Preface The term ‘Pest’ in English, derived from the Latin word ‘Pestis’ means ‘causing destruction’. As the name indicates, pests cause extensive damage to cultivated crops and other vegetations, besides destroying household articles and other possessions and attacking livestock and even humans. Some pests are responsible for causing or spreading a few serious diseases in man and livestock. Pests include insects and several other non-insects belonging to invertebrates and vertebrates. Pests are responsible for causing enormous economic losses. According to a survey conducted in India in 1976, it has been established that a total loss upto 18 per cent is caused as a result of pest attack every year. Of this about 33 percent loss is due to weeds, 26 percent due to diseases, 20 percent due to insect and non-insect pests, 6 per cent due to rats and 7 per cent in warehouses. The monetary loss had been estimated to exceed Rupees 5,000 crores at that time. Among the pests, insect pests are more destructive and are responsible for causing huge losses. Insects constitute slightly over 50 per cent of all living organisms viz, other Arthropods, plants and animals put together. They are ubiquitous and are found in every place on this world where life can be sustained. There are about 1.0 million species of insects, of which comparatively a small percentage of about 1,000 species are pests in the true sense, while the others are wild and harmless. Many species are beneficial because of their role in our ecosystem. Some are a part of the food chains of wild creatures, while some others are either predators or parasites. A vast majority of insect pests are predominently polyphagous. Many of them feed on the foliage or other plant parts. Some of them bore into plant parts, such as stems, branches, roots, flowers, fruits or grains and feed on the inner contents. Some pierce the plant parts and suck and feed on the plant sap, while some others are vectors of virus and mycoplasma diseases. In nature there is hardly any plant species, which is free from attack by insect pests of one type or other. Even plants, which possess insecticidal properties, such as Azadirachta indica, Calotropis procera, Allium sativum etc. are also subjected to attack by some pests. It is an established fact that insects came into this world more than 250 million years ago, while man came into existence only about 1.0 million years ago. Over the several million years, insects have survived because of their innate adaptations to live under any adverse environmental conditions. Actually it is man who has intruded into the domain of the insects. In order to meet his requirements of food, clothing and shelter man started cultivating crops and in doing so, the natural habitats of the insects were destroyed. The insects on the other hand have gradually changed their food habits and have started attacking the crops raised by man to meet their own requirements of food and shelter. Thus many insects have attained the status of crop pests leading to large scale destruction of crops. From the time man stepped in, a stifle has started between the insects and man and the struggle to gain supremacy has begun. Man considers insects as his enemies and to safeguard his interests tries to destroy them by various means. However, inspite of his vast potential, supremacy, intelligence and ingenuity, it has not been possible for man to eliminate these much inferior creatures completely and the struggle is going on as a never ending ordeal. Unlike plant pathogenic microorganisms, such as fungi, bacteria, viruses, mycoplasma etc., which cannot be seen with naked eye, almost all the pests can be seen with naked eye or with the aid of a simple lens and the damages caused by them are also quite clearly visible and so appropriate control measures can be taken up at the proper time to control them. Knowledge about the nature of damage caused, life cycle and dispersal of pests goes a long way in adopting suitable control measures at the proper time. In this context this book, which has been compiled as per the syllabus of B.Sc.(Ag.) Degree course of the Agricultural Universities will be of great help and guidance to the students of Agriculture. It consists of three chapters. The first chapter deals with ‘Pests of field crops’. The second chapter deals with ‘Pests of horticultural crops’ and the third chapter deals with ‘Pests of household and livestock pests’. Detailed account of each of the major pests and possible measures to control them have been given. Besides the major pests, list of minor pests which may assume serious proportions when environmental conditions become favorable for them has also been furnished. The book, I hope will also be of immense help to the officials working in the Department of Agriculture, people interested in Scientific farming as well as the General Public. Numerous illustrations have been given to amplify the nature of damage and the life cycle of the pests so that the reader can understand and follow the text easily. In the recent past, there is a tendency to revert back to the old system of natural farming or organic farming so as to safeguard the quality of the soil and to protect the atmosphere from pollution, which is a welcome proposition. But we have upset the natural ecosystem to such an extent that it may not be possible to revert to the old system of organic farming in the near future by avoiding the use of pesticides and inorganic fertilizers altogether for crop production. However, it is necessary to take utmost care in the judicial use of such chemicals. Only when absolutely necessary pesticides should be used and when using such chemicals care should be taken to select appropriate chemicals. They should be used at the correct and recommended dosage, and at the proper time when the pests are in the most vulnerable stage to ensure maximum control of the pests. In the compilation of this book, I have gathered informations from several books, journals and other media and I am very much indebted to the authors concerned. Ackowledgements are due to collegues who have supplied me with informations and also to friends and well wishers who have inspired, helped and encouraged me in my endeavor to complete the book. I wish to place on record my sincere thanks and appreciation to M/S. New India Publishing Agency, 101, Vikas Surya Plaza, Pitam Pura, New Delhi - 110 088 for the excellent manner in which the book has been brought out.

PESTS OF CEREALS Rice (Oryza sativa) Rice is the staple food of a vast majority of people throughout the world, especially in India. Rice crop is grown in about 75 million acres, which is about one-third of the total world area under rice. The warm and humid environment for the rice crop is best suited for invasion by several insect pests and as many as 85 species of insects are known to infest this crop. The damages caused by different pests extend from the seedling to harvest stages of the crop. Some of these pests are widely distributed and cause extensive damage. The more important pests are described below: 1. Rice stem borer or Rice yellow stem borer Scirpophaga (Tryporyza) incertulas Order - Lepidoptera Family - Pyraustidae Among the pests, which ravage rice crop, ‘rice stem borer’ is a major one and infests rice crop at all growth stages, from seedling to flowering. It is a specific pest of rice alone and is more serious during the months of October-January. The pest has a wide distribution in all Asian countries. The damages caused by this pest ranges from 5-20 per cent. Generally, late varieties of rice are more severely infested than the early maturing varieties, because of the possibility of the pest multiplying in larger numbers by the time the late varieties come to maturity. Cold weather with high humidity and low temperature prevalent during October-December is found to be conducive for the multiplication of the insect.

Mango (Mangifera indica) 1. Mango hoppers (i) Amritodes atkinsoni (ii) Idioscopus niveosparsus and (iii) I. clypealis Order - Hemiptera Suborder - Homoptera Family - Cicadellidae Nature of damage. Three different species of hoppers are found to cause damage to mango trees. During some years, especially during the months of November-February, when the mango trees come to flowering, the pest appears in large numbers. During the other months, the pests are seen in much lesser numbers in an active form, while the other insects hibernate under the bark of the trees. Even in the peak period of pest occurrence, after a few heavy showers, the number of insects is considerably reduced. During the cold season, when the trees put out the flower spikes, thousands of hoppers, young and adults appear in large numbers, pierce, suck and feed on the sap from the tender shoots, flower stalks, flowers and buds. This drain of the sap causes the buds and flowers to dry, wither and they are shed in large numbers, as a result fruit production may go down by 25-60 per cent. When a severely infested tree is approached, thousands of hoppers hop or fly about and make a rustling noise, as they dash against the foliage. The hoppers exude a sweet, sticky fluid excretion and this fluid thrown out by myriads of these insects after feeding on the tree sap, wets the soil underneath the trees and on the surface of the leaves of the trees. In case of severe infestation, the fluid may fall down in drops. The secretion attracts scores of flies, bees and other insects, which come to feed on the secretion. The infested tree presents a sickly appearance. The trees get devoid of buds and blossoms. The leaves appear shiny and are covered by ‘sooty mould’, a fungal disease. Thousands of caste skins of the nymphs are found on the shoots and leaves. The continuous damage caused to the trees year after year by the pest makes them loose their vigor gradually and eventually leads to severe reduction in their yielding capacity. Life cycle of the pest. The female hopper inserts spherical, pale whitish eggs singly into the plant tissues through slits made in the young shoots, flower stalks and flower spikes. The eggs hatch in 4-6 days and the young nymph hatching out of the egg looks quite similar to the adult. The nymphs are very active and move about rapidly along the flower spikes and shoots, suck and feed on the plant sap. They are smaller in size, wingless and unable to fly or jump. The young ones moult their skin a few times during their growth and become adults in 10-15 days. The adult hoppers are small insects, about 3.0 mm. in length with a wedge-shaped body. The head is broader and the body gradually narrowing backwards. The legs are well developed, especially the hind legs. The general color is light greenish-brown. They are extremely active and can fly and hop around. They have a tubular, sucking mouthpart by which they puncture the tender plant parts and floral parts. The adults of Idioscopus clypealis are smaller, with two black spots on the prothorax and a few black spots on the front portion of the head, while those of Idioscopus niveoparsus are slightly bigger with three black spots on the prothorax and whitish, distinct cross bands on the light brownish forewings. The adults of Amritodes atkinsoni are bigger than the other two species, about 5.0 mm. in length, with two black spots on the prothorax. Two or more generations may appear during the flowering season of mango trees (Fig.71).

Insect and non-insect pests cause extensive damage to standing crops, stored grains and stored products resulting in huge economic loss. Besides these, several pests cause annoyance, as well as attack livestock such as, cattle, poultry and pet animals. Some others damage household articles such as, clothing, upholstery, carpets, paper, books, leather articles, wooden and bamboo furniture and all sorts of wooden structures. These obnoxious creatures besides consuming any kind of food materials, spoil them by contaminating and polluting them with their faecal matter and urine and impart a repulsive, bad odor and make them unfit for consumption by humans and livestock. The damages caused by them pave the way for easy access and infection by some of the saprophytic microorganisms, which hasten the deterioration process. A few of these microorganisms produce mycotoxins, which are poisonous and may even be fatal to the consumers. Among the household pests, cockroaches, crickets, silver fish, ants, white ants, carpet and powder post beetles and clothes moths are quite important. These insects not only cause annoyance but different types of flies, mosquitoes, bugs, fleas and lice either suck and feed on the blood from humans, cattle, poultry etc. but are also responsible for disseminating several disease causing microorganisms.

Appendices Appendix-I : List of insecticide formulations approved by the Government for plant protection purposes and dosage to be applied.