REPORT OF THE ENTOMOLOGIST AND BOTANIST 231 



SESSIONAL PAPER No. 16 



Mr. Norman Griddle reports that ' The Eed Turnip Beetle became rather trouble- 

 Bome last summer to cabbage, radishes, turnips and a few other garden plants. I 

 noticed, too, that it had a preference for radishes in ihe seedling state. A few of these 

 plants left to go to seed would, I think, make excellent traps for the beetles, and could 

 be sprayed from time to time to destroy those which have gathered there.' 



The Purple-backed Cabbage "Worm [Evergestis (Pionea) straminalis, Hbn.]. — 

 Occasional reports have been received at different times during the past ten years of 

 the presence of short bristly caterpillars attacking cabbages and turnips in the Mari- 

 time Provinces. This injury was for the most part to turnips, and was generally 

 noticed late in the season, the caterpillars congregating on the crowns of the turnips 

 and eating cavities into the roots, as well as consuming the leaves. During the past 

 season this caterpillar seems again to have been somewhat abundant, particularly on 

 Cape Breton Island, whence Mr. E. J. Williams, of Little Bras d'Or, sent specimens, 

 together with notes on the occurrence. He also reports that in some years whole fields 

 of tfabbage and turnips have been destroyed by these caterpillars. Among the speci- 

 meirs sent by Mr. Williams were a large number of half-grown larvae of the Spotted 

 Cutworm (Noctua c-nigrum, L.), which undoubtedly had been responsible for some of 

 the injury described by him in the following note. Writing under date of October 

 24, he says : — ' I am sending you some of the caterpillars I spoke of. They are very 

 gregarious in their habits; they start under the leaves right on the ground but mine 

 their w&j up to the head, tunnelling it hollow.' 



In 1903 Mr. C. H. Young, of Ottawa, made some observations on injuries by this 

 species upon cabbages near Old Chelsea, Quebec, twelve miles from Ottawa. The 

 caterpillars, however, were not very numerous in this instance, and were not noticed 

 to bore into the stems as mentioned above, but lay exposed on the leaves, and only two 

 or three caterpillars were found on a single plant. Full-grown larvas collected by Mr. 

 Young on July 11 produced moths on August 8. 



There is little reference to this species in the literature on injurious insects; but 

 under the name of Pionea eunusalis, Walk., there is an account, with a good figure 

 of the larva, by Thaddeus Harris in his Entomological Correspondence, page 322, stating 

 that on October 30 and November 1, 1841, he had found larvse on the leaves of horse- 

 radish. He thus describes the attack : ' They eat large holes out of leaves, leaving 

 finally only the veins untouched- They live beneath the leaves, stretched out by the 

 sides of the midrib. They creep regularly, not haltingly, and move pretty fast. When 

 alarmed or disturbed, they curl quickly and loose their hold and fall to the ground. 

 Found the same on turnip leaves, October 20, 1844. Their ravages were considerable,' 



The Purple-backed Cabbage Worm is closely related to the Cabbage Pionea (Ever- 

 gestis rimosalis, Gn.), which is a well known pest of the cabbage and turnip. That 

 species, however, does not occur injuriously in Canada. The following is a descrip- 

 tion of the caterpillar, and is made from the specimens sent by Mr. Williams : — 



Body tapering slightly to each end; length, three-quarters of an inch by one- 

 eighth at the widest part; head, a shield divided into two spots on the second segment, 

 and a small plate at the end of the body, black. The general colour of the back, pur- 

 ple with a brownish tinge, the lower part of the body, pale greenish. The body is 

 marked with the ordinary bristle-bearing tubercles and a rather conspicuous yellow 

 band on each side, where the breathing pores are placed. The six tubercles above the 

 F.ide lines are rather more conspicuous than those below the lines and are of a deeper 

 black. The tubercles are all black, but have white marks at their bases, which form 

 a part of an indistinct network of lines over the whole upper part of the body. These lines 

 are broken up into dots, or seem to be narrow, broken, thread-like longitudinal lines con- 

 necting the tubercles in each series. There is also an equally indistinct line whicH 

 runs transversely across the middle of each segment, and one in each intersegmental 

 fold, the whole forming an open network composed of two series of very indistinct 

 but perceptible lines running at right angles to each other. The chief character by 



