204 TRUCK-FARMING AT THE SOUTH. 



ture. The crop will be matured before frost, which 

 generally occurs about November 1st, when it should 

 be dug and the seed stored away, as recommended above. 



DISEASES AND INSECTS. 



The fungoid disease, sometimes so destructive to the 

 potato crops of Europe, and of the northern part of this 

 continent, will rarely, if ever, affect our early crops of 

 early varieties, and the later ones must be exempt in 

 consequence of the heat, as cool moisture seems neces- 

 sary for the development of this disease. 



The earliest crops at the North escape great injury 

 from the Colorado Potato-beetle (Doryphora W-Uneata), 

 and ours will therefore remain exempt from that pest, 

 should it come South. The insects infesting the potato 

 at the South are of the Lepidoptera: 

 First Gortynia nitela (the Potato-stalk borer). 

 Second Sphinx quinquemaculata (the Potato-worm). 



Among the Coleoptera. 



Third Baridius trinotatus (the Potato-stalk weevil). 

 Fourth Lema trilineata (the Three-lined Leaf -beetle). 

 Fifth Lachnosterna quercina (the White-grub). 

 Sixth Deloyala clavata (the Clubbed Tortoise-beetle). 

 Seventh Lytta marginata (Margined Blister-beetle). 

 Eighth Lytta vittata (Striped Blister-beetle). 

 Ninth Lytta cinerea (Ash-grey Blister-beetle). 

 The first three of these attack the plant only in the 

 larval state. 



Numbers 1 and 3 are more injurious than any 

 others, as they devour a vital part, and live within the 

 stalks. The Potato-stalk Borer lives within the stalks 

 of several plants, including the Dahlia and other flowers, 

 and attacks the tomato as well as the potato. When 

 full grown, it enters the earth, and in about two months 

 comes out as a small moth, fig. 50. 



