Stock composition of northern neotropical honey bees: mitotype and morphotype diversity in Mexico (Hymenoptera: Apidae)

International audienceAbstractThe stock of honey bees in the northern neotropics is likely a composite of European and African lineages, but the genetic makeup of most populations in this region has remained unstudied. We analyzed the genetic composition of honey bees across temperate and tropical regions of Mexico using mitochondrial and morphometric analyses. The results showed that honey bees from Mexico are descendent almost in similar proportion from matrilines of African and European origins. However, morphometrics indicate that most colonies are the result of extensive introgressive hybridization with Africanized bees. While large-scale displacement of European honey bees seems to have occurred in the tropical regions, higher frequencies of colonies with a mixed range of African-European markers were identified in the temperate areas. Our results suggest that the outcome of the hybridization between Africanized and European honey bees in Mexico has been significantly associated with climate

The effect of food reserves on the production of sexual offspring in the stingless bee Melipona beecheii (Apidae, Meliponini)

A long-term study on the production of sexual offspring in relation to food stores was conducted in the stingless bee Melipona beecheii. Firstly, the production of sexuals was followed during one year in 10 colonies kept under natural conditions. Of the brood produced, 22.9% were males, and of all female brood, 14.6% were queens. Secondly, we measured the effect of experimentally manipulating the amount of food stores. One set of colonies started with 1.5 kg of food reserves and were regularly fed with pollen and nectar while another set were subjected to reduced food reserves of 0.5 kg, and were not given any extra food. Throughout the study, colonies with no treatment had brood and adults of both sexes all year round with no evidence of their presence being linked to swarming. Colonies with reduced food stores produced fewer males (0.7%) and queens (10.5%) than untreated colonies or colonies with enlarged food stores. The production of sexuals in colonies with enlarged food stores (23.4% males, 13.5% queens) did not differ significantly from that under natural conditions. We conclude that in Melipona only colonies that have accumulated large food stores produce sexuals that contribute to the reproductive population. This may lead to marked differences in the amount of sexuals produced by different colonies, although at the population level sexuals may be present all year round.status: publishe

Caste ontogeny and the distribution of reproductive cells on the combs of Melipona beecheii (Apidae: Meliponini)

The duration of the development phases of workers, males and gynes was studied in Melipona beecheii, an economically important stingless bee species in southern Mexico. We also determined if gynes and male cells were distributed in clusters on the combs as in other Melipona where laying workers exist. The results showed that the total length of development for the workers was 52.72 ± 1.28 days. In the case of the gynes and males, it was 50.80 (± 1.52) and 53.43 (± 1.12) days, respectively. We found that clustering of male cells in M. beecheii was an uncommon occurrence. We suggest that the main factor explaining the reduced frequency of male cell clusters is that males are not worker-produced in this species, compared to other species of Melipona in which males are worker-produced. Factors related to pollen availability could determine the presence of clustered males in some colonies of this species

Seven new species of Lasioglossum (Dialictus) Robertson, 1902 (Hymenoptera: Halictidae: Halictini) from the Yucatán Peninsula, Mexico

Lasioglossum is a large genus of halictid bees with high species diversity in morphologically rather cryptic species groups. With more than 1900 described species, the taxonomy of the genus is complex and largely unresolved in many regions. For practical reasons, systematic reviews are restricted in scope either geographically or to particular species groups. In this study we focus on the subgenus Dialictus of the genus Lasioglossum from the Yucatán Peninsula in Mexico. In previous studies we identified members of the genus as important pollinators of cash crops in the region, and genetic analyses suggested the existence of seven molecular taxonomic units (mOTU). Based on additional morphological differences, we here describe these mOTUs as novel species, Lasioglossum (Dialictus) yucatanense Landaverde-González sp. nov., L. (D.) paxtoni Landaverde-González sp. nov., L. (D.) ameshoferi Landaverde-González sp. nov., L. (D.) aureoviride Landaverde-González & Husemann sp. nov., L. (D.) paralepidii Gardner sp. nov., L. (D.) milpa Landaverde-González sp. nov. and L. (D.) nanotegula Landaverde-González & Husemann sp. nov., and provide keys and images to assist in their identification

Data from: Sweat bees on hot chillies: provision of pollination services by native bees in traditional slash-and-burn agriculture in the Yucatán Peninsula of tropical Mexico

Traditional tropical agriculture often entails a form of slash-and-burn land management that may adversely affect ecosystem services such as pollination, which are required for successful crop yields. The Yucatán Peninsula of Mexico has a >4000 year history of traditional slash-and-burn agriculture, termed ‘milpa’. Hot ‘Habanero’ chilli is a major pollinator-dependent crop that nowadays is often grown in monoculture within the milpa system. We studied 37 local farmers’ chilli fields (sites) to evaluate the effects of landscape composition on bee communities. At 11 of these sites, we undertook experimental pollination treatments to quantify the pollination of chilli. We further explored the relationships between landscape composition, bee communities and pollination service provision to chilli. Bee species richness, particularly species of the family Apidae, was positively related to the amount of forest cover. Species diversity decreased with increasing proportion of crop land surrounding each sampling site. Sweat bees of the genus Lasioglossum were the most abundant bee taxon in chilli fields and, in contrast to other bee species, increased in abundance with the proportion of fallow land, gardens and pastures which are an integral part of the milpa system. There was an average pollination shortfall of 21% for chilli across all sites; yet the shortfall was unrelated to the proportion of land covered by crops. Rather, chilli pollination was positively related to the abundance of Lasioglossum bees, probably an important pollinator of chilli, as well indirectly to the proportion of fallow land, gardens and pastures that promote Lasioglossum abundance. Synthesis and applications. Current, low-intensity traditional slash-and-burn (milpa) agriculture provides Lasioglossum spp. pollinators for successful chilli production – fallow land, gardens and pasture therefore need to be valued as important habitats for these and related ground-nesting bee species. However, the negative impact of agriculture on total bee species diversity highlights how agricultural intensification is likely to reduce pollination services to crops, including chilli. Indeed, natural forest cover is vital in tropical Yucatán to maintain a rich assemblage of bee species and the provision of pollination services for diverse crops and wild flowers

Script for CCA analysis and visualization

File with the script for execute the CCA analysis and visualize the result

Species

abundance and identity of species for the CCA analysi