@article {14012,
	title = {Pre-exposure to sex pheromone did not affect mating behavior in the sweetpotato weevil Cylas formicarius},
	journal = {Journal of Pest Science},
	volume = {84},
	number = {1},
	year = {2011},
	month = {March},
	pages = {93-97},
	abstract = {In sterile insect technique (SIT) programs, the released sterile males are important for their effectiveness. The use of sex pheromones to collect males is economical; however, pre-exposure to sex pheromones may affect male mating behavior, and would thus reduce the effectiveness of the SIT programs. Males exposed to sex pheromone may become attractive to other males due to pheromone adsorption on their body impregnation, prevent mating and reduce the dispersal of sterile males. We examined the effect of pre-exposure to sex pheromone on the mating behavior of male sweetpotato weevil Cylas formicarius. Pre-exposure to high-dose sex pheromone for 24 h did not affect the male mating behavior of C. formicarius, and the exposed males did not attract other males. These results suggest that male C. formicarius that were collected from a mass-rearing facility using sex pheromone can be effectively used in SIT programs.},
	keywords = {Cylas formicarius},
	isbn = {1612-4758},
	author = {Kuriwada, Takashi and Kumano, Norikuni and Shiromoto, Keiko and Haraguchi, Dai}
}
@article {14011,
	title = {Age-dependent investment in death-feigning behaviour in the sweetpotato weevil Cylas formicarius},
	journal = {Physiological Entomology},
	volume = {36},
	number = {2},
	year = {2011},
	month = {Jun},
	pages = {149-154},
	abstract = {Because life-history theory predicts that risky behaviours such as mating should increase as life expectancy decreases, predatory avoidance is expected to decrease with age. However, this prediction has not been examined. In the present study, the effect of age on death-feigning behaviour, a form of predatory avoidance behaviour in the sweetpotato weevil Cylas formicarius (Summers) (Coleoptera: Brentidae), is investigated by performing a longitudinal study. Because the effects of mating history and age usually cannot be distinguished, mating history is controlled. The results show that only female weevils decrease the investment in death-feigning behaviour with age, whereas male weevils do not show any age-related change. In addition, death-feigning behaviour of mated females is longer than that of virgin females, possibly because additional mating partners would be not needed by mated females.},
	keywords = {Cylas formicarius},
	isbn = {0307-6962},
	author = {Kuriwada, Takashi and Kumano, Norikuni and Shiromoto, Keiko and Haraguchi, Dai}
}
@article {14008,
	title = {EFFECT OF IRRADIATION ON DEATH-FEIGNING BEHAVIOR IN THE MALE SWEETPOTATO WEEVIL CYLAS FORMICARIUS (COLEOPTERA: BLENTIDAE)},
	journal = {Florida Entomologist},
	volume = {93},
	number = {1},
	year = {2010},
	month = {March},
	pages = {39-44},
	abstract = {The sterile insect technique (SIT) is widely used to suppress or eradicate target insect pest populations. The effectiveness of SIT depends on the ability of the released sterile males to mate with and inseminate wild females. Irradiation is effective for sterilizing mass-reared insects, and the negative impacts of this procedure are not limited to reproductive cell damage. In this study, we evaluated the death-feigning that is considered as an antipredator behavior of male Cylas formicarius (Summers) (Coleoptera: Blentidae) irradiated with 200 Gy, which is the dose used in the SIT program in Okinawa Prefecture. Irradiated male insects were observed in the laboratory for 10 d after irradiation. On d 0, fewer irradiated males feigned death than nonirradiated males. The number of irradiated and nonirradiated males who feigned death and the duration of their death-feigning were about the same from 2 d after irradiation. On the basis of our results, we discuss the optimal release time of irradiated male C. formicarius.},
	keywords = {Cylas formicarius},
	isbn = {0015-4040},
	author = {Kuriwada, Takashi and Kumano, Norikuni and Shiromoto, Keiko and Haraguchi, Dai}
}
@article {14010,
	title = {Inbreeding avoidance or tolerance? Comparison of mating behavior between mass-reared and wild strains of the sweet potato weevil},
	journal = {Behavioral Ecology and Sociobiology},
	volume = {65},
	number = {7},
	year = {2011},
	month = {July},
	pages = {1483-1489},
	abstract = {Inadvertent selection is an important genetic process that frequently occurs during laboratory culture. The mass-reared strain of the sweet potato weevil Cylas formicarius exhibits stronger inbreeding depression than the wild strain does. When inbreeding depression occurs in a population, mating with a close relative is often considered maladaptive; however, in some contexts, the inclusive fitness benefits of inbreeding may outweigh the costs, favoring individuals that tolerate a low level of inbreeding depression. Theory predicts that mass-reared strain weevils will avoid inbreeding while wild strain weevils will tolerate inbreeding. To examine this prediction, we compared the effect of relatedness on the mating and insemination successes in mass-reared and wild strains of C. formicarius. While close relative pairs of the wild strain copulated less frequently than non-kin pairs, almost all mass-reared strain pairs copulated irrespective of relatedness. The results showed that the strain with weak inbreeding depression (wild strain) avoided inbreeding, whereas the strain with strong inbreeding depression (mass-reared strain) tolerated inbreeding. The contradiction between the theoretical prediction and our results is discussed from the perspective of laboratory adaptation, mating systems, and life history of C. formicarius.},
	keywords = {Cylas formicarius},
	isbn = {0340-5443},
	author = {Kuriwada, Takashi and Kumano, Norikuni and Shiromoto, Keiko and Haraguchi, Dai}
}
