2l6 
Psyche 
[September 
Conclusions 
The vertical acrylamide gel electrophoretic patterns of the hemo- 
lymph proteins provide an excellent taxonomic character for the 
separation of the two sibling species L. mactans and L. variolas , at 
least in one geographic area, and this technique should prove useful 
in further systematic studies of the genus Latrodectus. Its usefulness 
would be considerably enhanced if we had additional information on 
geographic variation in this character and knowledge of the func- 
tional nature of the various protein fractions from the hemolymph, 
particularly that of fraction 3. Unfortunately little is known about 
the biochemistry of spider hemolymph and even less about that of 
Latrodectus species. Boyd (1937) published serological evidence for 
the presence of hemocyanin in Latrodectus and Finlayson (1937) 
reported the presence of a protein-like, toxic substance he called 
arachnolysin. 
Literature Cited 
Abalos, J. W. 
1962. The egg sac in the identification of species of Latrodectus (Black 
Widow Spiders). Psyche, 69: 268-270. 
Boyd, W. C. 
1937. Cross-reactivity of various hemocyanins with special reference 
to the blood proteins of the black widow spider. Biol. Bull., 
73 (1) : 181-183. 
Coates, M. 
1967. A comparative study of the serum proteins of the species of 
Taricha and their hybrids. Evolution, 21 (1): 130-140. 
Finlayson, M. H. 
1937. Some properties of the venom and arachnolysin of L. indistinctus. 
S. Afr. J. Med. Sci., 2(4) : 151-155. 
Hubby, J. L. 
1963. Protein differences in Drosophila I. Drosophila melanogaster. 
Genetics, 48 (6) : 871-879. 
Hubby, J. L. and H. H. Throckmorton. 
1965. Protein differences in Drosophila II. Comparative species genetics 
and evolutionary problems. Genetics, 52(1): 203-215. 
Levi, H. W. 
1959. The spider genus Latrodectus (Araneae, Theridiidae) . Trans. 
Amer. Micros. Soc., 78: 7-43. 
1966. The Three species of Latrodectus (Araneae), found in Israel. 
J. Zool. Lond., 150: 427-432. 
Manwell, C. and C. M. Ann Baker. 
1963. A sibling species of sea cucumber discovered by starch gel elec- 
trophoresis. Comp. Biochem. Physiol., 10: 39-53. 
McCrone, J. D. and H. W. Levi. 
1964. North American widow spiders of the Latrodectus curacaviensis 
group (Araneae: Theridiidae). Psyche. 71(1): 12-27. 
