Butterfly diversity in relation to nectar food plants from Bhor Tahsil , Pune District , Maharashtra , India

Floral attributes are well known to influence nectar feeding butterflies. However, there is paucity of information on food resources of adult butterflies as compared to that of larvae. The present study was carried out from Bhor Tahsil of Pune District, Maharashtra, India, during August 2007 to August 2009. A total of 64 butterfly species were recorded. Family Nymphalidae dominates in the study area, followed by Lycaenidae, Pieridae, Hesperiidae and Papilionidae. Nineteen nectar food plants were identified belonging to 10 plant families. Plants of the Asteraceae family are more used by butterflies as nectar food plants. Visits of butterflies were more frequent to flowers with tubular corollas than to non-tubular ones, to flowers coloured red, yellow, blue and purple than those coloured white and pink and to flower sources available for longer periods in the year. Species abundance reached the peak in the months during August to November. A decline in species abundance was observed from the months December to January and continued up to the end of May. Our findings are important with respect to monitoring butterfly and plant diversity and defining conservation strategies in the Bhor Tahsil.

The problems of environmental damage and degradation of natural resources have received increasing attention throughout the country.Pune District is one of the important industrial districts in the state of Maharashtra.The increased industrialization and urbanization has manifold effects on the ecology of this region.It has 14 tahsils, out of which Bhor Tahsil was selected for the study of butterfly diversity in relation to nectar food plants.Bhor Tahsil is famous for historical places, tourist places and dams.
Butterflies are scaled wing insects belonging to the order Lepidoptera of class Insecta.There is an intimate association between butterflies and plants and their lives are exceptionally interlinked (Feltwell 1986), which leads to different patterns in their distribution depending on the availability of their food plants.
Feeding is a significant activity and food may often be the most decisive factor affecting distribution, abundance and movements of animals.In butterflies, this has a special relevance because food and mode of feeding are different in the larval and adult stages (Kunte 2000).
Butterflies and their caterpillars are dependent on specific host plants for foliage, nectar and pollen as their food.Thus butterfly diversity reflects overall plant diversity, especially, that of herbs and shrubs in the given area.Herbs and shrubs start their life cycle in the beginning of the monsoon and complete it by the end of the postmonsoon season.While some shrubs like Lantana camara shows flowering throught out the year.
Earlier, various workers like Kunte (1997) studied seasonal patterns in butterfly abundance and species diversity in four tropical habitats in the northernWestern Ghats.These four sites are close to Pune City within a radius of 20km.Kunte (2001) studied the butterfly diversity of Pune City along the human impact gradient; Rane & Ranade (2004) studied butterflies of Tamhini-Dongarwadi area, Mulshi, Maharashtra; Padhye et al. (2006) studied season and landscape wise distribution of butterflies in Tamhini, northern Western Ghats of India; Sharma (2009) studied the fauna of Bhimashankar Wildlife Sanctuary, Maharashtra; Tiple et al. (2006) studied factors influencing nectar plant resource visits by butterflies and implications for conservation on Amravati University campus.Further, Tiple et al. (2009) investigated butterflyflower morphological interrelationships for 108 butterfly species and 20 plants at Nagpur.

Material and Methods
Bhor is located 54km away from Pune City in a south-westerly direction.It is situated between 18 0 45'N & 73 0 15'E.It has an elevation of about 591.43m.Bhor Tahsil has an irregular shape, having an area of 892km 2 , bordered by Tahsil Khandala of Satara District on the east, Mahad of Raigad District on the west, Wai of Satara District on the south and Velhe, Haveli and Purandar tahsils on the north (Image 1).
The flora of Bhor Tahsil has a great diversity which includes many exotic species.The climate is moist but healthy.The vegetation is mainly of dry deciduous type and scrub type.It is due to moderate and irregular rainfall.The actual rainfall in Bhor Tahsil during the period August 2007 to August 2009 was 2603mm, as provided by the Regional Meteorological Centre, Mumbai.
The study area was fully explored during August 2007 to August 2009 and then probable areas were decided.To study the seasonal patterns/diversity in butterfly abundance in relation to nectar food plants, the entire year was divided into three seasons.The three seasons of the year are premonsoon from February to May, monsoon from June to September and postmonsoon from October to January.The study area was visited twice in each season during the two years i.e. 2007-2008 and 2008-2009.In the said investigation the selected sites were surveyed mainly between 0730 and 1230 hr.Butterfly species were N Image 1. Bhor Tahsil map, Pune District, India identified directly in the field visually with the help of field guides followed by photography, in difficult cases, rarely by capture.Collection was restricted to those specimens that could not be identified directly.All scientific names follow Varshney (1983) and common English names follow Wynter-Blyth (1957).Classification of butterflies is after Gaonkar (1996).
Benthum & Hooker (1862) system of classification is followed for plants.GPS readings and biotopes of a few sites in Bhor Tahsil area are given in Table 1.

Results
During the course of study, 64 species of butterflies belonging to five families were recorded in Bhor Tahsil.Out of 64 species, six belong to Papilionidae, eleven to Pieridae, 23 to Nymphalidae, seventeen to Lycaenidae and seven to Hesperiidae.Species belonging to the family Nymphalidae were the most dominant (36%) followed by Lycaenidae (27%), Pieridae (17%), Hesperiidae (11%) and Papilionidae (9%).
The status recording was as follows: VC -very common (75-100 sightings), C -common (50-75 sightings), NR -not rare (25-50 sightings), R -rare (5-25 sightings) and VR -very rare (1-5 sightings).Among the 64 species 15 were found very common, 27 species common, 17 species not rare and five species were found rare.None of the species were observed in very rare category from the study area.Six species (Pachliopta hector, Neptis jumbah, Hypolimnas misippus, Lampides boeticus, Euchrysops cnejus and Acytolepis puspa) come under protection of the Indian Wildlife (Protection) Act 1972.Out of the 64 species 27 species were recorded from botanical and nursery gardens, 55 from forest areas, 33 from grasslands, 58 on plantations and 51 from scrub biotope.Results are indicated in Table 2. Nectar food plants of butterfly species and floral characteristics of plants are indicated in Table 3. Mud puddling is usually observed in males.However, females of Hypolimnas bolina and Hypolimnas misippus were also observed while mud puddling (Table 4).
Ten families of plants are used by butterflies as nectar food plants, as recorded from the study area: six plants of the family Asteraceae, two plants of each family Asclepiadaceae, Caesalpiniaceae, Fabaceae and Verbenaceae, while only one plant of each family Amaranthaceae, Apocynaceae, Malvaceae, Rubiaceae and Thymeleaceae.Visits of butterflies were more frequent to flowers of herbs and shrubs rather than to flowers of trees (Table 4).

Discussion and Conclusions
The species abundance rose from the beginning of the monsoon, from the months June to July and reached a peak in the months from August to November.A decline in species abundance was observed from the months December to January and continued up to the end of May.A previous study (Wynter-Blyth 1956) had identified two seasons as peaks, March-April and October for butterfly abundance in India.However, our finding observed peak period in the months from August to November, in line with the findings of Kunte (2000).Bhusal & Khanal (2008) reported that there is a significant correlation between species diversity and spring season, indicating the abundances of diverse species was positively affected by approaching warmer days, high relative humidity and more rainfall.These factors help to flourish diverse vegetations, which are vital food sources for many butterfly species.Gutierrez & Mendez (1995) suggested that the abundance of butterflies is not affected by altitudes but it is more related to the availability of food plants.A similar seasonal variation in species abundance was observed by Prajapati et al. (2000) in Daman of Makawanpur District of central Nepal.Plants have importance in increasing the butterfly diversity and their abundance in the area.In study area, maximum species of butterflies were recorded on plantation biotope, followed by forest and scrub biotope.However, grassland and botanical and nursery gardens are not observed as rich biotopes; heavy grazing pressure on grassland and use of pesticides in gardens have adversely affected diversity of butterflies in these biotopes.The nectar flowering plants visited by   Tiple et al. (2006Tiple et al. ( , 2009) ) in their study area of Amravati University Campus and Nagpur, Central India, respectively.The herbs from the study area namely Celosia argentea, Tridax procumbens and Tephrosia purpurea are more used by butterflies, probably due to the fact that the flowering period of these herbs is throughout the year.The shrubs namely Calotropis gigantea and Lantana camara also have a flowering period throughout the year, so they are more used by butterflies as their food plants.A few species of butterflies were observed feeding on either animal droppings or on ripe fruits or while mud puddling (Table 4).Mud puddling is usually observed in males, but in our findings females of Hypolimnas bolina and Hypolimnas misippus butterfly species were observed doing mud puddling.Mathew & Binoy (2002) reported that females of Appias albina darada were found to be very much active in mud puddling.The requirement of more water and salt could be the reason for this.
Monitoring and mapping biodiversity is the first step in systematic conservation planning (Margules & Pressey 2000).In the study area, events like grazing pressure, influx of tourists, construction of highways, use of pesticides and change in land use pattern, are mainly responsible for diversity loss of both butterflies and plants.Members from family Lycaenidae largely feed on grasses and cattle grazing affected their diversity  and abundance.In the United Kingdom grazing by cattle and sheep has been practiced as a management tool (Pollard 1991) and there is ample scope for such practices in India.A total of five species of butterflies from the study area are designated rare while describing their status and justifies its inclusion in scheduled list suggesting the need for strict conservation measures (Table 2).As reported by Kunte (2000), an objective revision of the scheduled list will be very useful in providing appropriate and adequate legal protection to Indian butterflies.Our findings are more important for monitoring butterfly diversity and nectar food plant diversity to improve the ecological utility of butterflies as indicator taxa and pollinating agents and defining conservation strategies in the study area.