160 MANUAL OF VEGETABLE-GARDEN INSECTS 



otluT \ariety {P. nchris), there are three distinct white spots 

 nearly one third the distance from the l)ase of the wing, the 

 middle one being the smallest (Fig. 92). Jnst inside the outer 

 line near the front margin of the wing is a fine yellow crescent 

 with a yehow spot lying within its concavity and with three 

 to five white dots on its h)wer and inner side. There is only 

 one generation annually. 



Control. 



No satisfactory method of reaching the borers in their bur- 

 rows is known. ]Much loss may be avoided, however, by de- 

 stroying all rank weeds in which the caterpillars live growing 

 in the vicinity of the garden and along the edges of fields planted 

 to tomatoes, potatoes, corn and other plants especially subject 

 to injury. 



References 



N. J. Agr. Exp. Sta. Rept. for 1905, pp. 584-587. 



111. Agr. Exp. Sta. Bull. 95, pp. 374-377. 1904. 



Franklin, 12111 Rept. State Ent. Minn., pp. 197-198. 1908. 



And in other papers published by Washburn. 



The Burdock Borer 



Papaipema cataphracta Grote 



Potato, tomato, rhubarb and corn have been reported in 

 Canada as injured by a stalk-borer closely related to the species 

 last treated. The insect ranges throughout the northern states 

 and Canada westward to Minnesota. The favorite food 

 plants of this caterpillar are burdock and thistle, but sunflow^er, 

 ragweed, golden glow, hollyhock and many other ornamental 

 plants are also subject to attack. The work of the borers 

 becomes noticeable in July, specimens one third to full-grown 

 being found till the first of August. The caterpillar is very 

 similar to the common stalk-borer but the stripes run from end 



