Top 20 Most Common Insects in Trondheim

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.

This species is unusual for a noctuid in that there is marked sexual dimorphism. The male has a wingspan of 27–32 mm but the female is much larger with a wingspan of 35–39 mm. The forewings are brown, speckled with black and marked with a bold white branched basal streak which gives the species its common name. The hindwings are dark brown with a white fringe.

The wingspan is 2.5 - 3 cm. The ground colour of the forewings may show whitish, grey, black or brown tints but the colour is extremely variable and there are strongly darkened forms. Characteristic is the protruding post medial line on the front wings, which usually reaches the post discal wavy line or interrupts it.

Named for its red-colored lower body, red-tailed bumblebee (Bombus lapidarius) is considered an important pollinator species for farmers in central Europe. This species is more egalitarian than other bumblebees: while the queen remains the dominant figure, there does not appear to be any form of hierarchy between worker bees themselves. The colonies are small, with fewer than two hundred workers at any time.

The common hawker , moorland hawker or sedge darner ( Aeshna juncea ) is one of the larger species of hawker dragonflies.It is 7 cm long with a brown body. The male has a black abdomen with paired blue and yellow spots on each abdominal segment, and narrow stripes along the dorsal surface of the thorax. In the female, the abdomen is brown with yellow or sometimes green or blue spots. The wings of both sexes display a yellow costa (the major vein running along the leading edge of the wings). This species lacks the green thorax stripes of the southern hawker.

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.

Agriopis aurantiaria, the scarce umber, is a moth of the family Geometridae. It was first described by Jacob Hübner in 1799 and it is found throughout Europe from Spain through Central Europe to Russia. In the south it can be found from the western Mediterranean to the Black Sea and the Caucasus. Its northern distribution reaches as far as central Fennoscandia. The species can be found in many different places, including deciduous forests, orchards, gardens as well as parks and settlement areas. The wingspan is 27–35 mm. There is a strong sexual dimorphism. The males have normally developed wings. The forewings are dark golden yellow or orange yellow to light brown and dusted with many black scales. There are three brown-grey transverse bands the outermost broken. Sometimes there are large black patches in the postdiscal area. The hindwings have the same basic colour as the forewings, but are however always paler with two thin, dark lines. The antennae are double saw combed.. The male differs from its congeners in its bright golden-brown colour. Forma include — ab. fumipennaria Heilweger. Forewing infuscated (violet -brown), only the fringe yellow; hindwing also more or less smoky. male-ab. fasciata Linstoiv has a dark band distally to the postmedian line. The flightless females have almost entirely vestigial wings, a clumsy body, tapering at the end of body shape and are grey brown. The stub wings have are grey with two black crosses. The egg is flattened at one end, longitudinally ribbed and purplish. The caterpillar is yellowish, inclining to ochreous, lined with brown on the back, and striped with purplish on the sides. The underside is dark purplish brown, inclining to blackish, and striped with yellowish. Adults are on wing from October to November. The larvae feed on various deciduous trees, including Betula, Quercus robur, Sorbus aucuparia, Rosa and Prunus padus.

Coenagrion hastulatum is 3 - 3.5 cm long.

The brown hawker ( Aeshna grandis ) is a large dragonfly about 7 cm long. It is a distinctive species and is easily recognised, even in flight, by its brown body and bronze wings. At rest, blue spots on the second and third segments of the male's abdomen can be noticed; these are absent in female.The nymph has stripes on the side of the thorax and distinct banding on the legs.