CHALCIDIDS INJUKIOUS TO FOREST-TREE SEEDS. 161 



ber, and November, 1905, and seemed to be of the opinion that the 

 great variation in the dates of emergence of this insect was due to the 

 irregularity of the hatching of the eggs and the coming to maturity 

 of the larvae. It may be, however, that the females which had 

 emerged in the receptacle containing the seeds oviposited withm the 

 seeds, thus accounting for the larvae found in the months of July, 

 August, September, October, and November, 1905, when the larvae 

 which would be adults in the spring of 1906 should bo feeding within 

 the seeds. MacDougall does not give sufficient information to make 

 his statement concerning variation m emergence conclusive, while 

 rearings by Crosby, Crosier, and Wachtl confirm this last supposition. 



The egg has been obtained by Crosby by dissection of a female and 

 is described by him as "white, smooth, and spindle-shaped with a 

 very long pedicel at the anterior end and the vestige of one at the 

 opposite end. Length of body of egg, .36 mm. ; tail-like process, 

 .9 to 1.2 mm." The larva described by Crosby is as follows: "The 

 full-grown larva is yellowish white with brownish mouth parts; 

 its length varies from 2.5 to 3.5 millimeters. The surface is 

 smooth without apparent sculpture, and the hairs are very sparse 

 and microscopic in size. The inner margm of the mandibles is pro- 

 vided with thi'ee sharp teeth." The pupa is described by Crosby as 

 follows: "The pupa is yellowish w^hite and in the female has the 

 ovipositor curved over the back and reaching to about the middle of 

 the thorax. Length of female pupa, 3 mm. ; of male, 2.5 mm. " 



The oviposition of this species is unknown, and the shape of the egg 

 after having been deposited is not known. Neither has this insect been 

 recorded as having been reared from the seeds of any Douglas fir raised 

 in the United States. All seeds from which it has been reared were 

 collected in Aberdeenshire, Scotland, on the estate of Mr. John 

 Crosier. In this statement we must except the seeds from wliich the 

 species was reared by Wachtl, as it is presumed that these were col- 

 lected somewhere in the northwestern United vStates. Crosby also 

 records the larvae within the seeds of Douglas fir in Colorado, but 

 these seeds came from a nursery firm and definite locality could not 

 be secured. 



Up to the present time this is the most mjurious chalcidid on 

 forest trees which has received the attention of any entomologist. 

 The attention which this insect has received m x\merica, with the 

 exception of the work done by Crosby, has been nil. MacDougall 

 recommends as protection from this species that the cones be gathered 

 as soon as ripe, and that, as soon as they will permit, the seed be 

 thrashed from them, and that this be fumigated without delay with 

 bisulphid of carbon. No experiments have been published concern- 

 ing the results of such fumigation, but except for killing the larvae 

 within the seed and preventing another generation of adults this 

 method can not be considered as valuable. 



