Category Archives: Insects

Sunflower tortoise beetle (Physonota helianthi)

sunflower tortoise beetle
Intermediate Adult

Sunflower tortoise beetle (Physonota helianthi) is a small leaf beetle. It occurs in the United States east of the Great Plains and in adjacent Canadian provinces. It is uncommon throughout its range.

There are three color phases that each adult undergoes. The teneral adult, freshly emerged from the pupal stage, is soft bodied and dingy white or ivory. The intermediate adult is black and white with numerous spots. This phase lasts about three weeks. The mature adult is entirely iridescent green. The upper thoracic plate and the two hardened wing covers each have a semi-transparent covering over the entire surface.

sunflower tortoise beetle
Mature Adult

Both larvae and adults feed on the underside of leaves. They occasionally defoliate the plant and can be a major pest. Larvae carry dried fecal matter over their body, presumably as a form of camouflage. The fecal matter is attached to a forked appendage on the last abdominal segment, and is held suspended over the body.

http://www.minnesotaseasons.com/Insects/sunflower_tortoise_beetle.html

Armyworm moth (Mythimna unipuncta)

armyworm moth
Photo by Alfredo Colon

Armyworm moth (Mythimna unipuncta), also called true armyworm and the white speck. is a migratory wainscot moth. It is medium-sized for a moth, large for a wainscot moth. It occurs in Europe, northern Africa, Iceland, North America, Central America, and northern South America. It is common throughout the United States and Canada, common and sometimes abundant in Minnesota. It does not survive cold winters. Adults migrate south in the fall and a later generation disperses north in the spring. Adults are found in Minnesota from March to November. Caterpillars feed on leaves and sometimes seed heads of mostly grains and other grasses, but also many broadleaf plants close to their infestations. After defoliating a stand of plants, they will move as a group to a nearby stand and resume feeding. They are often a serious agricultural pest, especially on wheat and corn.

Armyworm moths are ¾″ to 1″ long. Their forewings are tan with dark peppering and a small but conspicuous white spot. The caterpillar is up to 2″ long.

http://www.minnesotaseasons.com/Insects/armyworm_moth.html

Mid-winter boreus (Boreus brumalis)

mid-winter boreus
Photo by Luciearl

There are fifteen species of snow scorpionflies (Family Boreidae) worldwide, thirteen species in North America, two in eastern United States including Minnesota. The two species in our state are both in the genus Boreus and are easily told apart by their color.

Mid-winter boreus (Boreus brumalis) is a small snow scorpionfly. It is common in the United States from Maine to Michigan, south to Tennessee, and in Canada in Nova Scotia and Ontario. There are isolated populations in Illinois, Wisconsin, and Minnesota. They are found in deciduous woodlands that have moss on the ground. Larvae live in moss and prey on small insects and other animals found in the moss, and possibly also on the moss. Adults prey on small insects and other animals found hibernating under stones and moss. They are seen on the surface of the snow on winter days when the temperature is above freezing feeding on other winter insects.

http://www.minnesotaseasons.com/Insects/mid-winter_boreus.html

Elm leafminer (Fenusa ulmi)

elm leafminer
Elm leafminer. Sorry for the poor quality of this photo. If a picture should be worth a thousand words, this one is worth a few hundred at most.

Elm leafminer (Fenusa ulmi) is a very small common sawfly. It is native to eastern Europe and Scandinavia. It was brought to North America most likely on imported elms. It now occurs in the United States from New England to the upper Midwest, in the Pacific Northwest, and in southeast Canada. Based on the scarcity of reports, it is still relatively uncommon in Minnesota.

Due to the small size of the adult, elm leafminer is most often identified by the damage the larva causes to its host plant. Mines are seen from mid-May to early June on American elm and slippery elm. The larva feeds between the upper and lower surfaces of the leaf. It creates a serpentine mine at first. That soon develops into a small blotch between two lateral veins, later into a large blotch on one side if the midrib. The mines are clear and the flattened, whitish-green or yellowish-white larva can be seen when viewing the upper side of the leaf. The infected part of the leaf turns brown and eventually falls off. A heavy infestation may cause the entire tree to defoliate, but the infected tree flushes again and survives.

http://www.minnesotaseasons.com/Insects/elm_leafminer.html

American dagger moth (Acronicta americana)

American dagger moth
Photo by Alfredo Colon

Dagger Moths (genus Acronicta) is a large genus with about 150 species worldwide, more than 73 species in North America north of Mexico. At least 28 species have been reported in Minnesota. The common name refers to a black, dagger-like dash on the forewings of many of the species. Most are gray with darker gray markings, and are difficult to identify.

American dagger moth (Acronicta americana) is the largest dagger moth in eastern United States. The adult is up to 1½″ long and has a wingspan of up to 2½″. It is gray or brownish-gray with dark markings and a black “dagger”. It is found in deciduous woodlands and forests across the United States and southern Canada. It is common and sometimes abundant east of the Great Plains, common in Minnesota.

The caterpillar is large and is covered with yellow or white hairs. It has two pairs of long black lashes near the front of the abdomen and a single thicker lash near the end. The lashes are tight groups of bristles. When the caterpillar is handled the bristles break off and embed in the skin of the handler. They contain a toxin which causes stinging and burning and can develop into a rash.

http://www.minnesotaseasons.com/Insects/American_dagger_moth.html

Black-and-gold bumble bee (Bombus auricomus)

black-and-gold bumble bee
Photo by Gerry Garcia

Black-and-gold bumble bee (Bombus auricomus) is common, large, colonial bumble bee. It occurs in North America east of the Rocky mountains. It is common in southern Minnesota, less common in the north. It is one of the largest bumble bees in Minnesota. Females (worker bees) are up to ¾″ long. It is found in grasslands and open areas. It lives in small colonies of about 35 workers.

Black-and-gold bumble bee is identified by its large size; there is a patch of yellow hairs on the back of the head; the thorax that is yellow on the front third, black on the rear two thirds, and has a very narrow yellow band at the rear; and the abdomen is black except for the entirely yellow second and third segments.

http://www.minnesotaseasons.com/Insects/black-and-gold_bumble_bee.html

Slender spreadwing (Lestes rectangularis)

slender spreadwing
Photo by Dan W. Andree

Slender spreadwing (Lestes rectangularis) is one of the most common and one of the most easily recognized damselflies in Minnesota. It occurs in the United States from the East Coast to the Great Plains and in adjacent Canadian provinces. It is found in partially shaded areas in marshes, ponds, lakes, and still backwaters of slow streams.

Adults are about 1½″ to 2″ long. The male thorax is dark brown with yellow sides and wide blue or gray shoulder stripes. The abdomen is dark brown above, yellow on the sides, and extremely long, about twice as long as the wings. The wings are clear with a dark spot near the tip and a pale vein around the tip. The female is similar but has light brown shoulder stripes on the thorax and a shorter and stockier abdomen.

http://www.minnesotaseasons.com/Insects/slender_spreadwing.html

Ferruginous tiger crane fly (Nephrotoma ferruginea)

ferruginous tiger crane fly
Photo by Alfredo Colon

With over 15,000 described species, the family Tipulidae (crane flies) is one of the largest families of true flies (Diptera). More than 1,600 species occur in North America. The subfamily Tipulinae (large crane flies) contains the largest of the crane flies. In North America, the vast majority of species are in the genera Tipula and Nephrotoma. The genus Nephrotoma (tiger crane flies) contains about 150 described species. The most common of these is ferruginous tiger crane fly (Nephrotoma ferruginea).

“Ferruginous” means reddish-brown or rust colored, but ferruginous tiger crane fly is more often described as orange in color. It is distinguished from other crane flies by the body color, the antennae that are entirely black except for the first two segments, and by a black spot at each end of a groove across the thorax.

http://www.minnesotaseasons.com/Insects/ferruginous_tiger_crane_fly.html

Wasp mantidfly (Climaciella brunnea)

wasp mantidfly
Photo by Bill Reynolds

Wasp mantidfly (Climaciella brunnea) is a large wasp mimic. It occurs across the United States, in adjacent Canadian provinces, and in Mexico and Central America. It is widespread but considered scarce.

With its mantid-like front legs wasp mantidfly looks similar to a praying mantis but it is not even closely related. This is an example of convergent evolution, where unrelated organisms, adapting to similar environments, independently evolve similar characteristics. It also looks similar to a paper wasp. This is an example of Batesian mimicry, making it look like another species that is unpalatable or dangerous to potential predators.

Adults emerge in late May through October. Males live less than a week, females up to a month. They can be found on flowers where they wait on and ambush small insects. During her time the female lays up to several thousand eggs. The small white eggs have short stalks and are attached to the underside of plant leaves. After an egg hatches the larva waits for and then attaches itself to a passing wolf spider. When the female wolf spider begins making an egg sac, the mantid larva crawls off the spider and onto the sac. It then gets wrapped up as the egg sac is completed and feeds on the spider eggs inside.

http://www.minnesotaseasons.com/Insects/wasp_mantidfly.html

Midwestern salmonfly (Pteronarcys pictetii)

midwestern salmonfly

Midwestern salmonfly (Pteronarcys pictetii) is a large, dark brown, giant stonefly. It is common in the Midwest from Minnesota and Wisconsin south to Kansas and Indiana. Adults are 1½″ to 2½″ long. The head narrows slightly in the rear and has a thin, bright orange, rear margin. The plate covering the thorax is highly sculptured and has a thin, bright orange stripe in the middle and three bright orange spots at the base. The legs are robust. The wings have many prominent veins.

Young (naiads) live in well aerated water of small and medium-sized streams. They eat particulate plant matter in the water and move very slowly. When disturbed they will pretend to be dead. They take 2 to 3 years to develop. Adults emerge from April to June and live for only 2 to 3 weeks. They are poor fliers and when disturbed they will run rather than fly away. They are sometimes found far from water. They are active at night (nocturnal) and are attracted to lights.

http://www.minnesotaseasons.com/Insects/midwestern_salmonfly.html