Preface

Insects are the most speciose organism on earth. Insects are adapted to all environments and ecosystems. Insects are one of the major components in the functioning of ecosystems. However, a handful of them pose serious threats to agriculture as pests of crops. In many crops, insects are the major constraint in achieving higher yields, thereby, affecting the productivity of crops. Further, a few species of insects damage the harvested produce in stores. Global estimates reflect a loss of 9.5 billion US\$ due to various biological stresses to crop plants of which insect pest damage accounts for 10.8% loss. Apart from causing direct damage to crops, insects also act as vectors of plant diseases, which further decreases crop yields. Apart from being pests, there is a wealth of insects that act as predators, parasitoids, and scavengers. Hence, the knowledge on the role of insects in agro-ecosystems is essential in sustainable crop production systems.

Various management tactics have been deployed to decrease the impact of insects in agriculture since time immemorial. Every time a new technique is deployed, insects have their own techniques to oust the management technique introduced. The most common control measure is the use of chemical insecticides. The impact of the insect pests in field and storage needs to be managed through innovation and sustainable techniques. Integrated pest management (IPM) is popular in combining all available techniques in one capsule to avoid yield losses due to insect damage. IPM techniques are preferred as it provide ways to maintain the environment in balance and provide livelihood for all organisms without reduction in yields. The most striking aspect of IPM is avoidance or minimum use of synthetic chemical compounds. Insecticide application is the last option in any cropping system under this approach. The risk of the 3 R's (development of resistance to insecticides, insect resurgence, and residues) is due to indiscriminate use of pesticides. In addition, there can also be an outbreak of secondary insect pests and destruction of natural enemies.

In the wake of climate change and invasive insects, it is the need of the hour to bring forth insect management techniques based on the basic understanding of how insects would respond to the introduced management techniques. Management through biological control agents, botanical pesticides, natural control, alternate cropping systems, and resistant varieties are a few of the important strategies followed in IPM.

This book deals with different aspects of IPM. Lepidopteran insects are major pests of field and horticultural crop plants. Parasitoids play a major role in controlling lepidopteran insects. An overview of the Hymenopteran parasitoids associated with lepidopteran pests is provided. Entomopathogens to manage *Spodoptera litura* (Noctuidae: Lepidoptera), a polyphagous pest attacking several crops, is detailed. IPM for stored product pests attacking processed yam and maize storage is also covered in the book and different storage structures have been suggested. The effect of the newer insecticide group, neonicotinoids, and its impact on pollinators is explained. The mechanisms of insecticide resistance due to oxidative stress on insects are also discussed. We hope the contents of the book will be useful to the scientific community to widen their understanding of IPM.

We thank all the authors for their valuable contribution in this book. We are indebted to the author service manager, Mr. Josip Knapic, for his sincere, timely correspondence, and his patient approach. Our special appreciation and thanks to the editorial and publication team of IntechOpen for their incessant encouragement, suggestions, and promptness in each stage of compilation of the book.

## **Dr. R.P. Soundararajan**

Associate Professor (Agricultural Entomology), Horticultural College and Research Institute (Women), Tamil Nadu Agricultural University, Tiruchirappalli, Tamil Nadu, India

## **Dr. Narayanasamy Chitra**

**1**

Section 1

Biological Control

Associate Professor (Agricultural Entomology) and Curator (TNAU Insect Museum), Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India
