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

Abstract

Long‐term forecasts of pest pressure are central to the effective management of many agricultural insect pests. In the eastern cropping regions of Australia, serious infestations of Helicoverpa punctigera (Wallengren) and H. armigera (Hübner)(Lepidoptera: Noctuidae) are experienced annually. Regression analyses of a long series of light‐trap catches of adult moths were used to describe the seasonal dynamics of both species. The size of the spring generation in eastern cropping zones could be related to rainfall in putative source areas in inland Australia. Subsequent generations could be related to the abundance of various crops in agricultural areas, rainfall and the magnitude of the spring population peak. As rainfall figured prominently as a predictor variable, and can itself be predicted using the Southern Oscillation Index (SOI), trap catches were also related to this variable. The geographic distribution of each species was modelled in relation to climate and CLIMEX was used to predict temporal variation in abundance at given putative source sites in inland Australia using historical meteorological data. These predictions were then correlated with subsequent pest abundance data in a major cropping region. The regression‐based and bioclimatic‐based approaches to predicting pest abundance are compared and their utility in predicting and interpreting pest dynamics are discussed.

Pest occurrence model in current climate - validation study for European domain

“…Mechanisms by which climate conditions aff ect the development of a species can also be analysed with the CLIMEX so ware tool used in present study. CLIMEX is a worldwide renowned so ware that has recently been applied in various scientifi c studies considering the potential distribution and spread of animal or plant species (OLFERT, WEISS, 2006;ZALUCKI, FURLONG, 2005;RAFOSS, SAETHRE, 2003;KRITICOS, et al, 2003;LOCKETT, PALMER, 2003;BELL, WILLOUGHBY, 2003;SUTHERST, 2000a;and SUTHERST, 2000b, among many others …”

The future of IPM: whither or wither?

“…These ideas formed the basis of an area-wide management (AWM) strategy, tested (Murray et al 1998) and then apparently successfully implemented on the Darling Downs in Queensland (Rochester et al 2002;Murray et al 2005a). Although the program of area-wide management appears to have worked, there is no mechanism for definitive validation and, as we have argued elsewhere (Zalucki & Furlong 2005), the abundance of Helicoverpa spp. during the period might simply reflect prevailing climatic conditions, which are reflected in the dramatic reduction in the area of cotton production (Fig.…”

“…This is probably due to the ecology and population structure of H. punctigera which breeds on native host plants in the absence of insecticides in inland Australia (Zalucki et al 1986(Zalucki et al , 1994Gregg et al 1995;Oertel et al 1999). Helicoverpa punctigera re-invades agricultural regions annually (Fitt et al 1989;Maelzer et al 1996;Maelzer & Zalucki 1999Zalucki & Furlong 2005). Conversely, H. armigera persists in agricultural areas, usually overwintering as diapausing pupae (Fitt & Daly 1990) and, although some moths invade from inland areas in the spring (Fitt et al 1989;Maelzer & Zalucki 1999, insecticide-resistant individuals persist between crop seasons (Scott et al 2005).…”

Climate Change Impacts on Czech Agriculture

“…Mechanisms by which climate conditions affect the development of a species can also be analysed with the CLIMEX software tool. CLIMEX is a world renowned software that has recently been applied in various scientific studies considering the potential distribution and spread of animal or plant species (Sutherst, 2000a, b;Bell & Willoughby, 2003;Kriticos et al, 2003;Lockett & Palmer, 2003;Pethybridge et al, 2003;Rafoss & Saethre, 2003;Zalucki & Furlong, 2005;Olfert & Weiss, 2006, among many others).…”