THE AMERICAN ENTOMOLOGIST. 



169 



the purpose of learning something of the 

 next and subterranean act in the drama. 

 The Cicada was found at the extreme end 

 of the burrow lying on its back, and the 

 long slender semi-transparent egg of the 

 wasp carefully slipped under the thigh or 

 femora of one of the front legs, 



I have never found more than one Ci- 

 cada in a burrow, but it seems strange that 

 the wasp should work so long and indus- 

 triously in order to bury one victim and 

 lay only one egg. — A. S. F. 



THE COLORADO POTATO-BEETLE. 



( Continued /ro)ii p. 118./' 

 NATUR.\L HISTORY AND TRANSFORMATIONS. 



Prof. Riley was the first to make known 

 the natural history and transformations of 

 the Potato-beetle, in the Prairie Farmer 

 for August 8, 1863, and they may be briefly 

 summed up as follows : The female beetle 

 deposits her eggs on the underside of the 

 leaves, in clusters of a dozen, up to fifty 

 or more. The eggs are of an orange 

 color, and hatch in about a week after 

 being laid, the grubs immediately com- 

 mencing to feed and continuing until ma- 

 ture, which occurs in from fourteen to 

 eighteen days, varying somewhat as the 

 weather may be favorable or unfavorable. 

 When full grown, the larvae descend to the 

 ground and hide under leaves or rubbish, 

 or burrow into the soil, where they remain 

 for about ten days, then come forth in the 

 perfect or winged form. Two to four 

 broods are perfected during the season, 

 according to the locality and length of the 

 season, the last brood descending into the 

 ground in the perfect or beetle state, and 

 remaining in a dormant condition over 

 winter, — reappearing as soon as the ground 

 has become sufficiently warm to awaken 

 them from their long slumbers. The 

 beetles at this "time may usually be seen 

 crawling about very rapidly, looking for 

 the first shoots of the potato as it appears 

 above ground, which they attack as though 

 their appetite had been sharpened by a 

 long fast. 



METHOD OF DESTROYING. 



The first step or most practical method 



of making war upon this insect is the de- 

 struction of the few or many that come 

 out of the ground in spring, for each 

 female killed at this time may safely be 

 said to represent five to ten hundred in the 

 succeeding generation, for she will, if not 

 prevented, lay about that number of eggs. 

 Some persons, however, claim that it is 

 much the best way to allow the beetles to 

 take their own course, and then destroy 

 the larvae a few days later, when they have 

 fairly commenced feeding upon the leaves, 

 by applying some one or more of the vari- 

 ous poisons recommended for this purpose. 

 That either the beetles or the grubs must 

 be destroyed in order to save the crop, is 

 now generally admitted, and the only room 

 for a difference of opinion is as to how it 

 should be done. Scores of different sub- 

 stances have been tried for this purpose, 

 copperas, lime, mandrake tea, and other 

 common insecticides, but none have proved 

 so effectual and economical as Paris green 

 and other arsenical compounds. That 

 these poisons are dangerous to have about 

 a place, is admitted, and so are sharp 

 knives, reapers, and mowers, still it is not 

 as easy to do without them as to be a 

 little careful in using, and thereby avoid 

 accidents. The Paris green is destructive 

 to the Potato-beetle in both its perfect and 

 larval states, and one pound of the poison, 

 mixed with twenty of pulverized plaster, 

 or of any common kind of flour, and 

 dusted over the leaves while wet with dew 

 in the morning, or after a shower, will 

 quickly cause the death of all the grubs 

 or perfect insects feeding thereon. 



A duster should be used for applying 

 the poison, and one made of tin, with a 

 perforated bottom, and attached to a handle 

 four or five feet long, will be found a very 

 convenient implement for this purpose. 

 But the operator should be careful not 

 to allow the compound to blow into his face, 

 or inhale it while at work, it being only 

 necessary for him to keep in mind that he 

 is handling a virulent poison, and act ac- 

 cordingly. The green may also be applied 

 by mixing it with water, but as it will not 

 dissolve, but is merely suspended in the 



