Food plant preferences and spatial dispersion patterns of the armoured ground cricket, Acanthoplus speiseri Brancsik (Orthoptera: Tettigoniidae)

Abstract

Food plant preferences and spatial dispersion patterns of the armoured ground cricket, Acanthoplus speiseri Brancsik were investigated. The average numbers of the ground cricket found feeding on each food plant per transect in each of the three study areas were tested for differences at the 0.05 level of probability by Duncan’s multiple range test. The variance/mean ratio (S2/X) was used to analyse spatial dispersion patterns. A. speiseri fed on 12 plant species from the Compositeae, Gramineae and Solanaceae families. Hyparrhenia nyassae (Rendle) Stapf., (Gramineae) and Rottboelia exaitata Linn. f., (Gramineae), were the most preferred food plants. The armoured ground cricket densities on the two food plants were insignificantly different from each other. The cultivated plants, Zea mays L., and Sorghum vulgare Pers., were fed upon opportunistically by the ground crickets. The variance/mean ratio identified aggregation in the armoured ground cricket populations in all three study areas (S2/X > 1, P < 0.001). The significance of the findings on food plant preferences and dispersion patterns are discussed in relation to future sampling and control of A. speiseri.