Insect-pollinated Species Research Articles

Half a Century of Temperate Non-Forest Vegetation Changes: No Net Loss in Species Richness, but Considerable Shifts in Taxonomic and Functional Composition.

In recent decades, global change and local anthropogenic pressures have severely affected natural ecosystems and their biodiversity. Although disentangling the effects of these factors is difficult, they are reflected in changes in the functional composition of plant communities. We present a comprehensive, large-scale analysis of long-term changes in plant communities of various non-forest habitat types in the Czech Republic based on 1154 vegetation-plot time series from 53 resurvey studies comprising 3909 vegetation-plot records. We focused not only on taxonomic diversity but also on the functional characteristics of communities. Species richness of most habitat types increased over time, and taxonomic and functional community composition shifted significantly. Habitat specialists and threatened species became less represented in plant communities, indicating a decline in habitat quality. The spread of trees, shrubs, tall herbaceous plants, strong competitors, and nutrient-demanding species in all non-forest habitats, coupled with the decline of light-demanding species, suggests an effect of eutrophication and natural succession following the abandonment of traditional management. Moreover, we identified specific trends in certain habitats. In wetlands, springs, and mires, moisture-demanding species decreased, probably due to drainage, river regulations, and increasing drought resulting from climate change. Dry grasslands, ruderal, weed, sand, and shallow-soil vegetation became more mesic, and successional processes were most pronounced in these communities, suggesting a stronger effect of abandonment of traditional management and eutrophication. In alpine and subalpine vegetation, meadows and mesic pastures, and heathlands, insect-pollinated species declined, and the proportion of grasses increased. Overall, these functional changes provide deep insights into the underlying drivers and help conservationists take appropriate countermeasures.

Population trends of insect pollinators in a species-rich tropical rainforest: stable trends but contrasting patterns across taxa.

Recent reports of insect decline have raised concerns regarding population responses of ecologically important groups, such as insect pollinators. Additionally, how population trends vary across pollinator taxonomic groups and degree of specialization is unclear. Here, we analyse 14 years of abundance data (2009-2022) for 38 species of native insect pollinators, including a range of Coleoptera, Lepidoptera and Hymenoptera specialists and generalists from the tropical rainforest of Barro Colorado Island, Panama. We estimated population trends across taxonomic groups to determine whether specialist species with a narrower range of interacting mutualistic partners are experiencing steeper population declines under environmental change. We also examined the relationship between climate variables and pollinator abundance over time to determine whether differences in sensitivity to climate predict differences in population trends among pollinator species. Our analyses indicated that most pollinator populations were stable or increasing, with few species showing evidence of decline, regardless of their degree of specialization. Differences in climate sensitivity varied among pollinator species but were not associated with population trends, suggesting other environmental factors at play for tropical insect pollinators. These results highlight the need for long-term population data from diverse tropical taxa to better assess the environmental determinants of insect pollinator trends.

Molecular characterization and identification of insect pollinators of Valeriana jatamansi Jones from Shimla Hills, Western Himalaya, India

Valeriana jatamansi Jones a perennial medicinal herb belongs to the family Caprifoliaceae and highly pollinated by wild insect pollinators. In present investigation a total of 51 species of flower visitors were reported on V. jatamansi at altitude range of 1,927 to 2,850 m, in different localities of Shimla Hills, Western Himalaya. The collected insect pollinator species were taxonomically identified and 29 of them were olecularly characterized and identified using the cytochrome c oxidase subunit 1 (COI) sequence from mitochondrial DNA (mtDNA). BLAST analysis revealed 98 to 100 per cent similarity with the existing GenBank sequences. The average AT content was found to be significantly higher (69.8%) compared to the GC content (30.0%), indicating AT bias in all sequences. Phylogenetic analysis of 29 different species of insect ‘pollinator of V. jatamansi revealed two clades, one shows phylogenetic relationship between 28 species which belongs to four orders Diptera, Hymenoptera, Hemiptera and Lepidoptera and the other shows the one species which belongs to order Coleoptera. This study contributes to increasing the number of published accounts of NCBI and helps to accurately distinguish the pollinator fauna of Valeriana Jatamansi.

Synchronised monitoring of plant and insect diversity: a case study using automated Malaise traps and DNA-based methods.

The occurrence and distribution of insects and their possible associations with plant species are largely unknown in Germany and baseline data to monitor future trends are urgently needed. Using newly-designed automated Malaise trap multi-samplers, the occurrence of insect species and their potential associations with plants was monitored synchronously at two contrasting field sites in Germany: an urban botanical garden and a forest research station. Taxa were identified by metabarcoding of the insects and the plant traces present in the preservative ethanol of the Malaise trap samples. For comparison, a botanical survey was conducted in the vicinity of the traps. Across both sites, we identified a total of 1290 exact sequence variants (ESVs) assigned to Insecta, of which 205 are known to be pollinators. In the botanical garden, we detected the occurrence of 128 plant taxa, of which 41 also had one of their known insect pollinator species detected. Insect species richness was highest in May, mainly attributed to an increase in Diptera. These results present a case study of the applicability of automated sampling and DNA-based methods to monitor the timings of flowering and corresponding activity of plant-visiting insects.

Pollinator insects on sugar palm (Arenga pinnata Merr.) in South Sumatera, Indonesia

Sugar palm production depends heavily on pollinator insects, including some insects related to A. pinnata. This study aimed to identify pollinating insect species, distribution, and biodiversity in four South Sumatran regions. Sweep nets and yellow sticky traps placed around the flowers of sugar palms were used to catch insects once a week. The trap is set up once every 24 hours. In the Ogan Ilir region, pollinating insect species such as Epuraea aestiva, Mystrops costaricensis, Elaidobius sp., Gabrius sp., and Brachypepluis sp. have been found. Apis meliefera, Apis cerana, Poliba occidentalis, Papilio sp., and Drosophila are found in the Musi Banyuasin of Ogan Komering Ilir (OKI). Drosophila, Graphium agamemnon, Appias libythea, Pothantus lydia, Mycalesis perseus, Vespa affinis, Tetragonula laeviceps, Tabanus sp., Aedes albopictus, Neurothemis fluctuans, Ypthima baldus, Cupha erymanthis, and Apis cerana were found in Muara Enim. Additionally, Muara Enim had the highest pollinator population, while Ogan Ilir had the lowest. Observations showed that the yellow sticky trap technique operated more effectively than the sweep net. The community is anticipated to gain from research by learning more about pollinating insects connected to sugar palms, their role in the surrounding ecosystem, and the bioecology of sugar palms.

Exploring the effects of habitat management on grassland biodiversity: A case study from northern Serbia.

Grasslands represent a biodiversity hotspot in the European agricultural landscape, their restoration is necessary and offers a great opportunity to mitigate or halt harmful processes. These measures require a comprehensive knowledge of historical landscape changes, but also adequate management strategies. The required data was gathered from the sand grasslands of northern Serbia, as this habitat is of high conservation priority. This area also has a long history of different habitat management approaches (grazing and mowing versus unmanaged), which has been documented over of the last two decades. This dataset enabled us to quantify the effects of different measures across multiple taxa (plants, insect pollinators, and birds). We linked the gathered data on plants, pollinators, and birds with habitat management measures. Our results show that, at the taxon level, the adopted management strategies were beneficial for species richness, abundance, and composition, as the highest diversity of plant, insect pollinator, and bird species was found in managed areas. Thus, an innovative modelling approach was adopted in this work to identify and explain the effects of management practices on changes in habitat communities. The findings yielded can be used in the decision making as well as development of new management programmes. We thus posit that, when restoring and establishing particular communities, priority needs to be given to species with a broad ecological response. We recommend using the decision tree as a suitable machine learning model for this purpose.

Heat and desiccation tolerances predict bee abundance under climate change.

Climate change could pose an urgent threat to pollinators, with critical ecological and economic consequences. However, for most insect pollinator species, we lack the long-term data and mechanistic evidence that are necessary to identify climate-driven declines and predict future trends. Here we document 16 years of abundance patterns for a hyper-diverse bee assemblage1 in a warming and drying region2, link bee declines with experimentally determined heat and desiccation tolerances, and use climate sensitivity models to project bee communities into the future. Aridity strongly predicted bee abundance for 71% of 665 bee populations (species × ecosystem combinations). Bee taxa that best tolerated heat and desiccation increased the most over time. Models forecasted declines for 46% of species and predicted more homogeneous communities dominated by drought-tolerant taxa, even while total bee abundance may remain unchanged. Such community reordering could reduce pollination services, because diverse bee assemblages typically maximize pollination for plant communities3. Larger-bodied bees also dominated under intermediate to high aridity, identifying body size as a valuable trait for understanding how climate-driven shifts in bee communities influence pollination4. We provide evidence that climate change directly threatens bee diversity, indicating that bee conservation efforts should account for the stress of aridity on bee physiology.

From petals to seeds: Understanding the role of hymenopteran and dipteran pollinators in the reproductive success of onion (Allium cepa L.)

An experiment was conducted to assess the pollinator community of onion (Allium cepa L.) as well to find the pollinators contributing to a higher onion seed production. Fifteen insect pollinator species belonging to two orders and two families were found to be visiting onion flowers. The dwarf honeybee, Apis florea F. (Hymenoptera: Apidae) was most frequent pollinator among bees. The maximum visitation rate was recorded in the case of Eristalinus aeneus S. (Diptera: Syrphidae), while the maximum stay time was recorded for A. florea. For observing the pollination effectiveness, we used pollinator exclusive approach, and four pollination trials were maintained i.e., 100%, 50%, 25% and 0% pollination. Pollinator effectiveness was accessed in terms of yield parameters such as umbel weight, number of seed and seed weight. Compared to 0% pollination, plants with 100% and 50% pollination levels showed 44- and 19-times higher seed production in onion, respectively. Six major pollinators were tested for their pollination efficiency. The single visit efficiency in terms of the number of seeds showed that plants with A. florea pollination showed higher seed yield. There was an increase in the number of seeds and seed weight per umbel, proving that A. florea is an effective pollinator in onion production. Moreover, syrphid flies also contributed to the onion seed production, though they were less efficient pollinators.

Diversity and foraging activity of coffee insect pollinators in land near and far from the forest of North Sumatra, Indonesia

Abstract. Sinaga RR, Maryana N, Hidayat P. 2024. Diversity and foraging activity of coffee insect pollinators in land near and far from the forest of North Sumatra, Indonesia. Biodiversitas 25: 240-248. Coffee (Coffea spp.) is among the plant species that depend on insects to aid in its pollination process, where insect pollinators serve as intermediaries facilitating plant pollination. This study examined the diversity, abundance, and visiting activity of insect pollinators in coffee cultivation located in different areas, specifically those near the forest and those far from the forest in Simalungun District, North Sumatra. The study was carried out from September 2022 to February 2023 in six coffee cultivation sites spread across four sub-districts in Simalungun District, i.e., Silimakuta, Pematang Silimakuta, Purba, and Dolok Silau. The study's results revealed the presence of 16 species of insect pollinators in coffee cultivation near the forest and 13 species in those located far from the forest. The identified insect pollinators species were from Order Hymenoptera; Apis cerana, Lasioglossum sp., Dolichovespula norvegicoides, Diptera; Stomorhina discolor, Musca domestica, Bactrocera papayae, Nephrotoma flavescens, Episyrphus viridaureus, Oebalia sp., Coleoptera; Pachnaeus sp., Cantharis sp., Scarabaeidae sp 1., Maladera japonica, Lepidoptera; Agrotis segetum, Bradina diagonalis, and Nyctemera baulus. Notably, the abundance of coffee insect pollinators was more pronounced in close proximity to the forest compared to areas far from the forest. Regarding the visiting duration of these insects, S. discolor exhibited the longest visit duration of 76.46±1.19 seconds per flower, and the shortest duration in A. cerana was recorded at 8.35±0.23 seconds per flower.

Diversity, Abundance, and Foraging Behaviour of Insect Pollinators in Litchi (Litchi chinensis Sonn.) under Hot and Subhumid Conditions

Insect pollinators and flowering plants have a long‐standing, coevolutionary, mutualistic relationship. One such example is the litchi tree (Litchi chinensis Sonn.), a fruit crop that relies on insect pollination. Litchi flowers are hermaphroditic, but they cannot self‐pollinate due to self‐sterility, unlike self‐pollinating plants. Therefore, insect pollinators are crucial to successful fruit development. To understand the pollinator’s foraging behaviour and diversity associated with litchi under hot and subhumid conditions, the present study was conducted on the Shahi variety of litchi at the ICAR‐Research Complex for Eastern Region, Farming System Research Centre for Hill and Plateau, Ranchi (Jharkhand), India. During the flowering period, a total of 19 species of insect pollinators from the orders Hymenoptera, Diptera, Lepidoptera, and Coleoptera were observed visiting litchi inflorescences. Apis mellifera and Apis dorsata were the most dominant pollinator species. Each species displayed distinct characteristics in terms of abundance and diversity. Varied foraging speeds (stay times) were also noted, with A. dorsata (6.94 s) being the fastest and Musca domestica (2.88 s) being the slowest. Pollinator activity was highest in the eastern direction, between 8:00 a.m. and 10:00 a.m. Apis florea had the highest foraging rate (visitation rate) (14.02 flowers visited per minute), followed by Apis mellifera, while Episyrphus taeniops​ had the lowest. Apis species were identified as the most abundant and frequent visitors in litchi orchards.

Keanekaragaman Serangga Penyerbuk Pada Perkebunan Stroberi (Fragaria sp.) di Desa Tongkoh Kecamatan Dolat Raya Kabupaten Karo Sumatera Utara

Pollinating insects are insects that have an important role as intermediaries for pollinating plants by collecting pollen and nectar found in strawberry flowers (Fragaria sp.). This research was conducted to determine the types of pollinating insects and the diversity of pollinating insects. This research was conducted in Tongkoh Village, Dolat Raya Sub District, Karo District, North Sumatra. Intake of pollinating insects is done by observation method. The results of the study obtained 3 orders and 7 families as well as 11 types of pollinating insects with a total of 147 individuals. The most common type of insect found was Apis cerana. The diversity index of pollinating insects was moderate with an H' value of 2.15. This indicated that the diversity of pollinating insects at the study site was in a stable condition because there were no pollinating insect species that were too dominant.

Key tropical crops at risk from pollinator loss due to climate change and land use.

Insect pollinator biodiversity is changing rapidly, with potential consequences for the provision of crop pollination. However, the role of land use-climate interactions in pollinator biodiversity changes, as well as consequent economic effects via changes in crop pollination, remains poorly understood. We present a global assessment of the interactive effects of climate change and land use on pollinator abundance and richness and predictions of the risk to crop pollination from the inferred changes. Using a dataset containing 2673 sites and 3080 insect pollinator species, we show that the interactive combination of agriculture and climate change is associated with large reductions in insect pollinators. As a result, it is expected that the tropics will experience the greatest risk to crop production from pollinator losses. Localized risk is highest and predicted to increase most rapidly, in regions of sub-Saharan Africa, northern South America, and Southeast Asia. Via pollinator loss alone, climate change and agricultural land use could be a risk to human well-being.

Pollinator Insect Found in Coconut Tree in Banyuasin Regency, South Sumatera

Insect pollinators are insects that play an important role in maintaining the existence of a plant species through pollination and maintaining the genetic diversity of plants in the population maintaining the existence of a plant species through pollination and maintaining the genetic diversity of plants in the population. Pollinator insects generally come from the Hymenoptera order. The purpose of this study was to determine the types of pollinator insect species that dominate coconut plantations in the Banyuasin area of South Sumatra. Data were collected by field observation using the plant survey method. The survey was conducted through direct observation of coconut plants owned by coconut farmers in the Banyuasin area. Observations were made on coconut plants by observing pollinator insect species that associate with flowers on coconut plants. Insect pollinator species found in coconut plantations in the Banyuasin area include Vespa affilish, Apis mellifera, and Apis dorsata. The most dominant type of pollinator insect found in coconut plantations in the Banyuasin area is Apis dorsata with 201 individuals. So, the results show that the abundance of individuals is high but has a low diversity index.

Pollinator Insect Found in Coconut Tree in Banyuasin Regency, South Sumatera

Insect pollinators are insects that play an important role in maintaining the existence of a plant species through pollination and maintaining the genetic diversity of plants in the population maintaining the existence of a plant species through pollination and maintaining the genetic diversity of plants in the population. Pollinator insects generally come from the Hymenoptera order. The purpose of this study was to determine the types of pollinator insect species that dominate coconut plantations in the Banyuasin area of South Sumatra. Data were collected by field observation using the plant survey method. The survey was conducted through direct observation of coconut plants owned by coconut farmers in the Banyuasin area. Observations were made on coconut plants by observing pollinator insect species that associate with flowers on coconut plants. Insect pollinator species found in coconut plantations in the Banyuasin area include Vespa affilish, Apis mellifera, and Apis dorsata. The most dominant type of pollinator insect found in coconut plantations in the Banyuasin area is Apis dorsata with 201 individuals. So, the results show that the abundance of individuals is high but has a low diversity index.

Diversity of Insect Fauna Actively Engaged in the Pollination of the Leguminosae Crop Vigna unguiculata (L.) in Jaipur, Rajasthan, India

This study was conducted to find out the insect pollinators actively engaged in the pollination of Vigna unguiculata (L.), in and around Jaipur, Rajasthan, India. About 20 species of Insect pollinators, belonging form 2 orders (Hymenoptera, Diptera), 7 families (Apidae, Dolichopodidae, Megachilidae, Muscidae, Halictidae, Syrphidae, Vespidae) and 10 Tribes (Anthophorini, Apini, Chrysosomatini, Eristalini, Megachilini, Meliponini, Muscini, Nomiinae, Vespini, Xylocopini) were recorded on this crop. These have been classified as belonging to 7 families and 11 genera. The number of species in these genera are Amegilla friese (02), Apis linnaeus (03), Ceratina latreille (01), Chrysosoma guérin-méneville (01), Eristalis linnaeus (01 species), Megachile latreille (02), Musca linnaeus (01), Nomia latreille (01), Tetragonula moure (01), Vespa linnaeus (01), Xylocopa latreille (06). The values of various diversity indices like the Simpson index, Shannon index, and Simpson index of diversity (1-D) are calculated as 0.16552, 3.0861, and 0.83448, respectively, indicating a significant abundance in the research area. Margalef's index was calculated to determine the species richness, and it was found to be 2.9595. The collision-entropy is 20, 8.53, 5.99 (r= 0,1,2) and Effective Number of Species is 2.29, 2.21, 1.17 (r= 0,1,2).

The behavior of insect pollinators in a teak (Tectona grandis L. f.) clonal seed orchard with weedy understory in East Java

Teak is an insect-pollinated species, and seed production depends on pollinators. The objectives of this study were to determine potential pollinators of teak and their foraging behavior in obtaining alternate food sources as the basis for management recommendations. Four traps, i.e. Moczarsky-Winkler selector traps, sticky traps, yellow-pan traps, and manual traps (insect net), were put up among blooming inflorescences during the flowering period of March to May. Insects were collected and counted weekly and identified. The presence and location of the pollen on their bodies were observed. The time and duration of foraging behavior, the duration of a single visit, the number of visits in an hour, and the landing position when approaching the teak flower as well as the understory were also observed. The result showed Ceratina sp., and Braunsapis sp. (Apidae), Nomia sp. (Halictidae) were potential teak pollinators in the CSO in East Java. The insect foraging behavior supports the ability to deposit pollen onto the stigma. The presence of Mimosa pudica in the understory plays as an alternate food source for pollinators. Intensive weeding and trimming of old or dead branches should be less practiced to enhance pollinators’ populations and nesting sites.

Feasibility of Insect Identification Based on Spectral Fringes Produced by Clear Wings

Due to the growing awareness that insects' diversity and populations are in decline, there is an increased need for monitoring insects. Entomological lidars and photonic sensors can monitor and remotely identify flying insects based on their backscattered signal in terms of oscillations-, polarization-, and spectral content. The backscattered light from insects is predominantly oscillatory and derives from the wings. This part of the signal is also more coherent and co-polarized than the light reflected from the insect's abdomen. Clear membranes can display soap-bubble colors due to thin-film interference, a feature that can be associated with the thickness of the wing. A hyperspectral camera can capture these wing interference patterns with hundreds of spectral bands and accurately identify the wing thickness. Here we investigate whether the spectral fringes can provide complementary information to aid remote species identification. We demonstrate that we can extract wing thickness and modulation depth information from spectral fringes of 87 species of common insect pollinators in Skåne, Sweden. The modulation depth of a fringe provides information related to insect wing thickness homogeneity, wrinkledness, or anti-reflectance features. Our results show that examined species display distinct modulation and wing thickness, and therefore such features can be used to improve the specificity of species identification of photonics sensors.

The brown honeyeater (Lichmera indistincta) is an effective pollinator in Australian blueberry orchards

Abstract The brown honeyeater (Lichmera indistincta) is a common bird species in Australia and is a pollinator of many native plant species but there are no records demonstrating evidence of effective pollination by honeyeaters in commercial cropping systems. We observed L. indistincta visiting rabbiteye blueberry flowers at a commercial berry orchard on the Mid North Coast of New South Wales and evaluated their capacity to transfer pollen. We did this by bagging flowers to prevent visitation prior to anthesis; after anthesis, we unbagged the flowers and waited for L. indistincta visits. After a single visit, we collected the stigma and mounted it on a slide to evaluate stigmatic pollen load. We observed the birds visiting blueberry flowers and foraging on nectar. We also found that L. indistincta deposited similar amounts of pollen to other common insect pollinator species, such as honeybees and stingless bees. As the commercial berry orchard blocks are surrounded by diverse remnant vegetation, we hypothesize that the vegetation is likely providing habitat for these birds. Our results indicate that berry growers with management practices that protect and support remnant vegetation surrounding blueberry orchard blocks may benefit from higher blueberry pollination services by supporting diverse pollinators within fields.

Flower morphology as a predictor of pollination mode in a biotic to abiotic pollination continuum.

Wind pollination has evolved repeatedly in flowering plants, yet the identification of a wind pollination syndrome as a set of integrated floral traits can be elusive. Thalictrum (Ranunculaceae) comprises temperate perennial herbs that have transitioned repeatedly from insect to wind pollination while also exhibiting mixed pollination, providing an ideal system to test for evolutionary correlation between floral morphology and pollination mode in a biotic to abiotic continuum. Moreover, the lack of floral organ fusion across this genus allows testing for specialization to pollination vectors in the absence of this feature. We expanded phylogenetic sampling in the genus from a previous study using six chloroplast loci, which allowed us to test whether species cluster into distinct pollination syndromes based on floral morphology. We then used multivariate analyses on floral traits followed by ancestral state reconstruction of the emerging flower morphotypes and determined whether these traits are evolutionarily correlated under a Bayesian framework with Brownian motion. Floral traits fell into five distinct clusters, which were reduced to three after considering phylogenetic relatedness and were largely consistent with flower morphotypes and associated pollination vectors. Multivariate evolutionary analyses found a positive correlation between the lengths of floral reproductive structures (styles, stigmas, filaments and anthers). Shorter reproductive structures tracked insect-pollinated species and clades in the phylogeny, whereas longer structures tracked wind-pollinated ones, consistent with selective pressures exerted by biotic vs. abiotic pollination vectors, respectively. Although detectable suites of integrated floral traits across Thalictrum were correlated with wind or insect pollination at the extremes of the morphospace distribution, a presumed intermediate, mixed pollination mode morphospace was also detected. Thus, our data broadly support the existence of detectable flower morphotypes from convergent evolution underlying the evolution of pollination mode in Thalictrum, presumably via different paths from an ancestral mixed pollination state.

The impact of geography and climate on the population structure and local adaptation in a wild bee.

Deciphering processes that contribute to genetic differentiation and divergent selection of natural populations is useful for evaluating the adaptive potential and resilience of organisms faced with various anthropogenic stressors. Insect pollinator species, including wild bees, provide critical ecosystem services but are highly susceptible to biodiversity declines. Here, we use population genomics to infer the genetic structure and test for evidence of local adaptation in an economically important native pollinator, the small carpenter bee (Ceratina calcarata). Using genome-wide SNP data (n = 8302), collected from specimens across the species' entire distribution, we evaluated population differentiation and genetic diversity and identified putative signatures of selection in the context of geographic and environmental variation. Results of the analyses of principal component and Bayesian clustering were concordant with the presence of two to three genetic clusters, associated with landscape features and inferred phylogeography of the species. All populations examined in our study demonstrated a heterozygote deficit, along with significant levels of inbreeding. We identified 250 robust outlier SNPs, corresponding to 85 annotated genes with known functional relevance to thermoregulation, photoperiod, and responses to various abiotic and biotic stressors. Taken together, these data provide evidence for local adaptation in a wild bee and highlight genetic responses of native pollinators to landscape and climate features.