Dobsonflies have a soft, brownish body. They can grow up to 7 cm long. Two pairs of large wings of nearly equal length with rounded tips are fixed to the insect’s thorax. They are transparent, with spots. On its head are a pair of compound eyes, as well as simple eyes, or ocellae.
The dermestid beetle is a dark brown or black beetle whose elytra feature a wide stripe of smaller, lighter hairs that range from yellow to grey or white in colour. This stripe has six black dots in the centre (three on each elytra) that vary in size and shape. Its head has two short, club-shaped antennae. Two pairs of wings are attached to its thorax. Under its elytra are two functional wings which are used when the beetle takes flight. Males and females have similar appearances and measure between 6 and 9 mm.
Around 20 species of Dermestidae live in Quebec. Dermestid beetles, whose name means “skin eater,” are frequently found in homes.
The most common, other than the larder beetle (Dermestes lardarius), are the black larder (Dermestes ater), the hide beetle (Dermestes maculatus), the carpet beetle (Anthrenus scrophulariae), the varied carpet beetle (Anthrenus verbasci), the black carpet beetle (Attagenus unicolor), the dermestid beetle (Trogoderma inclusum) and the warehouse beetle (Trogoderma variabile).
The order of Megaloptera includes some 300 species divided into two large families: Corydalidae (dobsonflies) and Sialidae (alderflies). There are 16 species of dobsonflies in Canada and at least five in Quebec. Among the 24 species of alderflies in North America, five are listed in Quebec, all belonging to the Sialis genus.
Megaloptera undergo a complete metamorphosis. The larvae, which are very different from adults, live in the water and are predatorial.
Dobsonfly larvae do not have the terminal filament at the base of their abdomen like alderfly larvae. They both breathe using tiny gills. Megaloptera larvae act as indicators of water quality, as they do not tolerate pollution well.
Dobsonfly and alderfly adults barely eat, although their jaws are strong and well adapted. Their imposing wings do not allow these insects to fly over long distances.
The polyphemus moth can be distinguished from other Saturniidae by its colouring that varies from pale to dark brown and is sometimes reddish or greyish. Each of its wings has a small, scale-less “window” called an eyespot. The eyespots on its front wings are oval and encircled in yellow. The eyspots on its back wings, with yellow, dark blue and black borders, look like large eyes. Its abdomen is covered with reddish-brown hairs.
When it first hatches, the caterpillar is yellow. After four moults, it reaches a length of 8 cm or more. At this stage, the caterpillar’s body is fluorescent green and silky, with a series of small orange spots and creamy white transversal lines. The caterpillar’s head is brown.
Once it reaches maturity, the caterpillar stops eating and spends several hours weaving a cocoon. The cocoon is attached to the host plant. In southern regions, it may fall to the ground. The rigid silk cocoon, often surrounded by dead leaves, is oval-shaped and pale grey. The chrysalis spends the winter in a dormant state, protected inside the cocoon. The adult emerges the following spring.
The giant water bug is the largest aquatic insect in Quebec. Its flat, hydrodynamic body and the long hairs on its middle and back legs make it a fast and efficient swimmer. It has large compound eyes on its head. It eats using piercing-sucking mouthpieces that form a sort of short, pointed beak, called a rostrum, under its head. It has a short respiratory tube at the end of its abdomen that consists of two flexible, retractable parts that can move back and forth.
Water bugs are Hemiptera with an aquatic lifestyle. Some of them, such as the giant water bug, water scorpion, water stick insect and water strider, are voracious predators. Others, such as the back swimmer and the water boatman, feed on algae and plant particles.
These bugs, like all Hemiptera, have back wings with thick, opaque tips that are more membranous than the wing base. Some of them, like the giant water bug, have a special appendage at the base of their wings that allow the insect to keep its wings tightly closed against its body. This adaptation to aquatic life makes the insect a better swimmer.
Water bugs undergo an incomplete metamorphosis. The newly hatched insect looks like a smaller version of the adult without wings, and generally lives in the same environment, feeding on the same prey.
The cecropia moth is the largest moth in Quebec. It can be recognized easily by its size, its body and legs that are covered with red hairs and its black and white striped abdomen. It has a white collar around the upper part of its thorax. Its reddish brown wings are marked with a white line. A white or red and white crescent appears on each wing. Moths of both sexes have feathery antennae.
When it first hatches (2), the caterpillar is black and measures just 5 mm. It begins eating immediately and moults four times before reaching its maximum size (3) after about eight weeks. At this stage, the caterpillar is 8 cm long and sometimes as long as 10 cm. It is green with two rows of yellow bristles on its back and two pairs of large reddish-orange bristles near its head. There are small blue bristles on the sides of its body.
Once it reaches maturity, the caterpillar stops eating and leaves its host plant. It looks for a branch to spin a silk cocoon around itself, (4) inside which it metamorphoses into a chrysalis. The cocoon is around 8 cm long, brown and streamlined. In Quebec, the chrysalis overwinters inside this cocoon. In May or June the following year, the moth (1) emerges, ready to mate.
The luna moth is one of the most beautiful moths. This magnificent insect, with its feathery antennae, is characterized by its emerald green colour and the extension of its back wings. The brown border of its back wings looks like a branch when the moth is resting. All four of its wings feature white circles with a yellow-orange (sometimes reddish) pattern, surrounded by a thin black border. Its abdomen is creamy white.
When it hatches, the caterpillar is green and brown spotted with long white hairs. Once mature, it measures 8 cm and sometimes more. The sides of its body are patterned with small black dots, a row of orange spots and a pale yellow line.
In our latitudes, the caterpillar leaves its host plant at the end of the summer and begins weaving its cocoon on the ground among dead leaves. The brownish, sometimes spherical cocoon is about 6 cm long. The caterpillar transforms into a chrysalis inside its cocoon and hibernates until the next spring. The adult emerges from the cocoon in mid-May.
With a wingspan that can reach 15 cm, some species in this family are among North America’s largest. In Quebec, there are around 10 species.
The wings of Saturniidae often present spots that look like eyes, called eyespots, which can scare away predators. Males are generally smaller than females, with larger antennae that are usually feathery or comb-like. The insect’s small proboscis does not allow it to eat. The insect lives for four to 10 days on the reserve of energy accumulated during the caterpillar stage.