THE EFFECTIVENESS OF HELMETED GUINEA-FOWL NUMIDA-MELEAGRIS (LINNAEUS 1766) IN CONTROLLING THE BANDED FRUIT WEEVIL PHLYCTINUS-CALLOSUS (SCHONHERR 1826), AND THEIR IMPACT ON OTHER INVERTEBRATES IN APPLE ORCHARDSIN THE WESTERN-CAPE-PROVINCE, SOUTH-AFRICA

The role of indigenous vertebrate predators, especially birds, in cont rolling pest insects is poorly known. This study quantifies the effect iveness of helmeted guineafowl Numida meleagris (Linnaeus 1766; Aves: Numididae) in controlling the banded fruit weevil Phlyctinus callosus (Schonherr 1826; Coleoptera: Curculionidae), a pest in apple and necta rine orchards in the Western Cape Province, South Africa. The impact o f guineafowl on other invertebrates and on apple crops is also assesse d. Periodic counts of weevils under trunk bands showed that guineafowl did not reduce weevil numbers significantly, but suction samples indi cated that weevils were more abundant in plots without guineafowl. On average only 1.07 weevils were found in 30 guineafowl crops (range 0-1 4 weevils). The results suggest that although guineafowl consume weevi ls, they have a negligible impact on large weevil populations. Other i nvertebrates, especially molluscs and elaterid larvae (Coleoptera) wer e often eaten. Guineafowl reduced insect diversity in apple orchards e ither directly through predation or indirectly by altering the structu re of the cover plants. The damage that guineafowl allegedly cause to apples was not confirmed.