Cucumber Beetle Management

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Cucumber Beetle Management Squash Bug
Management (Cucurbit Yellow Vine Disease)

• Celeste Welty
• Ohio State University
• February 2002

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Cucurbit Yellow Vine Disease

• New bacterial disease
• Infects squash, pumpkin, melon
• Not in cucumbers
• Vectored by squash bug
• Range
• Oklahoma, Texas, Kentucky for 10 yrs
• Confirmed in OH, MI in 2003

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Cucurbit Yellow Vine Disease

• gt28 days until symptoms seen
• First plants usually turn yellow
• Cut stem shows phloem ring is brown
• Plants collapse prior to fruit maturity
• Please alert diagnostic clinic if found

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Squash Bug Control

• Recommendation from Kentucky
• Must start control on day of planting
• Soil treatment with Admire or Platinum (although
  squash bug not on labels)
• Or weekly foliar treatment with Pounce or other
  pyrethroid
• Other ideas
• Marathon II (by Olympic), same A.I. as Admire,
  allowed on greenhouse transplants apply 1 d
  before planting

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Squash Bug Control

• Mechanical control options
• Row covers until flowering
• Rogue out first infected plants
• Flame the plants when they are through bearing
  fruit to destroy inoculative insects

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Cucumberbeetles

• Important damage (adults)
• Chew seedlings
• Transmit bacterial wilt
• Chew on fruit surface
• Less critical damage
• Larvae chew on roots
• Adults chew on flowers

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Bacterial wilt of cucurbits

• Vectored by cucumber beetles
• Transmitted in feces
• Enters via wound in plant, such as feeding wound
• Hosts
• Well-known killer of cukes melons
• Recently adapted to kill squash pumpkins but
  slower to kill

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Bacterial wilt on pumpkins

• Study in Indiana (G. Brust 1997)
• Plant susceptibility
• most at cotyledon stage
• slightly at 1-leaf, 2-leaf stages
• Howden more susceptible than 14 other varieties

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Pumpkin seedling after in-furrow treatment with
Admire, under heavy pressure from striped
cucumber beetle
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Bacterial Wilt Management Trial

• Split plot design
• Main plots (4 replicates)
• Direct seed (5/28/03)
• Transplant (6/20/03)
• Sub-plots
• 8 chemical treatments
• Magic Lantern pumpkin
• OARDC Western Branch, Clark County

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Bacterial Wilt Management Trial

• Target the vector (beetles)
• 1. Admire at-plant 24 oz/A
• 2. Admire chemigation 24 oz/A
• 3. Admire at plant 12 oz/A, with later Admire
  chemigation 12 oz/A
• Target the pathogen
• 4. Messenger
• 5. Actigard
• Target vector pathogen
• 6. Admire AP 24 oz/A Messenger
• 7. Admire AP 24 oz/A Actigard
• Control
• 8. Untreated check

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Bacterial Wilt Management Trial

• Admire
• True systemic only if applied to soil
• Once canopy develops, soil application not
  feasible with standard equipment
• If planting delayed, insecticide not needed if
  beetle activity past peak
• Chemigation
• Advantage of ability to apply to root zone
• Advantage of timing as needed once beetle
  activity increases

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Bacterial Wilt Management Trial

• Seeding vs transplanting
• Advantages
• Uniform stand
• Bypass rodent seed-eating problems
• Delay until mid-June allows bypass cucumber
  beetle peak
• Apply Admire as plug drench without special
  equipment
• Disadvantages
• Mechanical transplanter lacking

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Bacterial Wilt Management Trial

• At-plant Admire, 24 oz/A
• Seeded in-furrow
• Transplant pre-transplant plug drench, 1.4 ml
  Admire in 1 liter water for tray of 72 plugs

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Bacterial Wilt Management Trial

• Planting time
• Direct seeded on 5/28/03
• Timing as planned
• Done shortly after field preparation
• Transplants
• Trays seeded 6/2/03 in greenhouse
• Admire plug drench move trays outdoors 6/11/03
• Planting delayed due to rains
• Transplanted on 6/20/03

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Bacterial Wilt Management Trial

• Admire chemigation
• Injected via drip irrigation system
• Seeded plots
• Intended for 5 days after seeding (pre-emergence)
• Delayed until 6/21/03 (2 true-leaf stage) due to
  frequent rains
• Transplant plots
• Intended to apply once new flush of beetles
  detected in mid-summer
• Delayed until 8/21/03 due to lack of flush

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Bacterial Wilt Management Trial

• Late-summer beetle control in plots where vectors
  being targeted
• Foliar spray of Sevin XLR, 1 qt/A
• One spray, 8/25/03

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Bacterial Wilt Management Trial

• Methods
• Plots scouted weekly
• Early whole plant
• Beetle damage on cotyledons
• Number of beetles per plant
• Late
• Beetles in flowers
• Beetle damage on fruit
• Harvest evaluation, 9/30/03

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Bacterial Wilt Management Trial

• Results
• Seedling scouting 6/25/03
• Beetles during flowering, 7/14/03 - 9/17/03
• Bacterial wilt incidence
• Harvest, 9/30/03

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Bacterial Wilt Management Trial Scouting
6/25/03 3-true leaf stageMain plot treatments
6/25/03
A
B
Number of Plants per Plot
6/25/03
B
A
Beetle Damage Rating
6/25/03
A
A
Number of Beetles per Plant
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Bacterial Wilt Management Trial Scouting
6/25/03 3-true leaf stageSub-plot treatments
A
B
B
C
D
CD
CD
CD
Number Plants per Plot
Beetle Damage Rating
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Bacterial Wilt Management Trial

• Admire stand establishment
• High rate best stand
• Low rate intermediate stand
• None poor stand
• Due to seedcorn maggot
• Field seeded immediately after field preparation
• Lot of weeds plowed under
• Weather cool and wet
• Ideal conditions for seedcorn maggot

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Bacterial Wilt Management TrialBeetle Trends
Number of Beetles per Flower
Beetle Species
of Population
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Bacterial Wilt Management Trial
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Bacterial Wilt Management Trial, Harvest
NS
Yield (kg per plot)
NS
Beetle Damage Rating (scale 0 to 3)
NS
Beetle Damage Rating (scale 0 to 3)
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Bacterial Wilt Management Trial, Harvest
Harvest, marketable orange fruit, 9/30/03
AB
ABC
A
BCD
CDE
CDE
DE
E
Yield (kg per plot)
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Bacterial Wilt Management Trial, Harvest
Fruit Stem (Handle)
Beetle Damage Rating (scale 0 to 3)
Fruit Rind
Beetle Damage Rating (scale 0 to 3)
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Bacterial Wilt Management Trial

• Conclusions
• Admire at-plant provided excellent control of
  seedcorn maggot cucumber beetles
• Admire chemigation advantage not seen due to lack
  of late season beetle surge
• Not enough pressure from bacterial wilt to
  evaluate Messenger or Actigard

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Variety Trial, 2003

• Objective check for differences in
• Susceptibility to beetle feeding
• Susceptibility to bacterial wilt
• 20 varieties
• 6 replicates
• 2 locations, Columbus S.Charleston
• Planted early for peak beetle pressure

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Variety Trial, Columbus DI on 6/10/03

• Pik-A-Pie 12.5
• GoldBullion 12.2
• Trickster 11.7
• GoldMedal 11.7
• HybridPam 11.3
• ProGold 11.2
• AutumnKing 10.5
• MysticPlus 10.3
• GoldRush 10.2
• Howden 9.5

• ConnectiField 9.3
• GoldStandard 9.0
• Lil-Ironsides 8.8
• AutumnGold 8.0
• Sorcerer 8.0
• GoldenGem 7.7
• Wee-Be-Little 7.0
• MagicLantern 6.5
• Jack-Be-Little 6.3
• BabyPam 5.7

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Variety Trial, S.Charlstn DI on 6/13/03

• Trickster 2.2
• HybridPam 2.1
• GoldStandard 2.1
• AutumnKing 2.1
• MysticPlus 2.0
• AutumnGold 2.0
• BabyPam 2.0
• Jack-Be-Little 1.9
• GoldRush 1.9
• Lil-Ironsides 1.8

• GoldenGem 1.8
• MagicLantern 1.8
• GoldMedal 1.8
• GoldBullion 1.7
• Howden 1.7
• Pik-A-Pie 1.6
• ConnectiField 1.5
• ProGold 1.4
• Sorcerer 1.3
• Wee-Be-Little 0.9

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Variety Trial, 2003

• Consistently high beetle damage
• Hybrid Pam
• Trickster
• Autumn King
• Mystic Plus
• Consistently low beetle damage
• Wee-Be-Little
• Sorcerer
• Magic Lantern

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Bacterial wilt of cucurbits

• Beetle species common in cucurbits
• Known vectors
• Striped cucumber beetle
• Spotted cucumber beetle
• Not known to vector
• Western corn rootworm beetle
• Northern corn rootworm beetle
• Pale-striped flea beetle

striped
spotted
western
northern
pale striped
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Vector Tests, 2003

• Compare known vector (striped) with 2 unknown
  vectors (westerns pale-striped flea beetle)
• Procedure
• Beetles field collected
• Fed on BW-infected plant for 48 hrs
• Placed on clean squash seedling for 48 hrs
• Plant evaluated 3 wks later
• 6 batches of lab tests, July to October
• 8-30 plants per species per batch

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Vector Tests, 2003

• Sum of 6 batches
• Species Number BW
• Striped cuke beetle 8 / 104
• Pale striped flea beetle 0 / 36
• Western corn rootworm 1 / 76
• Untreated check 0 / 0

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Vector Tests, 2003

• Conclusions
• Surprised that striped not more BW
• Western corn rootworm appears able to vector
  bacterial wilt
• Pale-striped flea beetle was not shown able to
  vector, but number of beetles tested was
  relatively small.