Brachynemurus abdominalis

Snap-trap Antlion
Brachynemurus abdominalis

Identification:
Head: Pale yellowish-brown with dark streaks and spots. Large protruding, multi-colored eyes.
Antenna: Segments brownish-yellow, ringed with dark brown. Tips clubbed (clavate), light yellowish-brown.
Thorax: Pale yellowish-brown; streaked darker. Neck (pronotum) with 2 or 3 dark streaks.
Wings: Female has clear wings with deep black veins. Outside (or lower) wing border has dark spots with white dashes in between; black spots are small on first row and large on next row. Both male and female have a faint white spot (stigma) near wing tip; stigma is usually larger on the female. Male wings can be same as the female or entirely tinted a faint yellowish with obvious yellow, long veins.
Legs: Legs thick and short; bright yellow (male’s pale yellow), speckled with black; feet whitish, spotted with black.
Abdomen: Female abdomen yellowish-brown, with darker streaks; tip of abdomen just reaching to wing tips. Male abdomen extending 1/3 past wing tips; last half of abdomen more reddish-yellow than female. 

Similar Species:
B. longicaudus has no white dashes in between spots. Male unmistakable – abdomen twice as long as wings.
The Clouded Antlion B. nebulosus female has dark wings with darker blotches (not spots) and some white on cross-veins. Male wings the same, but a bit darker and with less white.
B. signatus male and female have black-veined wings with no marks.

Size: Female 23 mm long. Male 25 to 33 mm long. Larva 10 mm long 

Flight Time: June to mid-August.

Habitat: Meadows & forest edges with sandy, bare soil.

Food: Larva eat aphids, mites, mealy bugs and particularly ants. Adults feed on nectar.

Life Cycle: Larvae are found in open sandy areas, living just beneath the sand surface. They do not form pits like the Common Antlion Myrmeleon immaculatus.

Comments: Essex County – Ojibway Prairies and Point Pelee National Park.  Also found at Long Point, and Manitoulin Island.

For information on synonyms, references and type specimens see next page

Quick ID Antlions

Quick ID
Antlions

Identification:
Antlions have long slender, transparent, net-like wings. Most of the antlions are identified by the spots or patterns in their wings.
Antenna are widened or clubbed at their tips and tips are usually curved.
Bodies are quite long, the male’s longer than the female’s, except for the Spot-winged Dendroleon obsoletus where length is the same in both male and female.
They are poor flyers. Attracted to lights at night.

Six species in Ontario:
Spot-winged Dendroleon obsoletus (southern Ontario)
Common Myrmeleon immaculatus (southern Ontario)
Clouded Brachynemurus nebulosus (southern Ontario)
Snap-trap Brachynemurus abdominalis (southern Ontario)
Brachynemurus longicaudus (northern – Georgian Bay)
Brachynemurus signatus (1992 & 1996 at Pinery Prov. Park, Grand Bend)

Similar Species:
May be mistaken for Damselflies and Dragonflies, but Damsels and Dragons have very short, hair-like antenna. Antlions have long, thick antenna; wider at tips (clubbed).

Flight Time: Generally June to August.

Life Cycle: Females lay their eggs on the ground, except for the Spot-winged Dendroleon obsoletus, which lays its eggs in tree holes. Larva are predators and feed on smaller insects. Pupae or cocoons are formed in soil (or tree holes) using silken threads and debris. Only one generation per year.

Quick ID:
Spot-winged Dendroleon obsoletus
Unmistakable – large dark, somewhat circular spots and dashes on wings. Legs entirely black.

Common Myrmeleon immaculatus
Outer edge of wings (costa) has rows of alternate light and dark dashes along wing edges but no spots like the Clouded Brachynemurus nebulosus. Legs: thighs (femora) yellowish; shins (tibiae) dark with yellow patches, feet dark.

Clouded Brachynemurus nebulosus
Outer edge of wings (costa) have one row of alternate light and dark dashes, but the white extends inward along cross-veins, forming an inverted T-shape and sometimes a U-shape. Wings also have vague dark spots and dashes with some white throughout, absent on the Common Myrmeleon immaculatus. Legs mostly brown with white hair fringe.

Snap-trap Brachynemurus abdominalis
Outer edge of wings (costa) have two rows of dark spots – 1st row has small dark spots; row above has large dark spots. Male wings can be the same as the female or have the wings entirely yellowish with thick yellowish-green veins and no other marks. Legs yellow, feet striped.

Brachynemurus longicaudus (Georgian Bay)
Outer edge of wings (costa) has a series of small evenly spaced, black dots in rows – all dots the same size. Also have large spots randomly placed on wings. Male abdomen twice as long as wings. Legs yellow with tiny black dots.

Brachynemurus signatus (Pinery Prov. Park)
Wings have no marks. Veins brown and yellow, but no thick yellow veins like male Snap-trap Brachynemurus abdominalis. Legs mixed dark and light.

Myrmeleon immaculatus

Common Antlion
Myrmeleon immaculatus

 

Identification:
Head: Face is shiny, grayish to dark brown with green eyes and a yellow stripe at the back of the eye.
Antenna: Dark, including clubs at tip.
Thorax: Neck (pronotum) grayish with a pair of faint yellowish spots at each corner nearest head. Thorax grayish.
Wings: Wings net-like with black and some white veins. A row of alternating and uneven black and white dashes inset from the outer or lower wing border. The female also has a small white patch (stigma) near the wing tip; patch on the male can be smaller or absent.
Legs: Upper legs light yellowish-white, lower legs dark with some light patches.
Abdomen: The female has each abdominal segment dark gray at base, turning dark brown with a light stripe at lower border of segment. Male abdomen is dark brown with light stripe at lower border of each segment. Male abdomen is longer than the female’s, but still does not reach to wing tips.

Size: 35 to 40 mm long. Larva 8 to 12 mm long.

Flight Time: Late June and July.

Habitat: Dry sandy areas.

Food: Ants and other small insects that slide into sand pits.

Life Cycle: Mating lasts nearly two hours. After separation the female cleans up by feeding on the remaining spermatophore. Females drop eggs in bare, sandy areas. Larvae, called Doodlebugs, only walk backwards. They dig perfectly round, cone-shaped holes in the sand and bury themselves at the bottom of the pit. They feed on ants and other insects that slide into the pit. The victim is injected with a liquid that disintegrates their innards which are then sucked up through the huge, hollow jaws of the Antlion. Antlions know enough not to eat the formic acid sac in the ant’s abdomen. Larva are not fully developed until between September and November, depending on weather. The larva bury themselves in the soil and form a round silken cocoon from silk glands at the tip of the abdomen. Adults are night flyers.

Comments: Essex County – Point Pelee National Park, Lake Erie Islands, Ojibway Prairies. Kent County – Rondeau Provincial Park.
Around the Great Lakes area, Antlions are also preyed upon by Bee Flies Anthrax species that lay their eggs in the sand pits of the Doodlebug larva.

For information on synonyms, references and type specimens see next page

Dendroleon obsoletus

Spot-winged Antlion
Dendroleon obsoletus

Identification:
Antenna have a dark base and dark clubs at tips. Mid area of antenna are orangish. Legs are all dark and thin. Both front and hind wings have conspicuous black or brownish-black circular spots and dashes. Newly emerged adults have very faint spots. Male and female abdomens are the same length – shorter than wings.

Size: 50 mm long. Larva 8 to 12 mm long.

Flight Time: July and August.

Habitat: Wooded areas. Larvae live in dry tree holes and prefer Oaks Quercus.  

Food: Larva feed on soft-bodied insects.

Life Cycle: Lay eggs in late summer in dry tree holes, particularly Oak Quercus. Larvae have been found in fine organic matter, with their legs holding balls of this solid substrate. The winter is usually spent in larva stage in hibernation. Pupate in cocoon spun with silken threads. Adults live only a few weeks. Life cycle is not well-known and larva may spend 1 to 3 years before maturing. Larvae are able to survive long periods of famine by reducing their metabolism.

Comments: Rare. Kent County – Rondeau Provincial Park. Not recorded for Essex County. In Middlesex County per BugGuide; also in Michigan.

For information on synonyms, references and type specimens see next page

Brachynemurus nebulosus

Clouded Antlion
Brachynemurus nebulosus

Note: Both photos of male and female found at Point Pelee National Park, Leamington, Ontario. 

Identification:
Head: Head dark, small; some yellow around antenna bases.
Antenna: Black, thick; only slightly clubbed.
Thorax: Neck (pronotum) narrow with 3 vague yellowish marks or streaks. Thorax dark with obscure yellowish to white marks.
Wings: Wings dark with small darker random spots (not in rows). Some of the wing veins are white, forming U-shapes, especially near the lower (outer) border of the wings. White stigma or spot nearer to wing tip on outside edge.
Legs: Short, pale yellow, speckled with black. Feet black.
Abdomen: Female abdomen dark, extending to wing tip. Male abdomen is slender, longer than wings, but not twice as long. Both have yellowish interrupted rings on base half, and yellowish dots or dashes on last half.

Similar Species:
The Snap-trap B. abdominalis has white dashes, not U-shaped between black dots on two rows.
B. longicaudus has evenly-sized black spots; male abdomen unmistakable – twice as long as wings.
B. signatus has black-veined, completely unmarked wings.

Size: Female 27, male 40 mm long. Larvae 13 mm.

Flight Time: June and July

Habitat: Sandy areas near ant nests.

Food: Larva feed on ants and other small insects.

Life Cycle: Larva are reddish, lower abdomen white with two black longitudinal stripes. They do not dig pits, but run across the sand and then dig a long channel, or bury themselves just beneath soil surface; usually near or on ant nests. Prey is grabbed by the mandibles and dragged backward until both are completely covered with sand. Pupa is a silken cocoon, covered with grains of dust.

Comments: Essex County – Point Pelee species list. Kent County – Rondeau Prov. Park species list Oct, 2009. Also Bosanquet Township.

For information on synonyms, references and type specimens see next page