Dave Morgan - Riverside, CDFA
when the gwss arrived in CA, the smoketree sharpshooter which was already here
has its own natural enemy complex. They switched over to the gwss and they are
doing a very good job. But only after about June, before that the wasp population
was lagging behind. Massive outbreaks at the beginning of the year. Takes wasps
a while each year to build up a population. There are three generations of wasps
per gwss generation, fast in reproduction.
Wasps, 14 days from egg to adult. Gwss, 50 days from egg to adult.
The gwss are affected very much by winter. I don't believe that they will colonize
and settle much further north than Sacramento. You might see sporadic outbreaks
one year to the next. Less likely to be a problem in the north. Fewer number of
host plants and not much citrus.
The citrus growers don't care about the gwss -- it doesn't damage the citrus,
and it loves citrus, so it would spread to nearby vineyards.
Also further North the disease is less likely to be spread; it will be limited
transmission between plants. There is some evidence that the plant freezing kills
the disease. Or even cooler temperatures. Remember the gwss comes from Florida,
a constant gentle warm climate.
North the gwss population growth will not get as severe as down south.
*** RE predators: the gwss are wonderful for predators to eat because of their
*** Assassin bugs (which have been increasing in California), lizards, birds,
bats, spiders, mantises (becoming more frequent). And gwss nymphs can be attacked
by ladybug and lacewings (larvae)
On the east coast gwss are curbed by microbes, fungus -- but not here so much,
cdfa.ca.gov --> Programs --> Biological control
[RE imported wasps.] We have imported 3 species only one of which is new to this
area. Gonotercus trigutattus. We have done releases last year and are continuing
to do them. Last month I went to Mexico: Valley Hermosos, Nueve Leon State, Tamalapis,
Vera Cruz State, San Luis Apopto ....
*** We bring back parasitized eggs. They are hard to find, which gives us good
hope that we can control them.
There will be two insectiaries that will raise the wasps.[ Right now Dave Morgan
is doing 3 mass raisings at UCR (difft departments, bldgs?).] There is a new insectiary
in Riverside in the construction phase. In Bakersfield, Cory Simmons of USDA Aphis
is moving into it at present, and predators, and will be doing releases ...
Also USDA ARS in Mission Texas (?S. America shipment?)
*** [What is the timeline??:] By the end of this month I will be releasing them.
But we need to find good release sites: where insecticides are not being used.
Because beneficial predators are very harmed by insecticides, as they travel around
searching for prey they pick up more insecticides than the more sessile prey insects.
Good release sites would be: Organic, ideally, or urban places, where insecticides
can't be used.
I have to tell you that actually we still see insecticides as the most useful
control in commercial situations.
*** Biological controls [?would be secondary?] and for places that can't be sprayed:
such as organic farms, urban situations, [then he mentioned Yosemite as a not-to-be
[?So when could I tell the Ag. Commissioner to get in touch with you to get some
of these wasps?] Actually I'm just a grunt. They should get in touch with Charlie
Pickett of Larry Besark. We will be attempting to achieve maximum coverage of
the area by contacting Ag. Commissioners. (A formal and regulated process, so
that people don't say "we got less wasps than they did", etc.) We're
hoping that they will pinpoint locations where we can do the releases. Every 50
square miles or so. And also through the CDFA monitoring system.