118 
Psyche 
[June 
proaching females were experimentally removed. The question 
arises: why does Hodotermes fly during the time of highest preda- 
tion and desiccation and not, like many other species, under damp 
and rather dark conditions during or soon after rain? Some aspects 
of adaptation to the extreme habitat are considered: in the arid areas 
the dry soil is often dusty and does not absorb the water rapidly. 
The rains often are short, heavy thunderstorms. After a first rain- 
shower the soil is generally flooded or muddy and swarming during 
or shortly after the rain would be fatal. Waiting for a repeated 
rainfall, when the soil is wet enough to absorb, as do certain other 
termites (e.g. Trinervitermes bettonianus ), could possibly mean 
waiting forever, since rainshowers may be very sporadic. The day 
after rain the soil is still humid, and if the sky is clear in the after- 
noon there is little risk for another flood immediately after the 
flight. Such a situation may be interpreted as a suitable flying 
condition from this point of view. It is worth mentioning that the 
species generally is obviously challenged to sunlight, as revealed 
also in the workers’ pigmentation, their developed compound eyes 
and sunlight orientation. 
Summary 
Swarming in Hodotermes mossambicus was always observed at 
the beginning of a rainy period in afternoons during sunshine, the 
day after a first rain. 
The dealate male exposes his sternal gland for airborne female 
attraction (“calling”) (Fig. 1). The male sternal gland is the largest 
ever found in termites (Fig. 3). The male begins with excavating 
into the soil while calling. The female (running about) is stimulated 
by the male pheromone from 250 cm up-wind and orients in a 
winding zig-zag run towards the calling male (Fig. 2). After they 
join, the male stops “calling” and the female takes part in digging. 
The behavior of “tandem run” was not observed. The pair disap- 
pears within minutes from the surface. 
References 
Bruinsma, O., M. Kaib, R. H. Leuthold and G. D. Prestwich. 
Trail Pheromones in Termites, Evidence for a Multicomponent System. 
Buchli, H.(in preparation) 
1960. Les Tropismes lors de la Pariade des Imagos de Reticulitermes lucifugus, 
Vie Milieu 11 : 308-315. 
