Insecta

Most leaf beetles are small – less than 1.2 cm long – but a few species can reach 2 cm. Their elytra (hardened wings) are often smooth and shiny, but occasionally have distinctive shapes or may be either ridged or pitted. They come in a variety of colours.

The legs are a distinguishing characteristic of these insects: the final heart-shaped segment, just before the claw, is bilobed. This segment is covered with special hairs that allow the beetles to walk along waxy stems and leaves.

Adult yellow mealworms are shiny, sturdy, dark brown to black beetles and measure around 16 mm (14–18 mm) in length. They are the biggest insect pests to infest whole and ground grains. Males are usually smaller and slimmer than females.

Depending on the species, mayflies range from 2 to 18 mm in length, excluding the antennae and caudal filaments. They are often whitish or yellowish in colour.

Mayflies have vestigial mouthparts and are therefore unable to feed. The membranous and extensively veined wings are held vertically when at rest.

Mayflies have two to three long filaments at the tip of the abdomen. These have a tactile role, stabilize the insect’s flight and, together with the wings, help prevent joined mating couples from falling to the ground.

Head lice are tiny wingless insects with a flattened body. They have three short pairs of legs equipped with claws that grasp the host’s hair.

Depending on the species, these elongate insects either have four wings or are wingless. Their long antennae are nearly half their body length. They are easily identified by the well-developed cerci located on the end of the abdomen. Females have long, straight-sided, stocky cerci, while males have narrower and strongly curved cerci.