Previous PageOur laboratory is not monitoring the 2008 flight of citrus cutworms, and will
not be posting
degree-day calculations for this insect this season. General information
regarding citrus cutworm
biology will be maintained however.
Citrus cutworm larvae may appear as early as 250 DD from the biofix of second consecutive moth
capture, but the easier-to-see second instar larvae arrive at about 350 DD.
The lower developmental threshold for citrus cutworm is 45.6°F, or 7.55°C.
Pheromone trap captures are an indicator of the timing of the moth flight only; heavy trap
captures do not necessarily correspond to heavy larval infestations, and on the other
hand,
blocks with relatively light moth captures have had worm populations well above the
economic threshold. Orchards with a history of citrus cutworm problems need to be
checked
weekly during the pre-bloom period, and special care needs to be taken at petal fall as
newly
forming fruit are very susceptible to cutworm damage.
The purpose of monitoring degree-days for citrus cutworm is to provide an estimate for a
window of time when a majority of eggs have already hatched but the worms have not grown
to the point that a Bt application would lose efficacy. Applications of selective
insecticides
such as Bt products at the proper timing are very effective against citrus cutworm while
maintaining
an integrated pest management program for other pests of citrus.
For more information about citrus cutworm biology and control click here.
Look for further information
regarding citrus cutworm in our IPM
Newsletters.
Growers and consultants interested in monitoring for citrus cutworm moths may request a
sample
of pheromone and instructions for use by contacting Greg Montez at (559)646-6500 or email
to
gregm@uckac.edu.