78 



INSECTS INJURIOUS TO VEGETABLES 



low the plow for them. Swine also search out and eat many 

 which they obtain by uprooting the turf. 



Of the insect enemies of white grubs are Tachina flies, wasps 



Fig. '^A.— Tiphia inomata- Parasite of white grub, a. Female wasp; b, head of 

 larva; c, larva from below; d, cocoon cut open. (After Riley) 



and parasitic Hymenoptera, mites, and predaceous ants. Among 

 these insects is the wasp, Tiphia inomata (fig. 44). Under 

 certain conditions white grubs are also much subject to infec- 

 tion by fungous parasites. 



REMEDIES FOR WHITE GRUBS 



Insecticides. — Good results have followed the use of bisulphid 

 of carbon and kerosene emulsion against some species. The 

 emulsion is diluted about ten times and poured on the ground 

 about the infested plants. Application is made just before rain- 

 fall, to insure the emulsion being washed deep into the soil so 

 as to come into direct contact with the larvse. If rain does not 

 fall within a day or two a copious watering should follow the 

 application. Gas lime is also valuable. (See page 34.) 



Fall ploK ing is a most effective remedy. The land should 

 be thoroughly broken, and loosened to expose the grubs and 

 beetles to the elements during winter. This is particularly 

 valuable in cold climates, as white grubs are unable to with- 

 stand exposure to severe frost. Cross-plowing is sometimes 

 advisable where there is severe infestation. This will insure 

 the ground being often disturbed, and, if kept clean of weeds 

 and other vegetation, the grubs can be "wiped out." 



Preventive measures are still more valuable. The best of 



