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16 



The Florists^ Review 



JuNB 17, 1920. 



rated parts of three states. They were 

 uncovered all winter and the ground 

 had frozen to a depth of several feet, 

 but this spring, when the growth 

 started up again, the midge was right 

 on the job, apparent evidence that 

 freezing does not clean them out. 



Proper Remedy. 



Fumigation in any form, whether gas 

 or tobacco, should be maintained so that 

 'th?"^poisonou8 fumes are in the atmos- 

 phere all the time, so long as there is 

 a midge in your place, so that the in- 

 stant the midge emerges from its har- 

 bor it comes in contact with the poison. 

 Tobacco dust is not reliable, because it 

 soon loses its strength and does not 

 completely cover the plant. 



In the previous article on the midge 

 I gave a formula for using nicotine, 

 with advice to use it strong enough to 

 burn the foliage. It is difficult to state 

 what proportion this requires. In the 

 winter, when ventilators are down tight 

 and there is little circulation of air, 

 considerably less nicotine is needed 

 than in the summer, when the venti- 

 lators are open day and night. I have 

 also found a great deal of difference in 

 the chemical action of water. Alkali 

 or lime rock water, or water from wells, 

 demands almost twice as much nicotine 

 as water from lakes, rivers or ponds. 



One grower situated just across the 

 road from another, but having a differ- 

 ent source of water supply, has to use 

 just twice as much nicotine as his neigh- 

 bor. The latter uses pond water, while 

 the former uses well water. 



For this reason I can only say, use 

 your nicotine spray strong enough to 

 burn the foliage. By nicotine spray I 

 mean your favorite brand, whatever it 

 may be. 



Successful Formula. 



Here I will repeat what I regard as 

 the most successful midge destroyer. If 

 you have a better one that is absolutely 

 dependable, kindly send it in for publi- 

 cation. My formula is nicotine in liquid 

 spray form strong enough to burn the 

 foliage (add enough yellow soap to 

 make it stick and spread evenly), to 

 which is added one tablespoonful of 

 lysol to each gallon of spraying solu- 

 tion. Lysol is a powerful disinfectant, 

 similar to carbolic acid, and can be had 

 at any drug store for 20 cents. 



To clean out the midge thoroughly, 

 spray your plants every day (twice a 

 day, morning and evening, is better), 

 leaving this film of nicotine on the 

 plants, so that whenever the midge 

 leOKBes out of its harbor it will receive 

 a grand reception at the hands of Lady 

 Nicotine. The smallest particle of 

 nicotine will kill a midge, but if Mrs. 

 Midge comes out and finds the plant 

 has just boon washed clean of all nico- 

 tine, she hurries around and plants 

 eighty to 150 eggs and dies a natural 

 (loath before you apply more nicotine 

 on the second day. 



Keep After Them. 



Eecently a grower asked how it is 

 that, after he cleaned out the midge 

 from his mums last winter, he is again 

 bothered with them this spring. One 

 should reniember that the eggs are ex- 

 tremely minute. They were probably 

 buried in the growth and lay dormant 

 till th plants matured this spring, 

 when the warm weather hatched the 

 midge rapidly. 



Wherever an egg is buried that is 



maturing there is a scar on the leaf or 

 stem. In some instances there are as 

 many as fifty eggs per leaf. As the leaf 

 grows, the scars prevent its maintain- 

 ing its natural shape and so it is badly 

 crippled and undersized. The eggs in 

 the stem, if more numerous on one side 

 than on the other, cause the bloom to 

 open sidewise and in some cases the 

 bloom may be turned downwards in- 

 stead of upwards. Therefore one should 

 remove the affected leaves as soon as 

 one sees them. 



One of the prominent chrysanthemum 

 growers of the middle west, when asked 

 as to the best method of combating the 

 midge, said, "After you have them all 

 cleaned out, keep on fighting them just 

 as though you still had them." 



D. W. Dumser. 



GOVERNMENT EXPERTS' ADVICE. 



Appears in New Bulletin. 



In bulletin No. 833, two investigators 

 of the Department of Agriculture have 

 collaborated in a study of the chrysan- 

 themum midge. In- this pamphlet, bear- 



" '^'y"'*i« y ^* ^j «P' wj >gy^^-y----,-^-ir.^'': 



Adutt Female Midge, Much Magnified. 



ing the date of May 31, 1920, C. A. 

 Weigol and H. L. Sanford present a num- 

 ber of interesting facts concerning the 

 life and habits of this insect. The facts 

 concerning its control have already been 

 presented in The Review. Some of the 

 descriptive matter of interest to clirys- 

 anthemum growers is given below: 



"When chrysanthemums are infested 

 by this midge, the attention of the 

 casual observer is most likely to be 

 drawn to the presence of galls. These 

 galls occur on the leaf, stem or flower 

 head of the chrysanthemum plant. After 

 the larvae hatch from the orange-col- 

 orod eggs, which are dejiositod by the 

 adult female on the surface cf tender 

 tips and new growth, they bore their 

 way into the tissues, thereby giving rise 

 to the galls. 



"The galls are cone-shaped and gen- 

 erally project obliquely from the sur- 

 face. The length of the gall when fully 

 developed is about one-twelfth of an 

 inch. When the leaf is affected, the 

 galls usually occur on the upper surface. 

 In such cases a slight swelling often 

 may be observed on the opposite, or 

 under side of the leaf. Growth and 

 development of both larva and pupa 

 take place within this gall. When the 



pupa is fully developed it pushes itself 

 out of the gall, still enclosed in the 

 pupal skin. The latter then splits do\Ara 

 the middle of the head and back to allow 

 the adult to emerge. 



"In the adult stage the midge is a 

 fragile two-winged fly, one-fourteenth 

 inch in length. The abdomen of the 

 male is yellowish orange, while that of 

 the female is reddish orange. The adult 

 on emerging leaves .its pupal skin pro- 

 truding from the opening pf the empty 

 gall. The adults emerge after midnight 

 and egg-laying takes place early in the 

 morning. 



Varieties Affected. 



"While the chrysanthemum midge has 

 been recorded from central and south- 

 ern Europe as seriously injuring the 

 common white or oxeye daisy (Chrysan- 

 themum Leucauthemum), as well as C. 

 corymbosum, C. atratum, C. japonicum 

 and G. myconis, its depredations in 

 North America are confined to prac- 

 tically all of the commercial chrysan- 

 themums, both the single and pompon 

 varieties. The first _ infestation in this 

 country was reported on the variety 

 Mistletoe, and according to Felt this 

 variety appears to be very susceptible to 

 the attacks of the midge. 



"Although several attempts have 

 been made to infest the Shasta daisy 

 and the common field daisy, C. Leucan- 

 themum, it has not been possible to get 

 the ovipositing female to lay eggs on 

 them. This is of much importance, for 

 should the infestation spread to this 

 common weed, there would be great diffi- 

 culty in eradicating this pest. 



"A. Gibsoii lists the following varie- 

 ties as being fairly free from injury: 

 Bob Pulling, Gertrude Peers, Daily Mail, 

 Oconto, Mrs. G. C. Kelley, W. " Wood- 

 mason, G. T. Quilleton and E. T. Quit- 

 tington. All the above varieties are the 

 blended product of C. indicum and C. 

 morifolium, both of which grow wild in 

 China and Japan. He reports the fol- 

 lowing varieties as being practically 

 ruined: Smith's Advance, Ivory, Boii- 

 naffon, William Turner, Western King 

 and Englehart. 



' ' Observations made by H. F. Dietz in 

 the middle west showed that the William 

 Turner variety had lost all the crown 

 buds. In case of a thick infestation on 

 the variety Dr. Enguehard all of the 

 ])lants had to be discarded early in the 

 season; also all Chadwick varieties, as 

 well as Elberon, Major Bonnaffon and 

 Golden Mensa. The varieties which 

 seemed to be least injured were Golden 

 Age, Harvard and White Bonnaffon. 



"In some of the greenhouses of th'' 

 District of Columbia during the season 

 of 1918-1919 such varieties as Mensa, 

 William Turner and the white and yel- 

 low Bonnaffon were completely ruiml 

 on account of the severe infestation. 



Control Recommendations. 



"From the life history it is clear tha' 

 certain points must be kept in mind it' 

 the best })ractical results are to be se- 

 cured. First, several generations are 

 always present in greenhouses durini^ 

 the spring and fall occurrences; second, 

 tlie adults emerge and mate during the 

 very early morning hours, and egg lay- 

 ing quickly follows; third, preliminary 

 control experiments show that the eg^' 

 stage may be controlled by means of 

 spraying or dipping the cuttings or 

 jdants; fourth, it has been demonstrated 

 [Continued on paffo 46.] 



