Sphenoptera chalcichroa arenosa Ob. (Col., Buprestidae) associated with the die-back of Acacia nilotica (L. Willd. ex Del.) in the Sudan
1988
El-Atta, H.A. (Khartoum Univ. (Sudan). Dept. of Forestry)
The die-back and mortality of Acacia nilotica (L. Willd. ex Del.) was due to the grub of the larvae of the buprestid Sphenoptera chalcichroa arenosa Ob. which tunnel under the bark of the stem or branches killing the tree gradually. The effect of the larvae on the diameter at breast hight (D.B.H. at 1.3 m), tree height, volume and the mean annual increment (M.A.I.) were recorded. The reductions were 50 cm to 3 cm = 30 per cent, 25 m to 20 m = 21 per cent, 0,028 to 0.013 m3 = 54 per cent and 0.001 to 0.0004 m3 = 60 per cent per year in D.B.H., height, volume and M.A.I. respectively on the basis of pooled values and these differences were significant (P below 0.001). Differences in individual study plots were recorded and were found significant. Description of the adult beetle and its larvae was provided. The investigation presents the first attempt to assess the effect of the beetle on various growth parameters of A. nilotica in the Sudan
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