TEMPERATURE-SENSITIVE DEVELOPMENT - CONSEQUENCES FOR LOCAL PERSISTENCE OF 2 SUBTROPICAL FIG WASP SPECIES

Larval development of the species-specific pollinators (Agaonidae, Hymenoptera) of the two native Florida fig species is markedly temperature-sensitive. Census data from a site near Miami indicate that Pegoscapus assuetus (the pollinator of Ficus citrifolia) and Pegoscapus jimenezi (the pollinator of Ficus aurea) take 7-8% longer to develop for each 1 C decrease in ambient temperature. However, development does not slow sufficiently to permit the wasps to remain within their sheltered larval habitat (the fig inflorescence) throughout winter, a season in which the short-lived adults have little chance of finding an oviposition site. The difficulty of wasp persistence through winter is probably a major factor limiting most fig-pollinator mutualisms to the tropics. The ability of a few species to persist at the northern limits of some subtropical regions, such as in S Florida, remains unexplained.