Top 20 Most Common Insects in Belgium

Contrary to what you may believe of its name, the gatekeeper (Pyronia tithonus) is a butterfly, not a heavily armored guard standing at an iron fence. The gatekeeper seems to have its own gate based on weather, as it cannot survive well in colder climates. It also survives through the two eyespots on the end of each of their wings, protecting them against bird attacks.

The painted lady is a migratory butterfly that spends part of the year in Northern Africa and then migrates to Europe during the warmer months. Although the adults feed on nectar from flowers, the larvae feed on the leaves of nettles and thistles.

Small and colorful, small tortoiseshell (Aglais urticae) is the national butterfly of Denmark. However, it is capable of surviving anywhere the common nettle leaf may be found, which the larvae of this species depend on. Once among the most common butterflies in Europe and temperate Asia, this species is experiencing rapid declines for reasons still being investigated.

The holly blue is a popular visitor to gardens in the southern portion of the British Isles where the butterfly gathers in large number. Unlike some species, females lay two broods in the spring and summer. Spring female holly blue butterflies are identifiable by the bands on their wings that are lighter than those from the summer brood.

The map butterfly is unusual in that its two annual broods look very different. The summer brood are black with white markings, looking like a miniature version of the white admiral and lacking most of the orange of the pictured spring brood. The eggs are laid in long strings, one on top of the other, on the underside of stinging nettles, the larval food plant.

The upperside forewings are a bright orange with a dark outside edge border and with eight or nine black spots. The hindwings are dark with an orange border. Some females also have a row of blue spots inside the orange border and are known as form caeruleopunctata. The undersides are patterned in a similar way but are paler. The black spots on the forewings are outlined in yellow and the dark colouring is replaced by a pale brownish grey. The hindwings are the same brown/grey colour with small black dots and a narrow orange border. The caterpillars (larvae) are usually green, but some have a purple stripe down the middle of the back and along each side.

Interestingly, individuals belonging to orange tip (Anthocharis cardamines) occupy different habitats depending on gender: the males inhabit the edges of forests, whereas the females prefer meadows. When laying eggs, females release pheromones to deter other females from laying eggs on the same flowerhead. They are picky about choosing their host plants, and females will avoid plants not fully exposed to sunlight.

Often confused for the ladybug, multicolored asian ladybeetle (Harmonia axyridis) is a separate species that, unlike the ladybug, is a household pest. It is considered particularly annoying for its habit of returning to places from which it is removed. One of the most variable species in the world, there are many different colors and patterns multicolored asian ladybeetle may display, making identification potentially difficult.

It rests with closed wings when not in flight.

Ochlodes sylvanus has a wingspan of 28–32 mm, which is similar in size to Chequered skipper. Although called "large" this is still a relatively small butterfly and not much larger than either the small or Essex skippers. The body is rather squat. The antennae are hooked at their tips. The upperside of the wings is orange-brown with a brown border and some lighter spots. The underside of the hindwings is greenish-yellow, marked with sparse yellow spots. The male has a broad scented androconial dark line across the top of the forewings. On the hindwings of the females there are brighter square marks. When the wings are opened, the forewings are obliquely folded, masking the hindwings. The faint chequered pattern on both the upperside and underside, and also the hook-shaped antenna tips, help to distinguish the large skipper from these two orange skippers. The Lulworth skipper also has patterned wings, but does not have the hooked antennae. The caterpillar can reach a length of 28 millimetres (1.1 in). It has a large blackish-brown head and a bluish green body, with a dark line down its back and a yellow stripe along each side.