A note from Kern County Entomology Advisor David Haviland, We are forewarned. The hills are drying up and after this rain, there could be a tide of False Chinch Bugs coming out of the hills. I remember in 2005(?) after the rains they were crawling everywhere and young avocado trees were getting hit pretty badly, requiring sprays certainly along orchard perimieters,
We get FCB every year in the south Valley and there are definitely two weather-related correlations. First, more rain equals more weeds equals more false chinch bugs. But also, weather effects drydown that affects the longevity of the migration event. In cool springs like we are having, vegetation tends to dry slowly and the migrations out of pastures and other weedy areas can last over a month. In years where we get blasted with 100 degrees in May, things dry down quickly, we get a massive wave of bugs, but then they go away quickly. The most fun is when somebody decides to disk up a heavily infested area, all the weeds dry at once, and the migration is a massive pulse. I'm not sure what will happen this year. We had over 10 inches of rain (more than twice the normal) in the south Valley and there is lots of vegetation out there, but then earlier this week we got about 0.25 inches of rain from the freak low-pressure system that lit up our skies with lightning on Monday and Tuesday. A lot of the vegetation out there is going to be able to hang on a little longer. I'm thinking that the false chinch bug call Siavash received will be the first of many that we get up and down the state this year.
As a side-note, in production ag, our biggest issues are when migrations get into young almond or pistachio orchards. They definitely kill young trees due to the toxin they inject. I've seen them also do some pretty good damage to cotton, beans, and tomatoes, but it is usually only a few rows on the edge. For homeowners is mainly just a nuisance, but it is hard to tell a homeowner not to worry about the thousands of bugs crawling all over their house.
https://ipm.ucanr.edu/agriculture/avocado/false-chinch-bug/
https://ipm.ucanr.edu/agriculture/avocado/false-chinch-bug/
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=43865
