Butterfly Conservation: Highland Branch

Moths of the month: August 2013

This is a monthly series illustrating several characteristic moths to look out for in our area. Text and photos by Roy Leverton.

You can also view the other months by selecting the links at the bottom of this page.


	Small Fan-footed Wave Idaea biselata July into early September. Woodland, scrub, hedgerows, gardens. Waves (Sterrhinae) are a southern subfamily, with numerous species in the Mediterranean but only a handful in our area. This is perhaps the most widespread and numerous. Like others in the genus, its caterpillar feeds on unspecified withered leaves, probably at or near ground level since it is rarely found. By day the delicate adults can be found resting on foliage or sometimes on walls and fences. At night they nectar at flowers, particularly rosebay willowherb, and often come to lighted windows. Click on the image to enlarge it.

	Dark Arches Apamea monoglypha Late June to early September. Anywhere with grasses. Dark Arches is one of our most ubiquitous and abundant moths, so any gaps in its distribution map reflect lack of recording effort rather than absence. Its caterpillar feeds on the roots and lower stems of coarse grasses, without any obvious habitat or climatic preferences. The adults have a muted general purpose coloration, suitable for resting concealed in the ground layer or in other nooks and crannies. Variation is considerable if unspectacular, from pale to dark, culminating in the intensely black melanic form aethiops as shown here. Click on the image to enlarge it.

	Treble-bar Aplocera plagiata July into September. Herb-rich grassland, including sand dunes and cliffs. Because St. John's-wort is the only larval foodplant, Treble-bar is a widespread but local species like the plant itself. Further south there are two broods a year, but our scotica race has only one, with the caterpillar hibernating while still small. The adult is more triangular than most in the carpet moth family, with strongly shape-disrupting markings that camouflage it at rest. Even so, any disturbance causes moths to take wing instantly, especially on a warm day. Should concealment fail, rapid flight is its second line of defence. *Click on the image to enlarge it.*

	Dun-bar Cosmia trapezina Late July to September. Deciduous woodland. This moth's unremarkable appearance belies an unusual lifestyle. Although its caterpillar can manage perfectly well on a diet of leaves, its preferred food is other caterpillars. It is a notorious cannibal, attacking caterpillars much larger than itself yet somehow avoiding reciprocal injury. How it does this would make an interesting study. In our area it is mainly an eastern species, being scarce or absent in the west and north. Oak woodland is a favoured habitat, but other deciduous trees and shrubs are readily used, and even raspberry. The adults are suitably camouflaged to rest by day in the leaf litter, being various shades of fawn, dun or rufous brown. Click on the image to enlarge it.

	Barred Red Hylaea fasciaria June into September, peaking in August. Pinewoods. Although it feeds on pine, Barred Red is a relatively low-density species that not even the Forestry Commission regards as a pest. It is found wherever its foodplant occurs. Despite the long flight period, probably there is only a single extended brood in our area. Since pine is evergreen, caterpillars can feed slowly through the winter, maturing at different times. The colour of adults varies, some tending towards brown or grey rather than red. They can occasionally be found at rest low down trunks or on the surrounding vegetation; otherwise they are mostly seen at light. Click on the image to enlarge it.