HATCHING IN THREE SPECIES OF NEUROPTERA.* 



Roger C. Smith, 



Associate Professor of Entomology, 



Kansas State Agricultural College, Manhattan, Kansas. 



This paper deals with the process of hatching in three 

 species of Neuroptera, viz., Chauliodes pectinicornis Linn, 

 Micromus posticus Walker, and Chrysopa oculata Say. The 

 observations were made with special reference to the egg 

 bursters. This account is therefore a brief description of the 

 appearance of the eggs at hatching, the process of hatching 

 and a description of the special structure enabling the embryo 

 to leave the shell. This structure in the three species mentioned 

 is of the same general type, but there are important differences. 

 The general process of hatching in each case, as well as the 

 appearance of the eggs at hatching, are very similar. 



1. Chauliodes pectinicornis Linn, 



The function of the egg burster in this species was observed 

 in 1912 by H. S. Barber, who did not publish upon the subject. 

 He very kindly sent the writer his sketches and photographs 

 and supplied the fresh material upon which these observations 

 were made. This material consisted of a large number of eggs 

 deposited June 16, 1919, in confinement by a gravid female 

 caught at lights at Plummer's Island, Maryland. When 

 received, June 20th, they showed advanced embryological 

 development and hatched under the writer's observation 

 June 24th. 



The eggs all lay on what was the dorsum of the embryo 

 (Fig, 4), the ventral side up, and with the prominent knobbed 

 micropyles all pointing the same direction. When these eggs 

 were ready to hatch, the two black eye spots could be very 

 plainly seen each side the mid-ventral line and near the micro- 

 pylar region. A little posterior to these were the very prominent 

 bifid amber-colored mandibles. Furthermore, in the mid- 

 ventral line between the eyes and above the mandibles was seen a 

 thin chitinous carina resembling a small knife blade. This 



* Contribution No. 78 from the Entomological Laboratory, Kansas State 

 Agricultural College. 



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