Mass production of entomopathogens in less industrialized countries

Publication Type

Journal Article

Journal Name

Annals of the Entomological Society of America

Publication Date

1-1-2000

Abstract

Chilo partellus (Swinhoe) and Chilo orichalcociliellus Strand (Lepidoptera: Crambidae) are gramineous stem borers that occur sympatrically in the southern coastal area of Kenya. Evidence over a 30-yr period indicates that the indigenous stem borer. C. orichalcociliellus, is being gradually displaced by the exotic stem borer. C. partellus. Comparative laboratory studies were conducted in several large-stemmed grasses to examine factors that may be involved in the displacement of C. orichalcociliellus, and to examine other possible effects of the invasion of C. partellus into Kenya. C. partellus had a higher fecundity than C. orichalcociliellus at 25 and 28°C. but not at 31°C. In addition more C. partellus than C. orichalcociliellus eggs survived to the first instar. C. partellus larve developed faster than C. orichalcociliellus in maize and sorghum. In this shorter developmental time. C. partellus consumed more maize than C. orichalcociliellus, but both species consumed equal amounts of sorghum. On a daily basis, C. partellus consumed more maize and sorghum than C. orichalcociliellus. A few C. orichalcociliellus survived to the pupal stage in napier and guinea grasses, whereas no C. partellus survived. The shorter developmental period of C. partellus. may give this species a competitive advantage over the slower developing C. orichalcociliellus. However, the ability of C. orichalcociliellus to complete development in two native grasses in which C. partellus did not survive may provide a refuge that has allowed C. orichalcociliellus to escape extirpation from the coastal area of Kenya.

Keywords

Adult fecundity, Chilo orichalcociliellus, Chilo partellus, Competitive displacement, Egg survival, Larval development

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