Nesting habits of Polyrhachis (Myrmatopa) flavicornis (Formicidae: Formicinae) in the lowland tropical rain forest of Peninsular Thailand

A study of the nesting habits of Polyrhachis (Myrmatopa) flavicornis Smith aimed to examine nesting sites, plants used for nests, nest material and colony composition of the nests in the lowland tropical rain forest of Peninsular Thailand. This study was conducted at twelve sampling sites as representatives of the lowland forest in four mountain ranges (Tenasserim, Phuket, Khao Luang and Khao Barithat) of Peninsular Thailand between March 2004 and July 2005. Nests of P.flavicornis Smith were found on the underside of plant leaves or between leaves. A total of 64 nests were measured for their size in height, width and depth, and included the number of entrances per nest. Various plant types and families were used for nesting sites both in the same and different localities. The most preferred plant type was shrub (43 nests, 32 colonies), followed by tree (15 nests, 14. colonies), climber (6 nests, 5 colonies) and herb (1 nest, 1 colony). Sixty-five nests (45 colonies) were found on plants of 17 families and the majority of plants were from the Euphorbiaceae (24 nests, 19 colonies), Rubiaceae (6 nests, 6 colonies) and Annonaceae (5 nests, 4 colonies). It was difficult to clearly distinguish between nests of P flavicornis Smith, with nests made of silk sheets covered with coarse and finely particulate material and other material such as plant tissue fragments, and the other arboreal nesting subgenera of Polyrhachis based only on nest characteristics. This study indicates that the polydomous P.flavicornis Smith with small colonies might obtain more advantages and have a wider distribution range in the lowland tropical rain forest of Peninsular Thailand because of their choice of nest site and materials.