VIII, B, 1 



Mitzmain: Stomoxys calcitrans Linnseus 



31 



In two cases recorded, as many as 20 batches of eggs were 

 laid by a single fly, and the greatest number of eggs deposited 

 by an individual was 632. In this instance oviposition occurred 

 one day preceding the fly's death, which took place on the 

 sixty-fifth day of its laboratory history. 



Table I. — Data on oviposition. 



Length of 

 time fly 

 was kept. 



Number of 



depositions 



made. 



Total 



number of 



eggs. 



Days. 







50 



7 



168 



34 



9 



182 



60 



20 



438 



72 



13 



435 



65 



20 



632 



70 



11 



318 



64 



15 



446 



In addition to the eggs laid, there were present after death 

 a substantial number in each of the females dissected. In 

 three of these the contents of the egg chambers in the dissected 

 ovarian tubes were counted. In order to simplify the count, 

 the chains of immature ova were not taken into consideration. 

 It was found that the contents of the ovaries of the fly which 

 had laid 632 eggs consisted of 90 ripe eggs and 98 partially 

 developed eggs, making a total of 820 for 1 female. This 

 number, 820, may be fairly accepted, I think, as the maximum 

 number of eggs produced by a female Stomoxys. Twelve bred 

 flies were employed for enumeration in oviposition. In these 

 cases the eggs produced were sterile. As the result of these 

 counts, no information can be added to that obtained previously. 

 The total number of eggs deposited by any laboratory-bred 

 female did not approach the maximum of the depositions made 

 by the captive flies. 



If the contents of the ovarian tubes can be accepted as a 

 criterion of the possible maximum of egg production, one in- 

 stance among the new flies would appear to establish the record 

 in this regard. A fly emerging April 1 laid 106 eggs previous 

 to its death, which occurred May 14, The dissected contents 

 of the ovaries showed 71 ripe eggs, 112 half -developed eggs, 

 and 840 immature eggs in various stages of development; a 

 total of 1,123 from 1 female. However, until further inves- 

 tigation, this number will not be accepted as the possible max- 

 imum number of eggs that would be deposited by a Stomoxys. 

 I prefer to consider 820 as the more authentic number. 



