August, '22] HOWARD: Mexican bean beetle 265 



Mr. F. C. Bishopp: That depends on the stage of development. We 

 find it is necessary for the grubs to be almost ready to emerge normally 

 in order to transform. Ordinarily it is not necessary to destroy any of 

 those squeezed out, with the exception of those which have taken on 

 the brown or black color, which is indicative of the time being ripe for 

 them to drop out. 



Mr. R. C. Treherne: Do either of these species occur on horses? 



Mr. F. C. Bishopp: We have found Hypoderma larvae to a certain 

 extent in the backs of horses. We consider the horse of little importance 

 in connection with possible eradicative or control work. It is an abnor- 

 mal host. That is also true of a good many other animals. 



Mr. E. G. Kelly: How do you mix the treatment? 



Mr. F. C. Bishopp: One part of iodoform to five of vaseline. As I 

 mentioned in another paper, we have found certain washes are effective 

 and we have hopes of developing them. Derris in soapy water has been 

 found to kill almost one hundred per cent, with a single application, 

 applied with a brush to the backs of the animals. I might say also that 

 the British Board of Agriculture is advocating the use of a tobacco 

 decoction on the backs of cattle. 



Mr. C. E. Fetch: Have you noticed any effect that wet springs have 

 on the prevalence of the grubs? 



Mr. F. C. Bishopp: Wet springs are always unfavorable to them. 

 That comes about in two ways, we think, first, due to the ill effect on 

 the pupae, and the second due to the effect on the flies when they want 

 to deposit their eggs. Most egg laying occurs in the sunshine and if you 

 have continued cool cloudy weather it results in the destruction of the 

 adults before they have a chance to deposit. Nearly always the next year 

 following a rainy, cool spring, you find a lower percentage of infestation. 



President George A. Dean: The next paper is by N. F. Howard. 



THE MEXICAN BEAN BEETLE IN THE SOUTHEASTERN U. S. 



By Neale F. Howard, Specialist in charge, Research Work on Mexican Bean Beetle, 

 Bureau of Entomology^ in cooperation with the Alabama Experiment Station, Alabama 

 Polytechnic Instilu te. 



The Mexican bean beetle {Epilachna corrupta Muls.) is rapidly 

 assimiing a prominent place among the foremost injurious insects of the 

 United States. It has demontrated its importance not only in actual 



^Progress report prepared December 15, 1921 at Birmingham, Ala., with the as- 

 sistance of Messrs. L. L. EngUsh, J. R. Douglass and others. Bureau of Entomology. 

 Some data published in the Quarterly Bulletin of the State Plant Board of Florida, 

 October, 1921, pp. 15 — 24, are not included. 



