Distribution of hoppers of the desert locust schistocerca gregaria (forsk.)in relation to herbage quality
2008
Obaid, K.S., Ministry of Agriculture and Forestry, Khartoum (Sudan) | El-Bashir, E., University of Khartoum, Khartoum (Sudan). Faculty of Agriculture, Dept. of Crop Protection
Field experiments were conducted at a farm in Salloom area, South West of Port Sudan (latitude 19 deg 22'N; longitude 37deg 06'E) to investigate the effect of host plant species and community structure on the distribution of hoppers of the desert locust, Schistocerca gregaria (Forsk.). The effects of host plant age and leaf nitrogen content on hopper development were also studied. Three plant species, generally known to attract desert locust; namely, Heliotropium spp., Aizoom spp. and Pennisetum glaucum were used in this study. Host plant species, its density, age and leaf nitrogen content greatly influenced the choice of desert locust hoppers for a particular host plant. Young seedlings of Heliotropium (1-2 weeks old) were more attractive to hoppers than seedlings of Pennisetum of the same age. On the other hand, older seedlings of Pennisetum (3-6 weeks old) were more attractive to the hoppers than seedlings of Heliotropium and Aizoom of the same age. Young seedlings of the three plant species had higher levels of leaf nitrogen content than the older plants, especially in the case of Heliotropium and Pennisetum, where 2 weeks old seedlings had about 30% more leaf nitrogen content than 12 weeks old plants. Hoppers fed on 2 weeks old seedlings of Pennisetum gained more body weight than those fed on 8 weeks old plants. The correlation coefficient between the hopper body weight and the leaf nitrogen content of the Pennisetum plants was positive and highly significant (r=0.93)
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