INSECTS AND PLANTS 55 



It is of interest to note that in dry sandy soils the tunnels 

 pass much deeper into the earth than in clay soils ; also, 

 in the autumn, the insects which are destined to winter as 

 pupae pass considerably further into the ground than their 

 relatives earlier in the season : by doing so they are pro- 

 tected against frost. 



The duration of the pupal stage varies from rather more 

 than ten days, in the summer, to over six months in the 

 case of the individuals which hibernate as pupae. When 

 emergence takes place, the moths push aside the layer of 

 earth at the top of the silk-lined burrow and come to the 

 surface with their wings still unexpanded; although un- 

 able to fly for several hours, they are able to run with 

 considerable agility. In colour they are even more 

 variable than the larvae, and no good purpose would be 

 served in attempting to describe all the varieties. During 

 the day the moths rest with their wings folded tightly 

 over their backs and never move from their position unless 

 disturbed, when they usually fly rapidly to another resting 

 place and quickly seek cover. 



Feeding and oviposition rarely take place by day ; it is 

 not till about four o'clock that the adults begin to become 

 active, and often they are not on the wing till much later. 

 In the case of the females, it appears to be absolutely 

 essential for them to feed before they are in a condition 

 to oviposit. Anthonomus grandis, Chloridea obsoleta, and 

 Alabama argillacea are a notorious trio, but, with them 

 out of the way, the cotton plant would not be immune from 

 insect attack ; what, for want of a better term, may be 

 styled pests of second rank, in the shape of the cotton 

 stainer, Dysdercus suturellus ; the cotton-leaf bug, Calocoris 

 rapidu8\ and the cotton-square borer, Uranotes melinus, 

 do an incalculable amount of damage to this essential plant. 



The periodical cicada, Cicada septendecim, is "un- 

 doubtedly the most anomalous and interesting of all the 

 insects peculiar to the American Continent." The most re- 



