Classification of degree of infested areas by pine processionary moth on regions?

Question

I'm making a thesis about pine processionary moth distribution on the regions of algeria! i'm making tests about if there are spatial autocorrelation of this insects on the regions. and i'm doing also hierarchical clustering of (degree of infest, small defoliation, medium defoliation, and high defoliation, and lattitude and longitude coordinates ) on each region to see the regions that have the same caracteristics on the variables i muntioned above! The problem is that i need some information about the effect of geographical location and climat on this specific insect ? i have made some statistical tests, and i have found that each year have diffirent cluster caracteristics for this regions, so can anyone help me to know why it's diffirent each year ? the final thing, if anyone could suggest to me some links, to previous some study on another country maybe , so i can take an idea of what do i have to include and do , and to compare also with my results ?

Answer 1

Hi Asked.,

Since pine processionary moth is a major pest in southern Europe, there's considerable literature out there on factors which COULD affect clustering. If there's nothing on predators etc. for this species in Algeria, you'd have to develop appropriate comparable data, before proceeding further? Basically, populations are controlled either by food supply (perhaps local rainfall makes the pines, etc. produce tastier biomass, etc.), or by predator (birds, wasps, bats) and pathogen prevalence. And by the egg-laying of the previous season. Ecological systems tend to run many variables; I suspect it it rare to actually get enough data to closely predict outcomes, except in restricted prey/parasite/predator associations.

-- Cheers, -- Mr. d.