Characterization of Indigenous Blastophaga psenes Fig Wasp Pollinator Populations, Timing of Adult Emergence and Cleptoparasitism, in Ficus carica in the Northwestern Region of Libya

Abstract

Inflorescences (syconia) of the caprifig trees Ficus carica were collected from six sites along an altitudinal gradient of 31-698 m in the northwestern region of Libya during 2014. Two species of fig wasps emerged from syconia; the fig pollinator wasp Blastophaga psenes L. (Hymenoptera, Agaónidae) which represented approximately 99% of wasps collected, and the cleptoparasitic wasp Philotrypesis caricae (L.) (Pteromalidae), collected from four sites and representing a first record in the region. Overall, 87.5% of syconia yielded at least one female B. psenes, with a range of 1-720 females emerging from these individual syconia. The lowest and highest mean number of B. psenes per syconium recorded for individual sites were 81 and 231, respectively; with the lowest number being recorded at the highest altitude site, although overall there was no relationship between altitude and number of wasps. Overall, pollinator wasps emerged from individual caprifig syconia over a maximum period of 27 days. Wasps emerged from each syconia over maximum period of 16 days; with about 34% emerged on the first day, 24% emerged on the 2^nd day and 15.4% on the 3^rd day. The short period of emergence may limit the value of older caprifig syconia sold in markets as a source of pollinators. Nonetheless, a field experiment showed that in 80% of fig syconia, pollination with the subsequent maturation of figs, could be achieved by a single B. psenes. This study provides a basis for comparison with other studies from the Mediterranean region and neighboring countries and a foundation for future research to improve pollinators management in Libyan fig orchards.

Keywords:

Caprifig, syconium, fig wasp, Blastophaga psenes L., Agaónidae, Philotrypesis caricae L., Pteromalidae.