Flight behaviour and migration of insect pests: Radar studies in developing countries (NRI Bulletin 71)

The use of radar to make direct observations of insects flying at altitude has provided many new insights into the phenomenon of long-range insect migration. In particular, the technique has produced a wealth of quantitative information on the spatial and temporal distribution of migrants in the air, on the direction, speed and duration of their displacements, and on their orientation behaviour. These data could not have been obtained by any other means, and it is probably fair to claim that our present knowledge of the magnitude and importance of high altitude insect movement stems very largely from radar observations. The pioneering field studies using the first specially designed entomological radar were undertaken in 1968, with the support of the UK Overseas Development Administration (ODA), and since that time ODA has been responsible for funding almost all of the applications of the technique in developing countries. The motivation for this work was the assumption that it was impossible to design efficient management strategies for migrant pest insects without a good knowledge of their migratory behaviour, and of the role which this played in their population dynamics. The ODA-funded studies thus focused primarily on pest species, and were carried out by the Radar Entomology Unit of the Natural Resources Institute (NRI) and its precursors. In this Bulletin, we give a brief account of the history of radar entomology, with emphasis on studies of insect pests. Next, the different types of entomological radar and some associated analysis methods are outlined, together with descriptions of some ancillary measurement techniques. We then describe in some detail the contributions made by the NRI Radar Unit to current knowledge of the flight patterns of a variety of major insect pests of agriculture and of human health. These pests include: grasshoppers and locusts, the African Armyworm moth, the Rice Brown Planthopper and other rice pests, the Old World Bollworm, and some mosquito vectors of human diseases. Recent developments directed towards long-term monitoring of insect aerial faunas (for environmental impact, biodiversity and conservation purposes), and towards observations of low-altitude flight, are included. The Bulletin concludes with a short overview, in which we speculate how the technique might find application in the future

Innovations in rice production (NIAS Books and Special Publications No. SP1-2013)

Agriculture is an integral part of India’s economy and society. It has about 130 million farming families; the majority of them are small and marginal farmers who practice subsistence agriculture. The green revolution which occurred in late 1960s was a turning point in Indian agriculture. There was remarkable growth in agriculture during the Green Revolution period and this sector has been successful in keeping pace with growing demand for food grains in the country. However during 1990-2010 the food grain production in the country grew at an average 1.4 per cent, whereas the population growth was at 1.6 per cent. Fortunately, we have achieved a food surplus during last two years. But in the long run, concern of food security is likely to become more intense with increasing population and decreasing land availability. By 2020, to meet the food demand of 1.3 billion populations, India needs to produce 281 MT of food grains with an annual growth target of 2 per cent. Rice is one of world’s most favoured staple foods and more than 90% of rice is produced and consumed in Asia. Rice being an important crop in India, there is a lot to focus on enhancing rice production and productivity. Rice is grown in 43.4 million hectares in kharif and rabi /summer season out of the total 141 million hectares of land under cultivation. The area under rice is likely to reduce in future years due to diversification policies adopted by the government. Currently, the rice production in the country is passing through serious constraints like plateauing of yield, water scarcity, increased use of agro inputs, irregular monsoon, increasing soil mineral stress, flash floods, water logging, labour scarcity, inadequate storage facilities, invasive pests & diseases, lack of policy innovations and inadequate institutional dynamics. India needs to focus on proper utilization of resources in diverse agro-climatic zones in the country by providing quality seeds, developing high yielding varieties/ hybrid rice, effective natural resource management, developing strategies on biotic and abiotic stress management, cost effective mechanization and promoting agricultural stewardship. Further, there is need to strengthen various initiatives by both State/ Central Government and cooperative involvement of all the stakeholders which will help in enhancing rice production and productivity in the country

The Chittagong story: studies on the ecology of rat floods and bamboo masting

Rodent population outbreaks due to the 50-year cycle of gregarious flowering and seed masting of Melocanna baccifera were first noted in the Chittagong Hill Tracts (CHT) of Bangladesh during the crop production cycle of 2008. The wave of flowering has steadily moved southward through the region each year, with seed masting still occurring in some areas of the CHT during 2010. Because of a lack of surveillance, it is not yet known whether all Melocanna bamboo forests across the region have now initiated flowering. Ecological surveys carried out during the masting event have provided some preliminary evidence that nearly all rodent species are able to exploit Melocanna bamboo seeds as a food resource, with nearly 30% of the seed fallen in forests damaged by rodents. Breeding potential of the predominant species found, Rattus rattus, appears to confirm that aseasonal breeding occurs due to the abundant supply of bamboo seed during masting events. These preliminary results obtained from ongoing research surveys are discussed in the context of the management response to the regional famine triggered by the severe crop damage caused by rodent population outbreaks

Rodent outbreaks: ecology and impacts

The impacts of rodents in both developing and developed countries are legendary. Myths and dogma about rodents and their population outbreaks abound. They are imbedded in the culture and language of many societies. In many instances, it is the acceptance of these outbreaks by society that is our greatest challenge. The reason these episodic outbreaks become etched in the socio-cultural psyche from the sparsely populated uplands of Laos to the considerably more affluent agricultural lands of Europe is that the impacts are often staggering - economically, socially, and even politically. The book is a collation of contributions from Asia, Africa, Oceania (Australia and New Zealand), Europe, and North America. The advent of ecologically based rodent management has stimulated the progress summarized in this book. The contributions provide a modern appraisal to an age-old problem through a better understanding of the mechanisms that lead to rodent outbreaks, why rodent population numbers increase under different circumstances, and the impact of outbreaks in a range of different agroecosystems and native forests in different parts of the world. This is an encouraging progress report driven by scientists passionate about rodents, about people, about conservation, and about improving our knowledge of these species and the ecosystems they inhabit. And, in a novel twist, there is an appendix of recipes for preparing rat meat. You will be more than tempted to try one of these dishes the next time you travel in Asia or Africa