S Krall¹, O Youm², and S A Kogo³

1. Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH, Postfach 5180, 65 726 Eschborn, Germany.
2. ICRISAT Sahelian Center, BP 12404, Niamey, Niger.
3. Direction de la Protection des Végétaux, BP 323, Niamey, Niger.

ICRISAT Conference Paper no. CP 978.
Krall, S., Youm, O., and Kogo, S.A. 1995. Panicle insect pest damage and yield loss in pearl millet. Pages 135-145 in Panicle insect pests of sorghum and pearl millet: proceedings of an International Consultative Workshop, 4-7 Oct 1993, ICRISAT Sahelian Center, Niamey, Niger (Nwanze, K.F., and Youm. O., eds.). Patancheru 502 324, Andhra Pradesh, India: International Crops Research Institute for the Semi-Arid Tropics.

It is often difficult to identify panicle pest damage and estimate yield losses due to the presence of multiple pests and other biotic and abiotic factors. In addition, the technology used to assess insect-related crop losses in pearl millet [Pennisetum glaucum (L.) R. Brown] is limited. This paper provides a description of the basic principles for identifying pest damage and covers the techniques available for evaluating losses resulting from such damage. Examples of crop loss assessment methods are given, with estimates of losses from selected pearl millet insect pests.

Biologically intensive integrated pest management has received wide support as being an environmentally friendly approach to crop protection. Besides an accurate identification of the causative pest, other prerequisites for integrated crop protection measures include detailed information on the extent of damage and the resulting yield losses. This information is available for a number of important crops (e.g., cotton), but is inadequate or completely lacking for many basic food crops. Pearl millet [Pennisetum glaucum (L.) R. Brown)] is a major food crop in Sahelian West Africa and is attacked by several insect pests. One hundred and sixty-one species were reported in Nigeria (Ajayi 1987), 84 in Niger (Guevremont 1982), and 81 in Senegal (Ndoye 1979). Knowledge of pest biology is available for only a few important species (Anonymous 1988, Gahukar 1989, Jago 1993a, Krall and Dorow 1993, Matthews and Jago 1993, Ndoye 1989, Sharma and Davies 1988). Many pearl millet insect pests, especially the panicle-feeding species, have not been studied adequately, and information on their pest status is often not available. Wewetzer et al. (1993) have reviewed the methods for the assessment of crop losses. Although advantages and drawbacks vary from one method to another, the overall merit of developing such methods remains crucial. Much work has been conducted on basic insect biology and on crop damage caused by a few insects, but relatively little on pearl millet pests. In this paper, an overview of the current state of knowledge is presented, and areas in which further research is needed are highlighted and discussed.

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