﻿TWO NEW GYNANDROMORPHS — KROMBEIN 59 



OBSEEVATIONS ON THE OCCURRENCE OF GYNANDROMORPHS 



IN NATURE 



It has been stated that gynandromorphs are of very rare occurrence 

 in nature. I have attempted to assemble some information from per- 

 sonal knowled<2:e and correspondence and am able to present the follow- 

 ing estimates : 



Of Myzine maexHata (Fabricius) I have examined al)out 2,500 speci- 

 mens, 1,700 to the date of my revision (1938) and several hundred 

 additional since that time. In the genus I have examined perhaps 

 10,000 specimens. The specimen recorded here is the first gynandro- 

 morph I have noticed. 



Mitchell ( Journ. Elisha Mitchell Sci. Soc, vol. 47, pp. 52-54, 5 figs., 

 1932) described a partial lateral gynandromorph of the megachilid bee 

 Megachile lathnaini.H Say. In response to my inquiry as to the number 

 of specimens of latimanus examined, Professor Mitchell writes : "My 

 belief is that they [gynandromorphs] are exceedingly rare. I can't 

 give you any accurate count or even close approximation of the number 

 of specimens of Megachile latimana I have seen, as I have not kept 

 detailed specimen records on all I have identified. I would guess the 

 number to be near a thousand, however. Of at least equal significance 

 it seems to me is the fact that the gynandromorphic specimen of M. 

 latimana that I described is the only one I have ever seen, in all of the 

 bees that have passed through my hands. I expect that number would 

 be nearly a hundred thousand, but again, that is just a guess. I have 

 seen quite a number of intersexes, in several genera, but onl}^ that one 

 gynandromorph." For an excellent discussion of intersexes and gyn- 

 andromorphs the reader is referred to Professor Mitchell's article 

 entitled "Sex Anomalies in the Genus Megachile with Descriptions of 

 New Species" (Trans. Amer. Ent. Soc, vol. 54, pp. 321-383, pis. 31-37, 

 1929). 



Prof. C. E. Mickel writes that of the species of North American 

 Mutillidae in which gynandromorphs have been reported, he has seen 

 a total of 1,002 Dasymutilla fulvohirta^ 313 D. gloriosa^ 154 D. hora^ 

 259 Pseudomethoca frigida^ and 416 P. siinillinm. Dr. Mickel also 

 says that he has seen a second gynandromorph of Pseudomethoca 

 frigida collected in Ohio. This specimen has never been described. 



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