Interference between ant species distribution in different habitats and the density of a maize pest

A field study conducted on maize plants growing in three different conditio ns (one or two rows cultivated along the walls of, houses in working-class districts of Yaounde, Cameroon; vacant lots of the city that we call <<urba n gardens>>; and an experimental field outside the city) revealed that the plants were attacked by the corn delphacid, Peregrinus maidis (Ashmed) (Hom optera; Delphacidae), a vector of maize viral diseases. Damages were signif icantly greater (1) along the walls than in the urban gardens; (2) in the u rban gardens than at the edges of the field; and (3) at the edges than in t he center of the field. The number of P. maidis individuals per plant was g reater on maize plants growing along the walls than in the urban gardens, w hile we did not record differences between the latter and those situated al ong the field edges or between edge and center of the fields, We recorded a significant correlation between ants and P. maidis presence an maize plant s. Destruction of ant nests by ploughing resulted in less ants foraging on maize and consequently fewer plants attacked by P. maidis. Ant species comp ete to attend P, maidis, although attendance is influenced by varying ant d istribution patterns under the three growing conditions. The number of P. m aidis individuals per maize plant varies as a function of the attending ant species. Comparison with controls where ants were excluded indicated no di fferences in levels of P, maidis when attended by Paratrechina longicornis (Latreille), while other comparisons with the controls resulted in signific ant differences. The number of P. maidis individuals per maize plant was si gnificantly higher when attended by Camponotus acvapimensis (Mayr) than by Crematogaster sp, or Pheidole megacephala (F.) and was also higher when att ended by both of the latter than by Myrmicaria opaciventris (Emery). We the refore advise (1) to avoid growing maize along the walls of houses in the c ities, (2) to destroy ant nests situated in and around the urban gardens, a nd (3) to plough prior to planting maize over a large zone around the field s.