This is from the budget proposal of the Washington State Dept. of Agriculture, 2016/7 biennium:
“Washington State forestry and agricultural industries will be protected from a destructive defoliating insect allowing the unrestricted export of timber, nursery products and Christmas trees.”
“Widespread areas of dead and dying trees create a wildfire hazard, decrease water quality, destroy salmon habitat, and would have an adverse impact on tourism.Native upland forests and riparian areas within Washington’s many national forests, parks and wilderness areas could be subjected to severe environmental degradation if AGM [Asian gypsy moth] establishes itself in Washington.”
Right away, the primary reason for spraying is revealed: a moth infestation might impact agribusiness. The WSDA is an agriculture department, not a health or ecology department, and their primary mission is to help agribusiness – human and ecological health (aside from timber forests) are a secondary issue. So it is natural for them to downplay any possible risks to human health against the possible damage to our timber and horticultural industries.
The budget proposal was written in late September 2015 and submitted October 5, 2015. At that time, WSDA already knew they had trapped 5 AGM, and proposed a budget of $5.375m over 2 years for eradication. Some of this is matching funds from the USDA, but a significant portion will have to be borne by the State. This includes 6 extra full time workers in 2016 and 12 in 2017. Some portion of this is likely for extra PR staff.
Gypsy moths, while in an initial phase of an infestation, have been known to defoliate trees, but in general, trees do not die from this defoliation (check back East at how Euro/American gypsy moth infestations proceed); only weak trees are are killed. Most survive. After a few years, the moth population starts to reach an equilibrium as natural predators and diseases are activated. If you just look at the native range of the Asian gypsy moth (Siberia) you will not see defoliated, dying forests. In fact, the extent of damage that would be caused by an established AGM population in the Pacific Northwest is unknown.
The response by agriculture departments has typically been “well, we don’t want to find out.” Unfortunately, we will almost certainly find out. With climate change and global trade increasing, more and more AGMs will be coming to the Pacific Northwest. Is our knee-jerk response going to be to spray more and more area each year with pesticides, until we finally have to give up? A smarter tactic needs to be crafted.