Top 20 Most Common Insects in Ireland

The speckled wood (Pararge aegeria) prefers to live in damp, dark woodlands. Unlike other butterflies, it's more active in shadier habitats rather than sunny ones. Males often fight over a perch, spiraling up to the treetops until they determine a winner. These perches are where the males find passing females.

The meadow brown (Maniola jurtina) is similar to the Gatekeeper in the way that it rests with its wings open due to the "eye spots" on either end of its wings that ward off predators. While the color is a deep brown, the caterpillar form is a beautiful bright green with little, white hairs and a dark line leading down its back.

Green-veined white (Pieris napi) is a distinctively white-winged butterfly that lays its eggs in a variety of food plants. This species displays observable differences dependent on sex: males possess only one dark spot on each forewing, whereas females display two. Unlike several of its cousin species, green-veined white prefers not to lay eggs in garden cabbages, rendering it less of a pest to farmers.

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.

European peacock (Aglais io) is a colorful butterfly that resides in temperate Asia and Europe – hence its common name. Its prominent eyespots deter would-be predators, who mistake them for the eyes of a bigger, more dangerous species. In recent years, this species appears to be expanding its range into previously uncolonized territory.

Cabbage white (Pieris rapae) derives its common name from its habits as a caterpillar, which is a ferocious pest for cabbage, kale and broccoli farmers. In North America, it is one of the first butterflies to emerge in spring, heralding the beginning of the season.

Aphantopus hyperantus is a medium-sized butterfly with a wingspan of up to 3.5 - 4 cm . The wing upper and lower sides are solid brown with small, yellowish-rimmed eyespots. The newly emerged ringlet has a velvety appearance and is almost black with a white fringe to the wings. The number and size of the eyespots is variable, they may be missing on the upper wing surface. The eggs are pale yellow when first laid, but become pale brown.The caterpillars are about 2.5 cm long. They are gray or light reddish brown and have dark, reddish brown and very fine dots. Dorsally there is a dark longitudinal line, which is widened at the segment boundaries. Toward the rear, this line is more intensely colored. The head is darker and has several faint longitudinal stripes.

Despite its common name, only male specimens of common blue butterfly (Polyommatus icarus) can accurately be described as blue; the females are predominately gray-brown, with only a dusting of blue and a scattering of orange spots. The adults live for only three weeks before dying.

Large white (Pieris brassicae) is visually similar but quite larger than its close relative P. rapae. It lays its eggs on food plants such as cabbages – the origin of its common name – leading to many farmers' classifying this species as a pest.

Red admiral (Vanessa atalanta) is a visually striking species of butterfly. Unusually territorial, males will compete for choice areas, and females will only mate with males that maintain their own territories. This butterfly is known for being particularly patient with human interactions, even to the point of perching on clothing or flesh.