Nantucket Pine Tip Moth Phenology and timing of insecticide spray applications in the Western Gulf Region

Abstract

others 2003). Two to five generations occur annually, depending on the prevailing climate (Berisford 1988, Fettig The Nantucket pine tip moth, Rhyncionia frustrana (Comstock) and others 2000a, Yates and others 198 1). Generations are (Lepidoptera: Tortricidae), is a common pest of pine plantations usually distinct, but considerable overlap may occur in throughout the Southern United States. The objectives of this study were to predict the phenology of R. frustrana populations regions with as few as three generations (Berisford 1988). throughout the Western Gulf region, and to provide optimal spray periods for locations that have three or four generations annually. Bivoltine populations are found in most locations north of The thermal requirements necessary to complete a generation were ~ a r ~ l a n d ( ~ a s h o m b and others 1978, Powell and Miller obtained from published data, and used in conjucrion with historical temperature data to model phenology throughout the region. Four 1978, Uates 1960), and throughout the mountain province generations were predicted to occur annually throughout many of of Virginia and North Carolina (Berisford and Kulman 1967, the pine producing regions of Louisiana, northeastern Texas, and Fettig and others 2000a, Lewis and others 1970). Three southern Arkansas. Three generations were predicted for the Ozark generations occur in much of the southern Piedmont and Ouachita hfountain ranges in Arkansas. Five generations were predicted for extreme southern portions of Louisiana and Plateau (Berisford and others 1992, Fettig and others throughout southeastern Texas. Spray timing prediction values were 2000a), and in the Coastal Plain of Virginia and parts of also obtained from published data and used to predict optimal spray North Carolina (Berisford and I(u1man 1967, Fettig and periods based on 5-day increments for each location where either Berisford 1999, Fettig and others 2000a). Four three or four generations occurred. Tables containing the predicted optimal spray dates are provided for numerous locations within each are reported for the Coastal Plain of Georgia (Berisford and state. Validations were conducted in Lousiana and east Texas to others 1992), South Carolina (Berisford and others 1992, determine the effectiveness of this technique to achieve adequate Gargiullo and others 1985, Moreira and others 19941, spray timing. There was 57 percent agreement between the optimal Alabama (Fettig and others 2000a), Mississippi (Fettig and spray periods and field-determined spray dates based on insecticide efficacy studies. Land managers who use contact insecticides, such others 2000a), and in southern California, where the insect as pyrethroids, can use these data for optimizing spray effectiveness was accidentally introduced (Malinoski and Paine 1988). within the Western Gulf region. This paper serves as a companion to Apparently, five generations occur in extreme southern a previously published work for the Southeastern United States ~ i b r g i a (Fettig and others 2000a, Ross and others 1989), (Fettig and others 2000a). and thus completes phenology and optimal spray period descriptions for R , frustrana throughout the extreme southern Alabama and Mississippi (Fettig and Southern United States. others 2000a), perhaps along the Gulf Coast (Uates and others 1981), and in northern Florida (Yates and others