First record of the carpenter bee Xylocopa pubescens (Hymenoptera, Apidae) in the Canary Islands confirmed by DNA barcoding

Island ecosystems are particularly vulnerable to the introduction of exotic species that can have an impact on local fauna and flora. Here, the carpenter bee Xylocopa pubescens is reported in Gran Canaria (Canary Islands, Spain) for the first time. This species is native to North Africa and the Near East and shows a rapid dispersion across the city of Las Palmas de Gran Canaria, together with a single record in the southernmost tip of the island. Different hypotheses about its arrival to the island are discussed.

Foraging activity of four bee species on sesame flowers during two successive seasons in Ismailia governorate, Egypt

Foraging activity of four bee species, Apis mellifera L., Osmia spp., Ceratina tarsata Morawitz and Xylocopa pubescens Spinola on sesame flowers was studied during two successive seasons of 2011 and 2012. Experimental observations were made during four periods of the day: 9:00-11:00 am, 11:00 am-1:00 pm, 1:00-3:00 pm and 3:00-5:00 pm, starting from initial flowering until the final session. Observation time was five minutes during each period and four bee species were observed visiting each square meter area. Five spots of 1 m2 area were selected randomly, and the number of different species of bees visiting was counted for five minutes by using electronic stopwatch, voice recorder and digital video camera. The results of the study indicated that the four bee species were most abundant on sesame flowers between 11:00 am and 1:00 pm, and between 1:00 and 3:00 pm. Among the bees, Apis mellifera was the predominant species, followed by Ceratina tarsata, in the season of 2011, while a reverse order of the two was recorded in 2012. The average time spent per flower was highly significantly different among these four species.

FLOWERING AND POLLINATION REQUIREMENTS IN CEREUS PERUVIANUS CULTIVATED IN ISRAEL

The flowering and pollination requirements of Cereus peruvianus (L) Mill. (Cactaceae) were investigated in Beer Sheva, Israel, in a three-year-old plantation which had been established from seedlings, in order to domesticate this plant as a fruit crop. Plants flowered during the hot season (May-October), and flowers opened for one night only. Variations were observed in the flowers' opening time, with the early-opening plants beginning to open two hours before sunset, and the late-opening plants opening close to sunset. Flowers were visited only by day-active insects: the honey bee (Apis mellifera) and the carpenter bee (Xylocopa pubescens). The visitors' behavior indicated that they were involved in pollination. Early-opening flowers were visited both in the evening and in the morning, whereas late-openers were visited only in the morning. C. peruvianus was found to be self-incompatible, and fruit set did not occur when flowers were hand self-pollinated. Hand cross-pollination resulted in very high fruit set (92%) and heavy fruits with a high seed number. Fruit set, seed number, and fruit weight were lower in open-pollination than in hand cross-pollination. This indicates limited pollination or fertilization in open- pollination and might be related to the briefness of the bee visits, reduced pollen germinability, and stigma receptivity during part of the visit period.