Psyche 
[March 
the previous paper that there is a striking correlation between total 
length of the spider and the coloration of different forms, the smaller 
ones being brighter colored, the largest ones dark. As shown below 
there is some variation among individuals in the number of molts un- 
dergone and it is possible that the brighter colored and smaller L. 
curacaviensis undergoes fewer molts than L. bishopi and L. variolas, 
and that the brightly colored populations of L. mactans in some parts 
of the world are made up of individuals that undergo fewer molts 
before maturity. Differences in the number of molts (4-9) of males 
with accompanying large differences in color and size in a laboratory 
culture of the araneid Nephila madagascariensis Vinson was reported 
by Gerhardt ( 1933) . 
Natural History 
A trip was made to Curacao in December, 1962, during the wet 
season. Despite a thorough search of the island, no L. curacaviensis 
were found. We had previously been advised by Drs. de Jong, a 
student of spiders and long time resident, that he had been unable to 
find the species, described in 1776 by Muller, and collected by Has- 
selt in i860. Two factors may have led to its disappearance. First, 
the habitat probably has become less favorable. Thirty thousand goats 
roam the island and they appear to have placed a strong selection 
pressure on the vegetation, favoring plants with long spines and those 
that are poisonous. Shulov (1940) has reported that an area heavily 
infested with L. pallidus was almost freed of them by the grazing of 
cows and goats. Furthermore, on this densely populated island any 
woody plants are cut for fuel. Both of these ecological factors may 
have contributed to the increased dryness of the island. One Latro- 
dectus collecting site of Hasselt was visited and was found to be 
moister than the island generally. Second, the introduced L. geome- 
tricus may have replaced L. curacaviensis , even though L. geometricus 
appears to be most abundant near Willemstad and human habitations. 
Although they are very similar morphologically, L. bishopi and the 
Florida populations of L. mactans and L. variolus can easily be dif- 
ferentiated on the basis of their color, ecology and behavior. 
Latrodectus bishopi shows a very distinct habitat preference. It is 
completely restricted to inland, dune-like areas that support a plant 
association called sand-pine scrub (Fig. 23). The vegetation is 
xeromorphic and is dominated by the sand pine, Pinus clausa. Beneath 
the pines there is a dense growth of evergreen shrubs but little or no 
herbaceous ground cover. For a more complete description of the 
association see Laessle ( I95f^f. 
