268 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



adults. The entire life cycle requires about one month and there are 

 many overlapping generations each year. 



Nature of Work. — The young and adults feed upon the tender shoots 

 and the older seed plants, making holes into or entirely destroying the 

 former and destroying the foliage of the latter. 



Distribution. — In the year 1904 the insect was reported as occurring 

 ;it Bouldin Island. California, In 1906 it was reported to occur in great 

 numbers at Oakley. 177 It is now likely to be quite widely distributed 

 throughout the central part of the State. 



Food Plant. — So far as known in this State the pest feeds only upon 

 asparagus, attacking principally the tender shoots, but also working 

 upon the skin and stems of the older seed plants. 



Control. — The control of this beetle is not so difficult as it would 

 seem, in view of the fact that arsenical sprays cannot be used upon the 

 tender marketable shoots, because of the poisonous effects to the con- 

 sumers. 



In the spring, when harvesting the shoots, it is advisable to leave 

 some of them for the beetles to lay their eggs upon, cutting and burning 

 these before the eggs hatch. Another practice is to keep all the seed- 



Fig. 259. — The common asparagus beetle, Crioceris asparagi Linn, a, adult ; b, egg 

 on leaf ; c, newly hatched larva ; d, full-grown larva ; e, pupa ; f, eggs attached to the 

 plant, a-e, greatly enlarged; f, slightly reduced. (After Chittenden, U. S. Dept. Agric.) 



lings, except a few for traps, cut down. Upon those left the beetles 

 will collect in great numbers and may be easily killed. In the spring, 

 or after they are covered with eggs, the plants should be cut down and 

 burned. 



As soon as the crop is harvested the seedlings and feathery plants 

 should be thoroughly sprayed with arsenical sprays, which will serve 

 to kill many of the mature beetles hefore they go into winter quarters. 

 One pound of lead arsenate to 16 gallons of water has given excellent 

 results. 



Dusting air-slaked lime or pyrethrum upon the larva? and spraying 

 infested plants with kerosene emulsion or tobacco extract and soap 

 (Black Leaf "40" 1 gallon, whale oil soap, 4 pounds, water 500 gallons) 

 are exceedingly effective in killing the delicate larva?. Brushing to the 



'"Chittenden, F. H., Cir. No. 102, Bur. Ent, U. S. Dept. Agric, p. 4, 1908. 



