TY - JOUR
T1 - The contribution of conservation biological control to integrated control of Bemisia tabaci in cotton
AU - Naranjo, Steven E.
AU - Ellsworth, Peter C.
N1 - Funding Information:
We thank Geoff Gurr, Charles Pickett, and one anonymous reviewer for helpful comments on earlier drafts of this manuscript, and especially Jon Diehl for his critical contributions to the development and conduct of this research. We also thank Daniel Ashton, Virginia Barkley, Kim Beimfohr, Francisco Bojorquez, Jeff Cantrell, Gilberto Castro, Rochelle Christensen, Johnny Fearn, Celso Jara, Donna Meade, Gregory Owens, Doug Sieglaff, and Enrique Yescas for technical assistance. Partial support was provided by USDA-CREES, Pest Management Alternatives and Extension IPM Programs, NAPIAP (Western Region), Western Region IPM Program, Western IPM Center, Arizona Cotton Growers Association, agrochemical industry and Cotton Incorporated.
PY - 2009/12
Y1 - 2009/12
N2 - Integrated control systems are based on the complimentary contribution of chemical and biological control fostered by conservation of natural enemies. Yet, in the 50 years since the integrated control concept [ICC] [Stern, V.M., Smith, R.F., van den Bosch, R., Hagen, K.S., 1959. The integrated control concept. Hilgardia 29, 81-101] was introduced there are few operational programs and even fewer attempts to analyze the mechanisms that allow chemical and biological control to act in concert. The dearth of demonstrable evidence for the ICC has eroded the credibility of biological control and its usage in operational IPM plans. We used in situ life tables within an experimental design to measure and compare the contribution and interaction of biological control and insecticides as tactical components within three pest management systems for Bemisia tabaci (Gennadius) in cotton. Insecticides were the key factor immediately following applications of broad-spectrum materials or one of two selective insect growth regulators (IGRs), and this mortality replaced that provided by natural enemies. Two to six weeks later, however, mortality from natural enemies, primarily predation, in the IGR regimes rebounded to the high levels observed in untreated controls and became the key factor. Mortality from natural enemies remained depressed in the broad-spectrum insecticide regime. Single IGR applications were sufficient to suppress B. tabaci populations throughout the season, while up to five broad-spectrum applications were needed to achieve comparable control. The chemical residual of IGRs was limited to several weeks, demonstrating a key role for mortality from conserved natural enemies that extended the control interval. This "bioresidual" allows for long-term, commercially-acceptable pest suppression following the use of selective insecticides. We provide a rare experimental illustration of integrated control, where chemical and biological controls "augment one another". Our approach and methodology could be applied to demonstrate and validate integrated control in many other systems, addressing a critical need for implementation of biological control in practicing IPM systems.
AB - Integrated control systems are based on the complimentary contribution of chemical and biological control fostered by conservation of natural enemies. Yet, in the 50 years since the integrated control concept [ICC] [Stern, V.M., Smith, R.F., van den Bosch, R., Hagen, K.S., 1959. The integrated control concept. Hilgardia 29, 81-101] was introduced there are few operational programs and even fewer attempts to analyze the mechanisms that allow chemical and biological control to act in concert. The dearth of demonstrable evidence for the ICC has eroded the credibility of biological control and its usage in operational IPM plans. We used in situ life tables within an experimental design to measure and compare the contribution and interaction of biological control and insecticides as tactical components within three pest management systems for Bemisia tabaci (Gennadius) in cotton. Insecticides were the key factor immediately following applications of broad-spectrum materials or one of two selective insect growth regulators (IGRs), and this mortality replaced that provided by natural enemies. Two to six weeks later, however, mortality from natural enemies, primarily predation, in the IGR regimes rebounded to the high levels observed in untreated controls and became the key factor. Mortality from natural enemies remained depressed in the broad-spectrum insecticide regime. Single IGR applications were sufficient to suppress B. tabaci populations throughout the season, while up to five broad-spectrum applications were needed to achieve comparable control. The chemical residual of IGRs was limited to several weeks, demonstrating a key role for mortality from conserved natural enemies that extended the control interval. This "bioresidual" allows for long-term, commercially-acceptable pest suppression following the use of selective insecticides. We provide a rare experimental illustration of integrated control, where chemical and biological controls "augment one another". Our approach and methodology could be applied to demonstrate and validate integrated control in many other systems, addressing a critical need for implementation of biological control in practicing IPM systems.
KW - Bemisia tabaci
KW - Bioresidual
KW - Contemporaneous mortality
KW - Integrated control
KW - Irreplaceable mortality
KW - Key factor
KW - Life tables
KW - Parasitism
KW - Predation
KW - Selective insecticides
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UR - http://www.scopus.com/inward/citedby.url?scp=70350015375&partnerID=8YFLogxK
U2 - 10.1016/j.biocontrol.2009.08.006
DO - 10.1016/j.biocontrol.2009.08.006
M3 - Article
AN - SCOPUS:70350015375
SN - 1049-9644
VL - 51
SP - 458
EP - 470
JO - Biological Control
JF - Biological Control
IS - 3
ER -