104 POTATO. 



sidered there would be no difficulty on this head, for the attack might 

 be expected to occur again as it had in previous years. 



In regard to measures of prevention or remedy, we do not at pre- 

 sent appear to have knowledge of any that would be at all applicable, 

 unless it might happen that in gardens where spraying is adopted to 

 keep off "Potato disease," that the chemical dressing would prove 

 deterrent if used sufficiently early in the season. 



The difficulty lies in the fact of the caterpillar turning customarily 

 (as noted in German observation) to chrysalis state in an earth-cell 

 in the ground in July ; from which the moth is recorded by British 

 observers as appearing in August and September. This puts the date 

 of development too early for breaking up the ground to be available 

 (as a general thing) so as to throw out the pupating caterpillars. 

 Consequently there is no obvious method of dealing with the attack as 

 there is with Gortyna flavago with which the caterpillar pupates in the 

 Potato stem. 



Further information on the attack might prove also of serviceable 

 interest relatively to Hop attack, as it is noted by Dr. Fletcher that a 

 nearly allied kind, Gortyna { — Hydrcecia) immanis, does much harm in 

 Ontario (Canada) by means of its caterpillar boring the leading shoot 

 of the Hops, and causing a disease known as "Bull-heads." * 



* See " Notes on Injurious Insects," by James Fletcher, in ' Insect Life,' U.S.A. 

 Department of Agriculture, vol. v. p. 125. 



