21 research outputs found
Effect of temporal data aggregation on the perceived structure of a quantitative plant-floral visitor network
No full textSeasonal turnover in plant and floral visitor communities changes the structure of the network of interactions they are involved in. Despite the dynamic nature of plant–visitor networks, a usual procedure is to pool year-round interaction data into a single network which may result in a biased depiction of the real structure of the interaction network. The annual temporal dynamics and the effect of merging monthly data have previously been described for qualitative data (i.e. describing the occurrence of interactions) alone, while its quantitative aspect (i.e. the actual frequency with which interactions occur) remain little explored. For this, we built a set of 12 monthly networks describing year-round plant–floral visitor interactions in a 30-hectare planted forest and its adjacent agricultural landscape at Bahauddin Zakariya University Multan, Pakistan. A total of 80 plant and 162 insect species, which engaged in 1573 unique interactions, were recorded. Most network properties (particularly the number of plants, visitors and unique interactions) varied markedly during the year. Data aggregation showed that while animal species, plant species, unique interaction, weighted nestedness, interaction diversity and robustness increased, connectance and specialization decreased. The only metric which seemed relatively unaffected by data pooling was interaction evenness. In general, quantitative metrics were relatively less affected by temporal data aggregation than qualitative ones. Avoiding data aggregation not only gives a more realistic depiction of the dynamic nature of plant–visitor community networks, but also avoids biasing network metrics and, consequently, their expected response to disturbances such as the loss of species.Fil: Sajjad, Asif. The Islamia University Of Bahawalpur; PakistánFil: Saeed, Shafqat. Muhammad Nawaz Shareef University Of Agriculture; PakistánFil: Ali, Mudssar. Muhammad Nawaz Shareef University Of Agriculture; PakistánFil: Khan, Fawad Zafar Ahmad. Muhammad Nawaz Shareef University Of Agriculture; PakistánFil: Kwon, Yong Jung. Kyungpook National University; Corea del SurFil: Devoto, Mariano. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Botánica General; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Yearlong association of Apis dorsata and Apis florea with flowering plants: planted forest vs. agricultural landscape
No full textThe yearlong association of two native honey bee species (Apis dorsata and A. florea) with 49 plant species was recorded in a planted forest and adjacent agricultural landscape at Multan, Pakistan. The study resulted in 588 interactions of A. dorsata with 40 plant species and 454 interactions of A. florea on 38 plant species. The most visited plants species by A. dorsata included Helianthus annuus, Citrus reticulata, Trifolium alexandrinum, Moringa oleifera and Calotropis procera, while the most visited plant species by A. florea included C. procera, Mangifera indica, T. alexandrinum, Coriandrum sativum and H. annuus. The peak abundance of bees and floral resources (i.e. number of plant species in flowering and abundance of floral units) was recorded during early March to late May followed by a gradual decline until December. Monthly abundance of both bee species was positively related to the floral resources, negatively related to relative humidity while it was not significantly related to temperature. The current study may serve as a baseline to track the degradation in ecosystem service of cross pollination and making new conservation strategies at local scale while future research should focus on tempo-spatial variations in foraging preferences, floral constancy and effect of foraging competition on crop pollination in different ecological regions of Pakistan.</jats:p
Effect of nitrophos fertilizer on pollinator dynamics and onion seed yield /
No full textThe yield of flowering crops depends on multiple factors, with pollination and the availability of nutrients being particularly crucial. However, fewer studies have explored the combined effects of nutrients and insect-mediated pollination on onions (Allium cepa L.). Here, we studied how different levels of insect pollination (0%, 25%, 50%, and 100%) and nitrophos fertilizer application (188, 375, and 750 kg/hectare) affect onion seed yield. We found that pollination benefits to yield were maximum at intermediate levels of nitrophos availability. A higher pollinator abundance was recorded at a high nitrophos level, followed by intermediate and low levels. Syrphid flies and honey bees were the most abundant insect pollinators. The abundance of honey bees was higher at a low nitrophos level, while syrphid flies were more abundant at a higher nitrophos level. Moreover, the umbel weight and seed number were higher at the intermediate fertilizer level. Also, single visits by insect pollinators were observed, and the highest umbel weight was found at the intermediate fertilizer level with a single visit from A. florea. This finding provides evidence that resource and pollination availability have interactive, nonlinear effects on seed production. Our results also support ecological intensification as a reliable strategy for sustainable agro-ecosystem management
In search of the best pollinators for canola (Brassica napus L.) production in Pakistan
No full textTo discover the pollinator community of canola (Brassica napus L.) and the best pollinators for canola production, an experiment was performed at the research farm of Bahauddin Zakariya University, Multan, Pakistan. The insect pollinator community was composed of 35 species in 3 orders and 14 families. Most of the bees (Hymenoptera) and a butterfly species (Lepidoptera) foraged for nectar, whereas all the flies (Diptera) foraged either for pollen or both nectar and pollen. Eight major pollinators were tested for their pollination efficiency. The nectar-robbing behavior of many species made it difficult to judge the efficiency of an insect on the basis of visitation rate and stay time; therefore, the amounts of pollen deposited and pollen harvested per visit were also measured. The single visit efficiency in terms of the number of seeds per pod revealed that Apis dorsata, A. florea, and Halictus sp. were superior for canola pollination, having Spears’ values of 1.62, 1.55 and 1.73, respectively. With the increase in the number of seeds per pod, seed weight per pod also increased, confirming the importance of these three pollinator species in canola production
Enhancing Alfalfa (Medicago sativa) Seed Yield: The Effect of Honey Bee (Apis mellifera) Supplementation and Efficiency of Other Pollinators
No full textAlfalfa (Medicago sativa) is an important fodder crop with 16–25% protein and 20–30% fibre content. It requires pollinators for seed development through a process known as “tripping”. Honey bees are preferred for their easy management and mass rearing to enhance pollination. In a field experiment, we tested three treatments: two honey bee colonies (moderately supplemented), three honey bee colonies (highly supplemented), and a control with no honey bee colonies. The colonies European honey bee, A. mellifera, were used, starting at the flowering stage. We assessed the abundance, foraging, and tripping behaviour of pollinators, as well as the number of seeds per pod, pod weight, and seed weight. Honey bees were the most abundant in supplemented plots, followed by solitary bees, with increased honey bee visitation in the second year. Megachile cephalotes, M. hera, and A. mellifera were the most efficient pollinators regarding seeds per pod and seed weight. The plot with two honey bee colonies had a higher seed yield than the one with three colonies. Conservation of these pollinators and the introduction of managed A. mellifera colonies can lead to sustainable alfalfa seed production. Our findings suggest that honey bee supplementation, along with conservation efforts for solitary bees, can enhance pollination and seed yield in alfalfa
Comparing the Efficacy of Single and Multiple Visits by Honey and Solitary Bees on Sunflower Seed Production
No full textSunflower (Helianthus annuus L.) is an important oil seed crop with a considerable acreage of cultivated hybrids in Pakistan. Sunflower crops depend on insect pollination for seed setting, as it attracts diverse pollinator fauna, mainly due to pollen and nectar availability. This study was conducted in the agricultural landscape of Multan, Pakistan, to evaluate the role of native and social bees in sunflower seed production. The abundance and diversity of pollinators were assessed. Effectiveness was tested regarding foraging behavior, including visitation rate, stay time, and seed set efficacy for single and multiple visits (5, 10, 15). Additionally, various reproductive success parameters were recorded: flower head (pseudanthium) diameter, flower head weight, seed weight/flower head, and number of seed/flower head. The results showed that the relative abundance of honey bees was the highest (77%) in both years, followed by solitary bees (17%), while syrphid flies were the least abundant (6%) on sunflower. Among honey bees, Apis mellifera and A. dorsata were the most abundant in both years, followed by the solitary bee Xylocopa sp. Furthermore, in single and multiple seed set efficacy (5 and 10 visits), the solitary bee Xylocopa sp. produced the maximum seeds, followed by A. mellifera. Higher seed production could be achieved with a focused conservation plan of solitary and managed bees on sunflower
Exploring the best native pollinators for pumpkin (Cucurbita pepo) production in
No full textAbstract.-Pollination in pumpkin (Cucrubita pepo) largely depends on activity of native insect pollinators, especially the bees. In order to explore the pollinator diversity and the best native pollinators for pumpkin production, an experiment was performed at the research farm of the Faculty of Agricultural Sciences and Technology, Bahauddin Zakariya University, Multan, Pakistan. The visitation frequency of the bees across staminate and pistillate flowers, pattern of diurnal and seasonal visitation, efficiency in harvesting and depositing pollen and resultant fruit set per single visit were evaluated. The insect pollinator community was composed of 18 species in 3 orders and 6 families. Nomia sp., Apis dorsata and Halictus sp. were among the most abundant (189, 399, 117 respectively) and efficient pollinators in terms of number of pollen grains harvested (3121.50±199.54, 2090.40±139.03, 798.45±109.39, respectively) and deposited (376.60±23.01, 204.15±20.63, 177.85±16.31, respectively). The single visit fruit set percentage also revealed Nomia sp. (36.66) as the best pollinator followed by the A. dorsata (23.33) and Halictus sp. (20.0). Conserving and enhancing these bee species may boost pumpkin production in Pakistan
Comparative Efficiency of Native Insect Pollinators in Reproductive Performance of <i>Medicago sativa</i> L. in Pakistan
No full textLucerne (Medicago sativa L.) is a cross-pollinated crop and requires entomophilous pollination for tripping of flowers and subsequent pod and seed set. To discover the best pollinators for lucerne seed production, a two-year field trial was carried out at the research farm of MNS University of Agriculture, Multan, Pakistan. Abundance and diversity of insect pollinators along with the foraging behavior were recorded in terms of tripping efficiency, stay time, visitation rate and pollen harvest. The single-visit efficiency of abundant insect pollinators was also evaluated in terms of number of seeds and seed weight per raceme along with germination percentage. Ten most abundant floral visitors (five solitary bee species, three honeybee species and two syrphid fly species) were tested for their pollination efficiency. Honeybees were most abundant in both the years followed by the solitary bees and syrphid flies. Single-visit efficacy in terms of number of pods per raceme, number of seeds per raceme, 1000 seed weight and germination percentage revealed Megachile cephalotes as the most efficient insect pollinator followed by Megachile hera and Amegilla sp. Future studies should investigate the biology and ecology of these bee species with special emphasis on their nesting behavior and seasonality
Nesting Biology and Ecology of a Resin Bee, Megachile cephalotes (Megachilidae: Hymenoptera)
No full textWe report the nesting biology and ecology of Megachile cephalotes Smith, 1853 for the first time in Pakistan. Wooden and bamboo trap nests were deployed at three different locations in Bahawalpur district, Pakistan, from January 2020 to May 2021. A total of 242 nests of M. cephalotes were occupied in all three locations with the maximum abundance in the Cholistan Institute of Desert Studies. Megachile cephalotes remained active from March to September (the spring and summer seasons). In a nest, females made 7–8 brood cells each having a length of 1.2–2.3 cm. Plant resin was used to construct cells and mud or animal dung to plug the nest entrance. A vestibular cell was also made between the outermost brood cell and the nest entrance that ranged from 1.4 to 2.5 cm in length. No intercalary cells were observed in the nests. The males took 65.3 days to become adults, while the females took 74.78 days. The sex ratio was significantly biased toward females in all three locations. Grewia asiatica was the predominant pollen grain species found in the brood cells. Megachile cephalotes were observed collecting resin from Acacia nilotica, Prosopis juliflora, and Moringa oleifera. Three cleptoparasites of this species were also recorded: Euaspis carbonaria, Coelioxys sp., and Anthrax sp. This study set up a background to encourage new studies on artificial nesting and provides tools for proper biodiversity management and conservation
Impact of Bee and Fly Pollination on Physical and Biochemical Properties of Strawberry Fruit
No full textImprovement in physical and biochemical properties of fruits through cross-pollination is a highly variable phenomenon. It mainly depends on the species of the pollinator and the nature of the crop being pollinated. It is therefore imperative to quantify the relative pollination effectiveness of an insect species for a certain crop species. In the present study, pollination effectiveness of two native bees (i.e., Apis dorsata and A. florea) and two syrphid flies (i.e., Eristalinus aeneus and Eupeodes corollae) were evaluated in terms of physical properties of strawberry fruits at Multan, Pakistan. The physical parameters of resultant fruits included length, pole, equator, fruit set ratio, number of days to reach market maturity, and shelf life. The biochemical properties of fruits resulted from open-pollinated plants (free insect visits) and caged plants (no insect visits) were also compared. The biochemical parameters included TSS (total soluble solids), TA (titratable acidity), vitamin C, and pH. Apis dorsata was the most abundant pollinator, followed by E. aeneus and E. corollae. Based on single-visit effectiveness, A. dorsata proved to be the most effective pollinator, in terms of physical properties, of strawberry fruit. Eristalinus aeneus outcrossed A. florea in terms of fruit set (%). The open-pollinated plants showed better physical and biochemical properties (26% higher TSS, 34% higher TA, but 25% lower pH value) in terms of fruits than the caged plants. Conservation of A. dorsata and E. aeneus can enhance physical and biochemical properties of strawberry fruits in the region
