Table Of Contentl^j^H University of
^^gk Massachusetts
UMASS Amherst
Library
BIOLOGICAL
OCT 2 5 1999
LIBRARY
SQtgNCES
UM/Morr.
Per Notes
SB
354 ^"ruit
F68
&
Prepared by the Department ofPlant Soil Sciences.
UMass Extension, U. S. Department ofAgriculture, and Massachusetts Counties Cooperating.
Editors: Wesley R. Autio and William J. Bramlage
Volume
62,'Q|^mber 1
WINTER ISSUE, 1997
Table of Contents
Positioning Unbaited Pyramid
Traps to Capture Plum Curculios
How Do Plum Curculios Approach
Host Trees and Pjrramid Traps?
Do Natural Sources ofOdor Enhance
Plum Curculio Attraction to Traps?
Petal Fall is the Most Attractive Developmental Stage
ofMcintosh Apple Trees to Plum Curculio Adults
Jim Anderson Dies
Peach Cultivar Trials: Observations and Comments
Agri-Mek: A 1996 Field Trial in a Commercial Apple Orchard
Fruit Notes
Publication Information:
Fruit Notes (ISSN 0427-6906) is published the each January, April,
&
July,andOctoberbytheDepartmentofPlant Soil Sciences, University
ofMassachusetts.
ThecostsofsubscriptionstoFruit Notesare$10.00forUnitedStates
addresses and $12.00 for foreign addresses. Each one-year subscription
beginsJanuary 1 andends December31. Some back issues are available
for $3.00 (United States addresses) and $3.50 (foreign addresses). Pay-
ments must be in United States currency and should be made to the
UniversityofMassachusetts.
Correspondence should be sent to:
Fruit Notes
&
Department ofPlant Soil Sciences
205 Bowditch Hall
UniversityofMassachusetts
MA
Amherst, 01003
UMASS EXTENSION POLICY:
All chemical uses suggested in this publication are contingent upon continued registration.
These chemicals should be used in accordance with federal and state laws and regulations.
Growersareurgedtobefamiliarwithallcurrentstateregulations. Wheretradenamesareused
for identification, no company endorsement or product discrimination is intended. The
UniversityofMassachusettsmakesnowarrantyorguaranteeofanykind,expressedorimplied,
concerning the use of these products. USER ASSUMES ALL RISKS FOR PERSONAL
INJURY OR PROPERTY DAMAGE.
IssuedhyUMassExlensuiii,RiihcilC, Hel^eseit.Director,infiirlheraiiceoftheiiclsofMay8iindJune30,
1914. UMaasExtensionoffersequalopportunityinprogramsandemployment.
Unbailed
Positioning Pyramid Traps
Plum
to Capture Curculios
Ronald Prokopy and Starker Wright
Department ofEntomology, University ofMassachusetts
In the 1996 Winter issue ofFruitNotes, we Trees were about 12 feet tall and about 10 feet
reported results ofour 1995 research on plum in canopydiameter. Soil beneathtree canopies
curculioresponses to unbaited"Tedders"traps. was treated with glyphosate in April and was
These traps are pjrramidal in shape, dark in devoid ofvegetationthroughoutourstudy. The
color, and are placed on the ground. They remainderoftheorchardfloorwas coveredwith
capture curculios that arrive on the trap grass, whichwas maintained at aheight of2 to
surface and subsequently crawl upward to the 4 inches. Dense woods, which we considered to
tip, where they enter an inverted screen funnel be prime overwintering habitat for plum
(a cotton boll weevil trap top) placed over the curculios, lay about 25feet northofthe endtree
tip, from which they cannot escape. ofeach row, and a large open field ofgrass lay
All reported tests to date using Tedders immediately south.
traps (hereafter referred to as pyramid traps) At the pink stage of bud development,
for capturing plum curculios have involved pyramid traps were placed in association with
deploying unbaited traps between canopies of each of the trees in the second through ninth
apple trees within rows. In 1996, we evaluated rows (Figure 1). One trap was placed 10 feet
unbaited pyramid traps at four different north ofthe trunk ofthe northernmost tree (15
positions on the ground in a small commercial feet from the woods), one trap 10 feet south of
apple orchard (Prokopy orchard) in Conway, the trunk ofthe southernmost tree ofa row (at
MA. In addition, we compared curculio the edge of the open field), one trap mid-way
captures by pyramid traps with captures by between the canopies ofthe northernmost and
unbaited cotton boll weevil trap tops placed in next northernmosttree ofarow, and onetrap 1
tree canopies. For each position or type oftrap, foot from the trunk ofthe center tree ofa row.
we compared daily trap captures with daily At the same time, a boll weevil trap top was
incidence of orchard fruit scarring by plum placed on the cut end ofa 4-inch uprighttwigin
curculios. the upper part of northernmost trees in the
second through ninth rows.
AM
Materials & Methods Traps were examined daily at 7 from
time of installation (May 14) until four weeks
Eachpyramidtrapwasblackandmeasured after petal fall (June 27). In addition to
40 inches in vertical height, 22 inches in base recording numbers of curculios captured each
width, and 2 inches in top width. Each was day, we also recorded daily (from full bloom on
staked to the ground to prevent toppling by May 23 until June 15) the number of fruit
wind. All traps were constructed from plywood receiving a curculio feeding or oviposition scar
in our laboratory, but beginning in 1997, traps in samples of five fruit per tree per day (200
of essentially identical type can be purchased fruit per day among 40 trees).
fromGemplers Inc., Mt. Horeb,WI (onlyknown Orchard treesreceived noinsecticidebefore
supplier). bloom but were treated with phosmet on May
The orchard consisted of ten rows of five 28 (80% petal fall) and on June 15. All traps
trees per row. Tree trunks were 20 feet apart were removed during treatment, which was
between rows and 13 feet apart within rows. appliedbyamotorizedbackpacksprayerto the
FruitNotes, Volume 62 (Number 1), Fall, 1997
WoodsJ
1
Scars
12 - DCaptured Adults
Insecticide Application
10
E
z
M
r
I
23-May 25-May 27-May 29-May 31-May 2-Jun 4-Jun 6-Jun 8-Jun 10-Ju 12-Jun 14-Jun
Figure 2. Egg-laying scars and trap captures from May 23 through June 15, 1996.
tree canopy and trunks. trap captures and daily numbers of sampled
fruit injured by plum curculios. Indeed, the
correlation between daily captures by pyramid
Results
traps attreetrunks and dailyfruitinjuries was
Unbaited pyramid traps placed adjacent to anegativeratherthan a positiveone (Figure 2).
tree trunks captured at least five times more In other words, during periods when captures
curculios than unbaited pyramid traps at any were greatest, injury was least.
otherposition and 15timesmorecurculiosthan
unbaited boll weevil trap tops placed in tree Conclusions
canopies (Table 1).
Captureofsubstantial numbers ofcurculios Our findings show that placing black
by unbaited pjn-amid traps next to tree trunks pyramid traps next to apple tree trunks is the
could entice one to believe that such captures mosteffectivepositioninterms ofcapturingthe
might be used as a basis for determining need greatest numbers ofplum curculios in an apple
for and timing of insecticide sprays against orchard. Results of additional studies (see
curculio. Unfortunately,thisdidnotprovetobe following article) indicate that the principal
thecaseintheConwayorchardin 1996. Infact, reason why this position is better than any
there was no trap position for which there was other position stems from the strong tendency
even a faint positive correlation between daily of curculios, when crawling, to move toward
FruitNotes, Volume 62 (Number 1), Fall, 1997
areas of greatest darkness within an orchard (Figure 2). It appears that during this time
(that is, toward tree trunks). Placement of period, most curculios arrived in tree canopies
black pyramid traps next to tree trunks byflight and not bycrawling up tree trunks (or
capitalizes on this behavioral tendency, which up pyramid traps).
isexpressedjustas stronglyin an understoryof What might be a solution to this
vegetation as on bare ground. shortcoming of pyramid traps during warm
Even at this most favored tree-trunk weather? One solution might be to use a
position, however, unbaited black p5Tamid powerful attractive odor in conjunction with a
traps fall well short ofbeing an effective means pyramid trap positioned next to a tree trunk
ofmonitoring the occurrence ofcurculio injury (seefollowingarticles). Anothersolution might
to apples. Additional studies (see following be to develop an effective odor-baited trap for
We
article) indicate that a principal cause for the use in the tree canopy. are working toward
failure of captures by unbaited pyramid traps both solutions.
ongroundtobegoodpredictors offruitinjuryin
tree canopies lies in the means by which
curculios approach pjrramid traps and ap- Acknowledgments
proach tree canopies: by crawling or by flight.
Evidence suggests that during warm weather, Thisworkwas supportedbygrantsfromthe
curculios may enter tree canopies directly by USDA Northeast Regional IPM Competitive
flight, bypassing tree trunks and pjrramid Grants Program, the USDA SARE Program,
traps. Injuryto fruitis greatest during periods State/Federal IPM funds, and the New
ofwarmweather, such as occurred fromJune 5 England Tree Fruit Growers Research Com-
through June 9 in the Conway orchard in 1996 mittee.
•Xa •Xa *1> vl* vL*
r^ 0^ 0^ #^
rp»
FruitNotes, Volume 62 (Number 1), Winter, 1997
