CONTENTS Introduction................... 3 History.................... 4 Material.................... 6 Methods.................... 8 Taxonomic morphology................ 9 Taxonomy................... 14 The genus Dysdercus................ 18 Key to the American species.............. 19 The Dysdercus mimus group............. 23 The Dysdercus jamaicensis group............ 42 The Dysdercus flavolimbatus group............ 60 The Dysdercus maurus group............. 93 The Dysdercus albofasciatus group............ 144 The Dysdercus fernaldi group............. 157 Infrageneric relationships............... 170 Host plants................... 183 Natural enemies.................. 189 Colour patterns and mimicry.............. 192 Appendix : External morphology of Dysdercus.......... 199 Literature................... 202 Index to the species; survey of type status and type locations.....214 INTRODUCTION Bugs of the genus Dysdercus are often serious pests of cotton. In piercing the bolls, they introduce micro-organisms which cause boll rot or a discolo-