124 



APPLIED ENTOMOLOGY 



time feed on the stems and when abundant do considerable harm. The 

 eggs are laid on the stems, singly, attached by one end, are dark brown 

 in color, and hatch in from 3 to 8 days according to the temperature. 

 The grubs (Fig. 114d), often called " slugs" are gray with black heads. 

 They feed from 10 days to 2 weeks, gnawing the stems and thus aid the 

 beetles in making these unfit for sale. Then they enter the ground and 

 pupate for about a week which is followed by the emergence of the adults. 

 The life cycle therefore is from about 4 weeks during hot weather to 6 or 



7 weeks in spring or fall. There are 

 at least two generations in the North 

 and probably three or four in the 

 South each year. 



The later generations feed on 

 the leafy growth and in the case of 

 young plants may seriously weaken 

 them. Eggs when abundant on the 

 stems cut for market are objection- 

 able, and a black fluid poured out by 

 the grubs when disturbed, often stains 

 the stems also. Fortunately, exces- 

 sive heat appears to kill many of the 

 grubs, and the alternation of severe 

 cold with much warmer periods in 

 winter, has a similar effect on hiber- 

 nating adults. Several parasites and 

 other enemies also reduce the numbers 

 of this pest. 



Control. Fresh air-slaked lime 

 dusted over the plants while these 

 are wet with dew is an excellent con- 

 trol measure for small areas. Fowls 



feed freely on the insects and are therefore of value when allowed to run 

 through the asparagus beds. For larger areas a frequent practice is to 

 keep the plants as closely cut as possible, leaving a few stems here and 

 there as traps on which the beetles can lay their eggs. These plants 

 should be cut once a week and destroyed, others being then allowed to 

 grow to take their places. Where cutting is not being done, spraying 

 with arsenate of lead a little stronger than the standard formula is a 

 very satisfactory treatment, the number of treatments required being 

 generally not more than two or three at most during an entire summer. 



The Twelve-spotted Asparagus Beetle (Crioceris duodecimpunctata L.). 

 This insect arrived in this country from Europe about 1881 and was first dis- 

 covered near Baltimore, Md. Though beginning its work here more than 20 

 years later than the other species, it has already nearly everywhere overtaken the 

 latter and is now widely distributed. 



FIG. 115. Eggs, larvae and adults of 

 Common Asparagus Beetle on the plant. 

 Natural size. (From U. S. D. A. Farm. 

 Bull. 837.) 



