Insects associated with sesame (Sesamun indicum L.) and the impact of insect pollinators on crop production

Abstract

A survey of insects associated with sesame, Sesamun indicum L. (Pedaliaceae) was conducted at the Agriculture Research Farm of The Faculty of Agriculture, University of Suez Canal during the growing seasons 2010 and 2011. All different insect species found on the experimental site were collected for identification. Sampling was done once a week and three times a day. Three methods were used to collect insects from the sesame plants (a sweep net, pitfall traps, digital camera and eye observation). A total of 31 insect species were collected and properly identified during the survey. Insects recorded on the plants were divided into four groups, true pollinators (Hymenoptera), other pollinators (Diptera, Coleoptera and Lepidoptera), pests (Orthoptera, Odonata, Hemiptera and Homoptera) and natural enemies (Coleoptera, Hymenoptera, Neuroptera and Dictyoptera). For studying the impact of insect pollination on sesame production, the experiment was divided in two: opened and non-opened pollination of sesame. 50 plants from nonopened pollination were covered with a perforated paper bag to allow the air to pass through and to prevent insects from approaching the plants. Quantitative and qualitative parameters were measured as follows: pod weight, number of seeds in each pod, weight of 1000 seeds, germination (%), seedlings vigour and oil content (%). Results clearly demonstrate that the opened pollination improved the crop production.Istrazivanje faune insekata u proizvodnji susama, Sesamun indicum L. (Pedaliaceae) sprovedeno je na Istrazivackom poljoprivrednom dobru Poljoprivrednog fakulteta, Univerziteta Suecki kanal, tokom dve vegetacione sezone (2010 i 211). Sve primecene vrste sa eksperimentalnog lokaliteta su sakupljene za identifikaciju. Sakupljanje insekata sa biljaka susama je obavljano jednom nedeljno, tri puta dnevno, pomocu tri metode (kecer, lovne jame, observacija digitalnom kamerom i vizuelno pracenje). Ukupno je sakupljena i pravilno identifikovana 31 vrsta tokom ogleda. Insekti koji su registrovani i sakupljeni sa biljaka su podeljeni u cetiri grupe, i to: pravi polinatiori (Hymenoptera), ostali polinatori (Diptera, Coleoptera i Lepidoptera), stetocine (Orthoptera, Odonata, Hemiptera i Homoptera) i prirodni neprijatelji (Coleoptera, Hymenoptera, Neuroptera i Dictyoptera). Za ispitivanje uticaja nacina oprasivanja na proizvodnju susama, ogled je podeljen u dve celine: prirodno ?otvoreno? oprasivanje i ?ometano? oprasivanje. Pedeset biljaka u delu ogleda sa ?ometanim? oprasivanjem su pokrivene perforiranom papirnom vrecicom kako bi se omogucio protok vazduha, a sprecilo doletanje insekata. Kvantitativni i kvalitativni parametri su mereni, i to: tezina mahune, broj semena u mahuni, masa 1000 semena, klijavost (%), vitalnost klijanaca, sadrzaj ulja (%). Rezultati rada ukazuju da je ?otvoreno? oprasivanje poboljsalo proizvodnju susama.