An insect rearing facility was established at the Kenya Agricultural Research Institute (KARI) Centre of Katumani in Machakos, Kenya, in 1999, and has to date improved significantly in its scale of operation. The primary purpose of this facility is to provide stem borers for use in resistance screening studies, insect bioassays and for oviposition/feeding preference studies within KARI projects. The stem borers that are reared are: Chilo partellus (Swinhoe), Chilo orichalcocilliellus Strand, Eldana saccharina Walker (Lepidoptera: Pyralidae) Busseola fusca Fuller and Sesamia calamistis Hampson (Lepidoptera: Noctuidae), with the bulk production being for the first two species due to their relative higher demand for use in resistance screening studies. This paper describes the insect rearing facility, procedures used, records taken, problems encountered during rearing and the steps taken to address them. Since initiation of the insectary in 1999, the scale of production has improved significantly, with the seasonal supply of insects increasing from 26,000 in long rains 2000, to 961,689 stem borers in the long rains 2001. There have also been improvements in the quality of production, record keeping and in the supply system in terms of synchrony of the stem borer supply with the various end-uses. As part of the efforts to improve the rearing techniques, a laboratory study was conducted to compare the survival to pupation of B. fusca larvae in large plastic jars (16 x 7.5 cm -250 ml of diet -20 larvae) compared to glass vials (7.5 x 2.5 cm -15ml of diet -1 larva). There was no significant difference in the survival to pupation of larvae reared in the plastic containers (80.5%) and the glass vials (85.2%) (t= 1.59; d.f = 10; P= 0.143). Since the plastic container saves on the time of infestation (egg batches can be used), is less breakable and is cheaper, it has now been adopted for the rearing of B. fusca at the Katumani insectary.

Global Maize Program

English

0409|AGRIS 0401|AL-Maize Program

Juan Carlos Mendieta

INT2460

CIMMYT Staff Publications Collection