Friday, 5 April 2013

Hypoponera ...


Hypoponera punctatissima (Roger, 1859), [Formicidae: Ponerinae], is a small brown ant with a functioning sting, a single substantial petiole (the body section connecting the alitrunk (mid-section) and gaster (the bulbous rear section) in hymenopterous insects) and a constriction between the first and second segments of the gaster. It is an underground species, where it lives and forages on small soil living arthropods. Only the alate gynes (the winged reproductive females of ants) are likely to be seen above ground.

The underground colonies can be polydomous (occupying and maintaining multiple nests) usually containing several queens, a few wingless worker-like males and around 200 workers. Its flight period is from May to September.

There is some dispute as to whether this should be treated as a native species because it is most often come across in greenhouses and other permanently heated buildings, though there is evidence for its presence 1600 years ago in northern Britain. Colonies have occasionally been discovered a long way from human habitation. It has been recorded outdoors from waste spoils warmed by fermentation or decay. It is a cosmopolitan species distributed throughout Europe, the tropics and sub-tropics. Isolated records have come from England, Wales and Ireland. At the time of writing it has not been recorded from Scotland.

Hypoponera schauinslandi (Emery, 1899) has rarely been recorded in Britain. It is a little smaller than punctatissima and can be separated in the gynes by measuring the head-width, head-length and scape length (the basal segment of the antenna). It has a tropical or sub-tropical origin and cannot survive outdoors in Britain. It has an unusual flight period of November to February which can act as a useful guide in its identification. H. schauinslandi was only recognised as present in Britain in 2000.

The alate gyne pictured above came from a small colony discovered living underground in a heated commercial premises in Worthing, West Sussex on 13th January 2012. The original colony, discovered in December 2004, was originally identified as H. punctatissima. My thanks to Mike Fox, Ant Record Coordinator for the Bees, Wasps & Ants Recording Society (BWARS), for confirming correct identification as H. schauinslandi. On 2nd January 2013, another single winged female was recorded from the same location.

It is possible that this is only the fourth known substantiated record for the UK.

Image copyright OUMNH. Photomicrography by James Hogan, Hope Department of Entomology.

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