1979] 
Leston Dispersal by Male Doryline Ants 
75 
remains to be placed in an evolutionary context. I cannot accept 
that synchrony results from a climatic shock bringing the species 
annually into phase: these are social insects, as adept as other ants in 
modifying their environment (Leston, 1973), whilst weather-induced 
synchrony is likely at best to extend over a few weeks only, not over 
a 400 day period as noted here. 
That all Old World dorylines studied—including Aenictini—have 
nocturnal male flights is indicative primarily, I believe, of high 
humidity preferenda: after all, these are hypogeic or, at least, 
ground-nesting species. The diel spacing out of flight times is con¬ 
sistent with this:, relative humidity in the wet tropics is minimal 
around 1500 hrs local time, maximal around 0500 hrs. The imme¬ 
diate post-dusk species are less tied to the highest RH value than are 
the pre-dawn ones. The species’ synchrony, 1 suggest, has evolved as 
a mechanism for oversaturation by potential prey. Male dorylines 
have large Tight muscles—protein—and much fat: they are preyed 
upon by frogs and toads (Wheeler, 1922) and probably a wide range 
of other nocturnal predators whilst isolated males, once landed, fall 
victims of the ever-present dominant ants. 
The logarithmic relationship in the species’ frequencies (Fig. 2) 
follows the pattern noted for many animals by Williams (1964) and 
others. It is paralleled in several organisms sampled in Ghana: mist- 
netted lower-storey birds, field collected snakes, pyrethrum knock- 
downed non-doryline ants and ultraviolet light-trapped paussid 
beetles, amongst others (Leston, 1972). 
Acknowledgements 
Field work in Ghana was supported by the Cocoa, Chocolate and 
Confectionery Alliance (U.K.) and the Ghana Cocoa Growers’ 
Research Association: subsequent help came from the Research 
Foundation of the University of Connecticut and the Institute of 
Food and Agricultural Science, University of Florida. Ms. Lyn 
Garling, Dr. W. H. Gotwald, Jnr. and Dr. C. W. Rettenmeyer have 
kindly read and commented upon the manuscript. 
Conclusions 
1. In an ultraviolet light-trap run for 400 days at Legon, Ghana, 
males of eleven species of doryline ants, in Dorylini, were captured.’ 
