Journal of the Indian Institute of Science最新文献

William Morton Wheeler (1865–1937) was among the greatest experts on ants and his influence on the field of sociobiology, along with that of his academic grandson E.O. Wilson, is second to none. In 1923, Wheeler published his landmark book “Social Life Among the Insects” (Wheeler in Social Life among the Insects, Haracourt, Brace, New York, 1923), which marked the beginning of the modern study of insect societies. In this centenary year of its publication, we are honoured and proud to pay tribute to William Morton Wheeler.

Hymenopterans present a fascinating diversity of social organisation, from solitary individuals building unprotected nests like the potter wasps to the very complex and highly organised societies of honey bees and most ants. A large number of paper wasps have intermediate levels of social complexity, and are designated as primitively eusocial, as they lack a morphologically distinct queen caste. Nevertheless, they have behaviourally distinct queens and workers, and are excellent model systems for understanding the intermediate steps in the process of social evolution, from solitary to complex social systems. Of the many facets of social organisation, the regulation of work in the colony and the establishment and maintenance of reproductive monopoly are the two aspects that are the most intriguing to sociobiologists. Ropalidia marginata and Ropalidia cyathiformis are two species of closely related paper wasps that are found in peninsular India, in the same habitat, and have much overlap in their ecology and ethology. However, this duo is also an interesting study in contrast in several aspects of social behaviour. Hence, together, they present an excellent opportunity for comparative study, to identify crucial steps in social evolution. In this article, we provide an overview of a series of studies that have been conducted by Prof. Raghavendra Gadagkar and his team over 4 decades at the Indian Institute of Science, Bengaluru, to unravel the evolutionary tale that these two species together elucidate.

This article provides an overview of the importance of outreach for biodiversity conservation and the author’s personal journey in promoting awareness about ants and their natural history, and conservation amongst the general public on ants. It also highlights the importance of educational materials such as books and posters which are important tools for outreach programmes. The article also highlights steps including Open Science that can be taken to increase outreach activities and contribute to the body of knowledge on social insects.

A review of the taxonomy, biology and distribution of social wasps belonging to the subfamilies Vespinae, Polistinae and Stenogastrinae of the following 7 countries: India, Pakistan, Bangladesh, Nepal, Sri Lanka, Bhutan, and the Maldives is provided here. In India, there are at least 104 species of social wasps out of about 1100 known species worldwide and they belong to 13 genera. Polistes is the largest genus with 42 species followed by the genus Ropalidia with 27 species. Each species is provided with its current taxonomic status, along with notes on ecology, biology and distribution on the Indian subcontinent. The study of social wasps is important in several ways, as they form valuable groups to understand the evolution of social life at different levels.

Research on honey bees, one of the most famous social insects, has been largely limited to studies on Central European populations of the Western honey bee, Apis mellifera. Most researchers view the biology and social organization of this phylogenetically derived species as the blueprint for all honey bees, although there is accumulating evidence that several important characters are unique physiological or evolutionary adaptations to living in a temperate climate. The review presents a personal (re)collection of research efforts, ideas, and opinions on the neglected Asian honey bees. There are two major take-home messages: (1) it is of utmost importance that India and other tropical Asian countries increase their research efforts to study and conserve honey bees and other insect pollinators to sustain biodiversity and human nutritional demands, and (2) the study of the behavior of the phylogenetically ancestral Asian honey bees will provide us with a profound understanding of the structure and flexibility in the social organization of honey bees.

Polistes is considered as one of the most widely and abundantly distributed, speciose genera of primitively eusocial wasps. The biology and behaviour of Polistes have been crucial to understanding the cooperation and conflicts among the nest members and have contributed greatly to our understanding of the functionality and evolution of eusociality. However, despite the wide geographical distribution, our perception of the genus has been shaped largely by the studies on the temperate species of Polistes. The diversity of Polistes species in Asia has been reflected through taxonomic reports but their nesting biology and behaviour are mostly unknown. Empirical studies on their behaviour in response to alternate conditions, like experimental removal of the queens, availability of extra food, etc. are also rare. The geographical origin of Polistes is also disputed. The speculation that Polistes originated in oriental regions can neither be confirmed nor refuted due to the lack of knowledge on Asian Polistes. Such missing information creates a large lacuna in our understanding of the origin and routes of dispersal of the genus. Here, we review the scattered studies on Asian Polistes and attempt to summarise and analyse the available taxonomic, behavioural and phylogenetic information. To date, 76 Polistes species have been reported from 31 Asian countries, out of which Vietnam, India and Japan have the maximum numbers of species. We also review the available behavioural studies on Polistes, mostly qualitative and conducted in Japan to show how these can provide a different perspective on Polistes biology. We also try to point out the major questions that need to be answered to get a broader overview of Asian Polistes. We suggest that more behavioural and phylogenetic studies on various species of Asian Polistes could provide the answers to questions like the geographic origin of the species, the evolution of hibernation (reproductive diapause) in the species, the diversification of nest founding strategies, the queen control on worker reproduction, etc.

The effectiveness of procuring food by any ant colony depends upon the strategies adopted while recruiting the foragers to fetch food and the geometry of paths that these recruited foragers employ for searching and harvesting the food. This paper analyzes these recruitment strategies and search paths adopted by ants, and attempts a synthesis of the possible evolutionary process shaping them. Ants exhibit a wide range of recruitment strategies that differ in the size of the foraging team and the interactions among its members. It is shown that these diverse strategies are strongly associated with the size of the ant colony. Small colonies recruit individual foragers, while large colonies recruit foragers en mass; moderate size colonies exhibit a mix of these strategies. This association between the colony size and foraging group is argued to be a consequence of the crisis in processing information in large colonies. While in small colonies, collective decisions to recruit individuals (and small groups) can be easily arrived at, by the ants at the colony level, in large colonies, the tsunami of information flow in space and time creates a crisis for integrating and processing the data. As a result, the task of recruitment is inevitably shifted from the nest level to the foraging paths where individuals are entrusted to self-recruit based on the information gathered by them; this leads to a seamless and spatially dynamic recruitment of workers resulting in an en mass foraging strategy. Further, the size of the recruited team is also shown to be shaping the geometry of the foraging paths. While individual foragers search and harvest food in a circular or sinusoidal movement pattern, the en mass foragers adopt trails or columns that grow and branch out in a bifurcating system. These foraging paths adopted by different group sizes are shown to be very effective in ‘managing’ the complex substrates they forage on, and also to be very efficient in maximizing the benefit-to-cost ratios of foraging.

The Himalayan Mountain system is a hotspot of biodiversity and harbors endemic flora and fauna. Different groups of organisms have speciated and proliferated in its abode. Ants of genus Myrmica are one such group whose diversification coincides with the formation of Himalayas. The species of this group are cold hardy and have adopted several survival strategies to cope with the harsh environmental conditions. The odyssey from egg to queen in Myrmica species takes about 1.5 years as these species must over-winter twice to complete its journey. Apart from their life cycle, these species form associations with other ant species residing in Himalayas, which are termed as social parasitism. From getting food from other ant species to raiding their nests for brood to manipulating worker force of host for its well-being are some of the associations observed in these Himalayan ants. A detailed account of natural history of Himalayan Myrmica species is provided herewith.