Awad Mohamed Awad

This study investigated the outgoing and pollen-gathering foraging activities of Apis mellifera jemenitica (AMJ) and Apis mellifera carnica (AMC) under a hot-arid environment in the presence of nectar-rich melliferous Ziziphus nummularia flora. The data revealed the differential effects of weather conditions and Z. nummularia flora on the foraging activities of the studied honey bee subspecies in the Rawdat-Khuraim oasis in central Saudi Arabia. Z. nummularia exhibited two flowering seasons, from June–July (season I) and August–October (season II), with a significantly higher mean flowering density observed during season II (404 flowers/m²) than during season I (235 flowers/m²). AMJ showed significantly higher foraging activities (outgoing and pollen-gathering) than AMC (exotic bees) during all months in each flowering season. The mean outgoing and pollen-gathering foraging rates of AMJ (32.40 ± 0.67 and 4.88 ± 0.40 workers/colony/min, respectively) were significantly higher than those of AMC (15.93 ± 1.20 and 2.39 ± 0.23 workers/colony/min, respectively). The outgoing and pollen-gathering foraging activities of the two subspecies fluctuated throughout the different times of day. Foraging activities were considerably high at sunrise (SR) and low at noon (N) during both flowering seasons. We also observed seasonal variations in the foraging activities of both bee subspecies. The mean foraging activities (outgoing and pollen-gathering) were slightly higher in season I (27.43 ± 1.21 and 4.46 ± 0.45 workers/colony/min, respectively) than in season II (21.71 ± 0.86 and 3.02 ± 0.22 workers/colony/min, respectively). The thermal window analysis revealed a significant difference between the flight activities (bees exiting and returning to the nest throughout the day) of AMJ and AMC; AMJ had a higher temperature threshold than AMC. The outgoing and pollen-gathering foraging activities within each bee subspecies were positively correlated. The present study can help researchers understand the performances of honeybees and the association of their performances with weather and nectar-rich flora conditions.

Phacelia tanacetifolia is a widely used food plant in the beekeeping and conservation of pollinators. The present work is the first report for its value as bees and insectary plants in Saudi Arabia. Insect species visiting on flowers of P. tanacetifolia were identified and clustered as pollinators, pests and natural enemies. Out of 54 recorded insect species, 26 species were from Hymenoptera followed by Diptera (eight species), Lepidoptera (eight species), Coleoptera (six species), Hemiptera (five species) and Neuroptera (one species). Hymenopterous insect (bees, wasps, and ants) were the abundant flower visitors and out of them, bees were at the top with the highest recorded species (18). Apis mellifera and Apis florea were the most common honey bee species visiting on P. tanacetifolia, and exhibited daytimes and flowering season-dependent foraging activity (visits/m²). Apis species showed preferential high foraging visits for nectar than pollen collection. The major flower visitor was A. florea and the time spent by A. florea in the flower was significantly higher than A. mellifera. Insect-pollinated flowers of P. tanacetifolia presented significantly high-seed set percentage (62%) than non-insect-pollinated flowers (14%). Nectar secretion of P. tanacetifolia fluctuated significantly during daytimes and months with the highest amount during noon-afternoon and March. Blooming period (six weeks: fore-March to mid-April), seed harvesting (late-April), flower density (9069 flowers/m²/day), nectar productivity (4 g/m²/day) and honey potentiality (1791 kg/ha/season) of P. tanacetifolia was also monitored. P. tanacetifolia can be an ideal potential plant to support honey bees and other insect pollinators in the hot-dry ecosystem of central Saudi Arabia.

Remote sensing (RS) and geographical information system (GIS) technology have seldom been used in apiculture. We applied these tools to map the optimum honey bee colony carrying capacity and estimate honey production during the honey flow of 'Talh' trees (Acacia gerrardii Benth. [Fabaceae: Mimosoideae]) in the Rawdat-Khuraim oasis, central Saudi Arabia . A SPOT 5 panchromatic image (2.5-m resolution) was used to delineate the distribution of Talh trees. ArcGIS was used in image processing and data management, analysis, and visualization. The outputs were maps of Talh distribution, an optimum spatiotemporal beekeeping plan, and predicted potential honey yield. Each Talh tree was predicted to produce a theoretical maximum of 8.5-kg Talh honey per season. Under the current nonoptimum distribution of apiaries, Rawdat-Khuraim produces 4,876-kg honey per season. Optimally, it should produce 9,619-kg honey per season from 1,278 colonies distributed in 12 beekeeping sites. This study provides a technical approach for the use of RS and GIS in describing, planning, and managing honey flows and predicting honey harvest through a spatiotemporal workflow.

Both climatic factors and bee forage characteristics affect the population size and productivity of honey bee colonies. To our knowledge, no scientific investigation has as yet considered the potential effect of nectar-rich bee forage exposed to drastic subtropical weather conditions on the performance of honey bee colonies. This study investigated the performance of the honey bee subspecies Apis mellifera jemenitica Ruttner (Yemeni) and Apis mellifera carnica Pollmann (Carniolan) in weather that was hot and dry and in an environment of nectar-rich flora. The brood production, food storage, bee population and honey yield of Yemeni (native) and Carniolan (imported) colonies on Talh trees (Acacia gerrardii Benth.), a nectar-rich, subtropical, and summer bee forage source in Central Arabia were evaluated. Owing to their structural and behavioral adaptations, the Yemeni bees constructed stronger (high population size) colonies than the Carniolan bees. Although both groups yielded similar amounts of Talh honey, the Yemeni bees consumed their stored honey rapidly if not timely harvested. A. m. jemenitica has a higher performance than A. m. carnica during extremely hot-dry conditions and A. gerrardii nectar-rich flow.

The nectar secretion of Ziziphus flowers was studied by removing and measuring the nectar every four hours, for two consecutive days, from 88 flowers of four trees (‘repeated sampling’). In another 120 flowers from the same trees, the accumulated sugar was measured at the end of the flowering stage. The mass of the nectar sugar was determined following the washing technique. The total amount of sugar per tree was calculated by multiplying the number of flowers per tree by the average mass of nectar sugar secreted per flower. The average mass of sugar produced per flower in repeated sampling was 0.79±0.54 mg/flower (range 0.09 - 2.48 mg). The average mass of sugar per flower for each of the four investigated trees was 1.43±0.53 mg, 0.72±0.27 mg, 0.94±0.39 mg and 0.37±0.26 mg, respectively. The differences among trees was statistically significant. For accumulated nectar, the overall average mass of sugar per flower was 0.55±0.23 mg (range 0.06 - 1.29 mg) and the average values for flowers on the investigated trees of Z. spina-christi were 0.69±0.26 mg, 0.41±0.16 mg, 0.51±0.16 mg and 0.53±0.21 mg; these variations were statistically significant. The average mass of nectar sugar calculated for the flowers with accumulated nectar sampling was significantly lower than the average mass of sugar recorded for repeated nectar sugar samplings (0.79±0.54 mg). According to this study, one Ziziphus tree is estimated to produce 3.6 kg of honey (range 2.2 - 5.2 kg), equivalent to about 900 kg of honey/ha (range 550 - 1300 kg). These figures indicate the high potential value of the plant for honey production. Nectar secretion was positively correlated with temperature, indicating the adaptation of the tree to hot climates.