Temporal and spatial patterns in pheromone-trap catches of Helicoverpa spp. (Lepidoptera: Noctuidae) in cotton-growing areas of Australia

Abstract

Helicoverpa armigera (Hiibner) and H. punctigera (Wallengren) are major pests of cotton and other field crops in Australia. Using data on the abundance of males in pheromone traps at many sites over three seasons, the spatial and temporal variation in trap catch of both species were examined using Taylor's power law and spatial autocorrelation. The distribution of both species was highly clumped, both temporally and spatially. Regression coefficients for the relationship of spatial mean to variance (b s ) were similar to those for noctuids in general, while similarly derived temporal values (£> t ) for H. armigera fell towards the upper end of the noctuid range and those for H. punctigera well above the range given by . Taylor and colleagues suggested that patterns of dispersion are speciesspecific and that they reflect density-dependent patterns of movement towards and away from centres of abundance. Although the relationship between variance and mean abundance for both spatial and temporal aspects of trap catches of Helicoverpa is well fitted by Taylor's power law, it is argued that these patterns of dispersion are a consequence of demographic and environmental stochasticity. Little need is seen to invoke specific densitydependent behaviours as the major factor responsible in this case. In addition, while Taylor's power law indicated both species had a similar clumped distribution, limited autocorrelation analysis suggested a random dispersion of pheromone-trap catches for H. armigera and small scale patchiness (over distances of 1-2 km) in trap catches of H. punctigera.

Efficacies of Four Pheromone-Baited Traps in Capturing MaleHelicoverpa(Lepidoptera: Noctuidae) Moths in Northern Florida

“…Helicoverpa armigera has been successfully trapped by wire cone, dry funnel (Kehat & Greenberg 1978), and delta (sticky) traps baited with sex pheromone in Australia (Baker et al 2011;Fitt et al 1989;Wilson & Morton 1989), Egypt (Salem et al 2008), Greece (Mironidis et al 2010), Hungary (Dömötör et al 2007;Keszthelyi et al 2011), andIndia (Basavaraj et al 2013;Srivastava 2010). Sex pheromone traps, along with light traps, were successfully used to document new distributions of H. armigera in parts of Australia where populations were not thought to exist (Fitt et al 1995).…”

Forecasting Helicoverpa populations in Australia: A comparison of regression based models and a bioclimatic based modelling approach

“…Research in the last 15 years has clarified the seasonal dynamics of the two pest Helicoverpa species in cropping and non-cropping systems in Australia. Around mid-to late-September each year a synchronous peak of moths of both species occurs throughout eastern Australia (Fitt et al, 1989). These moths are in the main migrants from vast areas of inland Australia.…”

Harmonic Radar Tagging for Tracking Movement ofNezara viridula(Hemiptera: Pentatomidae)

“…Studies addressing spatial distributions of insects in agricultural landscapes often use sampling methods such as sweep nets, drop cloths, and pheromone traps (Knight and Croft 1987, Fitt et al 1989, Gage et al 1990, Hoffman et al 1992, Byers 1993, ReayÐJones et al 2009, ReayÐJones 2012 or mark-recapture methods (Jolly 1965, Begon 1979, Nichols 1992, which cause disturbance that may impact normal behavior. Various tracking (Wallin and Ekbom 1988, Riecken and Raths 1996, Webb and Shine 1997 and remote sensing methods (Riley 1989) have been used to study movement, migration, and behavior of organisms.…”