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A bug’s life: A guide to Portland’s insects

As summer approaches, it brings all sorts of local (and not so local) creepy crawlies. With the help of Dr. Susan Masta, arachnologist and curator of the insect collection at the PSU Museum of Natural History, I investigated some of our most interesting six-legged neighbors in the Portland area.

Largest: Common green darner

Shaped like a darning needle—long and slender, but wider at one end—this dragonfly is typically seven to eight centimeters in length, and that doesn’t even factor in the span of its four large wings. Male darners are bright green with a few blue abdominal segments, while females are a brownish-green. Anax junius uses coastal regions for migration, so shallow points along the Willamette, Columbia or an Oregon beach might be good places to spot one. But pay attention—though vibrant, they’re incredibly fast, zipping through the air to catch smaller insects for food.

Loudest: Cicadas

Most of us can recall the metallic screeching these large, scary-looking-but-harmless bugs make. Whether or not the noise drives you nuts or reminds you of peaceful summer afternoons, cicadas are loud. A Cincinnati entomologist measured a cicada call at 94 decibels—that’s somewhere between a lawn mower and a motorcycle revving 25 feet away. But according to Masta, Portland’s cicadas are not as loud as eastern U.S. populations. It’s also worth pointing out that this “song” is for only one purpose: sex. Male cicadas produce the sound by rattling abdominal membranes—for all intents and purposes, shaking their butts. Clearly it works; the cicada family has been around since Permian times.

Beautiful but destructive: Azalea lace bug

These insects are stunning, when you can see them. At about a tenth of an inch long and almost translucent, they’re hard to spot. Off-white with intricate, lacy, iridescent wings, Stephanitis pyrioides hang out on the bottom of azalea and rhododendron leaves, where they suck the life out of the plants like gorgeous little chlorophyll-eating vampires. This bleaches the leaves and makes them spotty, severely damaging the plant. This Japanese-native species was first observed in Washington in 2008, moving down to Oregon in 2009. Given the amount of azaleas and rhododendrons in Portland, they don’t appear to be going away anytime soon.

Nastiest: Burying beetles

These common insects are only about half an inch to just under an inch long and black with red to yellowish-orange bands across their backs. Though they have curious eating habits—munching on and laying eggs in small animal carcasses—they’re ecologically significant. The local supply of carrion seems to vanish before we notice it, but if these beetles and other decomposers were to disappear, organic nutrients would take far longer to cycle back into the soil, and we would all be wading through dead stuff to get to class. Love may make the world go ‘round, but burying beetles help, too.

Smelliest: Stink bug

Though there are many species of stink bug in the area, one particular species, the brown marmorated variety, gets lots of local attention for damaging crops. These shield-shaped beetles eat an estimated 170 species of plants, according to the Oregon Department of Agriculture, including major exports like grapes, berries, hops and hazelnuts. However, Pentatomidae (the stink bug family classification) have another claim to fame—the airborne allergen and stinky smell they generate from dorsal glands to ward off predators. To humans, the odor smells like anything from cilantro to coriander to skunks, but there’s one general consensus: It reeks.

Hardest working: Yellow-faced bumble bee

This species pollinates nearly year-round in greenhouses and nature. Commonly confused with other bumble bees in the area, Bombus vosnesenskii is black with a yellow head and a yellow stripe near the end of the abdomen. According to the USDA, this bee (also called the Vosnesensky bumble bee) makes up about three quarters of the Bombus species at Fort Vancouver Historic Site and is also abundant at the Lewis and Clark monument closer to the coast. While many pollinators are declining, this bee does quite well around here—though some scientists worry about how increasing urbanization will impact the species’ nesting and forage patterns.

Weirdest-looking: Snakeflies

Masta describes this insect as something between “a prehistoric creature, E.T. and Godzilla.” Snakeflies are less than an inch long but nearly everything about them seems stretched: an elongated head is connected to a long neck, connected to a lengthy abdomen, covered in wings that extend beyond the body. Females have a thin extension from the abdomen, often mistaken for a terrifying stinger but it’s just an ovipositor. While it’s creepy that snakeflies swivel their heads to grab food, these insects aren’t aggressive and even eat the larvae and eggs of other insects—great news if you have a garden.