180 Relation of Grass Insects to Cultivated Crops 



worms were destroyed either by the Carabid larva or by the remaining 

 wire worms. 



Examination of a lark's nest containing fledglings showed the follow- 

 ing insects dead or badly damaged : 



4 adult Tipula oleracea. 



2 larvae of Tipvla spp. 



1 ,, Apamea spp. 



3 "Surface larvae." 



Jackdaws probably do much good in destroying insects, slugs, etc. 

 One family consisting of, probably, two adults and three young birds 

 visited a " seeds " field, after the crop had been cut, persistently for about 

 a week at the end of June, evidently searching for slugs, beetles and 

 insects in general. Hooper (8) gives an instance of a jackdaw being shot, 

 when taking food to his brooding mate, the beak contents on examina- 

 tion revealing thirteen wireworms, four grubs and a few other insects. 



VII. SIBEVIARY. 



1. Insects which are parasitic alike on grasses, cereals, and other 

 crops will, when these latter are unavailable, take up their quarters in 

 the grasses and plants growing in the situations herein mentioned and, 

 when the crops are again available return to them and commit their 

 ravages. 



2. Observations were conducted over a period of nine months on 

 certain insects which attacked both grasses and cultivated crops in a 

 limited area in Shropshire, viz. the farm of the Harper Adams Agri- 

 cultural College, near Newport, and the immediate neighbourhood. 



3. The observations indicate a danger of harbouring pests among 

 the vegetation on headlands, hedgerows and waste places; grasses in 

 particular, being susceptible to their visitation, are decidedly important 

 factors in tiding pests over from season to season and this in itself sug- 

 gests the advisability of keeping hedgerows and headlands clean. 



VIII. BIBLIOGRAPHY. 



The following have been consulted: 



(1) Board of Agriculture and Fisheries. Reports... occurrence... Insect pests on Plants 



1917 and 1918. 



(2) Cameron, A. E. (1913). Journ. Econ. Biol. Sept. vra, Pt. 3. 



(3) CoLLiNGE, W. E. Manual of Injurious Insects. 



(4) CoLLiNGE, W. E. and Shoebotham, J. W. (1910). Journ. Econ. Biol, v, No. 3. 

 1(5) Collin, J. E. (1918). Ann. App. Biol, v. No. 2, p. 81. 



