»^wi— ^w -i '^.■^ i 'wwy^j jt i t»a. i i j««^wiP»'wawBawfwy»y a^>|,' |i i ' «i; » w'»j.i»ll»o ; i . <i .M i i »i>?r<«>j>» ^ j »i . ^ ^^ ^ " . ' "•■^ * ""»■ ' < < ww»iwai W.^il i FiiM )f 



A97 



86-100% of (.he larvae died, and no adults emerged. In a field-cage test follow- 

 ing spray applications of diflubenzuron (0.25 lb/acre in 10% cotconseed oil) 

 to cotton plants, 89% of the tobacco budworm larvae were in the 1st or 2nd 

 instar at a time when the check only had 52% in those stages, indication of a 

 retardation of the larval cycle. Also, emergence of }... boll weevils, Anthonomiis 

 grand is Boheraau, from 1/3-grown and full-grown squares was reduced 66 and 27%, 

 respectively. 



983. , and Harding, J. A. 1977. Activity of 0-ethyl S-propyl organophos- 

 phorus compounds against tobacco budworms and boll weevils. J. Econ. 

 Entomol. 70: 92-94. 



In the laboratory, sprays of organophosphorus compounds with the 0-ethyl S- 

 propyl moieties were 5-lOOX more active against a susceptible strain of the 

 tobacco budworm, Heliothis virescens (F.), and all except ER-9700, 9362, 9306, 

 and NTN-9306 were 2-3X more active against the boll weevil, Anthonomus grandis 

 Boheman, than certain alkyl or aryl 0,0-dialkyl organophosphorus compounds. 

 LDcq's for topical applications of Bay NTN-9306, (0-ethyl £-[A-methylthio) 

 phenyl] ^-propyl phosphorodithioate) to a susceptible and a field-collected 

 strain of the tobacco budworm differed ca. 8X (0.024 and 0.19 mg/g after 48 h, 

 respectively); this might indicate a potential for resistance to this new class 

 of organophosphorus compounds. In the field, NTN-9306, Rohm & Haas RH-218 (0- 

 ethyl S-propyl 0-(2,4,6-trlchlorophenyl) phosphorothioate) , and Ciba Geigy CGA- 

 15324 (0-(4-bromo-2-chlorophenyl) 0-ethyl S-propyl phosphorothioate), each 

 applied at a rate of 1 lb/acre, reduced damage to bolls by Heliothis spp. (pre- 

 dominately the tobacco budworms) 81-85% compared with bolls in untreated plots. 



984. ; Harding, J. A.; and Davis, J. W. 1977. Isomers of (3-phenoxyphenyl)methyl 

 (t) -ci8 , trans- 3- (2 , 2-dichloroethenyl) - 2 , 2-dimcthylcyclopropanecarboxylate 

 against boll weevils and tobacco budworm. J. Econ. Entomol. 70: 226-228. 



1 



