[Pollinator] neonic use in California

[James Cane]

Hey BeeFolk- last week we read about the imminent recertification of
neonics for crop use. You may have noticed that in the accompanying map of
use intensity, central California was a deep maroon color, indicative of
heavy use. My guesses as to the crops and use were all wrong, however. Here
is the explanation sent to me by a California colleague who is intimately
familiar with the context.

jim

==============

In the Central Valley the neonics are probably mainly going on table
grapes, wine grapes and citrus. On California grapes they are used against
vine mealy bug (VMB) and Glassy winged sharpshooter (GWSS), as well as on
citrus to fight scale insects, thrips and overwintering GWSS. These are all
piercing, sucking insects. GWSS is a big mover of Pierce’s disease. GWSS
overwinters in evergreen citrus and then move into the vineyards after the
first true grape leaves emerge. The mass movement is an ecological
adaptation to escape their parasitoid wasp, *Gonotocerus ashmeadi,* which
is a weak flyer.


Alternative effective controls for VMB include mating disruption, good
hygiene and various organic products. Because wine grapes are crushed the
day of harvest there is no issue with the cosmetics of the grape.


Conventional table grapes have zero tolerance for cosmetic defects, unlike
organic table grapes.


Almond and other tree nut growers use as few products as possible due to
the profit margins.

...and then from a web site posting about implications:

California is proposing restrictions on neonics that would include
prohibiting the use of the chemicals on certain flowering crops that
attract bees when they are in bloom. They would also limit the use of
multiple neonicotinoids and regulate how growers can apply the chemicals in
the state.

The DPR estimates that use of neonicotinoid pesticides in California will
drop by about 45% once it implements the regulations




-- 
James H. Cane
Native bee and pollination ecologist
Emeritus USDA-ARS Bee Lab, Logan, Utah
owner -  *WildBeecology*
*https://www.researchgate.net/profile/Jim-Cane
<https://www.researchgate.net/profile/Jim-Cane>*

"Knowledge and comprehension are the joy and justification of humanity"
 Alexander von Humboldt
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