Invertebrates of the Presidio

Acari (or Acarina) are a taxon of arachnids that contains mites and ticks. The diversity of the Acari is extraordinary and its fossil history goes back to at least the early Devonian period. As a result, acarologists (the people who study mites and ticks) have proposed a complex set of taxonomic ranks to classify mites. In most modern treatments, the Acari is considered a subclass of Arachnida and is composed of two or three superorders or... less ↑

Trapdoor spiders (superfamily Ctenizoidea, family Ctenizidae) are medium-sized mygalomorph spiders that construct burrows with a cork-like trapdoor made of soil, vegetation and silk. Some similar species are also called trapdoor spiders, such as the Liphistiidae, Barychelidae, Cyrtaucheniidae and some Idiopidae and Nemesiidae. Some Conothele species do not build a burrow, but construct a silken tube with trapdoor in bark crevices. less ↑

Theridiidae is a large family of spiders, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders. The diverse family includes over 2200 species in over 100 genera) of three-dimensional space-web-builders found throughout the world. Theridiid spiders are entelegyne (have a genital plate in the female) araneomorph ecribellate (use sticky capture silk instead of woolly silk) spiders that often build tangle space webs and have a comb of serrated bristles (setae) on the tarsus of... less ↑

Metepeira labyrinthea, the labyrinth orbweaver, an American dollar coin sized spider, with thin legs and a round, bulbous abdomen; it is a member of the Araneidae family, of genus Metepeira. The female’s length is 5.3 mm, its carapace 2.3 mm, abdomen 3.3 mm, and extended legs 18.4 mm. The carapace is brown or gray, and the abdomen is dark with a white pattern. The legs alternate pale brown and dark brown, and the sternum is dark brown with a longitudinal... less ↑