82 Kansas Academy of Science. 



reach the surface of the hull, but still leaves a thin epidermal film un- 

 cut on the outer face. This action appears necessary to enable the 

 insect to free itself when it matures as a moth, since the adult, not being 

 provided with mouth-parts for gnawing, so far as known, would other- 

 wise be utterly imprisoned in its birthplace and perish there. It is able, 

 however, to break the film, probably by exerting pressure against it, for 

 effecting emergence. The blotch which consequently marks the position 

 of the hollow on the inner side of the hull is the first clue to any injury 

 having been done to the grain. Up to this juncture, the larva seemed 

 to have fed close to the hull, thus forming a shallow channel instead of a 

 perfect burrow in the kernel. In all of such cases, the larva finally 

 pupated within the cavity that it had eaten out during the time of its 

 occupancy. 



The matter of working out the particulars of the development of an 

 insect when much of its life is spent in concealment within a product 

 requires special aptitude and patience. Such attendant conditions have 

 to be met in the study of most grain pests inclusive of the present 

 species. Success in prosecuting the work depends on the availability of 

 an ample supply of infested material that will permit losses of stages 

 occasioned by the frequent removal of specimens for examination and 

 still leave a sufficient number for the perfection of observations on the 

 course of life from start to finish. 



Owing to the lack of exact data on the deposition and hatching of 

 eggs, nothing more than tentative calculations could be made on the 

 time required for growth of the larvae. The intervals from date of con- 

 finement of the parents until each of the three pupae was detected, less 

 ten days allowed for the issue of larvae to take place at the start, cover 

 respectively fifty, fifty-two and fifty-five days for the growth of the 

 larval stage in each instance. With an average larval term of slightly 

 more than fifty-two days, the medial date of pupation fell on May 17. 

 Since the estimates are fully cited in the remarks and schedule given 

 under the concluding topic entitled, "Attainment of a Generation," ref- 

 erence to them should afford a more comprehensive understanding of 

 the reckonings and save their repetition here. 



PUPATION. 



In the preceding discourse treating of the larval stage, some of the 

 features of pupation have necessarily been mentioned. Further atten- 

 tion, however, is called to the schedule included in the final part of this 

 paper under the heading of "Attainment of a Generation," in which 

 th pupal periods of three additional examples are reckoned. Although 

 the records are insufficient for making a positive calculation of the time 

 required for the development of each pupa, of which the durations were 

 not exactly determined, yet the data will serve to establish a tentative 

 estimate. As near as could be reasonably computed, the pupal period 

 in no instance was less than nine days nor more than twelve days. 

 According to the deductions so obtained, the average time came to 

 nearly eleven days. 



Besides the statements already made concerning the pupal stage, but 

 few remarks remain to be given on the subject. Some interest is af- 



