© CAB International 2015. Brassica Oilseeds: Breeding and Management (eds A. Kumar et al.) 193 Introduction Brassicaceae are cultivated the world over under varied agroclimatic conditions (Suwabe et al., 2006; Hong et al., 2008) and for diverse agricultural usage. Oilseed brassicas have be- come important sources of oil and protein due to the increased oilseed production of Brassica rapa, B. juncea, B. napus and B. carinata in the past three decades (Font et al., 2003). B. napus alone contributed 58.56 Mt out of total oilseed production of 446.97 Mt amounting to 13.1% during the year 2010/11 (USDA, 2011). Over the course of domestication for thousands of years, domesticated plants have lost many of the genes controlling defence mechanisms employed by their ancestors to ward off herbi- vores, including insect pests. Very little atten- tion was paid by plant breeders to maintain adequate levels of insect and disease resist- ance in them as synthetic pesticidal chemicals were available for their management, which at that time were thought to be satisfactory. More emphasis was placed on the selection for crop productivity and desirable quality traits. Further, globalization of the production system and monoculture over large areas al- lowed insects to multiply with ample food and space available to them. The Pest Complex A wide diversity of insects is associated with brassicas in different parts of the world (Lamb, 1989). Even in a speciic region, different spe- cies of insects attack at different crop growth stages. The insect pests feeding on these crops can be broadly classiied as chewing (Coleop- tera, Lepidoptera, Hymenoptera), piercing and/or sucking (Heteroptera, Homoptera, Thysanoptera) and putrifying (Diptera). A number of insects reported to be associated with brassicas are listed in Table 11.1. Aphids Complex The family Aphididae comprises about 4700 species in the world (Remaudière and Re- maudière, 1997), of which 450 species are en- demic on crop plants (Blackman and Eastop, 2000), but only 100 have successfully exploited the agricultural environment to the extent that they are of signiicant economic importance (Blackman and Eastop, 2007). They are the spe- cialized phloem sap feeders resulting in sig- niicant yield losses in many crops partly due to their capacity for extremely rapid population 11 Insect Pests Sarwan Kumar 1 * and Y.P. Singh 2 1 Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana, 141004, Punjab, India; 2 ICAR-Directorate of Rapeseed Mustard Research, Bharatpur, 321303 Rajasthan, India *Corresponding author, e-mail: Sarwanent@pau.ent (c) CABI 2015 sarwanent@pau.edu