Top 20 Most Common Insects in Delft

Ischnura elegans can reach a body length of 2.5 - 3.5 cm and a wingspan of about 3.5 cm. Hindwings reach alength of 1.4 - 2 cm. Adult male blue-tailed damselflies have a head and thorax patterned with blue and black. There is a bi-coloured pterostigma on the front wings. Eyes are blue. They have a largely black abdomen with very narrow pale markings where each segment joins the next. Segment eight, however, is entirely pale blue. At rest, the wings of most damselfly species are held back together, unlike dragonflies, which rest with their wings out flat. The thorax of juvenile males has a green tinge. Female blue-tailed Damselflies come in a variety of colour forms.Juveniles may be salmon pink, form rufescens; violet, form violacea and a pale green form. The colour darkens as the damselfly ages. Mature females may be blue like the male, form typica; olive green thorax and brown spot, form infuscans or pale brown thorax and brown spot, form infusca-obseleta.

The silver, comma-shaped marked on the butterfly’s wings give it the common name the Comma. It is a common butterfly in southern Britain that was once on the verge of extinction in the 1930s. The butterflies are often found at the edge of forests, close to meadows with plenty of nectar-rich wildflowers.

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.

It is a fairly large dragonfly (the length of 4.5 - 5 cm, 3 - 3.5 cm abdomen, rear wing 3.5 - 4 cm.) with relatively broad, flattened abdomen, but not as broad as to chaser species. With age, adult males develop extensive blue pruinescence on their abdomen, offset by yellow lateral patches. The middle lobe of the pronotum is large and notched in the middle. The chest is yellow or yellowish-brown. The base of the hind wings do not show a dark opaque spots. The pterostigma is dark brown or black. On the front wings pterostigma 2 - 3 mm long. Anal appendages are black. The females and immature males are a deep yellow color, with wavy black lines dorsally on their abdomen. Males and females have the costal vein (the leading edge of the wing) yellow or black.

The silver y (Autographa gamma) has an interesting name that comes from the silver, y-shaped patterns on each of its wings. Patterns on those wings also provide for decent camouflage. Its colors can be different depending on the local climate. You may catch them in your garden given their love of taking nectar from flowers.

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.

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.

It rests with closed wings when not in flight.

Bird-cherry ermine (Yponomeuta evonymella) is a species of moth with variable population fluctuations; in some years relatively few caterpillars appear, and in others they swarm in great masses, defoliating numerous trees and leaving them covered in silk. The trees often do not die, although their growth may be hindered for years afterward. If disturbed, these moths immediately drop to the ground to confuse pursuers.

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.