REQUIREMENTS OF INSECTS 



6. E. E. Snell and F. M. Strong, Ind. Eng. Chem., Anal. Ed., 1939, 



11, 346. 



7. R. E. Feeney. J. H. Mueller and P. A. Miller, /. Bad., 1943. 46, 



563. 



8. S. H. Hutner, ibid., 1942, 43, 629. 



9. M. S. Dunn, N. N. Camien, S. Shankman, W. Frankl and L. B. 



Rockland, /. Biol. Chem., 1944, 156, 703. 



10. J. L. Stokes, M. Gunness, I. M. Dwyer and M. C. Caswell, ibid., 



1945, 160, 35. 



11. H. Mcllwain, Nature, 1946, 158, 898. 



12. M. G. Sevag and J. S. Gots, /. Bad., 1948, 56, 723. 



17. EFFECT OF RIBOFLAVINE ON HIGHER PLANTS 



Riboflavine appears to have no stimulatory effect on the growth 

 of higher plants and, indeed, it is said to be synthesised during the 

 germination of oats, wheat, barley and maize, ^ and in the root-tips 

 of various plant species. ^ The riboflavine content of cereals, peas and 

 beans increased considerably during germination^ — from 0-6-2-0 to 

 2 -0-12 '4 /Ltg. per g. of dry matter. 



References to Section 17 



1. P. R. Burkholder, Science, 1943, 97, 562. 



2. J. Bonner, Bot. Gaz., 1942, 103, 581. 



18. RIBOFLAVINE REQUIRE2V1ENTS OF INSECTS 



Riboflavine is essential for the normal development of the beetles, 

 Ptinus tectus, Tribolium confusum and Silvanus surinamensis and of 

 the moth, Ephestia elutella, but not of the beetles, Sitodrepa panicea 

 and Lasioderma serricorne.^ The difference in the requirements of 

 the two groups of beetles was shown to be due, as with aneurine 

 (see page 115), to the presence in the last two insects of intracellular 

 symbiotic micro-organisms capable of synthesising riboflavine, which 

 then became available to supply the metabolic needs of the host. 

 Neither Lasioderma nor Sitodrepa g:rew in the absence of riboflavine 

 when reared from sterilised eggs. 



Riboflavine was also necessary for the development of the larvae 

 of the mosquito, Aedes aegypti,^ of Tenebrio molitor,^ of the fruit fly, 

 Drosophila melanogaster,^ and of the larvae of the rice-moth, Corcyra 

 cephalonica.^ 



In two species of insects, namely the American cockroach,^ Peri- 

 planeta americana, and Tineola bisselliella ,'^ riboflavine accumulated 

 in the Malpigbian tubes, even when the diet contained little or no 



205 



