PIKRINAK: PIKRIS JIAPAE. 1215 



which makes its escape from its host, sometimes before, sometimes after, 

 the change to chrysalis. 



A few words iiiiiy be addeil regarding I'teromaUis ])ii[)arum, of which I 

 have reared and counted over two tliousand specimens in Europe, in order 

 to determine the proportion of the sexes. Hyperparasitism is very common, 

 but from nineteen chrysalids attacked by this parasite alone, 481 males 

 and 677 females were obtained, the number varying from 22 to 132 speci- 

 mens and averaging (Jl for each chrysalis ; the chrysalids were always 

 broken open to include in the count those that did not hatch. These all 

 emerged between February 7 and May 1 at Mentone in southern France. 

 In some instances the entire brood would emerge in a single day ; at others 

 the bulk would emerge the first day and others wo.uld straggle out one 

 after another for a week or more ; sometimes again they would come out daily 

 or almost daily for several weeks, as in one instance from February 24 to 

 March 14 ; in another, the most extended, from March 18 to April 28. Males 

 and females seem to be equally early and late. In almost all cases where the 

 total number was very great, the males exceeded the females ; while when 

 the number was small the females were many times more numerous than 

 the males ; as a whole the females averaged a little over 35 to a little over 

 25 males, and in only one-third the instances where the number of the 

 females fell below the average, the males outnumbered them ; the most 

 excessive case was 84 males and 12 females, or 7 to 1. The greatest relative 

 excess of females over males was 36 females to 2 males, or 18 to 1. One 

 thing that struck me as curious was the much greater activity of the 

 females ; the specimens were killed by the fumes of a sulphur match under 

 an inverted tumbler, and before dying a far greater proportion of females 

 than of males would leap out of the box in which they had hatched to die on 

 the floor outside. Those inside and outside were separately counted in 

 many instances ; this may serve as an example : outside, 5 males, 30 

 females; inside, 11 males, 4 females. When they first emerge from the 

 chrysalis they make little flying leaps of about three centimeters, but not 

 often in quick succession ; if they chance, as not infrequently, to fall on 

 their backs, they curl up the legs and remain motionless ; they are on the 

 whole sluggish, and permit themselves to be seized with the forceps while 

 resting on the butterfly chrysalis from which they have emerged ; and will 

 then cling with such tenacity that I have moved the chrysalis in forcibly 

 removing them. 



In this country the hyraenopterous parasites so far known are only two 

 in number, both of them identical with European species and the most 

 efficacious of them, namely, Pteromalus puparum (89: 1-2) and Apanteles 

 glomeratus (88: 12). The former of these was first noticed at work in 

 1869 by Mr. Ritchie of Montreal, and reared by him from the chrysalis in 

 the following year : but there are specimens in the British Museum taken 



