The genus "Mycoplasma" uses vertebrate and arthropod hosts. The Haemosporidia have more complex lifecycles that alternate between an arthropod and a vertebrate host. Krill belong to the large arthropod subphylum, the Crustacea. Jurassic beetles are a species of arthropod from the Jurassic. It consumes a variety of arthropod species, including insects and spiders. It is the application and study of insect and other arthropod biology to criminal matters. The enzyme chitinase produced in the stomach helps digest the chitinous cuticle of arthropod prey. Lava fleas are a species of hard shelled arthropod. Ingrowths of the arthropod exoskeleton known as apodemes serve as attachment sites for muscles. Malpighian tubules are slender tubes normally found in the posterior regions of arthropod alimentary canals. Further than their arthropod status, the identity of these early herbivores is uncertain. Numerous other arthropod, protozoal, and parasitic infections have been described. Other important factors determining geographic distribution of arthropod vectors include rainfall, humidity, and vegetation. Most of arthropod biodiversity is concentrated on Great and Lesser Caucasus ranges. A single nematocyst has been shown to suffice in paralyzing a small arthropod ("Drosophila" larva).