REQUIREMENTS OF INSECTS 

 References to Section 20 



1. C. L. Hamner, Bot. Gaz., 1940, 102, 156. 



2. D. G. Clark, Plant Physiol., 1942, 17, 137. 



3. C. E. Minarick, ibid., 141. 



4. E. C. Minnum, Bot. Gaz., 1941, 103, 397. 



5. P. F. Smith, Anier. J. Bot., 1942, 29, 56. 



6. L. Gisiger, Mitt. Lebensm. Hyg., 1943. 34, 315. 



7. A. E. Hitchcock and P. W. Zimmerman, Contrib. Boyce Thompson 



Inst., 1941, 12, 143. 



8. J. Bonner, Bot. Gaz., 1942, 104, 475. 



9. P. Nobdcourt, Compt. rend., 1943, 216, 902. 



10. P. R. Burkholder and I. McVeigh, Proc. Nat. Acad. Sci., 1942, 28, 



440 ; I. McVeigh, Bull. Torrey Bot. Club, 1944, 71, 438. 



11. J. Bonner, Amer. J. Bot., 1942, 29, 136. 



12. A. S. ChaikeHs, /. Amer. Pharm. Assoc, 1946, 36, 343. 



13. M. A. Roulet, Experientia, 1948, 4, 149- 



21. ANEURINE REQUIREMENTS OF INSECTS 



Insects require in their diet several members of the vitamin B 

 complex if they are to develop normally, and aneurine has been shown 

 to be essential for the growth of the fruit -fly, Drosophila melanogaster } 

 of various species of mosquito,^ of the beetles, Tenebrio molitor,^ 

 Tribolium confusum,^' ^ and Ptinus tectus ^ and the moth, Ephestia 

 eliitella.^ The beetles, Silvanus surinamensis, Sitodrepa panicea and 

 Lasioderma serricorne did not apparently require either aneurine or 

 most other members of the vitamin B complex,^ and this was shown 

 to be due to the presence in these last three insects of intracellular 

 symbiotic micro-organisms capable of synthesising some of the vita- 

 mins ; on sterilising the larvae, no growth occurred in the absence of 

 aneurine. This observation affords a striking parallel to the pheno- 

 menon of intestinal synthesis in animals. A number of early workers 

 considered that the function of these intracellular symbionts might 

 be the provision of accessory food substances,^ and their predictions 

 have been amply fulfilled. 



Aneurine, together with other menibers of the vitamin B complex, 

 was necessary for the growth of sterile larvae of the mosquito, Aedes 

 aegypti, to the fourth instar."^ 



An attempt has been made to utilise insect larvae, for which 

 aneurine is an essential nutrient, as a test organism in vitamin B^ 

 assays. Thus, Sarma et al.^ found that the pyruvic acid content of 

 the larvae of the rice moth {Corcyra cephalonica) increased from about 

 20 to 164 mg. per 100 g. of dry weight when maintained on a vitamin 

 Bi-deficient diet for thirty-five days, and that this decreased to half 



115 



