|GRASELA, JAMES - Retired ARS Employee|
|MCINTOSH, ARTHUR - Retired ARS Employee|
|Ringbauer, Joseph - Joe|
|Goodman, Cynthia - Cindy|
Submitted to: In Vitro Cellular and Developmental Biology - Animal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/12/2012
Publication Date: 5/12/2012
Citation: Grasela, J.J., McIntosh, A.H., Ringbauer Jr, J.A., Goodman, C.L., Carpenter, J.E., Popham, H.J. 2012. Development of cell lines from the cactophagous insect: Cactoblastis cactorum (Lepidoptera: Pyralidae) and their susceptibility to three baculoviruses. In Vitro Cellular and Developmental Biology - Animals. 48:293-300.
Interpretive Summary: The unintentional introduction of the cactus moth, a successful biological control agent used for the control of prickly pear cactus in Australia, Hawaii, South Africa, and various Caribbean islands, has posed concern as a threat to endangered species of cactus in the southeastern United States and to commercial and agricultural cactus crops in Mexico. Current strategies used by the US-Mexico bi-national program to eradicate the cactus moth from Mexico and stop its westward movement in the US include: host plant removal, the manual removal and destruction of egg masses and infected cacti stems, and the release of sterilized cactus moths. One approach not taken until now is the development of a cactus moth cell line to facilitate the investigation of insect viruses as an alternative control method for the moth. Consequently, we established cell lines from cactus moth tissues that were able to support infection by two different viruses. This finding will impact scientists working on cactus moth control by facilitating the quick screening of different viruses that could be developed into alternative biocontrol measures.
Technical Abstract: The unintentional introduction of the cactus moth, Cactoblastis cactorum, a successful biological control agent formerly employed in the control of invasive prickly pear cactus species (Opuntia spp.) as a possible threat to native, endangered species of cactus in the southeastern United States as well as with the potential to cause a major infestation of commercial and agricultural cactus crops in Mexico. Current tactics used by the US-Mexico bi-national program to eradicate the cactus moth from Mexico and mitigate its westward movement in the US include host plant removal, the manual removal and destruction of egg-sticks and infected cacti stems, and the Sterile Insect Technique. One other approach not taken until now is the development of a cactus moth cell line as a tool to facilitate the investigation of baculoviruses as an alternative biocontrol method for the cactus moth. Consequently, we established C. cactorum cell lines derived from adult ovarian tissue designated as BCIRL-Cc-AM and BCIRL-Cc-JG. The mean cell population doubling time was 204.3 and 112 h for BCIRL-Cc-AM and BCIRL-Cc-JG, respectively with weekly medium change, while the doubling time was 176.6 and 192.6 h for BCIRL-Cc-AM and BCIRL-Cc-JG, respectively with a daily change of medium. In addition, the daily verses weekly change in medium was reflected in the percentage viability with both cell lines showing higher levels with a daily medium change. Of the three baculoviruses tested, only the recombinant AcMNPV-hsp70Red and GmMNPV at a MOI of 1.0 were able to demonstrate significant production of extracellular virus (ECV) in each of the cell lines, whereas both cell lines were refractive to an HzSNPV challenge at an MOI of 10. In this study, we have demonstrated both the successful development of a C. cactorum cell line and its ability to support a complete baculovirus infection. Additionally, the availability of a cactus moth cell line will facilitate the analysis of viruses prior to using the more expensive bioassay test. Finally, it is hoped with the knowledge presented here that baculoviruses may also be considered as an alternative biocontrol method for the cactus moth.