[ 124] 



relative merits of particular varieties. This is likely to be the case 

 80 long as other factors such as quality and source of seed, type of soil, 

 particular agricultural practice, manuring, and so on, are not con- 

 sidered. But there is general agreement that the newer varieties of oats 

 have distinctly less power of recovery, because they do not tiller well. 

 This is well borne out by wide experience. 



Another practice which has been found of service in overcoming 

 Tipula is to efiect a "change of seed." Seed grown on the coast and 

 sown in an inland locality, and seed grown in the Lothians and sown 

 in Aberdeenshire have in both instances proved more resistant where 

 larvae were at work, than native grown oats. Further, seed from an 

 early district and sown in a late one, also from a light soil to a heavy 

 one, have in both instances been proved satisfactory measures against 

 losses from Tipula attack. 



The subject of preventive agricultural practice and remedial 

 measures in relation to Tipula are dealt with in a further paper. 



REFERENCES TO PLATES. 



Plate XVIII. Tipula paludosa. Larvae. 3 times natural size. 



Plate XIX. a. Head armature of Tipula paludosa. (A) antenna; (B) mandibles; 

 (C) first maxiUae; (D) fused second maxillae; (E) labrum; (F) internal basal support 

 of appendages. 



b. Newly hatched larva of Tipula paludosa. 



Plate XX. View of larvae in soil within glass rearing cage, showing their burrows and 

 damaged oats, which were grown between the glass and the soil. Sketched from nature. 



REFERENCE. 



Bbldjo, Th. Beitrag zur Naturgeschichte versohiedener Arten aus der Familie 

 der Tipuliden. Zool. Bot. Oesellach. in Wien, xxm, Bd. 1873, pp. 575-592. 



