The fundamental and realized niche of the Monterey Pine aphid, Essigella californica (Essig) (Hemiptera: Aphididae): implications for managing softwood plantations in Australia

Abstract

Essigella californica is a pine aphid native to western North America. In Australia, E. californica is considered an invasive pest that has the potential to cause severe economic loss to the Australian forestry industry. Two CLIMEX models were developed to predict the Australian and global distribution of E. californica under current climate conditions based upon the aphid's known North American distribution. The first model (model I) was fitted using the reasonably contiguous set of location records in North America that constituted the known range of E. californica , and excluded consideration of a single (reliable) location record of the aphid in southern Florida. The second model (model II) was fitted using all known records in North America. Model I indicated that the aphid would be climatically restricted to the temperate, Mediterranean and subtropical climatic regions of Australia. In northern Australia it would be limited by hot, wet conditions, while in more central areas of Australia it is limited by hot, dry conditions. Model II is more consistent with the current Australian distribution of E. californica . The contrast in geographical range and climatic conditions encompassed between the two models appears to represent the difference between the realized niche (model I) and fundamental niche (model II) of E. californica . The difference may represent the strength of biotic factors such as host limitation, competition and parasitism in limiting geographical spread in the native range. This paper provides a risk map for E. californica colonization in Australia and globally. E. californica is likely to remain a feature of the Australian pine plantations, and any feasibility studies into establishing coniferous plantations in lower rainfall areas should consider the likely impact of E. californica .

Should species distribution models use only native or exotic records of existence or both?

“…In terms of a definition, native species occur naturally in a locality, or have existed for many years, in that area (Sellmer, 2010), while exotic species, also termed introduced, non-indigenous or non-native species, are those living outside the species' native distribution, having arrived at the location through human activity, either deliberately or accidentally (Sax and Gaines, 2008). It should be noted that available georeferenced occurrences at global or continent scales can be found in datasets such as Global Biodiversity Information Facility In a study by Wharton and Kriticos (2004), CLIMEX software and all distribution records of Australia's economy (Shabani and Kotey, 2015).…”

Invasive species and climate change: an agronomic perspective

“…Many of these models use a simplistic approach to species interactions usually focusing on single-host plant climatic interactions (e.g. Julien et al 1995;Wharton and Kriticos 2004). To be able to forecast invasive species demographics on a geographical scale would require a means to assess multispecies interactions with respect to predation, competition, and facilitation-data which is rare or absent from the current literature.…”

Predicting the potential distribution ofSirex noctilio(Hymenoptera: Siricidae), a significant exotic pest ofPinusplantations

“…The first method is to obtain parameter values of climatic requirements by carrying out experiments (e.g., [46]) or from literature (e.g., [32]). The second method is to estimate the parameter values using climate data in the species' native range (e.g., [63]). In the second method the parameter values are then adjusted iteratively until the indices for growth and survival at locations within the native range show high values (i.e., persistence), while the indices at locations outside of the native range show low values (i.e., extinction).…”