RESEARCH ARTICLE The Relationship of Visiting Insect Diversity and Density of Valeriana jatamansi with Increasing Altitude in Western Himalaya Arun K. Jugran 1 • Ravindra K. Joshi 2 • Indra D. Bhatt 2 • Ranbeer S. Rawal 2 • Lok Man S. Palni 3 Received: 4 August 2017 / Revised: 4 November 2017 / Accepted: 15 December 2017 Ó The National Academy of Sciences, India 2017 Abstract In light of the recent evidences that pollinators have a significant implication for maintenance of pollen- mediated gene flow, the present study has been undertaken to investigate flowering phenology and visiting insect diversity and density in 9 different populations of Valeri- ana jatamansi. The performance of the V. jatamansi breeding system was also investigated at an experimental site. Field experiments were performed on control and visiting insect excluded plants (a total of 90 plants). Across populations, a total of 76 visiting insects belonging to 20 species were recorded. Comparison of visiting insects excluded plants and natural plants revealed 63.49% seed setting produced by natural-pollination, whereas only 37.51% of seeds were produced by self-pollination. Sig- nificantly higher seed viability (t = 4.284; p \ 0.02) was recorded in seeds from control plants as compared to vis- iting insect excluded plants. Similarly, higher seed germination (38%) and seed weight were recorded in control plants as compared to visiting insect excluded plants. The total insect number (r =- 0.707) and species diversity (- 0.897) exhibited significantly (p \ 0.05) negative relationship with altitude. A significant negative correlation existed between plant density and altitude (r =- 0.772; p \ 0.05). The study provides further evi- dence that pollinators (and their diversity) are critical for sustaining genetic diversity and consequent adaptive capability in V. jatamansi. Keywords Breeding Á Habitat types Á Flowering phenology Á Valeriana jatamansi Á Pollination Introduction Seeds enable plants to have an independent dispersal phase and to potentially increase the genetic diversity of a spe- cies, thus promoting adaptation to changing environments and the long-term sustainability of a plant species [1]. Seed and seedling life stages represent a reservoir of genetic variability in natural populations [2]. Pollination is the first step in the process of seed formation, and pollination failure results in the decline of genetic diversity and sub- sequently affects population status and species demography [3]. Recent studies have exhibited that the diversity of insect pollinators influences the reproduction and diversity of wild flowering plants [4]. In this context, pollinators have a substantial effect on the maintenance of pollen- mediated gene flow and thereby influence the genetic structure of plant populations. However, the diversity and density of the insect pollinators found to vary with altitude and habitats. Native pollinators are therefore vital for the maintenance of diversity within an ecosystem. Despite the Significance Statement Insect diversity and density on V. jatamansi populations decreased with increasing altitude which may play role in decreasing genetic diversity of this species. These finding have significance with conservation and breeding of V. jatamansi. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s40011-017-0954-9) contains supple- mentary material, which is available to authorized users. & Arun K. Jugran arunjugran@gmail.com 1 G. B. Pant National Institute of Himalayan Environment and Sustainable Development, Garhwal Unit, Srinagar, Uttarakhand 246174, India 2 G. B. Pant National Institute of Himalayan Environment and Sustainable Development, Kosi-Katarmal, Almora, Uttarakhand 263 643, India 3 Graphic Era University, Dehradun, India 123 Proc. Natl. Acad. Sci., India, Sect. B Biol. Sci. https://doi.org/10.1007/s40011-017-0954-9