Autumn Meadowhawk

Autumn Meadowhawks are smaller than most dragonflies. When they land, they often perch with their wings tilted forward, a key characteristic in Meadowhawks. They are found in diverse habitats, such as near ponds, marshes, bogs, or pools. They are most active between August and October, which gives them the name Autumn Meadowhawk. Mature males are bright red with a single black mark on the abdomen. Immature males have a yellow underside that darkens with age. Females are lighter in color but similar looking to the males. Their legs are light brown/orange. The Autumn Meadowhawks are unusual in which males do not patrol their territory like most species of dragonflies. They will mate, and the female will lay the eggs on the water’s surface. The larvae eat small aquatic insects and the adults eat larger terrestrial and aquatic insects.

https://www.insectidentification.org/insect-description.php?identification=Autumn-Meadowhawk-Dragonfly

Gnojewski, K., & Chmura, K. (2024). Pocket Field Guide to Boise’s Dragonflies. Life Outdoors.

Backswimmer

Backswimmers get their name from swimming upside down on their back and using their long hind legs to propel themselves forward through the water. They are found in artificial water sources or slow-moving streams and ponds. They have an oval-shaped body that is usually tan and black with dark red eyes. The nymphs look like small adults without wings. Backswimmers look very similar and are often confused with water boatmen, but they swim differently and do not have dark parallel line patterns like water boatmen. These insects are covered in small hair-like structures called setae and microtrichia, which allow them to store oxygen and stay underwater for up to 130 days without resurfacing. They are voracious predators and feed on various aquatic organisms such as other aquatic insects, tadpoles, fish eggs, and small fish. They use vegetation to hide and ambush prey. After catching their prey, they pierce it with their sharp beak and release digestive enzymes to paralyze and turn the prey’s insides into liquid. They then use their mouthparts to suck up all of the fluid.

https://entnemdept.ufl.edu/creatures/AQUATIC/backswimmer.html

https://pondinformer.com/backswimmers-notonectidae/

Blue Dasher

Blue Dashers can be found throughout the United States. They are common in the Treasure Valley and are active from May through October. The females and males look strikingly different. The mature males are bright blue with turquoise eyes. The females have a brown and yellow striped abdomen and multicolor eyes. The top of the eyes are brown qhile the bottom is blueish gray. The female’s body will become more blue as they age, but they will never be as colorful as the males. The Blue Dasher can be easily confused with the Western Pondhawk, but it is smaller and has a white face, while the Western Pondhawk has a green face. They prefer still water sources such as lakes, ponds, and marshes but can also be found in slow-moving streams. The adult and larva stage feed on aquatic insects. The naiads can live up to two years underwater before maturing and live for another few years as adults.

https://theinsectguide.net/blue-dasher-dragonfly/

Gnojewski, K., & Chmura, K. (2024). Pocket Field Guide to Boise’s Dragonflies. Life Outdoors. 

Blue-eyed Darner

The Blue-eyed Darner is a large dragonfly found throughout the United States and Mexico. The males have big blue eyes and a brown and blue mosaic color pattern, giving them their name. The females, however, have brownish eyes and usually have yellow or green markings rather than blue. At the end of the male’s abdomen, the cerci are forked and hooked. We have five mosaic darner dragonflies in Boise, and they are nearly impossible to tell apart without examination. The Blue-eyed Darner is often found in flight by water sources. They will mate in flight and the female will lay the fertilized eggs in the water. Naiads will live in the water for a few years, feeding on small aquatic insects, tadpoles, and even small fish, before molting into a fully winged adult.

https://www.insectidentification.org/insect-description.php?identification=Blue-Eyed-Darner

Gnojewski, K., & Chmura, K. (2024). Pocket Field Guide to Boise’s Dragonflies. Life Outdoors. 

Bluet Damselfly

Bluet Damselflies are small, beautiful, and usually blue; however, some can be green or orange. They are incredibly hard to determine down to species. The name Bluet Damselfly applies to multiple species and even to two different genuses. They look similar to Forktail Damselflies, but they do not have the fork. They are often found on grasses surrounding ponds and lakes. They hunt aquatic insects like dragonflies but are much less aggressive and cannot stay in flight as long. They have many predators such as larger damselflies, dragonflies, birds, spiders, and other insects. 

https://www.nps.gov/miss/learn/nature/bluetdamselflies.htm

Caddisfly

Caddisflies are known for their larvae appearance in their cases. Under the water, they secrete silk and then use sand, rocks, leaves, twigs, or anything else they can find to create a casing. They can be divided into five groups depending on how they construct their casing: saddle-case caddis, purse-case caddis, tube-case caddis, free-living caddis, and net-spinning caddis. The larvae can either be transportable, where they will take their casing with them as they move through the water, or fixed to a rock unable to move. The larva stage can last between one to two years. The larvae are brown, green, or olive and have gills to breathe underwater. They are omnivores; some species are predators while others feed on dead plant matter. Caddisflies regulate the population of algae and are a necessary food source within the ecosystem. The lifecycle of a caddisfly is egg, larva, pupa, and then adult. As adults, they feed on nectar and other plant matter due to their underdeveloped mouthparts, meaning they are not capable of biting humans. The adults look similar to moths: however, they do not have the same mouthparts, their wings are coved in hairs instead of scales, and their wings fold in a tent shape. They are generally brown, grey, or duller colors, and their antennae are often the length of their body. The adults live between a few weeks to a year depending on species.

https://ofacts.org/invertebrates/caddisfly/

Chinese Mystery Snail

Chinese Mystery Snails are small, olive colored snails with a coiled spiral shell to the right. They get their name from females giving birth to fully developed snails that suddenly disappear. When alive, this snail has an operculum covering the opening, similar to a trapdoor. You can tell the snails pictured are dead since there is no covering. You can find them on the bottom of lakes and rivers or washed up on shore when dead. They are invasive to Idaho and many places throughout the world. They are native to Asia but have been transported through the aquarium trade and released into the wild. It is illegal to buy, possess, sell, or transport these snails in numerous places due to the significant decline they cause in ecosystems. 

https://www.dnr.state.mn.us/invasives/aquaticanimals/chinese-mystery-snail/index.html

Common Green Darner

The Common Green Darner is one of the most abundant dragonflies found in North America. They are the sixth darner dragonfly in Boise, but are not considered one of the five mosaic darners. The mature males have a yellow/green head, bright green thorax, and a blue abdomen. Immature males have a brown abdomen, which can cause them to be confused as females. The females are almost entirely green with a brown stripe down the abdomen. Green Darners are often found along ponds and marshes. The adults eat a variety of flying insects, while the naiads eat small aquatic insects, tadpoles, and small fish. The naiads will overwinter in frozen-over ponds and emerge as adults the next spring. Some of these dragonflies choose to migrate South during winter. They will lay their eggs before passing and the new generation will migrate back North to mate before continuing the cycle. Some may also choose not to migrate. 

https://entomology.umn.edu/common-green-darner

Gnojewski, K., & Chmura, K. (2024). Pocket Field Guide to Boise’s Dragonflies. Life Outdoors. 

Crane Fly

Crane Flies are very common in the Treasure Valley. These flies have very long, fragile legs and are one of the biggest flies we have. They are often confused with being a large mosquito, but they are not in the same family as mosquitos and the females do not require a blood meal to reproduce. Crane Flies are also known as mosquito hawks; however, they do not eat mosquitos either. In fact, the adults do not feed at all. The larvae are laid in detritus near a water source and feed on the decomposing organic matter. They are often found along streams or flood plains. As the larvae help break down organic matter and the adults do not feed, these insects are not pests. There is no need to harm crane flies or be frightened of them.

https://texasinsects.tamu.edu/crane-fly/

Forktail Damselfly

Forktail Damselflies get their name from tiny projections off the tip of the abdomen of males. They are hard to see with the naked eye, making these damselflies easily confused with the Bluets. They are narrow-winged and some of the smallest damselflies. The males have a dark abdomen with a blue tip. Females are polymorphic and are orange when immature, eventually turning a lighter shade of blue. This color change and her behavior allows the male to distinguish when a female is sexually mature. The female will avoid the shore until she is ready to reproduce. After mating, she will lay each egg individually and unguarded along the water near aquatic vegetation. Mate guarding is common for Odonata, but researchers believe it is unnecessary for the Forktails since the females effectively discourage male attention.

https://uwm.edu/field-station/bug-of-the-week/forktails-two/

Giant Water Bug

Giant Water Bugs are large aquatic insects with a flat, brown, oval body. They are commonly known as Toe Biters throughout the United States since they will bite people’s toes and feet when they are in the water. They can also spray an unpleasant smelling fluid up to a few feet from their anus as a defense mechanism. Giant Water Bugs are excellent hunters. They have cilia on their back legs to help them move faster in the water and use their front pincer-like appendages to hold prey while they suck them dry with their piercing mouth parts. They release a digestive enzyme that turns the insides of the prey into liquid before sucking it all out. They will hunt tadpoles, small fish and arthropods, and other aquatic insects. They are found in ponds, marshes, and slow-moving streams, usually hidden in vegetation. The females can lay over 100 eggs. Interestingly, the males provide parental care by either carrying the fertilized eggs on their back until hatching or guarding them. It only takes two months for them to reach adulthood. The adults will overwinter at the bottom of ponds or streams.

https://www.nps.gov/articles/giant-water-bug.htm

Giant Water Scavenger Beetle

The Giant Water Scavenger Beetle is the largest aquatic beetle in the United States. They are oval and black with their legs covered in cilia to help them swim faster. They can be found in deep ponds or lighted sidewalks at night. The larvae eat small aquatic insects, fish, tadpoles, and snails, while the adults feed mostly on decaying plant matter. The adults can also eat small aquatic insects, fish, and snails. The adults hold air bubbles under their elytra and use spiracles to absorb the oxygen throughout their body, allowing them to resurface less frequently. The females will wrap the fertilized eggs in silk from their spinnerets and attach them to floating debris along the water’s surface. The larvae will spend their entire lives underwater and when they are ready to pupate, the pupae will leave the water and bury themselves, preferably in clay soil.  After 10 days, they will emerge as adults.

https://entnemdept.ufl.edu/creatures/MISC/BEETLES/water_scavenger_beetle.html

Little Yellow Sally Stonefly

The Little Yellow Sally Stonefly name applies to 60 similar species of stoneflies. They are usually pale yellow or bright green. The adult females have red egg masses on the tip of their abdomen. They are found in well-oxygenated, fast-flowing rivers. Nymphs live under rocks and feed on other aquatic insects. When ready to hatch, the nymphs will crawl to the shore and molt into adults. They are often unable to make it to shore and end up being eaten by fish, namely trout. They are some of the only stoneflies that emerge as adults during the daytime. The females will lay eggs back into the water after mating and then die. Her body will float down the river just as the unlucky nymphs and become fish food. 

https://www.discountflies.com/blog/entomology-of-the-little-yellow-sally-stonefly-hatch/

https://henrysforkanglers.com/hatch-chart/small-stoneflies/

Mosquito

Mosquitoes are perhaps the most hated insects of all time. They are vectors of disease, including West Nile Virus, Dengue, Zika, and Malaria, but not all mosquitoes can carry these diseases. Most mosquitoes are considered nuisance mosquitoes, which means they do not carry diseases, and the mosquito’s saliva usually only causes a small, itchy bump due to being allergic to the saliva itself. Only certain genuses can transfer diseases, and the individual must bite something infected, have the virus replicate for 2-3 weeks within her body, have it reach the salivary glands, and then bite another organism. Only female mosquitoes bite, because they require a blood meal to produce eggs. Female mosquitoes have piercing mouthparts for blood while male mosquitoes have mouthparts for sucking nectar. After mating, the females lay their eggs in natural and artificial water sources with little to no flow. This can include along stream banks, marshes, irrigated fields, holes in trees, old tires or planters, and many other sources. The eggs will hatch within a few days to months into larvae, then become pupae after five days as larvae, and finally adults after two or three days as pupae. They live entirely underwater until they become adults. While mosquitoes are certainly a nuisance and can be dangerous, they are a vital food source for other organisms, and the males provide pollination and nutrient recycling.

https://www.cdc.gov/mosquitoes/index.html

https://feedingnature.com/what-do-male-mosquitoes-eat/

Non-biting Midge

Non-biting Midges are often confused with mosquitoes. They look similar, but they are in different families and behave much differently. These flies are small with long legs and can be brown, grey, or green. Their front legs point forward when they land. The males and females are easy to tell apart as the males have fluffy antennae, which you can see pictured above. They can be found in a variety of environments, including fast-moving streams, ditches, lakes, or slow and deep rivers. Midges are an incredibly important food source in aquatic and terrestrial ecosystems. The larvae and adults are preyed upon by fish, waterfowl, spiders, diving beetles, water boatmen, dragonflies, and other predatory aquatic insects. The larvae and adults feed on organic debris and help water quality. Adult midges swarm to find a mate, which can be a nuisance but is usually not a problem. When you walk through a swarm of tiny, flying insects, they are likely midges.

https://content.ces.ncsu.edu/biology-and-control-of-non-biting-aquatic-midges

Signal Crayfish

Signal Crayfish are large crustaceans, up to 7 inches, with a blue, red, and brown shell. They have long antennae, eight legs, and two front claws. They have a white spot near their claw hinge that looks like a signal flag, giving them their name. Signal Crayfish are native to Idaho but have become invasive in other parts of the world due to the aquarium trade. The specimen is required to have a permit when transporting in certain areas. Their diet consists of plant matter, fish eggs, other crayfish, and invertebrates. They can be found in springs, streams, rivers, lakes, and wetlands. The females can produce up to 400 eggs that they will carry through the winter and until the hatched crayfish are able to swim on their own. They can live over 9 years.

https://www.dnr.state.mn.us/invasives/aquaticanimals/signal-crayfish.html

Small Minnow Mayfly

Small Minnow Mayfly is a common name for all species of mayflies in the family Baetidae. They are small, have a light sand to dark brown color, have clear wings that may have brown spots on the edges, and have two long filamented cerci. As nymphs, they normally have three cerci, but some species have two. They spend a majority of their lives as nymphs. They are excellent swimmers, and their diet consists of benthic algae and detritus. These mayflies are very sensitive to pollution, making them great indicators of water quality. When it is time to emerge as an adult, or imago, they will slowly float to the surface of the water, making them an easy target for predation. When they first emerge from the water, they are sub-imagos. After a few hours, they will molt into the sexually mature form, imagos. Imagos are active during warm months usually in the morning and afternoon. To reproduce, the male imagos will form a swarm above the water’s surface. The female imago will fly into the swarm, mate, and then lay the fertilized eggs underwater. The imagos live for only a few hours, making this entire stage focused solely on reproduction. 

https://www.sanbi.org/animal-of-the-week/small-minnow-mayfly/

Twelve-spotted Skimmer

Twelve-spotted Skimmers are named for the number of dark spots on their wings. The males and females have three dark spots on each wing, with the last spot on the outer edge of each wing, adding up to a total of 12 dark spots. The males also all have two white spots on each wing between the dark spots; however, the females only have dark spots. The males have a dusty gray abdomen, while the females are brown with yellow stripes. They are commonly confused with the Eight-spotted Skimmer. The Eight-spotted Skimmer looks nearly identical but only has two dark spots on each wing and the edge of the wing ends in a white spot. Twelve-spotted Skimmers are common throughout all of North America. They are fast and agile fliers commonly found along ponds and lakes.  

https://www.insectidentification.org/insect-description.php?identification=Twelve-Spotted-Skimmer

Gnojewski, K., & Chmura, K. (2024). Pocket Field Guide to Boise’s Dragonflies. Life Outdoors. 

Water Boatmen

Water Boatmen are small, oval-shaped, and usually dark brown with dark, parallel lines. Their back legs are oar-shaped and covered in setae to help them swim. They have a segment on their forelegs shaped like a scoop used to hold onto vegetation while underwater to prevent them from floating to the top. The nymphs look like smaller versions of the adults without wings. They are often confused with Backswimmers, but Backswimmers do not have the parallel lines or a scoop-shaped segment, and Water Boatmen are a darker color and do not swim upside down. Water Boatmen are often found in ponds or slow-moving streams with vegetation. They are strong fliers and can end up in various artificial sources of water after flying through the night. Unlike many of the other aquatic insects, they are not predaceous. They use their piercing mouthparts to feed on plant matter. They are preyed upon by other aquatic insects, fish, birds, and amphibians. Males will create swarms and rub their forelegs against their heads to create a squeaky sound to attract females, much like crickets. Females will mate and then lay the eggs attached to aquatic vegetation underwater.

https://mdc.mo.gov/discover-nature/field-guide/water-boatmen

https://pondinformer.com/water-boatman-corixidae/

Water Strider

Water Striders are fascinating insects that have the ability to walk on water. They are dark brown and skinny with four long legs and two shorter legs in the front. Their tarsi have tiny hairs on them that they use to capture air and repel water. This allows them to walk on the membrane of the water’s surface caused by water tension. They can be found in still water sources like ponds or natural pools. They are predators and use their front legs to catch aquatic insects and larvae, their middle legs for propulsion, and their hind legs for steering. The adults may have no wings, short wings, or long wings. The females have evolved a shield over their genitalia, believed to protect them from forced mating and increase mate selectivity. The males have evolved vibrational signaling that attracts the females as well as predators, believed to increase mating opportunities by intimidating females into quick copulation, as the females being on their backs during copulation makes them more susceptible to predator attacks.

https://www.nwf.org/Educational-Resources/Wildlife-Guide/Invertebrates/Water-Striders

https://www.britannica.com/animal/water-strider

Western Pearlshell Mussel

The Western Pearlshell Mussel is six inches long, has a brown or black shell, and can be purple, pink, or white inside. They can be found in perennial, cold-water streams and rivers containing salmonids. Mussels are filter feeders that feed on particles of algae, plankton, or dissolved organic material suspended in the water column. They filter the water and recycle the nutrients into larger particles, which provides food for other aquatic invertebrates. They can use their foot to move short distances but will end up staying in relatively the same place their whole life. They require a host species of either salmon or trout to survive. The female’s eggs are fertilized by filtering sperm in the water. After they are fertilized, the eggs become parasitic larvae called glochidia. In order to reproduce, the female mussels release a mucous containing the glochidia that will attach to the gills of salmonids. After being attached to the fish for a few weeks to months, they will detach as juvenile mussels. They can live up to 100 years old. 

https://www.fws.gov/species/western-pearlshell-margaritifera-falcata