International Journal of Research ISSN NO:2236-6124 A Study on the Congregation of Adult Butterflies on Non-floral Resources at Different Locations in Jalpaiguri district of West Bengal, India Panchali Sengupta1*, Narayan Ghorai2 1Department of Zoology, West Bengal State University, Berunanpukaria, Malikapur, Barasat, District-24 Parganas (North), Kolkata-700126.West Bengal, India Email id: [email protected] 2Department of Zoology, West Bengal State University, Berunanpukaria, Malikapur, Barasat, District-24 Parganas (North), Kolkata-700126.West Bengal, India email id: [email protected] Abstract Several instances of puddling, as reported among different herbivore arthropods, appears quite interesting. Significantly, congregation of adult butterflies at several non-floral resources (wet soil/mud, animal dung, bird droppings, carrion, rotten/fermenting fruits) were examined at different locations in Jalpaiguri district adjacent to the tea estates, villages and agricultural tracts. Different species of papilionids and pierids congregate on wet soil patch and puddle collectively. However other species of nymphalid, lycaenid and hesperid are found to puddle individually, without associating with others on resources like excrements and carrion. Irrespective of any species newly emerged males, and aged females are found to puddle. Interestingly, each species belonging to a particular family have a specific range of puddling duration. Such specificity in puddling among species of a family could probably be associated with their need for a common nutrient. Keywords:, congregation, hesperid, lycaenid, nymphalid, papilionid, pierid *corresponding author Volume VIII, Issue VI, JUNE/2019 Page No:5877 International Journal of Research ISSN NO:2236-6124 Introduction Puddling is a widely recognised fascinating event in the life history of any herbivore arthropods except beetles targeted towards accumulation of specific micronutrient (Mollemann, 2010). Several literature illustrating the beauty of such puddling behaviour among hymenopterans (Butler, 1940; Kaspari et al., 2008; Bänziger et al., 2009), dipterans (Kaspari et al., 2008), lepidopterans (Boggs & Jackson, 1991; Smedley & Eisner, 1995; Launer et al., 1996; Boggs & Dau, 2004; Pola & García-París, 2005; Molleman, 2010), fruit flies (Hendrichs et al., 1991, 1993) and locusts (Trumper & Simpson, 1993; Shen et al., 2009) are available. Accumulation of butterflies at mud puddles, pond edges, damp soil, carrion, animal dung and bird droppings are equally interesting (Adler & Pearson, 1982; Pivnick & McNeil, 1987; Sculley & Boggs, 1996; Beck et al, 1999; Hall & Willmott, 2000). Additionally, fermenting fruits being loaded with essential carbohydrates and alcohol also help in fuelling several body processes among butterflies (Norris, 1936; Brakefield, 1994; Braby & Jones, 1995; DeVries et al., 1997; Tang et al., 2013). Among nine botanical provinces of the Indian subcontinent, the eastern Himalayas are blessed with unique diversity of plants and animals (Das 1995). Specifically the Himalayan region of West Bengal with several national park, sanctuaries and reserve forest sustain enormous biodiversity (Allen et al., 1997; Sivakumar & Prakash, 2004; Sivakumar et al., 2006; Chettri et al., 2008; Roy et al., 2012). Although studies highlighting the diversity of butterflies from this ecoregion are available (Chowdhury & Soren, 2011; Ghorai & Sengupta 2014; Sengupta et al., 2014; Bhattacharya et al., 2016), information regarding their resource utilization still needs to be investigated. Besides depending on floral resources (i.e. nectar and pollen), butterflies engage in supplementary feeding to gain some extra benefits (Mollemann, 2010). Such a wide repertoire of feeding substrates as utilized by butterflies could probably help in expanding their already diverse gene pool in turn enriching such ecosystem. The present study has therefore been designed to identify different non-floral resources exploited by adult butterflies across different regions in Jalpaiguri district, West Bengal, India. Researchers believe that puddling intensity shows interspecific variation across different sex and age classes (Collenette, 1934; Adler, 1982; Adler & Pearson, 1982; Berger & Lederhouse, 1985; Boggs & Jackson, 1991; Launer et al., 1996; Sculley & Boggs, 1996). Accordingly, this study has also been formulated to recognize any sex and age specific preferences among butterflies engaged in foraging from such non-floral resources. The tendency of species to form associations or to feed individually at puddle sites has also been explored. The duration of feeding by each species from such substrates has been documented and any similarity in their feeding pattern has been discussed. Study Area: The entire study was undertaken by three trained field assistants between April 2018- March 2019 at five study sites (S-I, S-II, S-III, S-IV and S-V) established at different locations adjacent to the tea estates, villages and agricultural tracts in Jalpaiguri district of West Bengal, India (Figure 1a i, 1a ii, 1a iii). S-I located in the surroundings of Satkodali village (Figure 1.b) was characterised by extensive wet patches along with dead rotten leaves and logs. S-II was situated in the nearby regions of Mathura tea garden (Figure 1.c). S-III established in Damsibad village (Figure 1.d) was found to be the most disturbed study site. Occurrence of animal dung, bird droppings, carrion and rotten/fermenting fruits were noted in this study site. S-IV located in Kohinoor Tea Estate (Figure 1.e) had extensive wet patches. S-V located in the agricultural tracts of Nurpur village (Figure 1.f) was slightly disturbed area. Importantly, carrion, animal dung, bird droppings, and rotten/fermenting fruits were also observed in this study site. *corresponding author Volume VIII, Issue VI, JUNE/2019 Page No:5878 International Journal of Research ISSN NO:2236-6124 Materials & Methods: Three fixed line transects (approximately 100 m length and 8 m breadth) were established at each study site. Butterfly species feeding from different non-floral resources (i.e. mud/wet soil, animal dung, bird droppings, carrion and rotten/fermenting fruits) were sampled. Butterflies which visited, settled down and remained at the resource for more than one minute were considered for this study. More importantly, butterflies were not killed or captured during the entire study to avoid disturbances caused to other species engaged in feeding. Specifically, puddling behaviour among species was confirmed, if they were observed drinking/sucking from the available resource. Such drinking behaviour was associated with the extension and uncoiling of proboscis as observed through binoculars (10 X 42). Scan sampling of butterfly species was conducted between 1000-1600 hours with 30 minutes interval. Importantly, each transect was sampled once a week. Resampling of the same transect was conducted twice, each after an interval of fifteen days. Butterfly behaviour was observed using binoculars (10X42) from a distance of three meters to reduce any disturbances. All these observations were photographed using Nikon-COOLPIX-P90 and videography was done on several occasions. Identification of species was done on the basis of sexual dimorphism (where ever possible) using published literature (Haribal Meena, 1992; Kehimkar, 2008). However in cases where sex could not be ascertained the individuals were identified only up to the species level. The mean number of butterfly species observed puddling at family and subfamily level was determined to ascertain the Resource Preference Index (RPI) at such level. Wing wear was used to determine approximately the age of the adults as wings are not repaired with age. Wing wear was rated using the 1.5-5.0 scale. Individuals were grouped into two classes: young (wing wear rating 1.5-2.0) and old (wing wear rating 4.5-5.0) for purpose of data analysis (Boggs 1987). However wing wear ratings of 2.5, 3.0, 3.5 and 4.0 were said to belong to intermediate age group. In order to recognize the extent of age and sex specific preference of butterflies, the mean number of butterflies belonging to each sex was plotted against the age of butterflies expressed as wing wear. A particular individual belonging to each species considered for focal sampling was selected on random basis. Three such observation were conducted to obtain the mean duration of puddling (expressed in seconds) of species across transects constructed at each study site. Hierarchical Clustering (using hclust function of the program-R) was used to illustrate a similarity in the duration of puddling among species across the study area. Results: Five butterfly families representing 89 species were observed puddling from different non-floral substrates in this study (Table 1). Highest RPI was recorded for papilionidae (60.54) and pieridae (56.68) on mud/wet soil at S-I and S-II respectively. On the contrary, maximum RPI was estimated for nymphalidae (65.69), lycaenidae (27.03) and hesperidae (18.35) at S-III (only for nymphalids) and S-IV (both for lycaenids and hesperids) (Table 2). The present survey thereby demonstrated relatively high abundance of papilionids and pierids at wet soil and river bed (Table 1, 2). Preferences for amino acid enriched carrion sources by nymphalids, hesperids and lycaenids were also displayed (Table 1, 2). Importantly, excrements originating from vertebrates being loaded with nutrients also attracted butterflies (Table 1, 2).Additionally, tropical lepidopterans