Creosote gall midge

Creosote gall midge
Gall created by Asphondylia auripila
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Cecidomyiidae
Subfamily:	Cecidomyiinae
Supertribe:	Asphondyliidi
Tribe:	Asphondyliini
Genus:	Asphondylia
Species:	A. auripila
Binomial name
Asphondylia auripila

The Asphondylia auripila group (Diptera: Cecidomyiidae) consists of 15 closely related species of gall-inducing flies which inhabit creosote bush (Zygophyllaceae: Larrea tridentata). They have partitioned the plant ecologically with different gall midge species inhabiting the leaves, stems, buds, and flowers of creosote bush. Each species induces a uniquely shaped gall but the insects are otherwise morphologically very similar and very difficult to tell apart. Their life cycle begins when the female oviposits into the part of the plant which her species prefers, she inserts her egg along with a fungal spore from a mycangia (a small pocket to store fungal spores). A gall forms and the fungal mycelium grows to line the inside of the gall, when the egg hatches the developing larva feeds upon the fungus. Adult emergence is timed with periods of plant growth associated with winter, spring, or summer rain fall. In contrast to many other groups of plant-feeding insects (which form new species through changes to new host plants) the evolution of new species in the A. auripila group seems to be a result of colonizing new parts of the same plant and/or colonization of new seasons of plant growth.

List of species by host-plant part:

Asphondylia clavata -leaf gall
Asphondylia pilosa - leaf gall
Asphondylia villosa - leaf gall
Asphondylia barbata - leaf gall
Asphondylia digitata - leaf gall
Asphondylia discalis - leaf gall
Asphondylia silicula - leaf gall
Asphondylia fabalis - leaf gall
Asphondylia bullata - stem gall
Asphondylia resinosa - stem gall
Asphondylia foliosa - stem gall
Asphondylia auripila - stem gall
Asphondylia rosetta - stem gall
Asphondylia florea - flower gall
Asphondylia apicata - bud gall
Asphondylia borrichiae - stem gall

References

^{[1] [2]}

1. Gagne, R.J, and Waring, G. 1990. The Asphondylia (Cecidomyiidae: Diptera) of creosote bush (Larrea tridentata) in North America. Proc. Entomol. Soc. Wash. 92:649–671.
2. Joy, J.B. and Crespi, B.J. 2007. Adaptive radiation of gall-inducing insects within a single host-plant species. Evolution 61(4):784-795.