138 Second Report on Ecommiic Zoology. 



The best way to clear them out of the soil is to turn chickens on 

 to the land when it is being chig in the spring ; they devour the 

 larva; greedily. Neither soot nor lime have any effect on these 

 insects. 



They may be killed in garden borders by injecting bisulphide of 

 carbon into the ground. 



The adult flies appear in May and June ; sometimes as early as 

 the middle of April. 



The Mustard Beetle or Black Jack. 



{Phsedon hetidse. ) 



The beetles referred to by the correspondent from Downham 

 Market under the name of " Black Jack " are the Mustard Beetle 

 {PJiseclon hetulae). 



An account of this pest will be found in the "Journal of the 

 Board of Agriculture," vol. Ix, no. 4, p. 524, 1903. 



The pest should be attacked by either collecting the beetles 

 with tarred cloths or wooden scoops drawn between the rows as 

 described on p. 525, or if a " strawsoniser " is available, by spraying 

 with Paris green. 



All necessary information is given in the paper referred to. 



(Since this report was written the specimens of attacked plants 

 have been received; leaves and stalks were covered with Phmlon 

 larvte of two kinds, F. coclilearife and J\ hetvlse. These could only 

 be destroyed by washing.) 



In answer to another communication, the correspondent was 

 informed that the larva:^ of the Mustard Beetle which he forwarded 

 would soon be mature ; they then enter the ground to pupate, and 

 in fourteen days or so, the summer Ijrood of beetles appears, and 

 these beetles spread devastation over the advanced mustard crop. 



The larvae should have been previously attacked ; they are in all 

 stages — some nearly mature, others only a week old. I'nfortunately 

 mustard is grown so close that more damage might be done by 

 getting at the larvse than the latter do themselves, but with long 

 spraying rods large areas could be sprayed with a small amount of 

 damage to the crop by the washers. 



Some plan .should be adopted by growers so as to allow a free 

 passage between the plants. 



