A commercial formulation of the insecticide hexaflumuron (Consult® 100 EC, Dow AgroSciences) not registered for use in the U.S. was evaluated for its potential as a toxicant and reproduction inhibitor for control of adult bollworm, Helicoverpa zea (Boddie), with feeding attractants and stimulants. When mixed with 2.5 M sucrose and ingested by sex pheromone trap-captured males, hexaflumuron had significantly different 24- and 48-hour lethal concentration (LC₅₀'s) of 262.94 and 104.68 ppm (ai wt:vol), respectively. Compared with other insecticides previously evaluated, hexaflumuron has low oral toxicity and is slow-acting. Feeding response evaluations at lethal and sublethal concentrations ranging from 1 to 10000 ppm with sex pheromone trap-captured males and laboratory-reared males and females indicated that gustatory responses were significantly reduced at concentrations above 10 ppm compared with sugar solutions without insecticide. The proboscis extension response was significantly reduced when hexaflumuron was mixed with 1.0 M sucrose at 50 ppm. There was no significant reduction in proboscis extension response between test solutions and control when 2.5 M sucrose was used. Percent larval hatch of eggs oviposited by laboratory-reared females during 3 consecutive days was drastically reduced at concentrations of 10 ppm and below when compared to eggs oviposited by females fed only sugar. Mean numbers of spermatophores per treated female were not consistently reduced compared to untreated females indicating that mating did not significantly contribute to reduction in larval hatch of eggs. When treated laboratory-reared males were paired with untreated females, there was no significant effect on frequency of mating or larval hatch of eggs; therefore, the effect of hexaflumuron on larval hatch of eggs is only on females. Based on these results, the formulation of hexaflumuron tested has potential for use as a reproduction inhibitor for adult control of bollworm with feeding attractants and stimulants. A critical assessment of hexaflumuron's potential under field conditions is needed before additional studies on changes in formulation and feeding stimulant to overcome feeding inhibition are warranted.