Beth Grafton-Cardwell and her team at Lindcove - Citrus Research ...

When Japan dropped its
phytosanitary requirements
for Fuller rose
beetle (FRB) in the mid-1990s,
interest in FRB control subsided.
However, FRB is in the spotlight
again as trading partners in Korea
and Thailand have raised phytosanitary
concerns about the possible
movement of FRB eggs on fruit
destined for those countries.
Except for clogging sprinkler
heads from time to time, FRB is not
a major pest of California citrus, and
adult beetles rarely if ever make it
into a packed carton for shipment.
The primary concern is eggs, which
are difficult to remove once laid
under the calyx. Since it is difficult
to remove or kill FRB eggs once
they are laid, it is important to kill
as many adults as possible before
eggs can be laid.
While Korea allows fumigation
for FRB at the port of arrival, other
destinations such as Thailand refuse
entry of fruit where FRB has been
detected. With more markets raising
barriers because of FRB, control
of this pest is becoming more important.
When fruit is denied entry
in export markets, it must be sold
in the domestic market. Since the
domestic market is already wellsupplied,
it is difficult to market
more domestic fruit without reducing
the price and in turn reducing
grower prices.
FRB control
FRB has proved difficult to
control because adults emerge from
the soil every month of the year
with peak emergence taking place
over the July-October period. When
adults emerge, they instinctively
look for avenues to climb trees
to lay eggs because they cannot
fly. When foliage is touching the
ground, there are many available
avenues for adults to reach foliage
20 Citrograph July/August 2011
Renewed focus on
Fuller rose beetle control
An FRB pupa with two larvae.
Leaf damage caused by Fuller rose beetle.
Fuller rose beetle adult.
Jim Cranney
FRB eggs under the fruit button of citrus.
All photos courtesy of UC Statewide IPM Program,
copyright 2000, Regents of the University of California.
and fruit. Skirt pruning and removing
weeds can minimize avenues for
entry to the tree, so fewer adults
reach the canopy to lay eggs.
In addition to skirt pruning,
the University of California is experimenting
with trunk sprays, and
both cryolite and carbaryl can be
effective as preharvest foliar sprays.
To detect FRB, look for typical
jagged patterns of feeding on foliage
and tap branches over a white
cloth to dislodge the adults. They
will drop and “play dead” so they
are easy to spot against the white
cloth.
Research for new control
measures
With the emerging importance
of FRB, UC Riverside’s Dr. Joseph
Morse and the Lindcove Research
and Extension Center’s Dr. Beth
Grafton-Cardwell plan to evaluate
existing and new foliar pesticide
treatments, how to make trunk
sprays more effective, and whether
Fidiobia citri (an egg parasitoid),
will control FRB. The Agricultural
Research Service’s Dr. Spencer
Walse in Parlier plans to evaluate
fumigants that could be used to kill
FRB eggs.
The goal is to find more and better
ways to control FRB and keep
export markets open. Meanwhile,
growers are encouraged to evaluate
their groves for the presence of
FRB and take steps to reduce the
populations.
In closing, I would like to add a
special note of appreciation to Dr.
Morse for his invaluable input to
this article. As many readers will
recall, it was Morse who took the
lead on FRB research when the
pest first became an issue for California
in the 1980s.
Jim Cranney is President of the
California Citrus Quality Council
(CCQC). l