Plant associations and rates of population interchange between two food plant areas for the armoured ground cricket, Acanthoplus speiseri Brancsik were investigated. A. speiseri was associated with 40 species of plants spread over 11 families. The ground cricket had a significantly high frequency of association at P = 0.05 with Rottboelia exaltata Linn. F. and Hyparrhenia nyassae (Rendle) Stapf. The ground cricket preferred members of the Gramineae to those of other families, 69% of the total number of ground crickets collected from the plants in this study were from grasses and among these Zea mays L. and Sorghum vulgare Pers. were opportunistic associations.
The rates of population interchange between two areas dominated, respectively, by Nicandra physaloides (L.) Gaertn. and R. exaltata with several species of Hyparrhenia were unequal. There was net emigration of 76.69 ground crickets to the N. physaloides area in 10 days.
The significance of the findings on plant associations and rates of population interchange between food plant areas of A. speiseri to future sampling and control of the ground cricket is discussed.