REPORT OF THE ENTOMOLOGIST. 



317 



arid trash will undoubtedly much lesson its numbers. Tin's is, in fnct, 

 almost the only practical method of fighting it. Mr. Howard states 

 that the application of lime has been tried to some extent, but seemingly 

 without result. On account of the habit which the bugs have of cluster- 

 ing in shriveled-np leaves in the morning when the dew is on the plants, 

 he advises going through the garden or Held with a pail containing live 

 coals, into which such leaves are dropped after plucking them off. In 

 small gardens the adoption of this remedy might pay, but we would 

 advise the substitution of water with a film of kerosene on its surface 

 fbr the live coals. Fortunately, however, we have available two insect- 

 icides that had not come into use when we first wrote on this insect. 

 These are pyrethrum and kerosene emulsion, which, as we have already 

 seen, Professor Forbes found perfectly satisfactory as against the Tar- 

 nished Plant-bug (Lygus lineolaris, Beauv.), and which we do not hesi- 

 tate to advise to be used in the same manner against the False Chinch- 

 bug, which, in habit and characters, is so closely related to the species 

 experimented on. 



THE CABBAGE PLANT-LOUSE. 

 (Aphis brassiccc Linn.) 

 Order Homoptera; Family Aphid id m. 

 [Plate VII; Fig. 4.] 



PAST HISTORY AND HABITS. 



The Cabbage Aphis is without much doubt an imported insect. Fitch 

 shows, by reference to the Transactions of the New York State Agri- 

 cultural Society for 1791, that it was already known in this country at 

 that early date, and states that it was probably introduced shortly af- 

 ter the cabbage-plant itself was brought over. In Europe, as in this 

 country, it occurs commonly on the turnip, radish, field cress (Isatis 

 tinctoria) shepherd's purse ( Capsella bursa pastoris), and charlock (Bras- 

 sica arvensis), in addition to cabbage, and upon this last plant, accord- 

 ing to Buckton, " it often crowds both the upper and under sides of the 

 foliage in such numbers that the leaves become hidden by the living 

 mass. Indeed, sometimes, weight for weight, there is more animal than 

 vegetable substance present. The leaves then become putrid, offensive 

 in odor, and quite disgusting to the eye."* This is a common sight in 

 this country also, and frequently whole fields of cabbage are rendered 

 unfit for the market by the work of this species. 



It abounds in all parts of the country where the Cabbage is culti- 

 vated, from Northern New York to Southern Georgui, and were it not 

 for its numerous natural enemies it would rank as the most serious of 

 the insect foes of this plant. 



It is found upon the under side of the loosened outer leaves of the 

 cabbage, or upou the upper side of the compacted inner leaves, either 

 wandering about singly or settled in large groups. It makes its ap- 

 pearance in June or Ju'3^, and remains until cold weather. Late in Oc- 

 tober, 1871, we noticed great numbers of this aphis flying in the city 

 of Saint Louis, filling the air iu every direction and flying into people's 



* Monograph of the British Aphides, II, 31. 



