Four cultivars of maize, Zea mays L. viz., CM 600, Basilocal, CM 500 and Kisan were examined for their relative resistance to the maize stem borer, chilo partellus (Swinhoe) in relation to nutrition. Freshly hatched larvae of C. partellus were allowed to grow on the leaf whorls of the cultivars in the laboratory at 27 ±.2°C and 70–90% r.h. The rate of growth, food consumption and its utilization, egg laying and egg hatchability were studied. The insects showed better growth when fed CM 600 or Basilocal maize; this was shown by a higher percentage pupation (56.8 and 54.8, respectively on CM 600 and Basilocal) as compared to (24.4 and 5.6 respectively) on CM 500 and Kisan. Pupal weights were higher (40.2, 45.2, 34.4 and 32.8 mg for male pupae and 57.6, 63.7, 51.8 and 35.8 mg for female pupae), when larvae were reared on CM 600, Basilocal, CM 500 and Kisan, respectively. The growth index decreased from 1.65 on CM 600 and 1.49 on Basilocal to 0.40 on CM 500 and 0.09 on Kisan. A better consumption and utilization of the cultivars CM 600 and Basilocal was shown as also expressed by the higher weights attained by larvae grown on these two than on CM 500 and Kisan. Growth rate slowed down to 0.068 on CM 500 from 0.161 on CM 600 maize. A similar trend was observed in egg-laying and hatchability of eggs. Number of eggs laid per female decreased from 290 on CM 600 reared C. partellus to 157 on Kisan reared insects and none of the eggs laid by the latter could hatch. The degree of resistance of the cultivars to C. partellus on the basis of nutritional factors in a decreasing order is: Kisan > CM 500 > Basilocal > CM 600.

Sources of information on the biology and ecology of Chilo species are reviewed on a world-wide basis, with emphasis on the major pest species which are stem borers of rice, maize, sugar-cane, sorghum and other cereal crops and grasses. Information on geographical distribution, host plants, general biology, ecology and population dynamics is summarized for the main species, especially for C. partellus (Swinhoe), C. suppressalis (Walker), C. infuscatellus (Snellen), C. sacchariphagus (Bojer), C. auricilius (Dudgeon), C. zacconius Bleszynski and C. agamemnon Bleszynski. Other species are also noted, including C. diffusilineus (de Joannis), C. panici Wang and Sung, C. terrenellus Pagenstecher, C. polychrysus (Meyrick), C. plejadellus Zincken, C. niponella (Thunberg) and C. orichalcociliellus (Strand). Requirements for additional and better organized information are identified.