477 



observed to be laid by one female was 234, but many more in various 

 stages of development remained in the ovaries after death. Young 

 larvae feed on the parenchyma of the leaf, but in the later stages eat 

 the entire leaf tissue. Pupation under natural conditions takes place 

 in the ground or under or among rubbish, a thin cocoon being previously 

 formed. 



CusHMAN (R. A.). Thersilochus conotracheli, a Parasite of the Plum 

 Curculio. — Jl. Agric. Research, Wasliimjton, D.C., vi, no.. 22, 

 28th August 1916, pp. 847-856, 9 figs., 1 plate, 1 table. 



The Ichneumonid, Thersilochus conotracheli, Riley, is the most 

 effective parasite of Conotrachelus nemiphar, Herbst, in Pennsylvania. 

 This species is apparently confined to C. nenuphar, from which it has 

 been also bred in Connecticut, New York, New Jersey, Ilhnois, 

 Missouri and Kansas. Adults of T. conotracheli emerge from their 

 cocoons between the end of May and the beginning of June. Females 

 kept in captivity and fed on syrup and water, lived from 10 to 15 days ; 

 those not suppUed with food or water Uved from one to four days. 

 The eggs are deposited in the young weevil larvae before the latter 

 have burrowed into the fruit to any considerable depth. The maxi- 

 mum length of the incubation period is six days. During the greater 

 part of the larval stage T. conotracheli is an internal parasite, but feeds 

 externally for a short time when approaching maturity. Maturity 

 is reached after the host has entered the ground and constructed its 

 pupal cell. Pupation occurs outside the body of the host. The 

 duration of the pupal stage is short, since adults have been found 

 mthin the cocoons as early as 28th August, though emergence does 

 not take place until the following spring. 



Descriptions are given of the developmental stages and a short 

 bibliography is appended. 



CooLEY (R. A.). Observations on the Life-History of the Army 



Cutworm, Chorizagrotis auxiliaris. — Jl. Agric. Research, Washing- 

 ton, B.C., vi, no. 23, 4th September 1916, pp. 871-881. 



Euxoa {Chorizagrotis) auxiliaris, Grote, is an important pest of crops 

 in the north-western parts of the United States. Egg-laying was 

 observed between 30th September and 12th October, 1915. Eggs 

 are deposited during the late afternoon in soil which has been recently 

 ploughed and harrowed. No attempt is made to oviposit on vege- 

 tation and in many instances the moths have been seen to fly from 

 grass or stubble fields to adjoining ploughed fields. Activity reaches a 

 maximum at temperatures from 60° to 70° F. The eggs are usually 

 placed two or three together on the underside of clods of earth, and in 

 one field examined the total number deposited averaged one or two 

 per square foot. Egg-laying is not necessarily confined to bare soil, 

 since an outbreak of this cutworm occurred in Utah in lucerne fields 

 which had not been ploughed in the previous autumn. The plants 

 however were some distance apart and eggs were probably placed on 

 the bare soil between them. The duration of the egg-laying period in 

 the field is at least two weeks. In the insectary, the incubation period 



