An improved infestation technique using eggs of the millet head miner (Heliocheilus albipunctella) (Lepidoptera: Noctuidae) in millet resistance screening

Abstract

The millet head miner moth, Heliocheilus albipunctella (De Joannis) (Lepidoptera: Noctuidae), is an important pest of pearl millet, Pennisetum glaucum, (L.) R. Br., in Sub-Saharan Africa and causes severe crop losses. Damage to the panicles is direct and caused by developing larvae. Management techniques are beingdeveloped among which is host plant resistance. Youm and Kumar (1995) reported little progress in identifying resistance due to lack of a repeatable and reliable screening method. Efforts for the past 5 years have been devoted to developing such a technique. Youm (1997) reported an improved technique based on the use of larvae where 35 - 45 larvae were efficient in causing 51 - 60% damage corresponding to a rating of 6 on a susceptible genotype. Though the use of larvae was promising, the present research shows that the use of eggs is more efficient than using neonate larvae. The use of 40 eggs per panicle resulted in 51 - 80% damage corresponding to a mean damage rating ranging from5.5 to 8.4 across several genotypes. A higher and more consistent infestation was obtained with eggs than larvae. Finally, egg handling was easier and infestation cheaper than using larvae. This technique should significantly improve screening millet for reaction to the head miner. It is recommended for use for future resistance screening of genotypes against the millet head miner to avoid the release of highly susceptible varieties on-farm.