March 2024 - 10

PEST MANAGEMENT
Pest update
The latest research, emerging pests and beneficials for
West Coast grape growers
BY DEBBIE EISELE
EDITORIAL DIRECTOR
I
n 2022, Fruit Growers News highlighted research in
California and other states related to imported wasps
to control the spotted-wing drosophila (SWD) fruit fly.
Kent Daane, Extension specialist with UC Berkeley and
stationed at the Kearney Agricultural
Research and Education Center for
the University of California, provided
insight on the latest in this on-going
research.
" There is a multistate and
multiagency effort to improve the
biological control of the spotted-wing
drosophila - Drosophila suzukii. After
years of work, a small wasp from Asia,
Ganaspis, was allowed to be released
in the U.S. This parasitoid attacks
fly maggots in the fruit and develops
on the maggots later emerging as
an adult from the fly pupa, " Daane
said. " Along with this wasp, a second
Asian parasitoid, Leptopilina japonica,
was found first in British Columbia,
Canada and has since spread to many regions in the U.S.''
The SWD team, which is funded through USDA and
local state or commodity grants, has been rearing and
releasing these two types of wasp species to improve
SWD control. " Bio-controls will especially target the
riparian zones that provide a refuge for the fly. In some
regions, such as Delaware, up to 70% parasitism has
been recorded in non-crop refuges. "
Yet with this success, the need for other tools has not
changed and the SWD team is working on many different
control tools.
" Insecticides will probably still be needed in the
commercial crops. SWD parasitism levels in California,
in particular, still remain low and it is suspected that the
hot-dry summers may not be conducive to the wasps'
establishment. Work will continue with
these and other beneficial insects, "
Daane said.
On the East Coast, the spotted
Spotted lanternflies feed on and
damage grape crops on the East
Coast and may be of concern for
West Coast regions in the future.
Photo courtesy of Virginia Tech.
lanternfly is found in large numbers, but
has been easy to kill with insecticides,
Daane said. This pest has not yet
established on the West Coast, but
is likely the next invasive species the
region will encounter. Additionally, he
noted that the West Coast and state
agencies are " actively monitoring " for
any presence of spotted lanternfly in key
places in California and other locations.
Daane said monitoring vineyards is
important to reduce the risk of insect
infestations in the vineyards.
" Vineyard managers and PCAs (pest
control advisors) monitor their blocks for common
insect pests - mealybugs, leafhoppers, mites, etc. In
California, they can make use of websites such as CDFA's
(California Department of Food and Agriculture) invasive
species site, cdfa.ca.gov/plant/pdep/target_pests.html,
where they can download information on invasive species
to share with field crews, " he said.
If unidentified pests are uncovered, contact the local
farm advisor or county ag commissioner to assist in
identifying the insect.
" The best advice is to simply be aware of new pests
and get them identified early
so control actions can be
implemented, " Daane said.
10 | MARCH 2024
http://cdfa.ca.gov/plant/pdep/target_pests.html
March 2024

Table of Contents for the Digital Edition of March 2024
