82 joi-rxal of economic entomology [vol. 7 



Methods of Oviposition by M. differentialis 



The usual text and figures have shown a recurved position of the 

 abdomen when illustrating the method of oviposition in grasshoppers. 

 Milliken/ however, has described the position of M. bivitattus, D. 

 Carolina, and S. shoshone. In his accompanying figure, the abdomen 

 and cavity is shown protruding greatly beyond the tips of the tegmina. 

 This is also described by W. D. Hunter.^ 



In an examination of twenty-one dijferentialis made during oviposition 

 by the junior author, no abdomen or excavation was found to extend 

 perceptibly ])ack of the tegmina. 



The accompanying plate 4 serves to illustrate the various positions 

 assumed by M. differentialis during oviposition. 



It has been our observation that the differentialis locust does not 

 begin to oviposit in this latitude before the first of October and this 

 season was no exception. In the ground covered by short buffalo 

 grass along the roadsides, or by paths through the alfalfa fields, are the 

 places selected for oviposition by M. differentialis. 



Mr. Henry Skinner: I would like to inquire whether the use 

 of oranges or lemons was original at this time, and I would also like 

 to know if Professor Dean can give us any estimate of the value of the 

 lemons and oranges in the mixture. 



Mr. George A. Dean: The use of fruit juices is not original 

 with the Kansas Experiment Station. It had previously been tested 

 in California, but its use was not general. When we tried it two or 

 three years ago we were convinced that it was very efficient. In case 

 it is left out of the bran mash about 75 per cent of the efficiency of this 

 material is lost. Fruit juices seem to attract the grasshoppers so 

 that they will feed on the poisoned bait. They will leave green corn 

 and feed on the poisoned bran mash. It seems to be more appetizing. 



Mr. R. a. Cooley: What kind of syrup is used? 



Mr. George A. Dean: I prefer common glucose syrup. We 

 also get a considerable amount of beet sugar syrup from Colorado. 



Mr. Wilmon Newell: I would hke to ask whether or not you 

 found this bran mash effective where the infestation was heavy and 

 where the hoppers had an abundance of food? 



Mr. George A. Dean: In a great many places the hoppers were 

 in the corn and fresh food was very plentiful, yet they would leave 

 the corn and also alfalfa and feed on the poisoned bran mash. 



Mr. E. p. Felt: I would like to ask if the weather conditions 

 had any material influence in increasing the efficiencj' of the poisoned 



' This Journal, Vol. 5, No. 2, page 232. 

 2 California Bui. 170, 190.5. 



