309 



dose of topical application and the effects of the carrier formulation. Doses 

 by topical application that inhibited egg hatch were much larger than doses by 

 ingestion. Water was an effective carrier, but crude cottonseed oil was highly 

 effective. The effectiveness of TH-6040 increased to a maximum during the first 

 3 days after application, then gradually declined. This indicates that absorp- 

 tion through the cuticle required several days, followed by an elimination, 

 deactivation or some other mechanism of decreasing concentrations of TH-6040 

 in the insects. 



601. . 1978. Contact transfer of dif lubenzuron (Dimilin) by boll weevils) 

 and the relation of site of application and effect on egg hatch. Entomol. 

 Exp. Appl. 23: 171-176. 



The growth-regulating chemical dif lubenzuron (tested as TH-6040, now formulated 

 as Dimilin®), N(4-chlorophenyl)-N-(2,6-difluorobenzoyl)urea) was (1) applied to 

 tarsi or to genital sternites of male or female boll weevils, Anthonomus grandis 

 Boheman, that were then placed with untreated weevils of the opposite sex; (2) 

 applied to genital sternites of either males or females and then placed with the 

 egg- laying females; (3) placed directly on the genital sternites of egg-laying 

 females; or (4) applied directly to the soft integument under the elytra. 

 TH-6040 applied to the soft dorsal integument produced a higher level of inhibi- 

 tion of egg hatch than did tarsal contact treatment. Application to males had 

 a distinct effect but much smaller, on egg hatch of eggs from their mates than 

 did direct application to the females. Application to hard cuticle (genital 

 sternites) was less effective than to soft integument (i.e., there was less 

 inhibition of hatch, and the rate of recovery was faster). 



602. , and Adams, C. H. 1966. Infection of Bracon mellitor (Kymenoptera: 

 Braconidae) by Mattesia grandis (Protozoa: Neogregarinidae) . Ann. 

 Entomol. Soc. Am. 59: 800-802. 



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