350 
Psyche 
[December 
curred in the coastal scrub and grassland region at Legon and 3 in 
the moist semi-deciduous forest region (2 at Kade and 1 at Tafo), 
and each involved predation on the species Anomma nigricans. Al- 
though all African populations of Oecophylla are considered to be 
one species, the observations at Kade involved the commonly occur- 
ring dark form. 
Discussion 
O. longinoda attacks both emigrating and foraging columns of 
Anomma , but attacks the columns at a limited number of selected 
points. In some cases the Anomma trails over which the columns 
move are marked by soil particle walls, while in other cases, the 
columns march along completely exposed trails or trails covered in 
part by grasses and organic debris. Some trails are subterranean or 
covered with soil particle ceilings built by the Anomma workers. In 
the observations reported here, the Anomma trails either had soil 
particle walls or were partially covered by organic debris (primarily 
leaves ) . 
Single Anomma workers are removed from the column by individ- 
ual foraging O. longinoda workers. The O. longinoda workers are 
either positioned outside of the soil particle walls or on leaves and 
twigs adjacent to or overhanging the Anomma column. An O. 
longinoda worker quickly thrusts its head into the column, grasps an 
Anomma worker in its mandibles and pulls it from the moving col- 
umn. In one case (Tafo) the O. longinoda workers removed Ano?n- 
ma workers from a diffuse column expansion. The Anomma workers 
are rarely alarmed by the removal of a single sister worker, although 
in one instance, the O. longinoda attack was so widespread that the 
Anomma column was subsequently disrupted. O. longinoda workers 
are obviously afforded some protection by the trail wall or by the 
space between the column and their position on the surrounding 
vegetation (Fig. 1). Anomma workers are generally excitable and 
easily disturbed, and thus it is surprising that they are usually so 
little disturbed during an Oecophylla attack. 
Way ( 1954) notes that O. longinoda grabbed A. nigricans workers 
from the column, but adds that the Anomma workers had “strayed 
from the main stream.” While it is true that the Anomma workers 
selected by O. longinoda foragers are peripherally located in the col- 
umn, they are not usually “strays.” Way (1954) also reports that 
Anomma soldiers were never taken, but I observed on several occa- 
sions soldiers being attacked and immobilized. Although most 
Anomma workers attacked were not of the soldier caste, this may 
