Archive for the Insects Category

BEETLES OF EASTERN NORTH AMERICA: EASTERN RARE CLICK BEETLE

Posted in Beetles, Insects with tags , , on April 26, 2010 by Dr. Art Evans

By Arthur V. Evans

The antennae of eastern false click beetles, Cerophytum pulsator (Haldeman) (5.4-8.5 mm), are comb-like (males) or saw-toothed (females).

The upper body surface of the eastern rare click beetle, Cerophytum pulsator (Haldeman), is dark reddish black to black, while the appendages and underside are usually lighter. The body is finely clothed with erect, yellowish setae. The elytra are somewhat dull, deeply grooved and finely, densely punctured.

Eastern rare click beetles are known from Pennsylvania to Florida, west to Illinois and Alabama. They prefer to live in mature, mostly deciduous forests. Adults are mostly active at night in spring and are collected at black light, in Malaise and Lindgren funnel traps, sweeping understory foliage, with rotten wood and bark, or in leaf litter. When held, they can “click” and are capable of jumping as a form of escape behavior.

© 2010, A.V. Evans

SKY ISLANDS, DESERT SEA-Part II, Hornworm Highway

Posted in Arizona, Insects, Moths, Musings, Predators/parasites/parasitoids with tags , , , , on April 26, 2010 by Dr. Art Evans

By Arthur V. Evans

Charged by the onset of the summer monsoons in July or August, the arthropods of Arizona’s Sky Islands and desert seas are stirred into action.  The sudden and intense infusion of life-giving moisture triggers a flush of activity: eggs hatch, hungry larvae gobble up new leaves, adults are released from their earthen or wooden chambers, eager to mate and reproduce.  It is this marvelous intensity of arthropod activity that has drawn me to the mountains, desert scrub and grasslands of southeastern Arizona for nearly 40 years.

My earliest impressions of Arizona’s desert seas were formed by numerous overland trips from California in the 1970’s. Within minutes of crossing the Colorado River, the first saguaros would greet us, stationed like lone sentinels high on the rocky ridges of the Dome Rock Mountains. Although these giant columnar cacti have become symbolic of all arid regions of the southwest, they are strictly indigenous to the Sonoran Desert. These and other nearby desert ranges are capable only of supporting plants and animals adapted to fleeting amounts of rain. The summer monsoons, even at their height, seldom penetrate this far north and west.

Driving east from Gila Bend to the Maricopa Mountains, the stands of saguaros become taller and denser. Compared to the deeply pleated trunks of their western brethren, the almost bulging flesh of these plants is a clear sign of increased precipitation. The saguaros’ spongy inner tissues rapidly expand to absorb and store seasonal supplies of water as a hedge against the inevitable drought ahead.  Even the spiny ocotillo stand taller and greener here, surrounded by dense thickets of palo verde.  Here all living things enjoy the increased benefits of living under the blanket of the summer monsoons.

Another sure sign of increased rainfall is the sporadic population explosion of green and black-striped hornworms, caterpillars of the white-lined sphinx moth, Hyles lineata. Dozens to hundreds of these insects race across the hot, blistering highway in a scramble for tender desert greens. Some years there are so many of the caterpillars that the pavement becomes slick with their crushed bodies. At night marauding three-inch-long shield-backed katydids of the genus Capnobates rip chunks of sun-dried caterpillar from the road and grind them up with their powerful jaws, while scores of ants carve up the leftovers and carry them back to their underground brood.

© 2010, A.V. Evans

BEETLES OF EASTERN NORTH AMERICA: FIRE-COLORED BEETLE

Posted in Beetles, Insects, Uncategorized with tags , , on April 26, 2010 by Dr. Art Evans

By Arthur V. Evans

The fire-colored beetle, Neopyrochroa femoralis (LeConte) (13-19 mm), is easily distinguished from other large pyrochroids in eastern North America by its black and orange legs.

The fire-colored beetle Neopyrochroa femoralis (LeConte) is easily distinguished from the only other large pyrochroid in eastern North America, N. flabellata (Fabricius), by its black and orange legs. The male has branched antennae and lacks a horn on its head. Adults are found under bark or at lights at night in spring and summer. This species occurs from Ontario and Quebec south to Georgia, west to eastern Nebraska and Texas.

© 2010, A.V. Evans

BEETLES OF EASTERN NORTH AMERICA: BUMBLE FLOWER SCARAB

Posted in Beetles, Insects, Scarabs with tags , on April 25, 2010 by Dr. Art Evans

By Arthur V. Evans

This bumble flower scarab, Euphoria inda (12-16 mm), resembles a bee in flight, right down to the buzzing sound as it flies low over the ground.

The bumble flower scarab, Euphoria inda (Linnaeus), is the most widely distributed species of Euphoria in North America, ranging from Quebec south to Florida, west to British Columbia, Oregon, Colorado, and southeastern Arizona. The head and pronotum are mostly black, while the elytra are yellowish-brown with variable black spots. The dorsal surface is shiny or dull.

The larvae develop in various accumulations of plant materials, rotten wood, and within the thatched nests of ants in the genus Formica. Adults emerge from their earthen pupal cases in late summer, overwinter, and become active again the following spring. They are often found flying close to the ground in the morning until midday, especially over piles of grass, edges of haystacks, compost piles, manure, and other plant debris. They are sometimes found in numbers drinking sap from wounds on tree trunks and exposed roots, or feeding on various flowers and ripe fruits.

© 2010, A.V. Evans

Note: The “Beetles of Eastern North America” series features descriptions that will appear in a slightly abbreviated form in my upcoming field guide to be published by Princeton University Press.

LUNA MOTHS ARE ON THE WING

Posted in Insects, Moths with tags , , , , , , on April 21, 2010 by Dr. Art Evans

By Arthur V. Evans

The luna moth, Actias luna (Linnaeus). Although the luna moth is native to North America, most of its relatives live in Asia.

Last night, while black lighting for beetles on a cool and still spring night in the Bull Run Mountains in northern Virginia, I was treated to an incredible display of luna moths, Actias luna (Linnaeus). Within an hour of turning on the lights, a baker’s dozen of these marvelously green and ornately tailed creatures had settled on the sheet and nearby tree trunks. Such a sight made me feel quite giddy and brought back a flood of memories of some of my earliest encounters with other spectacular insects as a young naturalist.

The first luna moth that I ever saw in Virginia flew through an unscreened upstairs window. It looked like a soft, green bat as it circled the light at the top of the stairs. It was all that I could do to keep it from being gobbled up by our cats!

They range throughout the hardwood forests of eastern North America. Luna moths were long known to naturalists by the time they were described by Carolus Linnaeus in 1758. The earliest known reference to luna moths in North America was in a note published James Petiver 1700, who had based his comments on a specimen collected in Maryland.

Like other moths and butterflies, the wings of luna moths are covered with scales that make up their colors and patterns.

Luna moths typically emerge from their cocoons in the morning. Powerful fliers, they are often attracted to porch lights and well-lit storefronts. There is only one generation produced in the northern parts of its range and two or three generations are produced in the south. Moths emerging in spring are bright green or blue-green with prominent reddish-purple margins on the outer forewings, while summer broods tend to be more yellow over all with yellowish outer wing margins.

Mating takes place after midnight. Pairs of luna moths sometimes remain coupled until the following evening. Eggs are laid singly or in small batches on upper and lower surfaces of leaves and hatch in about a week. The ravenous and solitary caterpillars feed on the leaves of a wide range of hardwoods, including birch, hickory, walnut, persimmon, and sweetgum. Different populations of luna caterpillars show regional preferences for host plants.

The feathery, or pectinate antennae of the male luna moth are covered with sensory pits that enable to them to detect just a few molecules of the pheromones released by receptive female moths.

Only when they are ready to pupate do the mature caterpillars wander away from the food plant. Cocoons are spun on the ground among the leaf litter at the base of the host tree. Each cocoon consists of a single layer of thin and papery silk that incorporates one or more leaves.

Sightings of the luna moth’s spring brood will still be possible over the next few weeks. Look for them at lights near wooded areas and you just might be treated to a glimpse of one of North America’s most spectacular animal species.

© 2010, A.V. Evans

FALCATE ORANGETIPS

Posted in Butterflies, Environment, Insects, Virginia with tags , , , , , , , on April 5, 2010 by Dr. Art Evans

By Arthur V. Evans

After a few false starts spring has finally arrived here in central Virginia, and not a moment too soon. In hopes of seeing some examples of the early spring insect fauna, I recently set out on a warm, sunny day for the James River Park near the 42nd Street entrance.

The orange and slightly hooked wing-tips were the unmistakable field marks of the male falcate orangetip, Anthocharis midea, the only species of orangetip butterfly found in the eastern United States.

The latest floodwaters from spring rains had only just receded, leaving a thin and dusty film of silt and debris high above the river’s usual channel in the park. Just past the flood residue, small plants had raised their tiny blossoms high to lure the season’s first pollen- and nectar-loving insects.

As I wandered upriver toward the Nickle Bridge, a flash of white with a hint of rich orange crossed my path. It slowly yet deliberately flitted about the freshly emerged sprigs of green that populated the edges of the path before finally settling for just a moment or two on a small flower. The orange and slightly hooked wing-tips were the unmistakable field marks of the male falcate orangetip, Anthocharis midea, the only species of orangetip butterfly found in eastern United States.

The females lack the orange patch, but are otherwise similar in appearance to the males. The wings of both sexes are mostly white; the underside of the hind wing bears a finely marbled yellowish-brown pattern. From tip to tip, their wings span no more than one-and-a-half inches across.

Falcate orangetips are among the first butterflies to emerge from their pupae in spring. Widespread in Virginia, they are found in a variety of habitats, including parks, rocky mountain outcrops, open deciduous and mixed pine-oak woodlands, sandhills, and floodplain forests, especially along stream and river courses.

Females lay their greenish-yellow eggs singly on the flowers of various cresses and other members of the mustard family. The eggs soon turn red and hatch into ravenous larvae that devour mostly seed pods, buds, and flowers, and not leaves. Because of the limited number of reproductive structures on each food plant, larger caterpillars will not hesitate to eat their smaller brethren to reduce competition for meager food resources.

Mature caterpillars are green or blue-green and sprinkled with shiny dark plates bearing short bristles. A yellow stripe runs down the length of the back, while a broad white stripe runs from the head and along each side and meet on its backside. The winter is spent, sometimes two, as a narrow chrysalis that is sharply pointed on both ends.

Don’t hesitate to look for these attractive insects in an open woodland or bottomland forest near you. By early June the falcate orangetips will all be gone, and you will have to wait until the following spring for the next generation to once again make their brief and welcome appearance as heralds of spring.

© 2010, A.V. Evans

CARPENTER BEES ARE BORING!

Posted in Ants, bees, wasps, Insects, Parental care, Pests with tags , , , , on April 1, 2010 by Dr. Art Evans

By Arthur V. Evans

It's spring and the eastern carpenter bees, Xylocopa virginica, are back!

The usual suspects of spring are all around me once again, including large, buzzing, blue-black eastern carpenter bees, Xylocopa virginica. They are noisily patrolling dead limbs and wooden structures in our neighborhood as they search for mates and nesting sites. Unlike the social honey bee imported from Europe, carpenter bees are solitary creatures native to North America. The bees buzzing around now reached maturity last summer. Back then they stretched their wings for a bit before tucking themselves away for the winter deep within the recesses in the very nest chamber where they had grown up.

Unlike the dark-faced female, the male Xylocopa virginica has a white "face."

White-faced and stingless, males are very territorial and spend much of their time claiming prominent flowering plants and bare patches of ground as their own. They aggressively drive off other bees and insects and often face-off with unsuspecting humans that unwittingly venture into their territory. The territorial borders of male carpenter bees are quite fluid and change from day-to-day. Amorous males regularly patrol flowers in search of females. Courtship involves lots of loud buzzing and aerial acrobatics, with the pair flying apart and coming together several times.

Dark-faced females are capable of delivering a painful sting, but are relatively docile. They chew their nest tunnels in dead trees, logs, or unfinished wooden structures, especially those with southern or eastern exposures. Females will consider exposed rafters, old house frames, picnic tables, rail fences, posts, trellises, and other exposed wood surfaces as potential nest sites.

With their powerful jaws working non-stop day and night, female carpenter bees will chew a perfectly round entrance hole that is about one half-inch in diameter. After tunneling in about one body-length, the tunnel turns sharply to the left or right at a 90º angle to follow the timber’s grain. They may construct two or more parallel tunnels from the main entrance that measure up to 14 inches long, each slightly wider than the entrance in diameter.

Sometime in May or June, the first egg is laid on a doughy pill of pollen about the thickness of a kidney bean at the end of a blind tunnel. The provision of pollen serves as the sole food source for the developing bee grub. The surrounding wood in the tunnel is then chewed into a fine pulp for form a disk-shaped partition that seals the egg off in its own cell. Each tunnel may have up to 6-8 cells.

Carpenter bees do not eat wood, but rely instead on flowers for nourishment. As the adults forage for pollen and nectar, they will mark each flower that they visit with a repellant chemical, or pheromone, that lasts up to 10 minutes. By skipping marked flowers carpenter bees can save time and effort by avoiding flowers recently depleted of their resources by other carpenter bees.

Tolerance is the key to appreciating carpenter bees. In spite of all the sawdust created by their nesting activities, they seldom cause severe damage. What damage they do cause is easily offset by their pollination services. Our gardens, fields, orchards, and forests would not be nearly as productive if it were not for their efforts and those of other pollinators. Besides, whether they are energetically visiting flowers, zooming through the air in conjugal bliss, or tirelessly engaged in nest-building, carpenter bees are just darned fascinating animals to watch!

© 2010, A.V. Evans

BACKYARD MONSTERS? NOPE, JERUSALEM CRICKETS!

Posted in Grasshoppers & crickets, Insects with tags , , , , on March 29, 2010 by Dr. Art Evans

By Arthur V. Evans

Jerusalem crickets of the genus Stenopelmatus (Greek for “narrow foot”) are found in a variety of habitats throughout much of western North and Central America. This individual was photographed in Costa Rica. Their large, humanoid heads have inspired fear and superstition wherever they are found. However, they are not venomous and bite only when handled.

My first encounter with one of these giant, almost ant-like creatures occurred when I was about seven or eight years old and living on the fringes of the Mojave Desert in southern California. The inch-long insect had thread like antennae attached to an oversized head, a wingless narrow midsection armed with thick spiny legs and a fat abdomen distinctly banded in black and tan. I approached the animal cautiously, but closer inspection revealed that the insect was dead, frozen forever in a sprawling, lifelike pose. I carefully picked up the stiff corpse and presented it to my dad, who told me it was a Jerusalem cricket.

Resembling a cross between Jiminy Cricket and a Cootie, Jerusalem crickets – or JCs as they are fondly known by some – are impressive animals. Their large, round and naked heads are fitted with two small black eyes suggesting the head of a child. Jerusalem crickets are often the subject of fear and superstition and have been given a variety of monikers.

They have been dubbed Child of the Earth or Niña del la Tierra in Spanish. The Navajo thought them deadly poisonous and called them “wó se ts´inii,’ or the “skull insect” or “bone neck beetle.”  Their powerful jaws are used for digging and chewing roots. Jerusalem crickets can bite with considerable force if handled, but are not poisonous in any way. In California, JCs are known as potato bugs due to their predilection for nibbling on potatoes and other crops in direct contact with the soil. Extensive damage to crops and gardens by these insects is rare. They also occasionally scavenge dead animal matter and may engage in cannibalism. The name “Jerusalem cricket” is believed to have originated in the 19th century when ‘Jerusalem’ was a commonly used as an expletive. It is easy to imagine that unexpected encounters with these crickets could easily illicit such outbursts until the name eventually stuck!

Jerusalem crickets, including the genera: Ammopelmatus, Stenopelmatus and Viscainopelmatus, belong the family Stenopelmatidae and are related to crickets and katydids. They resemble the large king crickets of South Africa and the giant wetas of New Zealand, both of which are now classified in the family Anostotsmatidae.

From the "Dark Side of Entomology." California Academy of Sciences.

Jerusalem crickets are distributed throughout much of western North and Central America, where they live in almost every imaginable habitat from coastal and desert sand dunes to montane and tropical forests. Of the more than 100 species of JCs known, only about a third been formally described in the scientific literature. Most of the 60-80 species living in the western United States call California home.

The Kelso Jerusalem Cricket (Ammopelmatus kelsoensis), Point Conception Jerusalem Cricket (Ammopelmatus muwu) and Coachella Valley Jerusalem Cricket (Stenopelmatus cahuilaensis) are all restricted to coastal or desert dunes. These sandy habitats are under assault from developers, off-road vehicle use, and agricultural interests. The localized distribution and sensitivity to habitat disruption of these and other JCs require further study and may result federal or state protection.

Adult males are distinguished by a pair of small black hooks located between the cerci, a pair of short projections near the tip of the abdomen. Adult females have the short blades of their egg-laying tube or ovipositor located just beneath the cerci.

Sexually receptive males and virgin females drum their abdomens on the soil to attract species of their own kind. The drumming is audible nearly 60 feet away and is “heard” by special organs located near the bottom of each leg of the JC.

Courtship involves a bit of a tussle and sometimes resembles an energetic wrestling match as the male grapples for position. Eventually the male deposits a sperm packet, after which the female may kill and eat her mate. The function of the sperm packet in JCs is not understood. In other crickets and katydids the packet not only provides the female with reproductive materials and a nutritious snack, it also serves to block the amorous advances of other males.

Eggs are probably laid in small clutches in the soil soon after mating. They are oval and white with a roughened surface. In California, JCs reach adulthood during the summer. Small nymphs appear either by fall or early the following spring. Hatchlings resemble miniature adults and may take nearly two years to develop, while individuals experiencing nutritional deficiencies or parasitic infections may take up to five years. Nymphs may molt up to eleven times before reaching maturity. Like stick insects, JCs can regenerate legs lost during molting. In time, the new leg may approximate a normal leg in size, increasing in size with each successive molt.

Plump and juicy, JCs are an excellent potential food source for many animals. Bats, coyotes, foxes and owls prey them upon. It is not uncommon to find their droppings and pellets studded with the tough and distinctive remains of JCs mixed with the bones and fur of other animals.

Tachinid flies and horsehair worms attack and parasitize Jerusalem crickets. Dead JCs found in or near pools and streams are often infested with horsehair worms that must emerge from the body of the host and complete their life cycle in the water.

When threatened, JCs may suddenly kick out to brandish their thick spiny hind legs, menacingly raising them up over their body. Others will somersault on their backs, flailing their spiny legs forcefully in the air. Their mandibles are opened wide, capable of delivering a painful nip. Some species produce a scraping sound when agitated by scraping their legs against rough plates on the side of the abdomen. A few Mexican and Central American species are even capable of jumping when disturbed.

Jerusalem crickets are usually found under objects on the ground during the cooler, wetter months of the year. Trails of oatmeal left along paths will attract foraging crickets that will follow the food-laden path as they feed. Pitfall traps (cans or jars sunk in the ground so the opening is flush with the surface) baited with oatmeal will also attract hungry JCs.

Jerusalem crickets do well in captivity. Because of their cannibalistic tendencies they must kept in separate containers. Fill an eight-ounce margarine tub with damp, sterilized, fine-grained sand and cover with a lid punched with a few small holes. The containers must be kept cool since temperatures exceeding 70 ºF may not only be harmful to JCs, but also encourages the development of mites.  Humidity is critical. The substrate must be kept moist, but not wet, at all times.

Fresh slices of apple or potato offered every 7-10 days will not only provide your animals with nutrition, but also help maintain humidity. Add washed romaine lettuce and “old-fashioned” oatmeal. Jerusalem crickets will also eat bread, grass roots and a variety of vegetables. Supplement their weekly feedings with bits of raw meat or soft-bodied insects such as greater wax moth larvae (Galleria melonella). Remove uneaten food items after a few days to prevent the growth of potentially harmful molds.

Both immature and adult JCs have been kept successfully in captivity, but reports on egg-laying have never been published. In the wild, eggs are probably laid well below the surface so they are not subjected to freezing temperatures.

Nymphs molt on their backs with the old exoskeleton positioned behind them. After molting is complete, the JC will right itself and eat the caste, recycling vital minerals needed for the development of the new exoskeleton.

Throughout the western United States JCs are familiar, yet exotic, insects. In spite of their secretive nature, they still make unusual and interesting pets, even if kept only for a short period. Much remains to be learned about these incredible animals. Carefully recorded observations of your captive JCs may help to reveal their mysterious lives.

References

Field, L.H. (editor). 2001. The biology of wetas, king crickets, and their allies. CABI Publishing. Wellingford, UK.

Poinar, G. and D.B. Weissman. 2004. Horsehair worms and nematode infections of North America Jerusalem crickets, field crickets, and katydids (Orthoptera: Stenopelmatidae, Gryllidae, and Tettigoniidae). Journal of Orthoptera Research 13(1): 143-147.

Weissman, D. 2005. Jerusalem? Cricket! (Orthoptera: Stenopelmatidae: Stenopelmatus); origins of a common name. American Entomologist 51(3): 138-139)

Weissman, D. The dark side of entomology. http://www.calacademy.org/science_now/archive/where_in_the_world/jerusalem_crickets.php (accessed 16 March 2011)

© 2010, A.V. Evans

BELLY UP TO THE GRAVEL BAR FOR TOAD BUGS

Posted in Aquatic, Defense, Insects, Predators/parasites/parasitoids, True bugs, Virginia, Virginia State Parks with tags , , , , on March 28, 2010 by Dr. Art Evans

By Arthur V. Evans

One of my favorite haunts for insect photography is a small and unassuming gravel bar located just downstream from the dam that keeps the Swift Creek Lake within its banks in Pocahontas State Park, Virginia.

The toad bug, Gelastocoris oculatus, is widely distributed throughout southern Canada and most of the United States.

Gravel bars are tough places to live. Their surfaces can reach blistering temperatures or be completely inundated by flooding waters. Still, they support insects adapted to live under such harsh conditions that are seldom found anywhere else.

Many larger species spend their days hiding under stones and their nights foraging for food and mates. Some smaller species spend their entire lives comfortably wedged between the narrow, wet spaces between pebbles and coarse grains of sand. And still others are just passing through.

Not long ago, with a rushing stream at my back, I slowly knelt down on thankfully padded knees to recalibrate my focus on this universe wrought small. It took me of bit of time and patience to get my head out of the hustle and bustle of modern-day life, shake off the city with its noise and congestion, and begin to really see and appreciate the tiny inhabitants of this rocky shoal.

Bit by bit I took in my surroundings. Suddenly, a bit of movement drew my eyes toward a small embankment. I kept staring at the spot as I inched toward it, hoping to see whatever it was moving again. But it didn’t. Then it did, and I zeroed in on the spot. Just as the short, warty bug with bulging eyes came into focus, it jumped away. It was a toad bug, Gelastocoris oculatus.

It was as if I had just seen an old friend. I can still remember my very first encounter with this species along the edges of Little Rock Creek that meandered slowly out of the San Gabriel Mountains to the southern fringes of the Mojave Desert in Southern California. This species of toad bug is widely distributed throughout southern Canada and most of the United States.

The rough bodies of toad bugs are usually dull and mottled with brown and black. The base colors range from almost entirely yellowish, reddish-yellow, grayish-black, to nearly black. As a result, toad bugs are masters of the disappearing act.

Their front legs resemble those of a praying mantis, only shorter and chunkier. And like praying mantises, toad bugs are voracious predators and use these legs to capture small insects.

In Virginia, both larvae and adults live gregariously in a variety of habitats along the muddy, sandy, or gravelly margins of ponds, streams, and rivers. Overwintering adults appear in spring to feed and mate.

From May through September each female lays a dozen or so white eggs at a time in the sand, probably 200 or more in their lifetime. The eggs hatch in about two weeks; another two or three months are required before the larvae reach adulthood.

The toad bug eventually abandoned the gravel bar and disappeared into some low herbaceous growth nearby. I turned to find a small coppery ground beetle with bulging eyes, bright green legs, and patches of purple on its back running across the gravel, but this is a story for another time.

© 2010, A.V. Evans

ALTERNATIVE SPRING BREAK AT THE VCU RICE CENTER

Posted in Education, Environment, Insects, VCU Rice Center, Virginia with tags , , on March 26, 2010 by Dr. Art Evans

By Arthur V. Evans

© 2010, J. Barton

Last week, I met a group of very dedicated and enthusiastic students from the Virginia Commonwealth University and Virginia Wesleyan College at the VCU Rice Center in Charles City County. They had spent the last several days participating in various activities as part of this year’s Alternative Spring Break. Sponsored by the Chesapeake Bay Foundation, Alternative Spring Break provides students with an opportunity to explore and give to their community by providing a week’s worth of environmental and conservation projects, such as planting trees, tending gardens, tidying  up parks and wildlife refuges, and stream cleanups. At the Rice Center, some of the students would have the opportunity to help me with my insect survey.

© 2010, J. Barton

After an impromptu presentation about my survey and some of the methods used to trap insects, my team of volunteers was ready to get started. They grabbed tools and traps and set out for the first trap site. Working like a well-oiled machine and with minimal direction, they quickly established two sets of Malaise, Lindgren, and pit fall traps in less than two hours.

Malaise trap. © 2010, A.V. Evans

What is a Malaise trap you ask? It’s like a tent with its walls on the inside and is specifically designed to capture flying insects, day or night. Upon hitting the internal nylon panels, most insects will eventually work their way up into a collecting container partly filled with alcohol. Malaise traps are usually used to catch flies, bees, and wasps, but other kinds of insects are captured, too. They are typically placed along roads, trails, streams, or forest edges. Up to 1,000 insects a day may be captured in a good site.

Lindgren funnel trap. © 2010, A.V. Evans

Lindgren funnel traps are designed to attract and capture wood-boring beetles and other insects that alight on tree trunks. They consist of a rain and debris guard with a dozen black plastic funnels suspended directly underneath. Attached to the bottom funnel is a specimen receptacle. Each trap is fitted with chemical lures that simulate the odors given off by dead and dying trees. Insects attempting to land on the trap fall down the funnels and into the receptacle at the bottom. Foresters use Lindgren funnel traps to monitor pest insects in stands of managed timber, especially bark beetles.

Pit fall traps connected by drift fences of metal flashing capture small crawling animals,

Pit fall traps. © 2010, A.V. Evans

especially insects and other arthropods. At the end of each drift fence is a single pit fall trap consisting of two 16-ounce plastic drink cups nested in one another and sunk so that the tops are flush with the soil surface. The inner cup is partly filled with environmentally “friendly” antifreeze (propylene glycol). Each cup is covered with 1/2” mesh and flashing to keep out both vertebrates and rain.

© 2010, A.V. Evans

Thank you so very much to all the students who joined me on that wonderful day. Not only did you help get the job done, you also inspired me with your camaraderie, energy, and sense of purpose.

© 2010, A.V. Evans

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