Reproductive ecology of two pioneer legumes in a coastal plain degraded by sand mining

ABSTRACT The present study evaluates and compares the phenology, pollination biology and breeding systems of Chamaecrista desvauxii (Collad.) Killip.and Clitoria laurifolia Poir. in a coastal plain degraded by sand mining in São Paulo State, Brazil, from January 2006 to May 2008. Flowering and fruiting events occurred in the warm and rainy season. Both species are self-compatible but only C. desvauxii was pollinator-dependent to set fruits. A small group of bees, comprising Eufrisea sp., Eulaema (Apeulaema) cingulata and Bombus morio, accessed the male and female floral structures and moved among individuals resulting in cross-pollinations. However, only B. morio was a frequent visitor and an effective pollinator. Although recruitment and survival of population in the study area are high for both species, we observed lower abundance and richness of visitors suggesting the possible lack of pollinators and pollen limitation.

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

Biodiversity loss is a global problem and island species/populations are particularly vulnerable to such loss. Low genetic diversity is one of the factors that can lead a population to extinction. Loss of bee populations is of particular concern because of the knock-on consequences for the pollination guilds that the lost bees once serviced. Here we evaluate the genetic structure of the bumble beeBombus moriopopulations on the mainland of South East Brazil and on nearby islands. We analyzed a total of 659 individuals from 24 populations by sequencing two mitochondrial genes (COI and Cytb) and using 14 microsatellite loci. Levels of diversity were high in most of populations and were similar on islands and the mainland. Furthermore, genetic diversity was not significantly correlated with island area, although it was lower in populations from distant islands. Our data suggest that long-term isolation on islands is not affecting the population viability of this species. This may be attributed to the high dispersal ability ofB. morio, its capacity to suvive in urban environments, and the characteristics of the studied islands.

Comunidade de abelhas (Hymenoptera, Apidae) e plantas associadas em área de mata atlântica em São Francisco do Sul, Santa Catarina, Brasil

A comunidade de abelhas nativas em uma área de mata atlântica no sul do Brasil foi estudada no período 2001-2003, utilizando-se rede entomológica em plantas floridas. Foram amostrados 1.519 indivíduos de 80 espécies e 4 subfamílias de abelhas. Houve predomínio de espécies de Apinae não corbiculadas e Halictinae e de indivíduos de Apinae corbiculados e Halictinae. As plantas associadas totalizaram 124 espécies de 46 famílias, das quais as mais visitadas foram Asteraceae, Fabaceae, Lamiaceae e Melastomataceae. Foram amostradas 11 espécies de abelhas não assinaladas para Santa Catarina. As abelhas mais amostradas foram Apis mellifera, Trigona spinipes, Bombus morio, Dialictus sp., Augochloropsis sp. 07, Trigona braueri, Augochlora (Oxystoglossella) sp. 05 e Tetragonisca angustula. A quantidade de indivíduos amostrados por mês, ao longo do período de coleta, evidencia um padrão bivoltino (maio e setembro-novembro). Algumas espécies de plantas foram visitadas apenas por Apis mellifera. Os índices de diversidade e equabilidade ficaram em 2,315 e 0,528, respectivamente. A curva de acumulação mostrou-se crescente. Os estimadores de riqueza apontam mais espécies. A riqueza e a abundância evidenciam um padrão de atividade de clima temperado. A composição da apifauna demonstrou maior similaridade com formação de floresta ombrófila densa de terras baixas.