﻿OF THE STATE ENTOMOLOGIST. 103 



Experiment 25. — Two egg-masses under same conditions as in Expt. 23, till Feb. 

 27th, when they were placed in earth in-doors. Those examined March 7th were 

 sound, and near the hatching point. 



These experiments, though not yet completed at the time this 

 MS. goes to the printer, yet establish a few facts that were somewhat 

 unexpected. The insect is a denizen of the high and arid regions of 

 the Northwest, and has often been observed to prefer dry and sunny 

 places, and to avoid wet land, for purposes of ovipositing. The belief 

 that moisture was prejudicial to the eggs, has, for these reasons, very 

 generally prevailed. The power which they exhibit of retaining 

 vitality, and of hatching underwater or in saturated ground, is, there- 

 fore, very remarkable — the more so when viewed in connection with 

 the results obtained in the succeeding experiment. That the eggs 

 should hatch after several weeks submergence, and that the young 

 insect should even throw off the post-natal pellicle, was, to me, quite a 

 surprise, and argues a most wonderful toughness and tenacity. After 

 being dried and soaked for over six weeks, under conditions that 

 approach to those of Spring, I found a good proportion of the eggs to 

 contain the full-formed and living young, which, though somewhat 

 shrunken, and evidently too weak to have made its exit, was still capa- 

 ble of motion. The water evidently retards hatching. An examina- 

 tion of the submerged eggs that remained unhatched long after others 

 had hatched, which had been under similar treatment up to a certain 

 time, and then transferred to earth, showed the jaws and tibial spines 

 to be still quite soft. It is, therefore, in preventing the proper hard- 

 ening of these delivering points, that water doubtless retards the 

 hatching, and prevents its accomplishment long before the embryon 

 perishes. Yet, when once life has gone, the egg would seem to rot 

 quicker in the water than in the ground. 



The results of Experiments 23 — 25 prove conclusively that water 

 in Winter time, when subject to be frozen, is still less injurious to the 

 eggs. 



Altogether, these experiments give us very little encouragement 

 as to the use of water as a destructive agent; and we can readily 

 understand how eggs may hatch out, as they have been known to do, 

 in marshy soil, or soil too wet for the plow; or even from the bottom 

 of ponds that were overflowed during the Winter and Spring. While 

 a certain proportion of the eggs may be destroyed by alternately soak- 

 ing and drying the soil at short-repeated intervals, it is next to impos- 

 sible to do this in practice during the Winter season as effectually as it 

 was done in the experiments; and the only case in which water can 

 be profitably used is where the land can be flooded for a few days 

 just at the period when the bulk of the eggs are hatching. 



