Pestic. Phytomed. (Belgrade), 30(3), 2015, 161–168 UDC 581.162.3:595.7:574.3:631.559(620) DOI: 10.2298/PIF1503161K Original scientific paper Diversity of insect pollinators with reference to their impact on yield production of canola (Brassica napus L.) in Ismailia, Egypt Soliman M. Kamel1, Hatem M. Mahfouz2, Abd El-Fatah H. Blal2, Maysa Said2 and Mahmoud F. Mahmoud1* 1 Plant Protection Department, Faculty of Agriculture, Suez Canal University, 41522 Ismailia, Egypt 2 Plant Production Department, Faculty of Environmental Agricultural Sciences, Suez Canal University El-Arish, Egypt (*[email protected]) Received: May 14, 2015 Accepted: June 19, 2015 SUMMARY A study of insect pollinators and their impact on canola yield was conducted during the 2013/2014 and 2014/2015 growing seasons. The study was carried out at an experimental farm, Faculty of Agriculture, Suez Canal University, Ismailia. The results revealed that 21 species of insect pollinators belonging to 14 families under four orders visited canola flowers. The abundance of Hymenoptera insects reached the maximum of 67.90%, followed by Diptera 14.97%, Coleoptera 13.61%, then Lepidoptera 2.26% as average of both seasons. In open pollination, Colletes lacunatus had the maximum percent abundance in the two seasons (30.45 and 29.34%, respectively) followed by Apis mellifera (12.34 and 17.73%, respectively), compared to other bees and different pollinators. Peaks of foraging activity of both C. lacunatus and A. mellifera were mainly observed from 1:00 to 3:00 pm and they corresponded to the number of flowering plants. Open pollination increased the number of pods per plant, seeds per pod, weight of 1000 seeds, yield per plant, yield per feddan (1 fed = 0.42 ha) and seed germination, compared to non-open pollination. Keywords: Insect pollinators; Diversity; Canola; Yield; Egypt IntRoductIon has a bright future in contributing to a reduction in oil deficiency gap between production and consumption of Canola, Brassica napus L, belongs to the family edible oils, particularly as it could be successfully grown Brassicaceae and is cultivated in many parts of the world, during winter season on newly reclaimed land outside standing out as an excellent economic alternative to the old zone of the Nile valley and thus get around other human consumable oils and biodiesels (Miri, competition with other crops grown in the old area of 2007; Marjanović-Jeromela, 2008). In Egypt, canola cultivation (Sharaan et al., 2002). 161 Soliman M. Kamel et al. There are several insect pollinators visiting canola included four replicates. The replicates were distributed in Egypt, but the honeybee, Apis mellifera L. (Apidae: in a complete randomized block design. Hymenoptera), is the most abundant pollinator of its flowers (Sayed & Teilep, 2013; Mahmoud & Shebl, 2014). observation and identification Canola has entomophilous flowers capable of both self- of insect pollinators and cross-pollination. The out-crossing rate range is 12- 47% (Becker et al., 1992) depending on cultivar. The Plants were examined weekly during the flowering flower of B. napus has a generalized open structure that period for collection and identification of different insect almost every group of pollinating insects can feed from. pollinators. Three methods were used to collect insect The yellow color of the flower with shallow placement of pollinators from the canola plants. A sweep net measuring visible nectar mostly attracts bees, flies, and butterflies 40 cm in diameter was used to collect insects flying (Kunin, 1997). over the plots and pan traps containing 4% formalin Pollination of canola can have positive effects, such solution were used to trap insects walking on the floor in as shortening of the period of flowering and raceme addition to visual observation. Observation of pollinators production, acceleration of ripening, increase in seed visiting canola inflorescences was recorded whenever weight (Rosa et al., 2011; Bommarco et al., 2012), seed possible before specimens were collected and preserved oil content (Bommarco et al., 2012) and seed yield. for identification. The collected pollinators were killed Klein et al. (2007) highlighted the importance of insect in a killing bottle and transferred to the laboratory. pollination for the production of fruits and seeds. Large insects were pinned, labeled and preserved in a Besides contributing to the preservation of natural collection box. Smaller insects were mounted, labeled ecosystems, bee pollination is one of the main sources and preserved too. Insects were identified to species for improvement of crop productivity (Mahmoud, 2012). where possible by using published systematic keys and Thus honey bees, A. mellifera, are considered the most direct comparison with museum specimens housed at important flower visitors (Delaplane & Mayer, 2000) the Department of Plant Protection, Ismailia. and most efficient B. napus pollinators (Free, 1993; Sabbahi et al., 2005). Foraging activity of bees The objective of the current study was to investigate Experimental observation was done during four the diversity of insect pollinators on canola flowers, periods of the day: 9:00-11:00 am, 11:00 am-1:00 the foraging activity of some bees and impact of insect pm, 1:00-3:00 pm and 3:00-5:00 pm, starting from pollination on canola yield. initial flowering until flower withering. The number of pollinators visiting each square meter area were counted for five minutes in each period. Four spots of MAterial AnD MEthods 1 m2 area were selected randomly, and the number of A. mellifera and Colletes lacunatus Dours was counted for Experimental design five minutes by using electronic stopwatch, voice recorder and digital video camera. The data were then interpreted A field experiment was conducted at the experimental and analyzed to assess the most favourable period of the farm of the Faculty of Agriculture, Suez Canal day for bee species to visit canola inflorescences and the University, Ismailia, Egypt, during 2013-2014 and 2014- most dominant species in each day and at particular 2015 seasons. Canola, cv. Serw 4 (the most common times of day. cultivar grown in Ismailia region) was sown on 21 October 2013 and on 20 October 2014. The soil of the Effects of insect pollination on canola yield experimental site was sandy soil (86.21% sand, 10.5 % silt and 3.29 clay) with pH 8.02 and EC 0.44 dsm-1. Before flowering began, 100 canola plants were Plants were thinned to one plant per hill and 20 cm caged by insect screen to prevent pollinators’ access distance between hills insured a density of 27.000 plants/ to inflorescences, and 100 plants were exposed to fed. Recommended cultural and agronomic practices pollinators. Plants were harvested at the end of the were applied from sowing to harvest. No insecticide fruiting period. The number of pods per plant and was sprayed in or around the experimental fields. The seeds per pod were counted, and the weight of 1000 experimental area was divided into two treatment areas seeds, yield per plant, yield per fed and germination (open pollination and caged plants). Each treatment percentage recorded. 162 Pestic. Phytomed. (Belgrade), 30(3), 2015, 161–168 Statistical analysis followed by Coleoptera (four species) and Lepidoptera (three species). The abundance of Hymenoptera reached Data obtained in the present study were subjected the maximum of 66.39 and 65.41% (average 65.90%), to an analysis of variance (ANOVA) with the honestly and was followed by Diptera 16.83 and 18.07% (average significant difference value calculated as Tukey’s statistic 17.45%), Coleoptera 14.30 and 12.17% (average 13.23%), at P ≤ 0.05. (SAS Institute 2004). and Lepidoptera 3.02 and 4.23% (average 3.62%) throughout the 2013/2014 and 2014/2015 growing ResultS seasons, respectively (Figure 1). Out of Hymenoptera species, two species of inflorescence visiting insects Diversity and abundance of insect pollinators showed high abundance, i.e. C. lacunatus (30.45 and 28.97%), and A. mellifera (12.34 and 17.67%). All species A total number of 1853 and 2026 insect pollinators of Hymenoptera visitors were observed as both pollen and associated with Brassica napus were observed over the nectar foragers, whereas all Diptera and Lepidoptera species 2013/2014 and 2014/2015 growing seasons. They belonged were observed as nectar foragers and only accidentally to 21 species in 4 orders (Tables 1, 2 and 3). Among the four transferred pollen. The three species of Coleoptera were orders, Hymenoptera and Diptera shared the maximum casual visitors of canola inflorescences and were not number of species (eight and six species, respectively), participating in nectar or pollen foraging (Table 1). Table 1. Species of insect pollinators visiting canola inflorescences during 2013/2014 and 2014/2015 seasons Order Family Species Common name Forage source* Apidae Apis mellifera L. Honey bee P/N Andrena ovatula Kirby Sand bee P/N Warncke Sand bee P/N Andrenidae Andrena mariana Andrena savignyi Spinola Sand bee P/N Hymenoptera Andrena fuscosa Erichson Sand bee P/N Colletidae Colletes lacunatus Dours Plasterer bee P/N Megachilidae Osmia latreillei Spinola Mason bee P/N Halictidae Nomioides sp. Sweat bee P/N Nititulidae Glischrochilus guadrisignatus (Say) Four spotted sap beetle C Scarabaeidae (Scop.) Hairy rose beetle C Coleoptera Tropinata squalida L. Eleven spotted lady beetle C Coccinellidae Coccinella undecimpunctata Coccinella septempunctata L. Seven spotted lady beetle C Fabricius Hover fly N Syrphidae Syrphus corolla Eristalis sp. Hover fly N sp. Flesh fly N Diptera Sarcophagidae Sarcophaga Wohlfahrtia sp. Flesh fly N L. House fly N Muscidae Musca domestica Fannia canicularis L. Little house fly N Pieridae Pieris rapae (L.) Cabbage white butterfly N Lepidoptera Nymphalidae Danaus chrysippus (L.) Plain tiger N Lycaenidae Polyommatus baeticus (L.) Bean butterfly N N - Nectar forager; PN - Pollen and nectar forager; C - Casual forager 163 Soliman M. Kamel et al. Table 2.