96 



N.S. ENTOMOLOGICAL SOCIETY. 



HYDROECIA MICACEA AS A GARDEN PEST. 



By W. H. Brittain, Provincial Entomologist. 

 TN the early summer of 1914, a boring caterpillar suddenly ap- 

 * peared in large numbers in the rhubarb plantation on the N S 

 Agricultural College Farm, and practically destroyed the crop The 

 infestation was repeated during the past season with equal severity and 

 reports of similar injuries occurring in the neighborhood were sent in 

 As the rhubarb is a plant usually so free from insect enemies, considerable 

 comment was caused by this outbreak. A number of adults were reared 

 to maturity and submitted to Mr. Arthur Gibson, who determined them 

 as Hydroecia micaceaEsp. 



No attempt has been made to make a detailed study of this pest but 

 sufficient has been done to determine the main points in its life history 

 and to point the way to the formulation of practical control measures. 



No sign of injury is noticed to the rhubarb until about the middle of 

 June or later, when a wilting of the leaves becomes evident On cutting 

 into an injured plant the larvae will be found boring in all directions 

 through the crown or in the stem. Late in July or early in August, the larvae 

 enter the ground and transform to pupae remaining in that state for about 

 three weeks or slightly less, the moths emerging during the greater part 

 of August and on into September. The first eggs were found on August 

 Aug. 31st, the favorite place of deposition being the stems of couch grass 

 (Agropyron repens) which was abundant in the rhubarb plantation The 

 eggs are laid loosely and sometimes in quite large numbers upon the stems 

 are often partly surrounded by the leaf sheath and can only be found aft' 

 er a careful search. The fact that, under natural conditions the egg of 

 the moth is deposited entirely on this weed, makes the method of control 

 appear sufficiently obvious, viz.: carefully to destroy all weeds etc udoh 

 which the eggs would likely be laid. ' '' 



The eggs of this insect are circular in outline, faintly ribbed and 

 sculptured. They have a faint pinkish tinge. Diameter 82 mm. 



The mature larva is about 35 mm. long, the body being soft, distinctly 

 segmented and without markings of a greyish color tinged with pink 

 sometimes quite deeply on the dorsal surface. The ventral surface 

 and the legs are paler in color. 



The head is a shiny chestnut brown; the mandibles almost black. 

 1 he tubercles are paler brown each provided with a stiff black bristle 

 The spiracles are shiny black. The pupae are brown in color and about 

 20 mm. long. 



