14 MISCELLANEOUS PUBLICATION 1297, U.S. DEPT. OF AGRICULTURE 



(70) Gibson, R. W. 1971. glandular hairs providing resistance to aphids 



in certain wild potato species. Ann. Appl. Biol . 68: 113-119. 

 Glandular hairs occur abundantly on Solarium polyadenium Grenm., S. 

 tarijense Hawkes, and S. berthaultii Hawkes. The exudate impedes Myzus per- 

 sicae and Macrosiphum euphorbiae movement and the aphids starve to death. 



(71) Greene, G. L., and Thurston, R. 1971. ovipositional preference of "heli- 



this virescens" for nicotiana species. J. Econ. Ent. 64: 641-643. 

 In general, Nicotiana plants with an average of 250 or more eggs of He- 

 liothis virescens had leaves with many protruding trichomes, and they were 

 very villous. 



(72) Johnson, B. 1956. the influence on aphids of the glandular hairs on to- 



mato plants. Plant Pathol. 5: 130-132. 

 Aphis craccivora and Myzus persicae did not generally become established 

 on Lycopersicon because of some physiological incompatibility rather than 

 to the physical effect of the glandular hairs. Some other species of aphids 

 are capable of living on tomato plants. 



(73) Parr, J. C., and Thurston, R. 1968. toxicity of "nicotiana" and "petu- 



nia" species to larvae of the tobacco hornworm. J. Econ. Ent. 61: 

 1525-1531. 



Forty-four species of Nicotiana and two species of Petunia were tested. Al- 

 though some of the toxicity may be caused by the alkaloids inside the leaf 

 which are ingested during feeding, much of the resistance to Manduca sexta 

 (L.) ( = (Johannson) ) is believed caused by contact with alkaloids in the 

 trichome secretions. 



(74) Reddy, G., Thurston, R. and Donough, H. W. 1970. trichome exudates as 



A MECHANISM FOR TRANSPORTING SOIL-APPLIED DISULFOTON TO LEAF SUR- 

 FACES in "nicotiana" species. J. Econ. Ent. 63: 2005-2006. 



Data suggested that systemic insecticides might be translocated by this 

 system to the surface of plants, thereby neutralizing the presumed harmless- 

 ness of soil treatments to predaceous insects. 



(75) Stoner, A. K. 1970. selecting tomatoes resistant to spider mites. J. Amer. 



Soc. Hort. Sci. 95: 78-80. 



Rapidly viewing plants of Lycopersicon spp. with the naked eye and saving 

 those with the greatest concentration of glandular hairs was as effective a 

 method of detecting those with resistance to Tetranychus cinnabarinus as ran- 

 domly counting glandular hairs with the aid of a microscope. 



(76) Frank, J. A. and Gentile, A. G. 1968. the relationship of glan- 

 dular HAIRS ON TOMATOES TO SPIDER MITE RESISTANCE. Amer. Soc. Hort. 



Sci. Proc. 93: 532-538. 



The resistance of tomato varieties to Tetrancychus cinnabarinus, as mea- 

 sured by oviposition tests, was found to be associated with the number of 

 glandular hairs on the leaves of Lycopersicon spp. 



(77) Thurston, R. 1970. toxicity of trichome exudates of "nicotiana" and 



"petunia" species to tobacco hornworm larvae. J. Econ. Ent. 63: 

 272-274. 

 Removing the trichome exudates of Nicotiana by various washing methods 

 reduced the toxicity of tobacco leaves to larvae of Manduca sexta. 



