Broad-Bordered Yellow Underwing

Adventure step • Meet the species

Overview

The Broad-Bordered Yellow Underwing (Noctua fimbriata) is a medium to large noctuid moth belonging to the family Noctuidae. With a wingspan of 5-6.2 centimeters, it is one of the larger species in its genus. The moth gets its English name from its distinctive yellow hindwings, which feature a broad dark brown to blackish border along the outer edge. The forewings are brown to grey-brown with complex markings and wave patterns that provide excellent camouflage against bark and lichen when the moth rests during the day. This species is well adapted to northern climates and occurs throughout the Nordic region, from southern Scandinavia up to mountain areas in the north. It inhabits diverse environments, from deciduous and coniferous forests to heathlands, meadows, and gardens. The larvae are polyphagous, meaning they can feed on many different host plants. However, they prefer herbaceous plants and grasses, particularly buttercups, dandelions, dock species, and various grasses. The caterpillars are nocturnal and hide in the soil or under plant material during the day. The adult moth flies in one generation per year, mainly during July and August, with flight times varying depending on geographic location and altitude. In southern parts of the range, they may begin flying as early as June. Like most noctuids, the species is nocturnal and is easily attracted to light, making it a common visitor to light traps used by entomologists to survey moth populations. The female lays her eggs in clusters on or near host plants, and the eggs overwinter before hatching in spring. The Broad-Bordered Yellow Underwing plays an important role in the ecosystem both as a herbivore (in the larval stage) and as prey for nocturnal predators such as bats and nightjars. The species is considered common and stable throughout its range and is not threatened. The moth is an excellent example of how insects have adapted to the seasonal variations of northern climates.