COLEOPTERA 



531 



asparagus, and lays oval, black eggs upon them. The larvas, which 



are small, brown, slug-like grubs, also feed upon the young heads in 



the spring, and later in the season a second 



brood feed upon the full-grown plant. Figure 



648 represents a head of asparagus bearing the 



eggs of this beetle, also a beetle and a larva 



enlarged. The beetle measures about 6 mm. 



in length. When this pest occurs, care should 



be taken to destroy all wild asparagus. This 



will force the beetles to lay their eggs upon the 



shoots that are cut for market. The larv« 



hatching from such eggs will not have a chance 



to mature. 



The grape root-worm, Fidia longipes. — This 

 insect is the most destructive enemy of the 

 grape occurring east of the Rocky Mountains. 

 The adult is a small, grayish brown beetle, 

 measuring about 6 mm. in length. It feeds on 

 the leaves in July, eating out characteristic 

 chain-like holes. The eggs are laid beneath the 

 loose bark of the vines. On hatching, the larvae 

 drop to the ground and burrow down to the 



roots, which they destroy, causing the death of the vine. Most of 

 the larvas do not transform till the following spring. The best means 

 of fighting this pest is to poison the beetles while they are feeding on 

 the leaves, and before they lay their eggs, by the use of a spray made 

 by dissolving six pounds of arsenate of lead in 100 gallons of water. 

 The Colorado potato-beetle, Leptinotdrsa decemlinedta. — A good 

 many insect tramps have come to us from Europe and from Australia, 

 and appropriated whatever pleased them of our grow- 

 ing crops or stored grain. But two of our worst insect 

 pests have swarmed out on us in hordes from their 

 strongholds in the region of the Rocky Mountains. 

 These are the Rocky Mountain locust and the Colorado 

 potato-beetle (Fig. 649). The latter insect dwelt near 

 the base of the Rocky Mountains, feeding upon the 

 sand -burr (Solamim rostratum), until about the year 

 1859. At that time it began to be a pest in the potato-fields of the 

 settlers in that region. Having acquired the habit ot feeding upon 

 the cultivated potato, it began its eastward march across the conti- 

 nent, spreading from potato patch to potato patch. At first the 

 migration took place at about the rate of fifty miles a year, but later 

 itwasmore rapid; and in 1874 the insect reached the Atlantic Coast. 

 The adult beetles hibernate in the groimd ; they emerge early in 

 April or May, and lay their eggs on the young potato plants as soon 

 as they appear; both larvas and adult beetles feed on the foliage of 

 the potato. The larvse enter the ground to transform. This pest is 

 usually controlled by the use of Paris green. 



Labidomera clivicollis. — This species is closely allied to the Colorado 

 potato-beetle and resembles it in size and form. It is of a deep blue 



Fig. 649. 



