148 
Psyche 
[June-AugUst 
SEX OF ADULT CECIDOMYID^ (OLIGARCES sp.) 
ARISING FROM LARV.E PRODUCED 
BY PEDOGENESIS. 
Reginald G. Harris. 
Brown University. 
Communicated from the Biological Laboratory, Cold Spring 
Harbor, Long Island. 
The question of the sex of adult forms arising from par- 
thenogenetically and psedogenetically produced individuals has 
called forth some debate and speculation, often in the absence 
of suitable date. Sturtevant (1923) summarized the evidence 
then available concerning some of the Chironomidae and Ceci- 
domyidse in the following statements. 
‘‘Parthenogenesis has been described in the Chironomid 
genera Chironomus, Corynoneura, and Tany tarsus by Grimm 
(1870) Johannsen (1912), Goetghebuer (1913), Edwards (1919) 
and others. Eggs are produced in some cases by the larvae, in 
others by the pupae, and in still others by the imagines. In all 
cases in which imagines have been produced by parthenogenetic 
(including paedogenetic) lines, these have been females and have 
bred parthenogenetically if at all. Males are known to occur in 
these genera, and in one case even in a species that reproduces 
parthenogenetically ; but in no case are males reported as arising 
from larvae known to have been produced by parthenogenesis. 
“The first case of parthenogenesis recorded among the 
Diptera was that of the Cicidomyiid, Miastor, discovered by 
Wagner (1863). In this case it is the larvae that reproduce par- 
thenogenetically. Imagines are often produced, but when they 
do appear both sexes are found (Meinert 1864, Wagner 1865, 
Kahle 1908). Kahle states that there is a significant excess of 
females, and Felt (1911) describes only the female, though he 
does not state that males were absent. It is not known whether 
the imagines breed at all, or not; Kahle states that he did not 
