Annals of Plant Sciences ISSN: 2287-688X Original Article *Corresponding Author: Dr. Prasad Erancheri, Department of Botany, University of Calicut, Malappuram, Kerala-673 635, India. Page| 230 Insect diversity and pollination biology of Leucas chinensis (Lamiaceae) Prasad Erancheri * and Sunojkumar P Department of Botany, University of Calicut, Malappuram, Kerala-673 635, India Received for publication: April 06, 2013; Accepted: June 02, 2013. Introduction The intricate methods by which cross pollination is accomplished in the Lamiaceae reflect a long history of co-evolution between plants and pollinators. In spectrum of pollination systems includes entomophily and ornithophily but no records in bat pollination or wind pollination in Lamiaceae (Huck, 1992). The main pollination system of the family includes nototriby and sternotriby. Bees, by far, most commonly observed pollinators of this family. The family is known for volatile oil glands that may stimulate the responses from pollinators (Beker et al., 1989). Previous studies on Leucas species (Shrihail K. Kulloli et al., 2011) confirm that ants were very common flower visitor. Materials and Methods The plant was collected from Munnar (Idukki district). The plant were multiplied and grown in the Calicut university Botantical garden for detailed study. Floral biology: Phenology is defined as the timing of biological events. Plants in the experimental plot were observed daily to study the flowering phenology; special attention was given to identify the flowering season, flower initiation, development, anthesis, anther dehiscence etc. The floral parts were studied by using hand lens and stereomicroscope (Leica CM, 1100). The measurements of the floral parts were taken with the help of a plastic scale. The number of pollen grains per flower was calculated as suggested by Shivanna & Rangaswami (1992). Pollen fertility was assessed by staining them in 1% acetocarmine. Pollen viability was estimated by tetrazolium test. Histochemical analyses were carried out in stigmas to study the presence of primary metabolites like starch, protein and lipids. For histochemical analysis thin hand sections were taken. Stigma receptivity analyzed by α- naphthayl acetate. In this test excised stigma dipped in 2 drops of α- naphthyl acetate solution for 30 minutes, after that, the stigma washed with phosphate buffer and observe the colour changes. Pollination biology: Continuous observations were made on the behavior of different floral visitors. The number of floral visitors, percentage of floral visit and stigma touch by insects were noted. Foraging period and foraging nature were observed. Frequency of visit calculated. After each visit stigma were observed by hand lens and confirmed the transfer of pollens by each visitors. The visitors were captured using hand net, killed using ethyl acetate or ethanol and observed under stereo microscope for pollen load on the body parts. Pollination systems such as apomixis, autogamy, geitonogamy and xenogamy and open pollination were tested. Result Leucas chinensis produce flowers throughout the year. Inflorescence initials are Abstract: Detailed studies were carried out on the Phenology, floral biology, pollination and breeding system of Leucas chinensis. The flowers were found throughout the year. The flower is typical Lamiacean bilabiate. The inflorescence is verticillaster. Inflorescence initials are generally activated in the leaf axils. Anther dehiscence mode is longitudinal. The pollen grains were spherical and tricolpate. The size of the pollen is 26.55 ± 3.0 and 85% of pollen viable at 12am. The stigma is dry type and receptive between 12am-1.00pm. The fruit is nutlet and seed ovule ratio is 4:4. In breeding experiment we found that apomixis not present in this Leucas member maximum fruit set occur in the open pollination and xenogamy (95% and 90% respectively). The flower offer nectar and pollen as rewards for floral visitors. Flowers were visited by several insects and butterflies. The potential pollinators were Apis cerana, Amegilla sp., Ceratina sp. and an ant species, Componotus parius. Keywords: Leucas chinensis, Pollination, Diversity, Nototriby, Amegilla