Unstable Paper Wasp

Polistes wasps, including Polistes instabilis, are large social wasps with yellow, brown and reddish markings. Body size ranges between 0.51–0.98 in (13–25 mm) with wings that are about 0.55 in (14 mm), which are folded longitudinally against the body. Male Polistes are typically smaller than females, have a yellow face, and hold their antenna curled at the tips, while females hold their antenna straight at the tips and have more dark markings on their faces. Nests are constructed with paper substance made by chewing up plant fibers, and they are typically connected a surface by a stalk. The cells of the nest are not covered as they are in some other wasp species.

Polistes instabilis can be found in tropical and subtropical areas. These include Central and South America, specifically Mexico, Belize, Guatemala, Honduras, Nicaragua and Costa Rica. Those found in Costa Rica tend to live in the lowlands, in dry forested areas. Once the rainy season ends in December, individuals migrate to higher elevation to wait out the winter. In the Yucatán Peninsula (México), this species and Polistes stabilinus (with similar morphology and overlapping distributions in Mexico and Central America; might be a synonym of P. instabilis) are both called Xananch'ak (Poqomam Mayan, "red mosquito"), Nichak (Yucatec Mayan, "red nose") or Avispa papelera (Spanish, "paper wasp"). They can be spotted during the rainy season, mostly during August–September, in the Yucatecan sub-tropical forests. Sometimes in Yucatec Maya they can be referred as well as Xanabchak ("red shoes" or "lightning shoes"), possible due to the similar pronuntiation between both Poqomam and Yucatec Mayan lenguages and the geographical distribution of Polistes.

Polistes instabilis feeds on caterpillars as well as nectar. When hunting caterpillars, the workers chew up the caterpillars extensively before returning to the nest. They distribute the ingested liquid to larvae, and caterpillar remains to other workers. Foragers will take nectar from many different plants such as soapberry, sumacs, vauquelinia, and Apache plume.