae). Journal of Arachnology 10: 19-22.
Whitcomb W.H., H. Exline, and R.C. Hunter. 1963. Spiders of the Arkansas cotton field. Annals of the Entomological Society of America 56(5): 653-660.
Whitcomb W.H., M. Hite, and R. Eason. 1966. Life history of the green lynx spider, Peucetia viridans (Araneida: Oxyopidae). Journal of the Kansas Entomological Society 39: 259-267.