B-3772 [1-6] Indian J. Anim. Res., AGRICULTURAL RESEARCH COMMUNICATION CENTRE Print ISSN:0367-6722 / Online ISSN:0976-0555 www.arccjournals.com/www.ijaronline.in Efficient pollinators of threatened taxa, Sarpagandha (Rauvolfia serpentina) under North Indian conditions Vadde Anoosha1, Sumit Saini* and H.D. Kaushik2 Department of Entomology CCS Haryana Agricultural University, Hisar-125 044, Haryana, India. Received: 22-12-2018 Accepted: 29-12-2018 DOI: 10.18805/ijar.B-3772 ABSTRACT An experiment was carried out to investigate the diversity, abundance and pollination efficiency of different insect visitors/ pollinators of Rauvolfia serpentina (Sarpagandha) during 2014 and 2015. This experiment was conducted at Medicinal Section, Department of G &PB, CCSHAU, Hisar. Sarpagandha flowers attracted wide varieties of insects belonging to 4 orders, 10 families, 16 genera and 17 species. Among them nine belongs to order Lepidoptera, one Coleoptera, two Diptera, and two Hymenoptera. Lepidopterans came out to be the most abundant pollinators of this crop. Peak abundance of major insect pollinators was recorded at 1000h-1200h while minimum abundance was recorded at 0600h -0800h. Amegilla zonata had the highest number of loose pollen grains, 23.50 (‘000), sticking to its body followed by Papilio demoleus and Pieris sp. Papilio demoleus was reported as most efficient pollinator followed by Amegilla zonata and Pieris sp. based on the pollination index. Long proboscis of lepidopterans i.e., Papilio demoleus and small sized hymenopterans i.e., Amegilla zonata plays key role in pollination of Sarpagandha. Conservation of these pollinators in natural ecosystem is must for pollination of these threatened taxa. Key words: Insect pollinators, Pollination efficiency, Pollen grains, Sarpagandha. INTRODUCTION attained a great importance as medicinal plant (Pullaiah, Pollination is one of the principal mechanisms in 2006). Roots and leaves of this plant contain several alkaloids the maintenance and conservation of biodiversity in general (Verma et al., 2010) out of those resperine is pharma- life of earth. Pollinators provide an ecosystem service that cologically most important (Blackwell, 1990). It has enables plants to produce fruits and seeds. Over 80 per cent lanceolate shaped pale green leaves in whorls of 3 to 5 leaves. of total pollination activities are performed by insects and It also has white and pink coloured flowers, having filiform bees (Klein et al., 2007). Around 30 percent of human food style and stigma is bifid having bilocular ovary with two is derived from bee pollinated crops (O’ Toole, 1993). ovules in each locule. The flowers of Sarpagandha have Pollinating insects are widely found in insect orders narrow and long tubular corolla. Such flowers make them a Coleoptera, Lepidoptera, Thysanoptera, Diptera and perfect representative of psychophilous pollination syndrome Hymenoptera (Singh and Garg, 2003). The structure of the negating all other syndromes (Wadhwa and Sihag, 2012). flowers, their degree of self-fertility and their arrangement Protogynous conditions of sarpagandha flowers need insect on the plant determines the extent to which a plant is pollinators for cross-pollination. Fruit is drupe, ovoid and dependent on insects for pollen transfer (Free, 1993; purplish black in color when it reaches maturity. Lot of Williams, 1994; Richards, 2001, Devi S et al., 2015). research work done on commercial crops as bee forage but Sarpagandha (Rauvolfia serpentina (Linn.) Benth., scanty information is available on underutilized medicinal ex Kurz.) is an evergreen shrub that belongs to the family plants. These plants also have important as medicinal crop Apocynaceae (Endress and Bruyns, 2000). Sarpagandha is and knowledge of their mode of pollination and pollinators a threatened species found in the sub-tropical regions. It is the need of the hour. They also serve as minor bee forage grows wild in India, Bangladesh, Sri Lanka, Myanmar, in the areas of scarcity. Keeping this idea in view, the present Thailand, Indonesia and Malaysia. Within India, it is grown study was undertaken to determine the efficient pollinators in almost all parts up to an altitude of about 1000 m above of sarpagandha. sea level. Five species of sarpagandha (viz., R. hookeri, R. MATERIALS AND METHODS micrantha, R. serpentina, R. tetraphylla and R. Verticillata) Pollination studies in sarpagandha were carried out have been recorded in India, of which R. Serpentina has at Research Farm, Department of Genetics and Plant *Corresponding author’s e-mail: [email protected] 1MPRNL, LBS Building IARI, New Delhi. 2CCS HAU, Hisar. 2 INDIAN JOURNAL OF ANIMAL RESEARCH breeding, CCS Haryana Agricultural University, Hisar, India RESULTS AND DISCUSSION during 2014 and 2015. Diversity of insect visitors/ pollinators: Sarpagandha flowers (Fig 1) attracted 17 species of insects. Out of these, Diversity of insect pollinators: Hand net with 30 cm ring Lepidopterans were the major floral visitors comprising from diameter was used to collect insects visiting the flowers three families viz., Papilionidae (Papilio demoleus and throughout blooming period (Anoosha et al., 2016, 2018a, Papilio polytes), (Fig 2) Pieridae (Eurema hecabe, Pieris 2018b). Captured insects were preserved as dry specimens sp., Anaphaeis sp., Pieris canidia, Belenois aurota, Pieris and were got identified from Division of Entomology, IARI, brassicae and Colotis etrida and Hesperiidae (Pelopidas sp.). New Delhi and a record of the flower visitors was prepared. They were followed in order of diversity by Dipterans from Abundance of insect pollinator: Abundance of most two families viz., Sarcophagidae (Sarcophaga sp.) and frequent insect visitors (number of visitors/m2 branch of a Syrphidae (Eristalinus obscuritarsis) and two species from tree/5minutes) was recorded from five randomly selected two families of Hymenoptera viz., Vespidae (Polistes branches with the help of stop watch. The abundance was olivaceus) and Apidae (Amegilla zonata) (Fig 3) and recorded at two hourly intervals, starting from Coleopteran from family Coccinellidae (Coccinella commencement to the cessation of insect activity and septempunctata). Out of 17 insects all were top foragers repeated at weekly intervals on the experimental plant except A. zontata which was side forager (Table 1). These (Anoosha et al., 2016, 2018a, 2018b). findings are in agreement with those of Wadhwa and Sihag (2012) who recorded 19 insect species visiting the blossoms Foraging Rate: Foraging rate of major pollinators was of sarpagandha. recorded in terms of number of flowers visited/minute. Ten observations were taken for each pollinator species. For this, Abundance of insect visitors/pollinators: Three insect observations were recorded at 2 hours interval from 0600 h species are major visitors of sarpangandha bloom. They were to 1800 h on a day and were repeated weekly interval during belonging to Lepidoptera (2), and Hymenoptera (1). Among blooming period. Loose pollen grains sticking on insect visitors: Insects were collected gently by forceps from the flowers to avoid shaking of body, and the hind legs of those pollinators which collected the pollen were amputated. Insects were captured at the time of their peak activity and were kept in 70% alcohol in vials. They were shaken vigorously to wash out pollen grains from its body. Ten samples were taken for each pollinator species. The numbers of pollen grains were counted with the help of a haemocytometer under the Fig 1: Flowers of Sarpagandha. microscope (15 x 10 magnifications). The identity of sarpagandha pollen was confirmed by using standard pollen slides (Anoosha et al., 2017). Number of pollen grains = pollen grain count x dilution/ number of squares (1mm2) counted Pollination efficiency of major insect pollinators: Comparative pollination efficiency of different insect pollinators was calculated on the basis of their relative abundance and foraging behaviour parameters such as Fig 2: Papilio demoleus. abundance, foraging rate and the number of loose pollen grains sticking to their bodies by using the following formula: Pollination efficiency = Abundance X foraging Rate X number of loose pollen grains sticking on the body of the bee Abundance and Foraging Rate were analysed in randomized block design and the results were compared. Loose pollen grains present on each species were calculated and compared using Completely Randomized Design (Snedecor and Cochran, 1989). Three factorial statistical analyses was done using OPSTAT software (Sheoran et al., 1998). Fig 3: Amegilla zonata. Vol. Issue , () Table 1: Diversity of insect visitors/pollinators of R. serpentina (Sarpagandha). Order Family Insect Species IP/IV Working Behaviour Lepidoptera Papilionidae Papilio demoleus Linnaeus IP T Papilio polytes Linnaeus IP T Pieridae Pieris sp. IP T Anaphaeis sp. IP T Pieris canidia Linnaeus IP T Belenois aurota Fabricius IV T Pieris brassicae Linnaeus IP T Colotis etrida (Boisduval) IV T Hesperiidae Pelopidas sp. IV T Coleoptera Coccinellidae Coccinella septempunctata Linnaeus IV T Hymenoptera Apidae Amegilla zonata (Linnaeus) IP T and S Vespidae Polistes olivaceus De Geer IV T Formicidae Monomorium sp. IV S Diptera Sarcophagidae Sarcophaga sp. IP T Syrphidae Eristalinus obscuritarsis (de Meijere) IV S Eristalis sp. IV S Hemiptera Scutellaridae Chrysocoris stolli Wolff IV T *IP –Insect Pollinator and IV – Insect Visitor, T – Top and S - Side Lepidopterans, maximum mean population was of P. From the present pollination