154 



The Colorado Beetle. 



eggs of the Colorado Beetle, and when placed in a box with 

 some ate them ravenously. Thus in the short space of time 

 that this potato pest has, apparently, been in this country it 

 has found one natural enemy which, on account of its 

 ravenous nature, could not but help materially in checking 

 its increase. 



The pupa of the Ladybird is orange with black marks and 

 spots, and resembles very closely the small grub of the 

 Colorado Beetle. A small Hemipteron, a green Nemocoris (?) 

 was also seen wandering about amongst the larvae, and 

 may have been feeding off them, sucking out the body juices 

 in the same way several species do in America. 



Closely-related Beetles. 

 There are three closely - related species of Doryphora, 

 namely, D. tindecemlineata Stal, D. juncta Germ, and D. 



c 



melanoihorcix Stal. The former has black legs, but otherwise 

 resembles the Colorado Beetle. 



D. melanothorax has an entirely dark thorax, not yel]ow, 

 with black spots and central mark. 



D. juncta, or the Bogus Colorado Beetle, has two of the 

 black lines on the wing cases very closely united, almost 

 forming one broad single line. This latter has often been 

 confounded with the true Colorado Beetle. It occurs in the 

 south and south-west of North America, and feeds on the 

 horse nettle [Solatium Carolinense), but never touches the 

 potato. 



A fourth species is said to exist, D. midtitaeniata Stal, but 

 I can detect no difference between it and D. undecemlineata. 



The larva of D. juncta differs from that of D. decemlineata 

 when newly hatched in being much paler, more the colour of 

 the adult decemlineata ; when full grown the larva of juncta 

 has a pale head, that of decemlineata a black head. 



The eggs also differ ; those of juncta are whitish, not 

 orange as in the Colorado Beetle, 



Should by any chance this pest become established in this 

 country, growers will have to employ the remedy that has met 

 with such marked success in America, namely, spraying with 

 Paris Green. Probably Arsenate of Lead would be found 

 even a more successful insecticide, and, as in orchards, one 

 less liable to harm the leafage. Fred. V. Theobald. 



