Notes on Fig-Insects^). 



Dr. Fritz Müller communicated the following notes on Fig-Insects: — 



"In his valuable paper on fig-insects (Feigen-Insecten. Wien, 1885), Gustav 

 Mayr has described thirty-seven species, which some years ago I had gathered 

 on the River Itajahy. Among these there are four new genera (Namiocerus, 

 Pliysothorax, Critogaster, and Ganosomä) established on wingless males, while 

 there is but one genus (Tetragonaspis) of which females only are described. 

 Thus Gustav Mayr was led to think that without doubt one sex only of several 

 genera was represented among the insects at his disposal. This, however, is not 

 the case. By carefully collecting the insects from a large number of figs, and 

 examining separately those taken from each fig, I have been able to refer all 

 of these genera of wingless males to females of other genera. 



"Ganosomä is the wingless male of Tetragonaspis, as was already suspected 

 by G. Mayr, G. robustiim being the male of T. flavicollis, and G. attemiatiim 

 (pro parte) that of T. gracilicornis. 



"Critogaster is the wingless male of Trichatdus, C. singularis being the 

 male of T. versicolor, female {T. versicolor, male, I suspect to be the winged 

 male to C nuda). When I formerl}^ collected the fig insects of PJiarmacosycea, 

 to which the genera letraptis and Critogaster appear to be limited, I had met 

 with this one species of Trichaiilus only; now I have found the females of 

 Critogaster piliventris and C nuda also. In these two species there are at the 

 same time winged and wingless males, the latter being by far more numerous; 

 of C. nuda I found one winged male to about ten females; of C piliventris I 

 have met with but one winged male among hundreds of females; of C. singu- 

 laris (Trichaiilus versicolor) , though this is by far the most common species of 

 the three, I have seen none. 



"Pliysothorax disciger is the wingless male of Diomorus variabilis. Dio- 

 morus produces very large galls, not connected, as far as I can judge, with the 

 flowers of the fig. From these galls I raised numerous females and winged males 

 of Diomorus, a few Physothorax, and one extremely curious male, intermediate 

 in any respect (colour, antennce, wings, &c,) between the winged males of Dio- 

 morus and the almost wingless Physothorax. I may add that the structure of 



I) Trans. Entom. Soc. London 1886. Proc. p. X — XII. 



