Defining honeybee subspecies in an evolutionary context warrants strategized conservation

Despite the urgent need for conservation consideration,strategic action plans for the preservation of the Asian honeybee,Apis cerana Fabricius,1793,remain lacking.Both the convergent and divergent adaptations of this widespread insect have led to confusing phenotypical traits and inconsistent infraspecific taxonomy.Unclear subspecies boundaries pose a significant challenge to honeybee conservation efforts,as it is difficult to effectively prioritize conservation targets without a clear understanding of subspecies identities.Here,we investigated genome variations in 362 worker bees representing almost all populations of mainland A.cerana to understand how evolution has shaped its population structure.Whole-genome single nucleotide polymorphisms(SNPs)based on nuclear sequences revealed eight putative subspecies,with all seven peripheral subspecies exhibiting mutually exclusive monophyly and distinct genetic divergence from the widespread central subspecies.Our results demonstrated that most classic morphological traits,including body size,were related to the climatic variables of the local habitats and did not reflect the true evolutionary history of the organism.Thus,such morphological traits were not suitable for subspecific delineation.Conversely,wing vein characters showed relative independence to the environment and supported the subspecies boundaries inferred from nuclear genomes.Mitochondrial phylogeny further indicated that the present subspecies structure was a result of multiple waves of population divergence from a common ancestor.Based on our findings,we propose that criteria for subspecies delineation should be based on evolutionary independence,trait distinction,and geographic isolation.We formally defined and described eight subspecies of mainland A.cerana.Elucidation of the evolutionary history and subspecies boundaries enables a customized conservation strategy for both widespread and endemic honeybee conservation units,guiding colony introduction and breeding.

Insect Pollinator Diversity and Their Influence on Yield and Quality of <i>Capsicum annuum</i>Linné(Solanaceae), Machakos, Kenya

Capsicum annuum (L.) yields have remained low due to poor quality fruits in developing countries such as Kenya, which could be attributed to inadequate insect pollination among other factors. The present study was conducted after the short and long rain seasons in 2018 to assess the diversity and abundance of insect pollinators of C. annuum and to determine their influence on yield. The experiment was laid out in a Randomized Complete Block Design with bagged and un-bagged pollination treatments. Insect pollinator assessment was conducted between 07:00 hours to 21:00 hours for one month during each season. Yield and quality were compared between the pollination treatments. During the entire study 13 insect pollinator species (3 orders, 7 families) were recorded onC. annuum flowers. Apis mellifera was the most abundant insect pollinator during the two seasons. The highest species diversity was recorded after the long rain season (H' = 1.85). With respect to time, species richness was the highest in the afternoon after the short rains and the highest in the morning after the long rains. The average yield parameters from both seasons showed that open pollination treatments had increased fruit weight (66.5%), seed weight (54.5%) fruit length (28%) and fruit diameter (30%) when compared to treatments bagged throughout. Findings from this study have shown that insect pollinator diversity varies seasonally and significantly influences the yield and quality of C. annuum. This calls for the need to practice sustainable agriculture so as to conserve insect pollinators of C. annuum for improved vegetable production in semiarid lands of Kenya.

Survey of insect visitation of ornamental flowers in Southover Grange garden, Lewes, UK

Ornamental flowers commonly grown in ttrban gardens and parks can be of value to flower-visiting insects. However, there is huge variation in the number of insects attracted among plant varieties. In this study, we quantified the insect attractiveness of 79 varieties in full bloom being grown in a public urban garden that is popular due to its beautiful flowers and other attractions. The results showed very clearly that most varieties （77%, n = 61） were either poorly attractive or completely unattractive to insect flower visitors. Several varieties （19%, n = 15） were moderately attractive, but very few （4%, n = 3） were highly attractive. Closer examination of Dahlia varieties showed that ＂open＂ flowered forms were approximately 20 times more attractive than ＂closed＂ flowered forms. These results strongly suggest that there is a great potential for making urban parks and gardens considerably more bee- and insect-friendly by selecting appropriate varieties.

Insect pollinator dependence of shea (Vitellaria paradoxa C.F. Gaertn.) in the Guinea Savanna zone of Ghana

Shea(Vitellaria paradoxa C.F.Gaertn.)is a multipurpose tree species indigenous to the Sudano Sahelian zone of Africa and occurs as the most abundant economic tree species in northern Ghana.The edible oil(shea butter)extracted from shea kernel is ranked as the most economic product of the species.Although fruit set and yield of shea are known to be influenced by insect pollination,the actual contribution of insect pollinators to its reproductive success has rarely been studied.This study estimated the percentage insect pollinator dependence and monetary value of insect pollination per bag of shea kernel(85 kg)in the Guinea savanna zone.Open pollination and insect exclusion treatments were applied to the flowers of 18 randomly selected matured shea trees and observed from the onset of flowering to fruit maturity.Proportion of total production value attributed to insect pollination approach was used in estimating the monetary value of pollination per bag of shea kernel with the average market price as proxy.The study revealed an insect pollinator dependence of 77%and 73%for fruit set and dry kernel yield,respectively.Mean number of fruit set per inflorescence varied significantly between insectexcluded and open-pollinated inflorescences(p<0.05).The monetary value of insect pollination was estimated at GH₵73.21(US$18.67)per bag of kernel as of August 2016.Shea is a high insect pollinator–dependent species and the conservation of insect pollinators would be critical to the sustainability of yield.