1920] ECONOMFC ZOOLOGY ENTOMOLOGY. 361 



infest the SliastJi daisy and tlie ((1111111(111 lickl daisy in this (■(Hiiilry liavc tluis far 

 failed. Several varieties, ail of wliieh are the hleiidt'd jiroduct of C iinticum and 

 C. morifoliitni, both of whieh j^row wild iu China and Japan, are fairly frtn' from 

 Injury. 



While primarily a preenhou.se pest, it was found by Gibson iu August, 1915, 

 occurrinfj; on both f,'reenliouse and outdoor plants at Ottawa, Canada, and the 

 autliors have found it to infest hardy chrysanthemums Knowing out of doors 

 all winter at Rosslyn, Va. A careful inspection of the entire stock at Kosslyn 

 revealed tlie fact that the insects had wintered over on tliese plants in the 

 immature stages, probably as either larvae or pupae within the galls. 



The adults emerge after midnight, and egg-laying takes place early in the 

 morning. The female shows a marked preference for the buds, or the tissues 

 just unfolding from the buds, in ovipositiou. Observations show from 5 to 135 

 eggs to have been deposited at one time, with an average of 32. Five days 

 were recjuired for the incubation of the eggs during April and from 3 to IG 

 days in September, depending upon the temperature. From 4 to 14 days, with 

 an average of 7 days, elapsed from the time the larva entered the tissue to 

 the first sign of a swelling or gall. From 21 to 46 days with an average of 

 28 days passes from the time the larva tirst enters the tissue until the emer- 

 gence of the adult. From 20 to 50 days were found by Britton (E. S. R., 41, 

 p. 158) to be required for transformation within the gall. Data presented in 

 tabular form which represent observations of 17 life history cages under 

 "Washington c<mditions, indicate that the total life cycle requires from 27 to 52 

 days, with an average of 35 days. 



There is a constant overlapping of broods when the greatest numbeis are 

 present, namely in the spring and fall of each year. The aestivation period 

 has been found to extend in Maryland, Virginia, and the District of Columbia 

 from the early part of June to the latter part of August. " In the spring of 

 1917, 1918, and 1919, 3 distinct generations were observed. The first genera- 

 tion stJirted about the middle (tf February, and the last adults of this gen- 

 eration emerged during the last few days of ApriL The second generation 

 .started about the middle of March, and the last adults issue<l around April 30. 

 The third generation started the latter part of April and emerged dui'ing the 

 early part of June. In the fall of 1918, when the occurrence increased agaiu 

 a sinnlar grouping of generations was evident, the first beginning about the 

 latter part of August, and the last adults emerging during the first days 

 of October. A seccmd generation started about the middle and hitter part of 

 September, maturing the first days of November, The third generation was 

 observed beginning about the middle of October and the last adults emerged 

 about November 25." 



It has been reiwirted to be attacked in California, by 2 parasites, namely, 

 Amhlj/mnus sp. and Trtrnstichus sp. Experiments show that tlie egg stage 

 may be controlled by spraying or dipping the cuttings or plants; that the adult 

 can be killed easily at the time of emergence by consistent spraying; and that 

 the adult is easily killed by fumigation, either with nicotjn papers or hydro- 

 cyanic-acid gas. Experiments applicable to general propagation practices show 

 conclusively that such measures offer a reasonable safeguard and protection 

 against doubtful stock and infested material without injury to the plants. 



"In case of a very light infestation, daily picking of gall-infested leaves Mill 

 hold the pest in check, but should this practice prove ineffective, nightly fumi- 

 gation for a period of 2 or 3 weeks may be resorted to. When a severe infes- 

 tation is encountered the most heavily infested plants should ho takt^n out 

 hnmediately and burned. This should then be followed l»y eitlier fumigation 

 or spraying as outlined. Fumigate every night, with either nicotin papers 



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