@article {14007,
	title = {Effect of Mass Rearing on Life History Traits and Inbreeding Depression in the Sweetpotato Weevil (Coleoptera: Brentidae)},
	journal = {Journal of Economic Entomology},
	volume = {103},
	number = {4},
	year = {2010},
	month = {Aug},
	pages = {1144-1148},
	abstract = {Inadvertent selection is an important genetic process that frequently occurs during laboratory culture and maintenance of biological control agents and other beneficial organisms used in procedures such as the sterile insect technique (SIT). We investigated effects of mass rearing and inbreeding depression on life history traits (number of progeny emerging from host plants, body weight, developmental period, and starvation tolerance) in the sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Brentidae). The effect of inbreeding was measured by comparing the results obtained from the full-sib crosses with those obtained from nonkin crosses in both wild and mass-reared strains. The mass-reared strain had more progeny than the wild strain. The developmental period of mass-reared strain was shorter than that of the wild strain. Other traits did not differ significantly between strains. We detected inbreeding depression effects on numbers of progeny, and the effects were more pronounced in the mass-reared strain. Hence, laboratory adaptation to mass rearing can produce changes in important biological attributes of sweetpotato weevils.},
	keywords = {Cylas formicarius elegantulus},
	isbn = {0022-0493},
	author = {Kuriwada, T. and Kumano, N. and Shiromoto, K. and Haraguchi, D.}
}
@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 {14006,
	title = {The effect of mass-rearing on death-feigning behaviour in the sweet potato weevil (Coleoptera: Brentidae)},
	journal = {Journal of Applied Entomology},
	volume = {134},
	number = {8},
	year = {2010},
	month = {Sep},
	pages = {652-658},
	abstract = {The aim of our study was to examine the effect of mass-rearing, in which there is no exposure to predators, on antipredator traits of insects for improving sterile insect technique programs. The duration of death-feigning (antipredator behaviour) in sweet potato weevil Cylas formicarius (Summers) (Coleoptera: Brentidae) after mass-rearing for 71 generations were compared with those in wild strain. There was no significant difference in the duration of death-feigning between wild and mass-reared strains. This indicated that the death-feigning behaviour of mass-reared strain was maintained for 71 generations even in the absence of,predators. We discuss the reasons why death-feigning behaviour is maintained after mass-rearing.},
	keywords = {Cylas formicarius},
	isbn = {0931-2048},
	author = {Kuriwada, T. and Kumano, N. and Shiromoto, K. and Haraguchi, D.}
}
@article {13992,
	title = {Assessment of Effect of Partial Sterility on Mating Performance in Sweetpotato Weevil (Coleoptera: Curculionidae)},
	journal = {Journal of Economic Entomology},
	volume = {103},
	number = {6},
	year = {2010},
	month = {Dec},
	pages = {2034-2041},
	abstract = {The sterile insect technique (SIT) is widely used to suppress or eradicate target pest insect populations. Although the effectiveness of SIT depends on the ability of released sterile males to mate with and inseminate wild females, the use of gamma radiation to induce sterility negatively impacts reproductive cells as well as somatic cells. Consequently, sterilization by irradiation drastically diminishes mating performance over time. In the current study, we evaluated the effect of irradiation dose intensity on fertility, mating propensity, and mating competitiveness in sweetpotato weevil, Cylas formicarius elegantulus (Summers) (Coleoptera: Curculionidae), for 16 d after irradiation. Although the mating propensity of males irradiated with 200 Gy, the dose currently used to induce complete sterility of C. f elegantulus in the SIT program in Okinawa Prefecture, was equal to that of nonirradiated weevils for the first 6 d, the mating propensity of males irradiated with doses between of 75 and 150 Gy was maintained for the first 12 d. The potential fertilization ability of weevils was highly depressed compared with the control weevils, even in those treated with 75 Gy. Mating performance was severely compromised in weevils that were irradiated with a dose of 100 Gy or more. These results demonstrate that partial sterilization can be highly advantageous in eradication programs for the sweetpotato weevil. We discuss the advantages of the application of partial irradiation in insect eradication programs.},
	keywords = {Cylas formicarius elegantulus},
	isbn = {0022-0493},
	author = {Kumano, N. and Kuriwada, T. and Shiromoto, K. and Haraguchi, D. and Kohama, T.}
}
