Genetic structure of island and mainland populations of a Neotropical bumble bee species

Author(s)

Francisco, Flavio O. ; Santiago, Leandro R. ; Mizusawa, Yuri M. ; Oldroyd, Benjamin P. ; Arias, Maria C.

• Document type: Journal article
• Source: JOURNAL OF INSECT CONSERVATION; v. 20, n. 3, p. 12-pg., 2016-06-01.

Abstract

As a consequence of founder effects, small population size and demographic constraints, island populations are often characterized by low genetic diversity and high inbreeding. The effects of inbreeding are more pronounced in haplo-diploid insects like bees than in similar diploid species, because their method of sex determination requires heterozygosity at a sex locus. Inbreeding leads to homozygosity at the sex locus and the production of non-viable diploid males. This means that island populations of bees are particularly prone to extinction. Here we determine the levels of diversity and isolation between islands and mainland populations of the bumble bee Bombus morio in southeast Brazil. We analyzed 659 individuals from 24 populations, sequencing two mitochondrial genes (COI and Cytb) and genotyping all individuals at 14 microsatellite loci. Surprisingly, genetic diversity was high and genetic isolation was low in all populations except Teodoro Sampaio (mainland) and Ilha da Vitria (island). Genetic diversity is not significantly correlated with island area, but is lower in populations that are more distant from the mainland. Except perhaps for Ilha da Vitria, we suggest that the island populations are unlikely to go extinct due to genetic factors. Finally, based on its genetic distance from all other populations, we identify a putative new subspecies in the Teodoro Sampaio region. (AU)

• FAPESP's process: 04/15801-0 - Biodiversity and sustainable use of pollinators, with emphasis on Meliponini bees
• Grantee: Vera Lucia Imperatriz-Fonseca
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
• FAPESP's process: 08/08546-4 - Genetic structure of island and mainland populations of bees from Atlantic Forest
• Grantee: Flávio de Oliveira Francisco
• Support Opportunities: Scholarships in Brazil - Doctorate