102 



DECIDUOUS EKUIT INSECTS AND INSECTICIDES. 



The developmental period of the parasite is somewhat longer nor- 

 mally than that of its host. 



The data on the development of the parasite are given in Table 

 VIII. 



Table VIII. — Data on rearing of Hyperallus calirose. 



Lot No. 



III.. 

 Ilio. 



II141 

 1116. 

 1117. 



H19. 



Total and aver- 

 ages 



Date of 

 confine- 

 ment of 

 larvae. 



Apr. 7 

 Apr. 16 

 July 12 

 Aug. 10 

 Aug. 12 



Aug. 19 



Condition of larvae 

 when confined. 



One-third grov,Ti . . 

 Nearly full grown . 



do 



do 



do 



.do. 



Date 



adult 



sawflies 



emerged. 



None. 

 ..do.... 

 July 26 

 Aug. 19 

 Aug. 20 

 Aug. 22 

 Aug. 23 

 Sept. 16 



Date 



parasites 

 emerged. 



May 12 

 May 17 

 Aug. 10 

 Sept. 1 

 Sept. 3 

 Sept. 4 

 Sept. 7 

 Sept. 18 



Number 

 of para- 

 sites 

 reared. 



12 



Period 

 from 



confine- 

 ment of 

 larvae to 



emer- 

 gence of 

 parasites. 



Days. 

 35.0 

 31.0 

 29.0 

 22.0 

 22.0 

 23.0 

 26.0 

 30.0 



27.5 



Period 

 from 

 emer- 

 gence of 

 sawflies 

 to emer- 

 gence of 

 parasites. 



Days. 



15.0 

 13.0 

 12.5 

 13.5 

 16.5 

 2.0 



14.1 



i This sawfly was undoubtedly from a prepupa, which held over beyond the normal time of emergence 

 for the brood, and the figure corresponding to it in the last column is omitted from the average. 



The parasite enters the ground in the body of the host and develops 

 within the pupal cell of the latter. When it has entirely consumed 

 its host and is full grown, it makes a very thin, brown, parchment- 

 like cocoon within the pupal cell and changes to the pupal stage, 

 emerging later as a light-brown and yellowish wasplike fly. 



This parasite is evidently not very abundant, as none was seen about 

 the trees, and only 13 individuals were reared from the several hun- 

 dred larvae of the sawfly confined. 



REMEDIES. 



Lack of time prevented the writer from making any tests of reme- 

 dies. Without doubt, however, an arsenical spray, such as arsenate 

 of lead, would very effectively destroy these insects, and this poison 

 is advised when the insects occur in sufficient numbers to warrant 

 treatment. The rapid increase in the spraying of peaches and 

 plums with arsenate of lead in self-boiled lime-sulphur wash for the 

 control of the plum curculio and fungous diseases of the fruit will 

 unquestionably result in keeping the peach and plum slug well 

 reduced in orchards. Its occurrence in injurious numbers is to be 

 looked for largely in small unsprayed home orchards, and the 

 remedial measures indicated should be followed when its presence in 

 undue numbers is noted. 



