232 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



earliest (App. 1), and since, as we have already seen (antep.228) the egg- 

 laying covers an average period of six or eight weeks in the same locality, 

 and lasts generally till frost, it follows that the eggs pass the winter in 

 every state of development — some with the fluids clear and limpid; others 

 with the embryo fully formed and ready at the first approach of spring 

 to hatch. This we found also to be actually the case, for many hun- 

 dreds of egg-masses examined during the winter of 1876-'77, from divers 

 parts of the infested region, showed every state of development. 



In the same locality hatching will take place — cccteris paribus — first 

 on light dry soils and on south and southeast exposures ; latest on low, 

 moist, and shaded or tenacious ground. 



We see, therefore, that the hatching will not alone vary according to 

 temperature and the earliness or lateness of the spring, but that it is 

 quite variable under the same conditions. In every instance there will 

 be a few hatching when the first hatched in the same locality are getting 

 wings, and we give it as a general rule that the bulk of the eggs hatch 

 out in the different latitudes about as follows : 



In Texas, from the middle to the last of March. 



In the southern portions of Missouri and Kansas, about the second 

 week in April. 



In the northern parts of Missouri and Kansas and the southern sec- 

 tions of Iowa and Nebraska, the latter part of April and first of May. 



lu Minnesota and Dakota, the usual time of hatching ranges from 

 early in May in the southern portions to the third week in the northern 

 extremity. 



In Montana and Manitoba, from the middle of May to the first of 

 June. 



In short, the bulk of the insects hatch in ordinary seasons about the 

 middle of March in latitude 35°, and continue to hatch most numer- 

 ously about four days later with each degree of latitude north, until 

 along the forty-ninth parallel the same scenes are repeated that occurred 

 in Southern Texas seven or eight weeks before. 



From a number of experiments which we have made on the eggs we 

 conclude that, with a constant temperature of 85^ F., with favorable 

 conditions of soil, the eggs v, ill hatch in from four to five weeks after 

 they are laid, and in a temperature of 75^ F. in about six weeks. Mr. 

 Itiley has had the eggs of Caloptenus atlanis (laid in July) hatched in 

 irom three to four weeks ; those of iragocephala viridifasciata (laid in 

 June) in three weeks ; and those of Acridium Americanum (laid in July) 

 in rather more than a month. 



nACITS OF THE YOUNa OR UNFLEDGED LOCUSTS IN THE TEMPORARY 



REGION. 



" The habits of the young insects as they occur in the temporary region, 

 and particularly in the country south of the forty-fourth parallel and 

 east of the one hundredth meridian, are as follows : Although possessed 



