Various Other Orders
Lists – Updated Feb 2024
Acari (Ticks & Mites)
There are about 900 species of ticks; most of them are hard ticks and about 90 of them are in North America. All ticks are parasitic, living on blood. Although not host specific, ticks tend to have a different host for a different life cycle.
Ticks are the bane of mammals. There isn’t a life cycle in this family that cannot suck blood. After each feeding they drop to the ground and molt into the next stage. The larvae of this family only have 6 legs; they gain the other 2 legs once they move to the nymph stage. In the colder area of the US, it can take up to 3 years for a tick to fully mature.
An adult female can lay an average of 2000-8000 eggs but are also known to lay up to 20,000 at one time. The tick’s life cycle requires 3 different hosts. After each feeding they drop to the ground and molt into the next stage.
Tick behavior is pretty interesting. They seek out their next meal by “questing” with the Haller’s organ. This is a sensory organ in their first pair of legs that detects heat, humidity, and chemicals. Questing is when they reach the plant’s uppermost area and wait with their forelegs extended. When their meal brushes past them they grab hold. I visualize them seeking a big ol’ hug!
Once hard ticks attach to their meal, they produce a “cement” that glues the hypostome in place. The hypostome is harpoon-like and is lined with teeth to anchor the tick.
Entromobrydae: Lepidocyrtus paradoxus
There are about 2000 species of known earwigs. Most earwigs are omnivorous but some eat only plants while others prefer decaying material. Earwigs are nocturnal. They spend their days tucked into crevices, under rocks, under logs, and under bark of trees. Adults will overwinter in the soil. Earwig females care for the eggs and their young through the first instar, which is somewhat unusual in the insect world.
Forfidulidae (Common Earwigs)
Another apt name for these are “thousand-leggers.” There are about 8,000 described species of millipedes. Their choice of food is decaying material. They are born with only 3 pairs of legs; they attain their numerous appendages and body segments with each molt.
Millipedes have a defense mechanism involving a nasty smelling chemical that oozes from each body segment. Their head segment does not have these glands, which explains why they coil up when in their defensive position. But if the head is attacked first and/or removed by a predator, then there is easy access to the rest of the millipede.
Gastropoda (Snails & Slug)
Baetidae (Small Minnow Mayflies)
Caenidae (Small Squaregilled Mayflies)
Polymitarcyidae (Pale Burrower Mayflies)
Gastropods are the least changed from their ancestors. There are almost 40,000 described species in the world and they occupy nearly every habitat on earth. Equally diverse is their feeding habits, their shapes, their colors, and their sizes.
Agriolimacidae (Terrestrial Slugs)
Meadow Slug — Deroceras leave
Discidae (Air-breathing Land Snail)
Geophilomorpha (Soil Centipedes)
Isopods (Pillbugs, Sowbugs, and Roly polys)
Isopods are normally referred to as pillbugs, sowbugs, or roly polys. They are nocturnal and can be found under rocks, under logs, or in crevices.
Oniscidae (Woodlice, Sowbugs, Pillbugs)
Lithobiomorpha (Stone Centipedes)
Mecoptera (Scorpionflies, Hangingflies, & Allies)
Neuroptera (Antlions, Lacewings, & Allies)
Daddy longlegs (aka harvestmen, Opiliones) are living fossils. They originated 350-400 million years ago and haven’t fundamentally changed since then. These were my favorite arachnids when I was a kid.
Here’s a few interesting facts from the “Amazing Arachnids”book.
- They are unusual among arachnids because they eat solid food, which also exposes them to parasites
- They are not venomous and have limited weapons to use against predators. Their main “weapon” is cryptic coloration but some rapidly bob up and down.
- They can also lose a leg, which can twitch for nearly an hour
- Many females will hide their eggs. Once mated and with male in tow (legs are looped) to guard her she looks for the perfect spot
- Depending on their location, eggs can open in 30 days or some overwinter
- Unlike other arachnids who have 8 eyes, daddy longlegs have only 2
These spiders are sometimes confused with Cellar spiders, but Harvestmen also do not use silk.
Walkingsticks are found in most habitats. There are around 3,000 species; all are nocturnal and plant eating. There are a variety of sizes with the females typically being larger. Colors vary, too, as they use color to blend into their environments.
This is the common northeastern US family. Color variations are brown or green. Losing an appendage is one of their defenses. The younger walkingsticks can replace this appendage when they molt, but the adults don’t have that option.
Females lay their eggs on the woodland floor, which completes their maternal duties. The eggs overwinter in the leaf litter. Sometimes ants will take the eggs to their nests, keeping them safe. Of course, they don’t do this for “free!” This service is rewarded by some tasty edible outgrowths on the eggs. The eggs hatch in the spring and the nymphs become adults during the summer and fall.
Psocodea (Barklice, Booklice, & Parasitic Lice)
Plecoptera epitomizes cold, clear, fresh water and are excellent indicators of water quality. They develop as nymphs in the water and live rather reclusively near to water. An interesting tidbit is the first recorded fly tied by a human mimicked a stonefly! These insects are close relatives of cockroaches but they have tails and the ability to fold their wings over their backs.
Their common name comes from the larval habit of crawling around and on top of stones and rocks. Their taxonomic name is derived from the “pleated wings” they have.
Here’s an interesting blog post, The Dragonfly Woman, written by an aquatic entomologist. In this particular link, she’s discussing how the know if the larvae you find is a stonefly, a mayfly, or a damselfly. If you’re a fly-fisherperson or just like to check out the local aquatic insect life, this is a good read.
Perlidae (Common Stoneflies)
Pteronarcyidae (Giant Stoneflies)
Trichoptera (caddisflies) are the most diverse and abundant organisms in freshwater habitats. They are important trout food sources and make up the majority of a trout’s diet.
Trichoptera comes from the Greek words for hairy wings and with close inspection, this description is very appropriate. They undergo the same metamorphosis as moths and butterflies do. In fact, moths, butterflies and caddisflies are classified under the superfamily Amphiesmenoptera, meaning “dressed up wing.” Trichoptera diverted from this evolutionary path when they developed respiratory systems that allowed them to be aquatic.
Trichoptera is a small order with only about 11,500 known species worldwide. There is an estimated 30,000 species yet to be described! North America has 26 known families with 23 of these familiar found in the eastern US.
Their life cycle takes nearly a year to complete, beginning with the initial egg. There are a few requiring two years to mature. Caddisfly larvae have a large range of temperatures, water quality, oxygen levels, food availability, and water currents in which they can survive and thrive. Most eggs will hatch in 2-4 weeks with some needing 9 months. Once hatched, the larvae have 5 stages of growth (called instars), normally completed in 6-10 months. Equally unique are the distinct pupal cases or shelters each larval species creates.
Adult caddisflies live 1-4 weeks, depending on the weather conditions. Once females are ready to lay their eggs, they return to their larval site. There are 4 basic egg-laying behaviors: 1) laying eggs beneath the water, 2) laying eggs on the water’s surface, 3) doing both, and 4) laying eggs at the edges of water.
Identification of Trichoptera is difficult. For the vast majority of caddis you cannot confidently use color. About 33% of the adults have been matched to their larvae. There are a couple books that cover the caddis genera fairly well as adults and larvae. But the species level literature requires numerous bookcases/file cabinets. Most females are more difficult to identify to species. In many genera (Nectopsyche, Wormaldia and others) they may be impossible to determine without using DNA. And many females have yet to be associated with their male.
Lepidostomatidae (Bizarre Caddisflies)
Limnephilidae (Northern Caddisflies)