ORG0N STAT: AGMIgIJLTURAL CCLLGE
Experiment Station
J. T. Jardine, Director
June 5, 1930.
ir. of Information, No. 31
Questions and Answers About the Cherry Fruit Fly
Nary questions about the cherry fruit fly were ashed by cherry growers
during the recent 'reetings in tne Jillamette Valley. The lnforletlon requested
by the growers is presented in this circular letter as answers to the questions
asked.
Life Nistory
Q. Now does the cherry fruit fly sDend the winter?
Te pupariun is found
A. The cierry fruit fly søends the nnter s s a Duparlui
under the infested cherry trees buried from two to three inches in the ground
Q. When does this pest emerge as flies from the soil?
A. The flies emerge from the soil during the latter part of Nay or early in
June, depending oi climatic factors.
Q. How long are the flies on the trees before egg laying begins?
A. The flies spend from 7 to 10 days on the foliage of cherry or other trees
before they begin laying eggs.
Q. Where are the eggs laid?
A. The eggs are leid under the skin of the cherry.
Q. How long does it take for the ogs to hatch?
A. The eggs hatch in about five days, i weather conditions are favorable.
Q. When does the maggot or larva become mature?
A. The maggot becomes mature in about 14 days.
Q. Where does the maggot go after reaching maturity?
A. The maggot drops to the ground and works its way into the ground where it
remains as a puparium until May or June of the next year.
6. Q. How long do the flies continue to emerge?
A. Flies may continue to emerge over a period of about three weeks.
Control
Q. When should the first spray be made against this pest?
A. The first spray should be put on as soon as the first fly is found.
Q. Is more than one spray necessary?
The second spray should be
A. Three sprays will be rocoimnended this year.
The timing of the third spray will depend
applied 7 days after the first.
upon the emergence of the fly.
2.
Q. What kind of a sprayer should cue use against this ?est?
Apply the solution as fairly
A. Either a power or hand sprayer can be used.
sides of the tree.
fine droplets on the upper surfaces of the foliage on all
this pest?
Q.. Is it necessary to drench a tree to control
t
e
spray
over
tue trees ad pernitcing the
Spot spraying or direo'in
A. Ia.
The spray should reach
liquid to fall on the upper surfaces of the foliage.
the upper portions of the tree.
Q. Should a spray be repeated after a heavy shower?
A. Yes.
Q. Should interplanted trees be sprayed?
interplanted with
A. All trees regardless of kind should be sprayed if they are
to cherry orchards should also
cherries. Brush along fence rows adjacent
'be sprayed.
sprayed as other varietie
Q. Should Royal Ann and varieties of sour cherries be
of cherries?
infestation, the tree may harbor
A. Yes. Even though Royal Anus may escape
Sour cherries are very susceptflies whioh'will infest cherries, later on.
ible to infestation.
B. Q. Can a sprayer be used that has previously contained lime sulfur?
to thoroughly wash spray tank
A. Yes. Precautions should be taken, however,
bef ore using.
By
cultivation?
Q. Can this pest be ôontrolled by cultural practices such as
parasites or by predators?
number of flies but
A. Cultivation, parasites and predators help to reduce the
such practice cannot be relied upon for complete control.
spray?
10. Q. What is the formula for tho praaration of the poison bait
A. Lead arsenate ------1/2 pound
Molasses - - - - - 2 quarts
10 gallons.
Water
S. C. Jones,
Assistant Entomologist.