168 
Psyche 
[Vol. 87 
Carlos and Olga Hobrecker for their hospitality at Lago Calima, A. 
J. T. Johnsingh and M. Gadgil for help and hospitality in India, 
Willis Gertsch for examining specimens of the spider, H. W. Levi for 
help with materials, R. W. Work for kindly examining specimens of 
the bolas and allowing me to use his photographs and unpublished 
data, H. Dahners for help with the moths, and M. J. W. Eberhard 
for a critical reading of the manuscript. Financial support was pro¬ 
vided by the Comite de Investigaciones of the Universidad del Valle, 
Cali, Colombia, and the Vicerectoria de Investigacion, Universidad 
de Costa Rica. 
Summary 
The form of the egg sac, variations in bolas construction and 
hunting technique, and other behaviors link Mastophora dizzydeani 
sp.n. to both reduced-orb weavers (Cyrtarachneae) and webless 
araneids (Celaeneae). The sticky ball is structurally complex, and 
includes both a substantial portion of volatile liquid and a mass of 
flattened, apparently spring-like thread; it elongates reversibly when 
it is swung. 
There was significant variation between individual spiders with 
respect to the species of moths that they captured. Adult females 
converted about 35% of the weight of their prey into eggs. They 
produce an unpleasant odor when handled. Newly emerged spider- 
lings apparently hunted without making a bolas, and preyed on small 
nematocerous flies. Males did not emerge already mature from egg 
sacs, and it may be that cannibalism within egg sacs accounts for the 
emergence of mature males in other species. 
Literature Cited 
Akerman, C. 1923. A comparison of the habits of a South African spider, Cla- 
domelea, with those of an Australian, Dichrostichus. Ann. Natal Mus. 5: 83-88. 
Chac6n, P. and W. G. Eberhard. 1980. Factors affecting numbers and kinds of 
prey caught in artificial spider webs, with considerations of how orb webs trap 
prey. Bull. br. arachnol. Soc. 5( 1 ):29 38. 
Clyne, D. 1973. Notes on the web of Poecilopachys australasia (Griffith and 
Pidgeon, 1883) (Araneida: Argiopidae). Aust. ent. Mag. 1: 23-29. 
Eberhard, W. G. 1976. Physical properties of sticky spirals and their connections: 
sliding connections in orb webs. J. nat. Hist. 10: 481-488. 
- 1977. Aggressive chemical mimicry by a bolas spider. Science 198: 1173— 
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