88 DISEASES OF CROPS. 



deposit her eggs, burrows down into the earth to a depth 

 of about six inches, where she leaves them ; and in the 

 course of about a fortnight the young larvse are hatched, 

 and proceed in search of nourishment." 



Prevention. — (1) Hand-picking would help to a certain 

 extent in keeping down this pest. (2) Pigs, ducks, and 

 poultry readily devour the grubs, as well as the beetles. 

 (3) Starlings, rooks, crows, nightjars, redstarts, and other 

 insectivorous birds make " sad havoc" amongst these farm 

 pests ; therefore they should be protected from injury. It 

 is most probable that the wholesale destruction of in- 

 jurious insects by birds i more than compensates for the 

 small amount of damage the latter may do to various crops 

 and fruits. 



Cure. — Dressings of quicklime, gas-lime, and drenoh- 

 ings of ammoniacal or gas-liquor (diluted with four or five 

 times its bulk of water) destroy large numbers of the 

 larvae of the cockchafer. The liquor can easily be applied 

 by means of a water-cart. " In very dry weather gas- 

 liquor ' burns up the grass,' but on the first appearance 

 of rain the herbage will again spring up with increased 

 luxuriance " (Treatise on Manures). 



The Click Beetles (Mater sputator, Elater ob- 

 scurvs, Elater sanguineus, Elater lineatus, Mg. 36) belong 

 to the ElateridcB, and " may readily be known by the 

 hinder angles of the thorax being pointed, and also by 

 their power of jumping up, with a slight clicking noise, 

 when laid on the back. Most of the species are black, or 

 bronzed, or partly black and partly yellow. E. sanguineus 

 (Fig. 36 C) is a bright-scarlet insect, with a black head 



• " Insectivorous birds appear to have an instinctive knowledge of 

 the position of the larva below the surface." 



