Stories about chiggers in Spanish moss.
Trombiculidae is the name of the family of mites that contains “red bugs.” Red bugs are the adult mites (they are not insects but mites that have eight legs, not six like insects) that run around on the ground in spring. They are tiny, only 1-2 millimeters long, but their red color makes them conspicuous when they run about on tile or concrete or paving stones. These adult mites are harmless to humans although you may wish to crush them when you read the rest of this article; these adults prey on insect eggs and tiny insects in the soil. It is the immature stages (larvae, no bigger than a third of a millimeter, and pale yellow or orange or even red) of these mites that sometimes cause a problem for humans. The larvae climb up grass blades and “latch onto” passing animals (mice, rats, rabbits, cats, dogs, deer and cattle). An excellent place to find them is a cattle pasture where they may latch onto you, but perhaps your lawn will do if your pets or your neighbor’s pets run around on it. Larvae of Trombiculidae are called chiggers in the USA. When they latch onto you they head for any bit of skin they can access, often your ankles and lower legs, but they can climb higher if they get under your clothes and often end up around your waistline, stopped from climbing higher by your tight belt.
The trombiculid larva has only six legs, though you won’t see them without a microscope. It punctures your skin (or that of other mammals or even birds) with its mouthparts and injects saliva into the puncture wound. The larva sucks up hemolymph from the wound, and this is repeated and forms a tube extending downward from the skin. The digestion of skin cells causes intense itching. After a few to many days, when the larva is engorged it drops to the ground and hides itself. It molts to the nymphal stage (a predatory not parasitic stage), and then after time to the adult which can mate (the females lay eggs).
An old wives’ tale in the southern USA is that Spanish moss in trees contains chiggers. That is strange because entomologists have NOT found chiggers in Spanish moss on trees, even despite repeated attempts. Nor have they found red mites (the adults). Indeed, what would be the point of chiggers “hanging out” in Spanish moss on trees when they need to find cattle or people or cats of dogs etc. which typically do not climb trees. How could such tiny mite larvae, hatching from eggs in the soil, manage to climb trees to get into Spanish moss?
REFERENCES: Rosenfeld, A.H. 1911. Insects and mites in Spanish moss. Journal of Economic Entomology 4: 398-309. ^ Whitaker Jr., J; Ruckdeschel, C. (2010). “Spanish Moss, the Unfinished Chigger Story”. Southeastern Naturalist. 9 (1): 85–94. doi:10.1656/058.009.0107.
Repelling chiggers: DEET, N,N-Diethyl-meta-toluamide frequently sold as “Off” sprayed on sneakers and socks and the lower parts of trouser legs does a good job in repelling chiggers.