ASPARAGUS INSECTS 203 



grubs begin feeding on the tender tips. The body of the newly 

 hatched larva is gray and its head and legs are black. The 

 grub becomes mature in ten days to two weeks. It is then 

 about Yo ii^<^b in length, dark gray in color, with the head and 

 legs shining black. On the segment behind the head there 

 are two shining black spots. The abdominal segments are 

 provided with prolegs which are used by the grub in maintain- 

 ing its hold on the plant (Fig. 130). When mature the grubs 

 fall to the ground and there just below the surface construct a 

 small earthen cell within which they transform to pale yellow- 

 ish pupae. Transformation to the beetles takes place in about 

 a week, although in 

 cool weather the pupal 

 period may be much 

 longer. In England 

 the insect remains in 

 the pupal state from 

 fourteen to twenty 

 days. After trans- 



p ^ . ,1 1-1 Fig. 130. — Full-grown larva of the common 



formation the beetles asparagus beetle (X 4|). 



require three or four 



days to harden before they are ready to make their appear- 

 ance above ground. The entire life cycle requires from three 

 to seven weeks depending on the climate. In the North 

 there are at least two generations annually and in the South 

 there are said to be four or five. 



In addition to the injury to the tender shoots in the spring, 

 the beetles and larvae seriously damage the plants after they 

 have leafed out. Both beetles and grubs feed on the leaves 

 and the epidermis is chewed from the stem. In this way the 

 growth of the plants is seriously checked and the proper develop- 

 ment of the roots is prevented. Plants stunted in this way 

 are not able to send up large and vigorous shoots, and the size 

 and quality of the crop are decreased. The common asparagus 



