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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #234907
Title: F1 Sterile insect technique: a novel approach for risk assessment of Episimus unguiculus (Lepidoptera: Tortricidae), a candidate biological control agent of Schinus terebinthifolus in the Continental USA

Author
item MOERI, ONOUR - UNIV OF FL
item CUDA, JAMES - UNIV OF FL
item OVERHOLT, WILLIAM - UNIV OF FL
item Bloem, Stephanie
item CARPENTER, JAMES

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2009
Publication Date: 4/22/2009
Citation: Moeri, O.E., Cuda, J.P., Overholt W.A., Bloem S., Carpenter J.E. 2009. F1 sterile insect technique: a novel approach for risk assessment of Episimus unguiculus (Lepidoptera: Tortricidae), a candidate biological control agent of Schinus terebinthifolius in the continental USA. Biocontrol Science and Technology. 19,S1:303-315.

Interpretive Summary: Federal regulations mandate that researchers in the field of classical weed biological control follow the precautionary principle when proposing the release of an organism that can affect our environment. However, the host range observed in traditional laboratory cage experiments typically is broader than what occurs in the field. Because open-field tests are prohibited in the area of introduction, the application of the F1 Sterile Insect Technique (F1SIT) could be used to conduct field testing in the proposed release area in a safe and temporary manner. In this study, we determined the minimum dose of radiation required to field test the tortricid Episimus unguiculus (Clarke), a candidate for biological control of Brazilian peppertree, Schinus terebinthifolius Raddi (Anacardiaceae) in Florida, USA. Male and female virgin E. unguiculus adults were treated with increasing doses of gamma radiation and either inbred or outcrossed to non-treated E. unguiculus adults. Results from this study suggest that use of the F1 sterile insect technique can provide a temporary and reversible way to test potential biological control agents in the proposed area of release. Further studies are needed to address the performance of irradiated biological control agents including oviposition, larval feeding preferences and survival, and host-finding behavior.

Technical Abstract: Federal regulations mandate that researchers in the field of classical weed biological control follow the precautionary principle when proposing the release of an organism that can affect our environment. However, the host range observed in traditional laboratory cage experiments typically is broader than what occurs in the field. Because open-field tests are prohibited in the area of introduction, the application of the F1 Sterile Insect Technique (F1SIT) could be used to conduct field testing in the proposed release area in a safe and temporary manner. In this study, we determined the minimum dose of radiation required to field test the tortricid Episimus unguiculus (Clarke), a candidate for biological control of Brazilian peppertree, Schinus terebinthifolius Raddi (Anacardiaceae) in Florida, USA. Male and female virgin E. unguiculus adults were treated with increasing doses of gamma radiation and either inbred or outcrossed to non-treated E. unguiculus adults. Five pairs of adults were placed in triangular waxed paper oviposition cages and allowed to mate and oviposit for two intervals of 5 days. Data from fecundity (number of eggs laid) and fertility (number of eggs that hatched) counts were recorded. The dose at which treated females were found to be 100% sterile was 200 Gy. The dose at which F1 females and males were found to be 100% sterile was 225 Gy. As the dose of radiation increased, there was an increase in sterility, a decrease in fecundity for both treated female crosses, and a higher ratio of F1 males to females.