MODE OF EGG-LAYING. 



223 



tbe insect leaves her eggs Ijefore emerging ; in this way the mass is 

 sometimes placed a foot below the surface. In abnormal or unhealthy 

 conditions, the eggs may be laid in exposed places without any hole, in 

 which case they doubtless never give birth to j'ouug. In other cases, 

 the female will till her hole almost entirely with the sebific matter. Nor 

 are the eggs invariably laid in the ground, for while we know of no ex- 

 ceptions to this normal position in sijretus, yet Mr. Boll informs us that 

 around Dallas, Tex., in 1876, the eggs of differentialis were very numer- 

 ously placed under the bark of elm and hackberry logs that had been felled 

 on low land. We have also received from A. W. Hoffmeister, of Fort 

 Madison, Iowa, the eggs of a species of Stcnohothrus, and the young that 

 hatched from them, the eggs having been thrust into holes made by 

 feome carpenter-bee in a fence-post j while Chloealtis conspersa habitually 

 bores in dead wood. 



MANNER IN WHICH THE EGGS ARE LAID. 



" The female, when about to lay her eggs, forces a hole in the ground 

 by means of the two paiis of horny valves which open and shut at the 

 tip of her abdomen, and 

 which, from their peculiar 

 structure, are admirably 

 fitted for the purpose. (See 

 Fig. 2, where h, c, show the 

 structure of one of each 

 of the upper and lower 

 valves.) With the valves 

 closed she pushes the tips 

 into the ground, and by a 

 series of muscular efforts 

 aiid the continued opening 

 and shutting of the valves 



she drills a hole, until in a Fig. l: Eockt mountain locust.— a, a, a, female in differ- 



- . , , . ent positions, oviprsiting; 5, egg-pod extracted from ground, 



leW minutes (the time vary- with the end broken open; c, a few eggs lying loose on the 



. , ,, , o .,* ground; d,e, show the earth partially removed, to illustrate 



ing Wltn tUe nature Ot tue an egg-mass already in place, and onebeing placed; /. shows 



... 14-1 1, 1 1 where such a mass has been covered up. (After Eiley.) 



soil) nearly the whole ab- ^ ^ ^ 



domen is buried. The abdomen stretches to its utmost for this purpose, 

 especially at the middle, and the hole is generally a little curved, and 

 always more or less oblique (Fig. 1, d). Now, with 

 hind legs hoisted straight above the back, and the 

 shanks hugging more or less closely the thighs, she 

 commences ovipositing." 



When the hole is once drilled there exudes from the 

 tip of the body a frothv, mucous matter, which fills up ^ „ ^ 

 the bottom of the hole, and bathes the horny valves, tain locust— Anai 



. n • -, • t 1 characters of female, 



This is the sebific fluid which is secreted by the sebific showini homy valves. 



or cement gland described with the other anatomical 



details given in Chapter IX. By rep.eatedly extricating and studying 



