DROSOPHILA PERCNOSOMA HARDY LEK SITES - SPATIAL AND TEMPORAL DISTRIBUTIONS OF MALES AND THE DYNAMICS OF THEIR AGONISTIC BEHAVIOR (DIPTERA, DROSOPHILIDAE)
Wj. Bell et Lr. Kipp, DROSOPHILA PERCNOSOMA HARDY LEK SITES - SPATIAL AND TEMPORAL DISTRIBUTIONS OF MALES AND THE DYNAMICS OF THEIR AGONISTIC BEHAVIOR (DIPTERA, DROSOPHILIDAE), Journal of the Kansas Entomological Society, 67(3), 1994, pp. 267-276
Drosophila percnosoma form leks and defend leaves on isolated trees (C
lermontia) in the Hawaiian rainforest. Males do not prefer lower leaf
groups, but more male-male agonistic interactions take place on the lo
wer leaf groups, suggesting that they may be preferred by the most agg
ressive males. D. percnosoma males show diurnal variation at leks. The
time of peak abundance was 1000 to 1300 hr, with numbers declining at
1500 hr. Male removal resulted in rapid occupation of previously occu
pied leaves. Agonistic interactions occurred non-randomly among the 15
leaves that were monitored, with larger leaves or particular leaves i
n a given leaf group being preferred. Males that win agonistic interac
tions are usually either the larger or the resident or both. An intera
ction begins when an intruder lands on an occupied leaf. Intruders may
decamp early if the resident is much larger. If the intruder remains
after landing, the agonistic interaction escalates to either wing flic
ks by the resident or to a side-to-side pushing match. Two males may c
ome together, oriented head-to-head, and then rear up anteriorly and '
'box'' with the front legs. This may be followed by mutual wing-raisin
g, and assumption of a side-to-side posture (each facing in a differen
t direction) with wings still extended. In this posture the flies appe
ar to push laterally, often toward the leaf margin. At any point eithe
r male may decamp.