Hosts or Prey
Aphids, leafhoppers, psyllids, spider mites, thrips, and other small arthropods
Identification
Anystis are 1/25 to 1/16 inch (1–1.5 mm) long, larger than most mite species. Adults are orange or red. The legs are covered with numerous, fine, short hairs. The distinct mouthparts project forward from the head. Adults' overall shape is broadly rounded at the rear and more narrow in front.
Larvae (first stage immatures) have 3 pairs of legs and are about 1/50 inch (0.5 mm) long. Nymphs and adults have 4 pairs of legs. The long legs appear to arise from a single point. This close spacing of the basal segments allows the mite's common behavior of twirling around, which is the source of the name whirligig mites.
The eggs are brown to orange, spherical, and about 1/100 inch (0.2 mm) long. They occur in a tight cluster or sometimes in a line on leaves, under loose bark, or in topsoil at the base of plants.
Life Cycle
Anystis species develop through six life stages: egg, larva, protonymph, deutonymph, tritonymph, and adult. Only females are known in some populations and they reproduce parthenogenetically (without mating).
Eggs are laid in clusters of about 1 to 2 dozen. Each female lays about 3 clusters totaling several dozen eggs during her lifetime.
The mites are highly mobile and move rapidly over plant surfaces. They are generally most active and abundant in spring. They can be hard to locate during winter.
Adults live about 2 to 3 weeks. During this time, they consume about 40 spider mites or 6 leafhopper nymphs per day or their equivalent when feeding on other arthropods.
Egg to reproductive adult development time is about 7 weeks when temperatures average 72ºF. About one-half of this time is spent inactive during molting (shedding their covering and growing a new, larger cuticle). Before each molt the immature mite encloses itself in a silken cocoon attached to plant surfaces.
The mite is generally absent from plants during mid-winter. How it overwinters is undocumented but it is speculated to be as adults or eggs in a resting condition in soil or other protected places. Anystis have at least two generations per year.
Habitat
Anystis occurs in trees, shrubs, and woody vines, such as apple, citrus, and grape. Anystis agilis is believed to be an important biological control agent of leafhoppers infesting grape.
Species
At least two similar looking Anystis species occur in California: Anystis agilis and A. baccarum.
More Information
- Anystid Mite: Citrus Thrips Predator, UC Riverside, California Agriculture
- A Taxonomic Study of Some Anystidae (Acari: Prostigmata), Entomology Memoir
- Biology of the Mite, Anystis agilis (Acari: Anystidae): A California Vineyard Predator, UC Berkeley, Annals of the Entomological Society of America
Scientific classification:
- Phylum: Arthropoda
- Class: Insecta
- Order: Acari
- Family: Anystidae
