EXPERIMENT STATION BULLETINS. 



255 



Specimens of injured plums were found on August 22, 1901, on the College campus by 

 Prof. U. P. Hedrjck of the College, who turned them over to the writer. A search under 

 the infested trees soon revealed the characteristic work of the gouger and led to the 

 finding of a number of the insects themselves. 



Reference to this insect is made in the Annual Report of the Board of Agriculture for 

 1894, page 210, by the Horticultural Department. There is, however, no mention made 

 of finding the insect, the short description being included merely to give completeness to 

 the list of plum insects. 



The finding of the insect in Michigan is not surprising though it confines its work 

 chiefly to the Mississippi valley and the West. In its methods of working and in its 

 life history, the gouger resembles somewhat the curculio. The insect passes the winter 

 in the adult condition feeding, in the spring, on the opening flowers of the plum in a 

 manner at once peculiar and ingenious. The part eaten is the ovule, or the part that 

 would, if left uninjured, in time become the seed. This ovule is in the center of the 

 basal part of the bloom and not easily reached direct, so the gouger cuts a hole in the 

 side of the calyx, or the green cup at the base of the flower, and reaching in with its 

 long beak, eats the coveted part. This of course causes the blow to fall which oftentimes 

 leads to the detection of the malefactor. Later the gouger feeds on the young fruits, 



Fig. 19. — Plum Gouger. Coccotorus prunicida. From photograph enlarged 4% times. Original. 



boring holes in them and also laying eggs in them. The method of egg laying is 

 described in detail by Prof. Bruner.* The egg is laid in a cavity cut in the flesh of the 

 plum with no concentric flap as in the case of the curculio. The young grub hatches out 

 and goes into the soft pit working therein, and developing while the pit hardens, 

 leaving no sign of its presence inside the pit and very little outside the plum except 

 perhaps a scar and sometimes a resulting malformation or gumming of the fruit. Here 

 in the pit, the pupal stage is passed and during the latter part of August the adult 

 emerges. It is a strange fact that the presence of this insect, large as compared with 

 the size of the plum, seems to interfere so little with the development and ripening of 

 the fruit, which takes place at about the usual time, sometimes being slightly accelerated. 

 Infested fruit sometimes appears tempting, though often gummed; it usually does not 

 fall until just before the exit of its inhabitant. 



* Insect Life, Vol. I, p. 89. 



