Abundance Of Visitors Research Articles

Floral structures affect on pollination events of sandalwood in four landraces along landscape gradients in Gunung Sewu, Java, Indonesia

Sandalwood, one of the most economic-endangered species, was the origin to the south-eastern islands of Indonesia, but is recently existed as new landraces in several community forests in Gunung Sewu Geopark, Indonesia. All of landraces consisted of three floral variants (YBF, refers to “yellow big flower”; RBF, “red big flower”; and RSF, “red small flower”, respectively). Our previous findings reported differences on floral structures among variants. In this study we further analyzed these variants differences and its consequence on pollination events, among four landraces represented each geographical zone in Gunung Sewu Geopark, in the 2016 flowering periods. The flowering traits of each variant and landrace were measured. Floral visitors diversity, visitation rate and pollination behaviour were observed in each of population and floral variants. Results showed that flower abundance, visitor diversity and visitor abundance varied with sites but were similar among floral variants. Flowers abundance was strongly correlated to the pollinator visitation rate. Visitors diversity varied with sites due to the differences on flower abundance, environmental condition and altitude. The cooler and wetter site was visited more by Dipterans and Hymenopterans. The warmer, drier and lower sites were visited more by Lepidopterans and Dipterans. Sites with fewer flowers received less visitor diversity and abundance. Visitors preference to a given floral variant might be attributed to the differences on floral structures, sizes and colors. Lepidopterans belong to the moth groups (Arctiidae, Hesperiidae and Noctuiidae) preferred to visit the yellow flowers of YBF variant, while those belong to the butterflies groups (Papillionidae, Nymphalidae and Pieridae) preferred the red flowers of RBF and RSF. All six families of Hymenopterans preferred to visit the red flowers with bigger size, RBF. In contrast, all four families of Coleopterans, as well as the four families of Hemipterans, preferred the yellow flowers of YBF. All four families of Dipterans made similar visits to both RBF and YBF which have bigger flowers, while the visitation was less in RSF.

Plant size influences abundance of floral visitors and biomass allocation for the cushion plant Thylacospermum caespitosum under an extreme alpine environment.

Variation in size may influence the abundance of visitors and reproductive allocation for cushion plants in the extreme alpine environments. To assess effects of plant size on the abundance of main visitors and reproductive allocation in Thylacospermum caespitosum populations at two altitudes, the abundance of the visitors, visiting frequency, total number of flowers, number of fruits, number of unseeded flowers, and reproductive allocation were investigated during the period of reproductive growth. Concurrently, the effects of plant size on the visitors' contributions to fruit setting rate were assessed by a bagging experiment. Our results showed that flies (Musca domestica and Dasyphora asiatica) were the main pollinating insects of T. caespitosum, and they could obvious facilitate (p < 0.05) the fruit setting rate of this cushion plant. Seed set and floral visitation were significantly influenced (p < 0.001) by plant size. Moreover, the reproductive allocation and fruit setting rate of T. caespitosum was influenced (p < 0.001) by plant size. More biomass was allocated to reproduction in plants of greater diameter. There is an increase in reproductive success (increases of fruit number with increase in plant size) in relation to plant size. In conclusion, the extent of M. domestica and D. asiatica to facilitate the fruit setting rate mainly depended on the size of T. caespitosum. Size‐dependent reproductive allocation occurred in T. caespitosum and was the chief factor affecting the contribution of flies to fruit setting rate. These traits reflect reproductive fitness of T. caespitosum related to plant size in extreme alpine environments.

Pollination by wild bees yields larger strawberries than pollination by honey bees

Abstract A diverse array of wild bee species may provide more effective pollination than the widely employed European honey bee (Apis mellifera L.). High species richness within crop pollinator assemblages has been linked to enhanced fruit and seed yields, but species richness is often confounded with abundance in studies of pollinator communities. We investigated the effects of bee diversity and species identity on pollen deposition and crop yield in the strawberry (Fragaria × ananassa) variety Jewel through a field experiment that independently manipulated the species richness and abundance of flower visitors. We used a new pollen deposition measurement technique to determine the pollen contribution of individual bees in an assemblage of flower visits. We compared the performance of wild bee species and managed honey bees, as pollinators of strawberry. We also calculated the influence of species richness, visit frequency and visitor identity on fruit mass, using the fruit that developed from each sampled flower. Species richness of flower visitors did not influence floral pollen loads or strawberry mass. Honey bees and wild bees deposited the same amount of pollen per visited flower. However, strawberries that developed from flowers visited by wild bees were heavier than flowers visited by honey bees. In addition, flowers visited by a combination of wild and honey bees produced strawberries that weighed less than flowers receiving purely WB visits. Synthesis and applications. Our findings show that honey bee pollination results in lower yields than wild bee pollination in a strawberry crop. Consequently, if managed honey bees in strawberry fields displace wild pollinators, growers may obtain suboptimal yields. Management efforts aimed at the maintenance or enhancement of wild pollinator populations may therefore be a cost‐effective way to increase both crop yield and biodiversity on strawberry farms.

Floral biology and pollination in Cucumis melo L., a tropical andromonoecious cucurbit

We studied floral biology and the role of flower visitors in fruit set of muskmelon (Cucumis melo L.). Muskmelon produced Staminate (hereafter ‘S’) and Hermaphrodite (hereafter ‘H’) flowers with a ratio of 18:1. Flowers opened around 40 days after planting and flowering continued for another 40 days. Longevity of both types of flowers was one day. Anthesis in S flowers was earlier (0545–0700 h) than that of H flowers (0700–0830 h). Anther dehiscence occurred 10–15 min after anthesis in both the flowers. The number of pollen grains in H flowers was significantly lower (2715 ± 143) than S flowers (4968 ± 398). Pollen viability and stigma receptivity was maximum between 1600 and 1800 h. The pollen tube of pollen grains from H flowers grew very slowly and never reached the ovary. There were two peaks in nectar production in a day (1000–1200 h and 1400–1800 h). Sixteen species of insects belonging to Hymenoptera (81.25%), Diptera (12.50%) and Lepidoptera (6.5%) visited muskmelon flowers. Major visitors were honeybees, Apis cerana F. and A. florea F. and both were efficient pollinators. Diversity and abundance of flower visitors positively correlated with floral abundance. In pollination exclusion experiments, no fruit set was observed in bagged, self-pollinated and the flowers artificially crossed only with other H pollen. But, those flowers hand pollinated with pollen from S flowers and ones that were allowed for open pollination set maximum fruits. The crop needs a minimum of 8–10 bee visits per flower to achieve the same level of pollination efficiency provided with natural/unrestrained visits.

The impact of spatio-temporal changes in flora attributes and pollen availability on insect visitors in Lamiaceae species

Abstract There is growing evidence that food, in particular pollen, limitation is the strongest factor in pollinator decline. We have considered the potential effects of diversity in plant-community attributes as well as variations in the pollen and energy amount on the abundance and frequency of insect visitors to the Lamiaceae species Salvia pratensis L., S. verticillata L., Thymus serpyllum L., Betonica officinalis L. syn. Stachys officinalis (L.) Trevis., and Origanum vulgare L. The species were grown in two different habitat types (dry grassland vs. railway embankment) in the Lublin Upland, Poland. We found significant inter-species, inter-habitat, and inter-year disparities in the pollen mass and total energy amount per unit area. Canonical correspondence analysis (CCA) revealed that the blossom cover, species richness, and diversity noted at the plant community level significantly influenced the distribution of insect visitors to Lamiaceae species. The pollen caloric value and pollen abundance (but not the protein content in the pollen) had a considerable impact on the abundance and frequency of honeybees, bumblebees, and solitary bees in Lamiaceae flowers. Butterflies, beetles and flies did not respond to these factors. The model including all variables explained 66.4% of the observed variance. The studied Lamiaceae species, due to abundant flowering and good pollen nutritional value should be considered in the protocols to improve food resources, especially for social bees; however, disparities in pollen quantity and energy amount should not be ignored.

Pesticides affect pollinator abundance and productivity of sunflower (Helianthus annuus L.)

Pollination is considered one of the prime ecosystem services on the planet and is performed mainly by bees. The indiscriminate use of agricultural pesticides for pest control was evinced as one of the foremost causes of these pollinator declines. Sunflower crops demand an intense use of pesticides and, at the same time, are highly dependent on cross-pollination, essentially mediated by bees, for an increase in seed production. This study aimed to evaluate the impact of pesticides on richness and abundance of pollinators and productivity enhancement in sunflower. The study was carried out at the Água Limpa Experimental Farm located in the municipality of Uberlandia, Minas Gerais, Brazil, from May to August 2015. We conducted the study in two experimental crops of sunflower (Helianthus annuus L.). In one of them, we used the agricultural defensive bis(dithiocarbamate) for pest control, while in the other we only used a mechanical method. In both experimental crops, we quantified floral visitors during eight days, from 8 am to 4 pm. After maturation of inflorescences, we determined the mass of achenes and percentage of seed oil extracted. The abundance of floral visitors, the mass of fruits, and quantity of oil in the seeds were significantly lower after treatment with the pesticide, thus evidencing its negative effect on the sunflower productivity.

Distance Effects on Diversity and Abundance of the Flower Visitors ofOcimum kilimandscharicumin the Kakamega Forest Ecosystem

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ ofOcimum kilimandscharicumin Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates thatOcimum kilimandscharicumflower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.

Intensification of Ethiopian coffee agroforestry drives impoverishment of the Arabica coffee flower visiting bee and fly communities

Intensively managed shade coffee plantations are expanding in SW Ethiopia, at the cost of the more natural coffee agroforestry systems. Here, we investigated consequences for the potential pollinator community of Arabica coffee (Coffea arabica L.) in its natural range. We surveyed coffee flower visitors at six different sites in the Jimma region in SW Ethiopia, and compared species richness and abundance between semi-natural coffee forests and shaded coffee plantations. Overall, we found six bee (Hymenoptera: Anthophila) and twenty fly species (Diptera: Brachycera) visiting C. arabica flowers. Species richness and overall abundance of flower visitors was significantly higher in the semi-natural forests compared to the plantations. A significantly higher abundance of non-Apis bees and hoverflies (Syrphidae) visiting C. arabica flowers was observed in the semi-natural forest plots, but numbers for other Diptera and honeybees (Apis mellifera L.) did not differ significantly between the agroforestry systems. Our results show an impoverishment of the coffee flower visiting insect community in response to agricultural intensification. This suggests a functional shift of the coffee pollinator community and, hence, may influence the stability of the provided pollination ecosystem services and coffee yield in the long term. We did, however, not quantify pollination services in this study.

Abundance of eggplant (Solanum melongena L.) flower visitors in Lalitpur, Nepal

In order to determine the abundance of insect flower visitors in growing crop of eggplant, Solanum melongena L., a field experiment was conducted in Khumaltar, Laliptur during summer-rainy season of 2012 to 2014. The insect flower visitors were monitored weekly by end-to-end walk method using sweep net at different time of the day, viz. 7-8 am, 12-1 pm and 4-5 pm. Then collected insects were identified using the reference insects/books available in Insect Museum of Entomology Division, NARC, Khumaltar. This study revealed that Hymenopteran were found to be the most dominant (90.75%) flower visitors; followed by Lepidopteran insects (9.25%). Among the identified insect species, Bombus sp. (60.22%) was the most frequently collected bees as flower visitor of eggplant followed by Apis mellifera L., A. cerana F., Syntomis sp. in all three years of field study. Other flower visitors, such as Anthophora sp., Andrena sp. and Halictus sp. were also found visiting the eggplant flower but their occurrence was minimal. Significantly (p&lt;0.05) higher number of insects visited the eggplant flowers at 7-8 am (58.48%) followed by those visiting during 4-5 pm (28.97%) and 12-1 pm (12.54%), respectively. For adequate pollination and healthy production of eggplant, conservation and utilization of flower visitors and their role in pollination is imperative. Journal of the Institute of Agriculture and Animal Science. Vol. 33-34, 2015, page: 101-104

The Refugia Attract Arthropods in a Paddy Field in Malang, East Java, Indonesia

A study on the effect of refugia areas to attract on Arthropods has been done in a semi-organic paddy field in Malang, from March to June 2017. The arthropod was measured by abundance, diversity and composition variables. Arthropod observations were performed on 6 plots of 1 m 2 each, consisting of 3 plots on the side near the Refugia area (treatment) and 3 plots on the opposite side (control). The refugia areas consisted of plants as follows chili ( Capsicum frutescens ), the wild cosmos ( Cosmos caudatus ), the long beans ( Vigna unguiculata ), and Marigold ( Tagetes erecta ). The visual encounter surveys method was conducted for 15 minutes on each plot. There were 2249 individuals of Arthropod observed visually in the study sites. This study showed that of the abundance (mean ± SE) of Arthropod visitors was lower in plots adjacent to refugia areas (treatment) (33.7± 2.63), than that far from Refugia area (control) (38.33 ± 2.54); while the taxa richness and diversity was higher found in treatment plots. The species richness in the treatment plots (12.2 ± 0.70) was higher than that in control (9.70 ± 0.51). The diversity of Arthropod visitors in the treatment plots (2.10 ± 0.07) was also higher than that in control (1.71 ± 0.07). Proportion of predator in the treatment plots was almost twice higher (33.14) that in the control plots (17.65); while that of herbivore was vice versa. This meant the refugia areas have attracted more predators. The composition of Arthropod visitors was remarkable affected by treatment. The abundance of common predator families such as Coccinellidae, Coenagrionidae and Oxyopidae were higher in treatment plots.

Availability of food resources for pollinators in three types of lowland meadows

The availability of floral resources is considered a key factor for the maintenance and conservation of pollinators. We compared the forage floral diversity of three types of lowland meadows (Molinia meadows, tall herb fringe meadows, and hay meadows) located in south eastern Poland. The total number of plant species was 125, including 84 species (67.2%) classified as plants visited by insects. The richness and diversity of forage flora differed between the types of meadow. The Molinia meadows and hay meadows were preferred by pollinators. However, different taxonomic groups of pollinators can respond to the variability and availability of floral resources in a different way. Molinia meadows are of particular importance for the abundance of Bombus spp., solitary bees, and flies. The RDA ordination model demonstrated that the floral community composition, plant species abundance, plant species richness, and floral attributes (size, shape, phenology) were all important for the abundance of insect visitors in the mosaic of meadows. The cluster analysis showed that most plant species were visited by similar groups of insects; however, their proportion differed considerably. Our results present arguments for inclusion of semi-natural meadows into conservation plans and for efforts of protection of highly effective floral resources aimed at maintenance of pollinators.

Insect Visitors of White Clover (Trifolium Repens L) and Their Relation With Environmental Variables in the Premises of Bhaktapur Multiple Campus, Nepal

White clover plant, Trifolium repens L. one of the important forage crop, entirely depends on insects for its pollination. The research aims to study diversity and relative abundance of insect visitors of white clover and their relation with environmental variables in open ground of Bhaktapur Multiple Campus. Quadrate sampling method was used to explore diversity of insect visitors. Observations of the insects were conducted at morning (09:00 AM to 10:00 AM), noon (12:00 PM to 01:00 PM) and afternoon (3 PM to 4 PM) each day during study period. There were 3472 individuals of insect collected that belong to 20 species in three orders: Hymenoptera (69%), Lepidoptera (27%) and Diptera (4%). Number of individuals of visitors were comparatively higher at noon (1426) than in morning (1256) and lower in afternoon (790 individuals). Number of species found in morning and noon were same (20 species) whereas number of species found in evening was less (16 species). Apis cerana and Lampides boeticus are the most dominant species belonging to orders Hymenoptera and Lepidoptera respectively. The relation of diversity with environmental variables was correlated by using Multivariate analysis test. The test showed significant effect of light intensity, humidity, temperature and the latter one was the most influential factor on the composition of species. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018 Page: 86-91

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.

Patterns of flower visitor abundance and fruit set in a highly intensified cereal cropping system in a Mediterranean landscape

In intensive agricultural landscapes, decreased pollinator numbers have often been attributed to the loss of natural habitats. However, several studies show that certain mass flowering crops, such as oilseed rape (OSR), can alter the pattern of pollinator abundance at a field and landscape level. These studies have focused mainly on bees; information about the effect of OSR crops on other taxa is missing. We evaluated the abundance of bees and other (non-bee) flower visitors, and the fruit set of insect-pollinated target plants (Raphanus sativus and Onobrychis viciifolia) on the margins of OSR and cereal fields in landscapes with varying densities of non-cropped habitats (landscape structure). The presence of OSR crops and wildflower resources in field margins had varying effects on the abundance of bees and non-bee flower visitors. Bee abundance was enhanced by OSR crops, but decreased in complex landscapes. On the other hand, the abundance of non-bee flower visitors depended on the landscape structure, particularly on the location of cereal fields. Despite the numerous and diverse communities of pollinators attracted by OSR crops and wildflower resources, fruit set was enhanced only for generalist insect-pollinated plant species, because competition processes for pollinators affect specialist plant species. We conclude that the incorporation of OSR crops and maintenance of wildflower resources in agri-environmental schemes should be considered to improve the pollination services in agricultural landscapes highly dominated by cereal fields.

Insect Visitors to the Annual Plant Community in a Xeric Environment in Central Mexico

The interactions between the plant community and their floral visitors might vary through space, causing changes in the structure and composition of the communities of floral visitors. Although numerous studies have addressed the variation in the communities of floral visitors through space, none of them have analyzed how the structure of the community of floral visitors for all the co-flowering annual plant species changes between sites. We describe how the community of floral visitors to annual plants varies through space in a xeric community in central Mexico. We collected all the insects visiting the flowers of the annual plants growing in 2 sites with contrasting plant density (low vs. high). We determined species richness, abundance, and diversity for the insect communities in each site. We established the similarity in the composition of the insect communities and the importance of environmental variables on the dynamics of the communities of floral visitors. Abundance and diversity of floral visitors were significantly higher in the low plant density site. The composition of the insect communities differed between sites (similarity = 32%). Changes in abundance of a few groups of insects seem to be related to environmental factors such as disturbance (Myrmecocystus mexicanus Wesmael [Hymenoptera: Formicidae] and Tiphiidae sp. 1 [Hymenoptera]), humidity (Curculionidae sp. 1 [Coleoptera]), and temperature (Dorymyrmex grandulus (Forel) [Hymenoptera: Formicidae]). Our results indicate that vegetation density has a strong effect on the community of floral visitors of annual plants, which in turn, might affect their reproduction and their interactions with other organisms within the ecosystem. ResumenLas interacciones entre las comunidades vegetales y sus visitadores florales pueden variar en el espacio, ocasionando diferencias en la estructura y composicion de las comunidades de insectos visitadores. Aunque diversos estudios han analizado la variacion espacial en las comunidades de visitadores florales, ninguno ha estudiado dicha variacion en la estructura de la comunidad de visitadores florales de toda la comunidad de especies anuales coexistentes. En este estudio se describe la variacion espacial en la comunidad de visitadores florales de la comunidad de plantas anuales de una zona xerica en la region central de Mexico. Se colectaron los insectos que visitaban las flores de las especies anuales que crecian en 2 sitios con densidad vegetal contrastante (baja vs. alta). Se determino la riqueza especifica, la abundancia, y el indice de diversidad de la comunidad de insectos en cada sitio. Se estimo la similitud en la composicion de las comunidades de insectos asi como la importancia de variables ambientales sobre la dinamica de las comunidades de visitadores florales. La abundancia y la diversidad de visitadores florales fueron significativamente mayores en el sitio con baja densidad vegetal. La composicion de las comunidades de insectos fue distinta entre sitios (similitud = 32%). La abundancia de unos cuantos grupos de insectos parece responder a factores ambientales como el disturbio (Myrmecocystus mexicanus Wesmael [Hymenoptera: Formicidae] y Tiphiidae sp. 1 [Hymenoptera]), la humedad (Curculionidae sp. 1 [Coleoptera]), y la temperatura (Dorymyrmex grandulus (Forel) [Hymenoptera: Formicidae]). Los resultados sugieren que la densidad vegetal tiene fuertes efectos sobre la comunidad de visitadores florales de las plantas anuales, lo que a su vez puede afectar su reproduccion y las interacciones con otros organismos dentro del ecosistema.View this article in BioOne

Rush hours in flower visitors over a day–night cycle

Abstract Most research on pollination has focussed on a subset of insect taxa within a narrow time window during daylight hours. As a consequence, we have a limited understanding of the diversity and activity of flower visitors during the night or belonging to taxa other than bees or syrphid flies. Here, we quantified the abundance and species richness of flower visitors in ruderal meadows over repeated 24‐h cycles (i.e. day and night), and identified abiotic factors influencing these patterns. From the plant perspective, we investigated the likelihood of being visited by an insect across a 24‐h cycle. Activity of flower‐visiting insects never dropped to zero over 24‐h. During the day, non‐syrphid Diptera and Hymenoptera were the most abundant, and species‐rich groups of flower visitors, Lepidoptera and Coleoptera during night. While two of the seven most frequently visited plant species were most likely to be visited during the day, five also had a high likelihood to be visited during the night. The abundance and species richness of flower visitors was positively related to temperature during both the day and the night, whereas there was only a positive relationship with brightness during the day. We conclude that non‐syrphid Diptera and nocturnal flower visitors are currently underappreciated. As the latter seem to respond differently to abiotic factors compared to diurnal species, they may potentially increase response diversity and resilience of plant‐pollinator communities. There is an urgent need to improve our understanding of their ecological role and potential decline due to global change.

Pollination biology of Agave horrida (Agavaceae) in the Chichinautzin mountain range, in Central Mexico”

Background: the predictability of nectarivorous bats and their greater fecundity efficiency promote specialized pollination systems in columnar cactus in central Mexico. Some authors have suggested the same pollination pattern for Agave genus, and even when recent meta-analysis does not find such pattern, they have suggested this could be due to the lack of descriptive studies of pollination for this genus.&#x0D; Hypothesis: according to the chiropterophily syndrome of its flowers, the most efficient pollinator of Agave horrida will be nectarivorous bats leading to a pollination system with a specialist tendency in this agave species.&#x0D; Studied species: Agave horrida and floral visitors.&#x0D; Study site and years of study: lava field of the Chichinautzin mountain range, in Morelos State in Central Mexico in 2005.&#x0D; Methods: we studied the floral biology of A. horrida , its floral offer (density of flowers in a given area), visitor rate, and visitor abundance, and conducted exclusion experiments for diurnal and nocturnal visitors.&#x0D; Results: A. horrida has protandric flowers with chiropterophilous characteristics (larger nectar production at night and nocturnal anther dehiscence and stigma receptivity). Nectarivorous bats were the most frequent flower visitors and the guild that most frequently presented pollen on their bodies. Pollinator exclusion experiments show that both birds and bats can successfully pollinate A. horrida . Nevertheless, the predictability and abundance of the nectarivorous bat Leptonycteris nivalis , along with the greater fruit and seed production than birds, makes it the most efficient pollinator.&#x0D; Conclusions: our results support the hypothesis of a specialized pollination system towards nectarivorous bats in agaves in central Mexico.

Alien plants have greater impact than habitat fragmentation on native insect flower visitation networks

AbstractAimHabitat fragmentation and alien species are among the leading causes of biodiversity loss. In an attempt to reduce the impact of forestry on natural systems, networks of natural corridors and patches of natural habitat are often maintained within the afforested matrix, yet these can be subject to degradation by invasion of non‐native species. Both habitat fragmentation and alien invasive species disrupt the complex interaction networks typical of native communities. This study examines whether an invasive plant and/or the fragmented nature of the forestry landscape influences natural flower visitation networks (FVNs), flower–visitor abundance and richness or flower/visitor species composition.LocationThe species rich and diverse grasslands in the KwaZulu‐Natal Midlands, South Africa is under threat from transformation, particularly by commercial forestry plantations, restricting much of the remaining untransformed grasslands into remnant grassland patches (RGPs). Remaining patches are under additional threat from the invasive Rubus cuneifolius Pursh (bramble). Sites were established in RGPs and in a nearby protected area (PA), with and without brambles present for both areas.ResultsFlower abundance and flower area of native plant species were greater within RGP than in PA, but only in the absence of R. cuneifolius. Flower–visitor assemblages differed between invaded and uninvaded sites and also differed between PA and RGP sites. Both areas lost specialist flower–visitor species in the presence of brambles. Network modularity was greatly reduced by the presence of bramble, indicating a reduction in complexity and organization. The structure of FVNs was otherwise unaffected by presence of bramble or being located in RGPs or the PA.Main conclusionsThe RPGs contribute to regional biodiversity conservation through additional compositional diversity and intact FVNs. Rubus cuneifolius reduces ecological complexity of both RGPs and PAs, however, and its removal must be prioritized to conserve FVNs.

Relative abundance and movement of flower visitors within ‘Black Doris’ plum orchards in Hawke’s Bay, New Zealand

The Japanese plum ‘Black Doris’ (Prunus salicina) is a self-infertile early-flowering crop so insufficient cross pollination and lack of pollinators could be factors to explain reported poor fruit set. This project assessed the relative abundance of flower visitors within a plum orchard and their movements among three orchards, as part of a wider study on plum pollination. Insect surveys conducted over three days across one orchard in 2014 identified a total of 479 individual pollinators. Honey bees represented 94.6% of all pollinators observed. To assess pollinator movement across the crop, 140 individual flower visitors were followed over a five-day period in 2014 and again in 2015 across three orchards. Bumble bees moved further within the orchard and visited more trees per minute than foraging honey bees, while silvereyes visited more than twice as many flowers per minute than any other insect flower visitor.

Insect visitors to avocado flowers in the Bay of Plenty, New Zealand

Insect pollination is key to ensuring adequate fruit yields within avocado orchards. Various bee and non-bee insect species have been considered as potential pollinators of avocado worldwide, but in New Zealand there has been little research into which insect species visit avocado flowers. In the Bay of Plenty, an important avocado production area, flower visitor abundance and diversity data were obtained by conducting observational surveys in four orchards in November 2015. Honey bees were the dominant flower visitors in all orchards surveyed, representing 92.9% of all insects recorded, but there was high variation in numbers among sites. Other common insects observed included the beetle, Zorion guttigerum (3.4%), and bumblebees Bombus spp. (1.6%). A better understanding of the interaction between honey bee stocking rates and flower visitor abundances within orchards could assist in improving pollination recommendations.