1970] 
Burns — Poanes hobomok 
129 
Taken together, the meager data assembled here from four un- 
related genera suggest, first, that Tf will tend to be a normally dis- 
tributed variable (in any particular species population and under 
similar environmental conditions) ; and, second, that it will vary 
widely from some groups of species to others. In the series Poanes : 
Erynnis : Colias : Danaus, mean T f s run a gamut from 38 minutes 
to nearly one hour to roughly 66 minutes to several hours. 
The excessively long Tf of D. gilippus may relate to the fact 
that individuals of this species are often distasteful to vertebrate 
predators that can learn to leave them alone. Similarly, it may be 
on this account that danaines can afford to mate so very many times 
(see Burns 1968; Pliske, in prep.). But inedibility does not explain 
why they mate so long or so much. Although it has been suggested 
that the high number of matings may partly derive from increased 
longevity conferred by distastefulness (Pliske, in prep.), far more 
than this must be involved because danaines will mate several times 
in what, for a butterfly, can only be considered rapid succession. For 
example, three pairs of D. plexippus in separate small outdoor cages 
at San Antonio, Texas, were seen to mate once or (usually) twice 
each day over a four-day period (R. O. Kendall, personal commu- 
nication). The question remains open. A correlation noted, in D. 
gilippus , between high mating frequency and a low population density 
associated with great mobility (Burns 1968) hints at directions for 
future inquiry. 
Until we have hard longevity data for these relatively long-lived 
danaine butterflies, we cannot be precise about the proportion of 
Table 1. Duration of copulation in 13 crosses of Poanes hobomok. 
Cross No. 
Date of Cross 
Female Morph 
T s (min.) 
63XA 
VIII-20-1963 
dark 
38 
63XB 
VIII-21-1963 
light 
39 
63 XC 
VIII-22-1963 
dark 
37 1/2 
63XD 
VIII-23-1963 
dark 
38 1/4 
63XE 
VIII-23-1963 
dark 
27 1/2 
63XF 
VIII-23-1963 
light 
30 
63XG 
VIII-28-1963 
light 
56 
63XH 
IX- 1-1963 
light 
36 1/2 
63X1 
IX- 3-1963 
light 
49 
64XA 
VIII-18-1964 
light 
37 
64XB 
VIII-24-1964 
dark 
41 
64XC 
VIII-27-1964 
dark 
34 1/2 
64XE 
IX- 2-1964 
light 
32 
