Blastobasis adustella belongs to the family Blastobasidae of which there are seven representatives in Britain.
A small moth with a 6-9mm wingspan(1). Dissection required for positive ID and even then apparently difficult. Marked as Most Likely Species based on appearance, distribution and abundance. It is single brooded and flies June-Oct (2).
It’s place in the Garden (Possible Resident)
Online sources and guides such as (2) below, suggest larva/caterpillars feed on a wide variety of vegetable matter including spongy galls, juniper and gorse seed pods. Within a silken gallery (2). Also in various decaying vegetable matter (1). Juniper and gorse are not present in the immediate locality, although Troopers Hill in Bristol (an acid grassland) does have an abundance of gorse and is only 1.5km away. In any case it’s abundance and wide-ranging distribution supports the view that it feeds on a wide variety of available plant matter.
Blastobasis adustella is a non-native that has successfully and swiftly invaded large parts of Britain. It is endemic to Australia, but along with other Blastobasidae species has spread from various locations around the globe, in particular the tropics and likely with the aid of man (shipping etc). As an adult predators of this species are likely the usual suspects, birds, bats as well as other invertebrates. The concealed larvae are seemingly well protected. Solitary wasps or parasitic invertebrates are the more likely threat.
How to encourage the species to your garden
Current distribution maps (2) suggest most locations in Britain are already populated by this species or one of its close relatives. It’s varying diet suggests it could well be a likely visitor to most gardens in Britain, if not an occasional resident providing it can find a regular larval food source in which to complete it’s life cycle.
Alternatively, you can lure moths to you by leaving a secure window open and a light on during the warmer months, or better still invest in a moth trap. Even if you don’t see this species, you may be visited by many other interesting species.
- UK Moths: Species Account Page. https://ukmoths.org.uk/species/blastobasis-adustella/– Accessed online 16th December 2022
- Sterling, P & Parsons, M (2012): Bloomsbury Wildlife Guides: Field Guide to the Micro moths of Great Britain and Ireland. Bloomsbury Publishing Ltd