MARCH 19, 1921 proceedings: entomological society 141 



rear end to its middle where it penetrates between the stomach walls (not 

 into stomach lumen), goes forward, unites with intestine, and the latter 

 emerges at top of stomach. The Malpighian tubules arise within the stom- 

 ach walls and emerge at the constriction between the two stomach com- 

 partments. 



It appears to be impossible in any way to homologise the connections of 

 the mouth setae to the head and their internal apodemes and muscle attach- 

 ments with these parts in biting insects. Yet all students of their embryo- 

 logical development, except one, agree that the setae are the true mandibles 

 and maxillae. If so the details of their transformations need to be followed 

 more closely than has yet been done. 



Mr. C. T. Greene presented a note on the larvae of the flies of the vStrat- 

 omyid genus Hennetia. The larvae of this genus are scavengers and have 

 been found in various places, as follows : 



Hennetia chrysopila Loew, a scavenger in holes in Opuntia made b}' other 

 insects, and in other decaying vegetable matter. H. Jiunteri Coq., habits 

 same as H. chrysopila. H. illncens L., in wax in beehives, in latrines, and 

 in decaying vegetable matter. Dunn reports this species breeding in large 

 numbers in a human cadaver in the Canal Zone. 



Larvae of Hennetia sp. weie found in raw rubber at Para which was shipped 

 to England. The larvae were presented to the U. S. National Museum by 

 Dr. C. Gordon Hewitt of Canada. 



330th meeting 



The 330th meeting was held April 1, 1920 at the Cosmos Club, with Presi- 

 dent Walton in the chair and 27 members and 2 visitors present. 



Program 



A. D. Hopkins: The hioclimatic law and its application to researcli and 

 practice in entomology. 



The results of detailed studies of the codling moth from Maine to California 

 and New Mexico were made available to the writer by Dr. A. L. QuainTance, 

 with a request for information on the application of the bioclimatic law to the 

 mapping of the distribution of the codling moth and its generations, the fore- 

 casting of spraying dates, etc. 



The methods utilized and the results were described and illustrated, and 



it was shown that forecasts could be made within the range of allowable error 



for any given place within the United States as to 



(a) The dates on or near which the first, maximum, and last hatching of the eggs of the 

 first and subsequent seasonal generations of the codling moth may be expected to occur; 

 {b) the number of generations expected; 



(c) the optimum time to spray; 



(d) the latitude and altitude limits of distribution of the insect; 



(e) the altitude limit of each number of complete generations of hatched eggs. 



Date constants of the egg-hatching were computed from the table of con- 

 stants for each of the six stations utilized, and when these were compared 

 with the recorded dates for all years and all events the average difference be- 

 tween the recorded and the constant dates was found to be within a range of 

 error allowable for local influences, etc. vSimilar computations for the falling 

 of the apple petals and the thermal meannormal for April to July, inclusive, 

 at each of the stations gave similar results. Thus the computations from the 

 falling of the petals and the thermal mean constants served as checks on the 

 computations from the egg-hatching constants. 



