Thursday, September 15, 2005
Back in midsummer we mused on how cute grasshopper nymphs can be, and wondered how destructive their future selves would be. Here's a late-instar nymph (technical term for a teenager)(you can see the wing buds just in front of the hind legs--a fully mature hopper's wings cover the abdomen) with some representative foliage damage on cestrum Newelii.
Grasshopper populations, like those of many agricultural pests, tend to build up in response to favorable weather conditions. Here in Tustin last winter we had plenty of rain and mild temperatures, which would be favorable; but the spring was cool and summer not very hot at all (both less favorable, but not especially unfavorable). The absence of very cold or freezing winter temperatures would result in higher survival among the overwintering adult population, and possibly the eggs laid in the previous autumn. In fact, we have not had a hard freeze here in many years, and we believe that trend is contributing to changes in both the types (notably the giant whitefly) and numbers of insects in our area. But since no one really is counting, a lot of this kind of talk is just speculation. Why isn't anyone counting?
How to save your crops from certain destruction by grasshoppers then? Read these IPM guidelines for grasshopper control for some good pointers. Integrated pest management (IPM) is a system of agriculture that views the farm or garden as an ecosystem, and seeks to prevent or reduce pests and their damage by managing the dynamics of the system. All the while recognizing that the grasshoppers are on the job 24/7, while the gardener must take time out to blog.