Behavioural castes, dominance and division of labour in a primitively eusocial wasp

Female wasps of the primitively eusocial species Ropalidia marginata may be classified, by a statistical analysis of their time-activity budgets, into three behavioural castes namely Sitters, Fighters and Foragers. We show that Foragers are primarily responsible for the risky task of foraging for food and have very poorly developed ovaries. Sitters and Fighters forage rarely if at all but share the bulk of the intra-nidal tasks such as feeding larvae and building the nest. Both Sitters and Fighters have better developed ovaries than Foragers. Queens of most colonies belong to the Sitter caste. There are no obvious morphological differences between queens and workers or between the behavioural castes. Queens are not necessarily the most dominant individuals in their colonies. Instead, most dominance behaviour is performed by a group of workers (the Fighters). Division of labour and social organization are achieved through behavioural caste differentiation and not, as in many other species studied, through a dominance hierarchy led by a despotic queen suppressing all her nestmates into worker roles. This suggests that behaviour patterns in such primitively eusocial insects are likely to be moulded by a complex interaction between selection at the individual and colony levels

Unmated queens in the primitively eusocial wasp Ropalidia marginata (Lep.) (Hymenoptera: Vespidae)

In the primitively eusocial tropical wasp Ropalidia marginata, five out of eleven colonies studied had an unmated female as their queen. In two colonies this was the case despite the presence of another mated individual in the colony. We found no detectable differences between colonies with unmated queens and those with mated queens. We argue that in species such as R. marginata, where intracolony relatedness is expected to be low and where sociality is likely to be maintained because several individuals have opportunities for direct reproduction in the future, individual selection is likely to override "the good of the colony" and lead to such phenomena as that of unmated queens

Access to Wikipedia among the Library Users of the University of Mysore, Karnataka

Abstract The present study has been carried out to ascertain the level of usage of Wikipedia among the library users of University of Mysore. To conduct this study, the questionnaire method was adopted. Simple random sampling was adopted for data collection. In total 150 questionnaires were distributed and 137 responses were received. The response rate was 91.33 percent and the users\u27 opinions that Wikipedia is very helpful to study purpose and also to get more information on a specific topic. The users point out that access to Wikipedia is essential for updating knowledge

Insect species diversity in Tropics: sampling methods and a case study

The tropical regions of the world generally have a richer store of biological diversity than other regions of the globe. But most tropical habitats face a significant threat of destruction. Yet, little is known about tropical biotic communities. Suspecting that at least part of the reason for the poor documentation of tropical insect communities is the lack of appropriate research methodology, we have endeavoured to standardize a package of methods for quantitative sampling of insects, suitable for tropical ecologists with modest research budgets. This methodology includes the use of a small light trap as well as net sweeps, pitfall traps and scented traps. The methods have been used to sample insect species diversity patterns in three replicate one hectare plots each in twelve selected sites in the Uttara Kannada district of Kamataka, India. During this case study, we have encountered 16,852 adult individuals belooging to 1,789 species. 219 families and 19 orders of insects. Here, we provide evidence that this methodology is adequate for sampling insects and differentiating habitats on the basis of the distribution of insect species. Some interesting biological problems that tropical ecologists can study with the data generated from the application of these methods are also briefIy illustrated

Aggressiveness of Ralstonia solanacearum isolates on Tomato

Bacterial wilt caused by Ralstonia solanacearum is the world’s most economically important destructive disease of crop plants. Fifty seven isolates of R. solanacearum causing wilt on different host plants were collected from different agro climatic zones of India of which 54 isolates were confirmed as race-1, biovar-3 and 3 isolates as race-1, biovar-3B based on morphological, physiological, biochemical and pathogenicity studies. All the isolates were authenticated as Ralstonia solanacearum by using two sets of primers (OLI1 & Y2 and Y1 & Y2). Serological identity of the isolates was done by using diagnostic kit obtained from International Potato Research Center, Lima, Peru and single chain variable fragment antibody specific to Ralstonia solanacearum. Fifty seven isolates of R. solanacearum were inoculated on tomato (Solanum Lycopersicum L) cv. Avinash-II under artificial conditions at bacterial concentration of 5x108 cfu/ml to test its aggressiveness; the results obtained are discussed in this paper

Ropalidia rufoplagiata: a polistine wasp society probably lacking permanent reproductive division of labour

Ropalidia rufoplagiata Cameron (Hymenoptera: Vespidae), a polistine species from penisular India, appears to be unique among all known primitively eusocial wasps. A total of 33 out of 46 identified females from an observed colony were found to oviposit on 1-17 occasions. No single predominant egg-layer could be identified during the 45-day period. Of the 17 dissected egg-layers, 12 were mated. All egg-layers showed several oviposition-related behavioural patterns including systematic, but indiscriminate, cannibalism of eggs and larvae, cleaning of empty cells, and guarding of freshly-laid eggs. There was no correlation between the egg-laying activity of the females (whether mated or not), oophagy, and their position in the dominance hierarchy. All nest-maintenance activities were performed exclusively by the egg-layers, while the non-egg-layers were mainly involved in the extranidal task offoraging. No significant morphometric differences between egg-layers and foragers could be discerned. Almost all the older individuals in the colony were egg-layers, while foragers were mainly younger animals. Such a temporal differentiation in reproductive labour suggests the absence of a permanent reproductive caste in this species

Queen success is correlated with worker-brood genetic relatedness in a primitively eusocial wasp (Ropalidia marginata)

Ropalidia marginata is a primitively eusocial polistine wasp in which, although there is only one queen at any given time, frequent queen replacements lead to a system of serial polygyny. One of the most striking features of this system is the enormous variation in the success of different queens. Measuring queen success as queen tenure, total number of offspring produced, number of offspring produced per day of tenure, and proportion of eggs laid that develop into adults, we show here that each measure of queen success is correlated with worker-brood genetic relatedness and not correlated with worker:brood ratio or the age of the queen at takeover. We interpret these results as meaning that queens are better able to obtain the cooperation of workers when worker-brood genetic relatedness is high

Serial polygyny in Ropalidia marginata: implications for the evolution of eusociality

This article does not have an abstract

Perceptions of Academic Librarians in Sri Lanka about Faculty Status and Teaching Information Literacy (IL)

Academic librarians working in higher education institutions in Sri Lanka have been enjoying faculty status for the last forty years. The study explores their self-identity, and their perceptions about the teaching role. In total, there are 140 academic librarians working in universities in Sri Lanka. A survey was conducted among them. An analysis of thirty one responses revealed that a significant number of respondents consider themselves as professionals rather than faculty member. A section of the academic librarians believes that the society does not recognize teaching by librarians. Another section generally opines that librarians are reluctant to take up the task of teaching, but the survey found out that 80% of respondents voluntarily teach at their institutions. It was also found that, as reported by many other studies, the academic programs that many of them had attended in library schools did not provide enough training for teaching jobs

Ant species richness and diversity in some selected localities of Western Ghats

We have sampled ants from twelve different localities in the Uttara Kannada district of Karnataka, India using both a package of standardized trapping methods as well as by intensive all-out-search. The relative efficacies of trapping versus all-out-search are compared. Different methods of trapping are also compared among themselves. A check list of all ants seen by all methods put together, identified up to the genus level is provided. Different localities are compared by the similarity and diversity 'of their ant fauna. A weak but statistically significant positive correlation between ant species diversity. and plant species diversity is demonstrated. This report provides the first estimates of the diversity and abundance of ants for any forest habitat of India