eTawau > Insects of Borneo > Nerve-winged insects > An antlion on the Tawau River

Not a dobsonfly — an antlion

An adult antlion resting on the bank of the Tawau River near the White Bridge, on a sunny July afternoon in 2007

Corrected 30 September 2026. This insect was listed on this site for years as a dobsonfly, "Corydalus cf. luteus". That was wrong twice over: it is not a dobsonfly at all, and Corydalus is a genus of the Americas that does not occur in Borneo. It is an antlion. The old page now sends visitors here.

It was resting on a dry stem by the river, long and grey-brown, with its wings folded tight along its body, and it did not move. I moved it onto a green leaf for better photographs, and it stayed there, still, while I took them. Close up it has the long, lacy, net-veined wings of a lacewing and the long body of a damselfly, and on its head a pair of short antennae that curl over at the tips like a fern shoot.

A long, slender grey-brown insect resting on a green leaf, seen from the side. Its long, narrow, clear wings with a dense net of fine veins are folded roof-like along its body, and its dark abdomen reaches past the wing tips. Short antennae curve forward from a large rounded eye. A fingertip is out of focus at the left edge. — **The whole insect.** Tawau River bank near the White Bridge, 7 July 2007, 4.00 in the afternoon, on the leaf I moved it to. My fingertip is at the left edge.

How you know it is an antlion

The head and thorax of the same insect from the side, with five labels: a short antenna thickening into a curved club; a large, rounded eye; bristly legs; a hairy thorax; and net-veined wings. — **The head from the side**, 3.57 pm. Reduced and labelled; nothing else altered.

Four groups of insects in Borneo have long bodies and long, net-veined wings, and they are easy to mix up. The antennae sort them out:

Antlion (Myrmeleontidae) — short antennae, about as long as the head and thorax, thickening gradually into a club. That is this one.
Owlfly (Ascalaphidae), the antlion's closest relative — very long antennae, often nearly as long as the body, ending in a neat round knob.
Dobsonfly (Corydalidae) — long thread-like or comb-like antennae, broad wings and, in many, big jaws; its larvae live in fast, clean rivers.
Dragonfly or damselfly (Odonata) — antennae so short and bristle-like you hardly see them, and huge eyes; their wings are held out flat or folded above the back, never roof-like.

A close view of the two antennae, lying side by side against a green stem. Each is made of many short, ringed segments, darker along most of its length, and thickens and curves over at the tip into a club. The edge of a large eye and the spotted head are at the bottom left, and a bristly leg lies alongside. — **The antennae**, 3.58 pm: many short segments, each antenna ending in a curved club. This one photograph is enough to rule out a dobsonfly. Reduced and labelled; nothing else altered.

How far the name goes. Antlion, family Myrmeleontidae, is safe on the antennae, the wings and the long slender body. Genus and species are not determined: the antlions of Borneo are separated on the pattern of the wing veins, the spurs on the legs and details of the male's abdomen, which these photographs do not show clearly enough. The record has been posted to iNaturalist, where specialists can take it further.

The same insect from above, lying along a dry pale stem: the ringed antennae stretched forward along the stem, a large iridescent green-blue eye, a spotted grey-brown head and thorax, and the net-veined wings folded along the body. — **Where I found it**, 3.55 pm: lying flat along a dry stem, grey on beige, which is how antlions spend the day. Reduced; nothing else altered.

The "lion" is the larva

The name belongs to the young, not the adult. An antlion larva is a small, fat, bristly animal with a pair of long, sickle-shaped jaws. In many species it digs a cone-shaped pit in dry sand or dust, often under an overhang where rain does not reach, and buries itself at the bottom with only its jaws showing. An ant that steps over the edge slides down the loose sides; if it tries to climb out, the larva flicks sand up at it until it falls into the jaws. Other antlion larvae dig no pit and simply lie in wait under the sand or in leaf litter. In some countries they are called doodlebugs, after the wandering trails they leave in the sand.

The adult is a different life altogether: a soft, rather feeble flier that is active from dusk and rests by day on stems and grasses, lying along them so that it looks like part of the plant. Finding one sitting perfectly still on a dry stem in the afternoon, as this one was, is the normal way to meet an adult antlion.

How big — not measured

There was nothing beside it to give a scale, so this record has no size. The fingertip in the first photograph is closer to the lens than the insect and cannot be used as a ruler. Antlions of this build are usually a few centimetres long, with the wings folded.

Harmless. Adult antlions do not bite or sting. This one was moved gently from its stem to a leaf for the photographs and left there.

The record

7 July 2007 · 3.55 to 4.00 pm · a sunny afternoon

Resting on a dry stem by the river

The bank of the Tawau River near the White Bridge, Kuhara Road, Tawau, Sabah — inside the Tawau River Triangle: the White Bridge is where Jalan Kuhara crosses the river, and where the river enters the Triangle. One adult antlion, not measured, alone, resting motionless on a dry stem of an unidentified plant. Grey-brown, with long, narrow, clear, densely veined wings folded roof-like along the body; the abdomen longer than the wings; short antennae thickening into curved clubs; large, rounded, iridescent eyes; bristly legs. Moved by hand onto a green leaf, where it stayed still for three more photographs. Neuroptera: Myrmeleontidae — an antlion. Genus and species not determined. Four frames, 15:55:48 to 16:00:23.
— iNaturalist observation 404723424

Words you may meet

Myrmeleontidae: The antlions. From the Greek for "ant" and "lion".
Neuroptera: The nerve-winged insects: lacewings, antlions, owlflies, mantidflies and their relatives, named for the fine net of veins in their wings.
Clubbed antenna: An antenna that is thicker at the tip than at the base.
Larva: The young stage of an insect that goes through a complete change, such as a caterpillar or an antlion's "doodlebug".
Megaloptera: The order of dobsonflies and alderflies — a separate order, not the one this insect belongs to.

Nerve-winged insects · About antlions · Owlflies
Tawau River Triangle — the ground this antlion was found on, and the other records made there
Insects with two pairs of wings · Insects of Borneo

About the photographs. Four frames by Wong Fook Yee with a Canon PowerShot A430, no flash, f/2.8, 5.4 mm, at 15:55:48, 15:57:49, 15:58:45 and 16:00:23 on 7 July 2007 on the bank of the Tawau River near the White Bridge, Kuhara Road, Tawau, Sabah. All four are camera originals that had never been opened in an editor. For this page they have been reduced, the first-taken frame turned upright as the camera recorded it, and two labelled; nothing has been sharpened, recoloured, added or removed. The insect was moved from a dry stem to a leaf after the first frame.

The account of antlion larvae, adult habits and the differences between antlions, owlflies, dobsonflies and dragonflies is from the general entomological literature. The locality, date, weather and behaviour are the photographer's own. All photographs © Wong Fook Yee. Page written 30 September 2026.