Author
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White, William |
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Submitted to: Midsouth Entomologist
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/15/2008 Publication Date: 7/15/2008 Citation: White, W.H. 2008. Utilizing Diapause in a Sugarcane Borer (Lepidoptera: Crambidae) Laboratory Colony as a Cost Saving Measure. Midsouth Entomologist. 1(2)76-80. Also available at: http:////midsouthentomologist.org.msstate.edu/Volume1/Vol1_1_TOC.htm Interpretive Summary: Being able to culture insects such as the sugarcane borer (an important pest of sugarcane, rice, and corn) in the laboratory is expensive, but it broadens the scope of research opportunities available to the scientist. One option available to reduce cost is to hold a founder population in a state of hibernation when not needed, and then bring these individuals out of hibernation to restart routine rearing operations at a later time. A procedure is outlined that puts larvae of the sugarcane borer into hibernation by placing them in cold temperature (65° F) and under shorten day length (12 hrs of light) and holding the larvae for five months. This procedure allowed approximately 750 larvae out of 1024 (75%) to successfully hibernate and later become moths. The procedure saved our laboratory approximately $1,600 in rearing supplies, but more importantly allowed us to redirect our insectary manager to other critical tasks during that period of time that insects were not needed. Technical Abstract: The ability to rear insects in the laboratory broadens the scope of research opportunities available to the scientist. We routinely rear the sugarcane borer, Diatraea saccharalis (F.), for our research in host plant resistance and biological control of this important sugarcane pest. Unfortunately, insect rearing is a costly process. One option to reduce cost is to hold a founder population in diapause during times when insects are not needed. These insects can then be brought out of diapause and allowed to reconstitute the colony. A procedure was developed to put larvae of the sugarcane borer into diapuase, hold these larvae for five months in cold storage, and then terminate diapause and allow the insects to complete development. This procedure involves inducing diapause at 18°C and 12:12; L:D and holding larvae for five months at 10° and 12:12 L:D. In 2007 our laboratory diapaused 1024 sugarcane borer larvae, terminated our routine rearing, and held the founder colony until January of 2008. Seventy-three percent of the founder colony diapaused in 2007 survived and produced healthy moths in 2008. We were not able to detect any adverse affects (i.e. malformed pupae) in the diapaused insects and within 30 days of initiating diapause termination we had resumed normal rearing operations. This procedure saved our laboratory approximately $1600.00 in rearing supplies, but more importantly allowed us to redirect our insectary manager to other critical tasks during that period of time that insects were not needed. |
