Field Guide

Land Invertebrates

Showing 1 - 10 of 17 results
Photo of a Xysticus crab spider, tan individual
Ground Crab Spiders
Xysticus spp.
Missouri has several species of ground crab spiders in the genus Xysticus. They are usually dull gray or brown with brown, white, or yellow markings. They typically live under bark or on the ground in leaf litter.
Photo of a firebrat, a type of silverfish
Silverfish (Firebrat)
Lepisma saccharina, Thermobia domestica, and other species
Silverfish are known worldwide, since they commonly live in our homes. There are a number of species in this family of insects, including the common silverfish and the firebrat.
Photo of a cellar spider in her cobweb with egg sac
Cellar Spiders
Pholcus, Psilochorus, and others in the Pholcid family
Cellar spiders look wispy with their incredibly long, thin legs and habit of bouncing rapidly in their cobwebs when disturbed, which turns them into a blur. Some species are very common in homes.
Photo of a Harvestman, viewed from above
Daddy Longlegs (Harvestmen)
About 6,500 species have been named so far, worldwide.
Daddy longlegs, or harvestmen, are familiar Missouri animals. They are not spiders, but opilionids. Unlike spiders, they have a fused body form and lack silk and venom glands.
filmy dome spider
Filmy Dome Spider
Neriene radiata (formerly Prolinyphia marginata)
The filmy dome spider is one of the most abundant woodland spiders in Missouri. Although the spider is tiny, its snare web, which looks like an upside-down silk bowl, is conspicuous throughout the year.
Photo of female spiny-bellied orbweaver (spined micrathena) on a leaf
Spined Micrathena
Micrathena gracilis
The color pattern can vary, but the ten-spined, chunky abdomen sets the female spined micrathena apart from all other spiders.
Photo of a land snail crawling on a rock.
Land Snails and Slugs
Approx. 150 species of land snails and slugs in Missouri
Most people know land snails and slugs when they see these interesting animals. Missouri has about 150 species in 25 families.
mosquito resting on a white fabric
Mosquitoes
About 50 species of mosquitoes in Missouri
Mosquitoes are small flies that look a lot like their cousins in the fly family, the crane flies and midges. Female mosquitoes, however, drink blood from vertebrate animals.
Elongate-bodied springtail on a brown leaf
Springtails
More than 8,000 species globally
Springtails, like insects, have six legs, but these tiny rounded, oval, or elongated creatures that hop quickly into the air are not insects. They have a separate lineage and many structural differences.
image of an Ichneumon Wasp on tree trunk
Ichneumon Wasps
More than 5,000 species in North America
Most ichneumon wasps are harmless, although the long ovipositor of the female is intimidating. Their larvae live as parasites inside caterpillars and other larval insects.
See Also
Photo of a Yellow-Collared Scape Moth
Yellow-Collared Scape Moth
Cisseps fulvicollis
The yellow-collared scape moth is more often “orange-collared.” And whether you think it looks more like a firefly or a wasp, it’s still a moth!
image of Plume Moth on blade of grass
Plume Moths
Nearly 150 species in North America north of Mexico
Slim, delicate plume moths are instantly recognizable by their T-shaped silhouette, long legs, and muted shades of tan and brown. It can be hard to separate the various species.
Photo of an Isabella Tiger Moth
Isabella Tiger Moth (Woolly Bear; Woolly Worm)
Pyrrharctia isabella
Not many people know the adult Isabella tiger moth when they see one, but we’re all acquainted with its caterpillar, the woolly worm, or woolly bear.

About Land Invertebrates in Missouri

Invertebrates are animals without backbones, including earthworms, slugs, snails, and arthropods. Arthropods—invertebrates with “jointed legs” — are a group of invertebrates that includes crayfish, shrimp, millipedes, centipedes, mites, spiders, and insects. There may be as many as 10 million species of insects alive on earth today, and they probably constitute more than 90 percent all animal species.