This document provides an overview of the primary insect pests affecting western pecan production, including aphids, pecan nut casebearer, and pecan weevil. It describes the biology and life cycles of each pest as well as methods for monitoring and managing infestations. In particular, it outlines economic thresholds for treatment, integrated pest management considerations and available control options like insecticides. The goal is to help pecan growers in western regions make informed decisions about pest control based on regional differences in pest pressure, cultivars and orchard conditions.

1. PRIMARY WESTERN PECAN
INSECT PESTS
New Mexico Pecan Short Course
September 8-10, 2010

2. Outline
• Background
• Aphid Complex
– Species
– Biology
– Management Considerations
• Pecan Nut Casebearer
– Biology
– Management Considerations
• Pecan Weevil
– Current Status
– Prevention

5. Two Distinct Pecan Growing Regions

6. Regionalization of Pecan Pest
Management Practices
1. Yield
2. Profitability
3. Pest Pressure
4. Primary vs. Secondary Pest
5. Cultivar

7. Pecan Leaf vs. Leaflet
Leaf/Compound Leaf
Leaflet

8. Pecan Aphid Complex
Black Pecan Aphid Yellow Pecan Aphid Complex
Blackmargined Pecan Aphid Yellow Pecan Aphid

9. Pecan Aphid Biology
Overwinter in bark as eggs
IJ. Park
Spring-eggs hatch, stem-
mothers arise
Populations build and decrease
over the season, winged and non-
winged females produces
Fall-males produced and mate
with wingless (apterous) females
eggs produced
No alternate-host in the
area

10. Aphid Feeding
1. Aphid manipulates stylet
between cells to find sieve
elements
2. Remove products produced
by photosynthesis
3. May compete with other tree
“sinks” for these products
• Susan Dunford, University
of Cincinnati –Photo Credit

11. Black Pecan Aphid
1. Adults dark black, nymphs dark grey
2. Wings extend past abdomen
3. Approximately 15 day lifespan
4. Produce approximately 35 offspring
5. Populations tend to be “clumped”
6. Little “honeydew” produced
7. Feed both sides of leaflet
Louis Tedders

12. Black Pecan Aphid Damage
1. Interveinal necrosis/defoliation
- Reductions in photosynthesis
2. May reduce nut quality*
3. Possible reductions in fruiting
sites (following year)*
4. Historically considered economic
5. Damage is visible

13. Yellow Aphid Complex
1. Yellow Pecan Aphid
Present in western orchards,
low populations
1. Blackmargined Pecan Aphid
Dominate species throughout the season
Jerry A. Payne, USDA Agricultural
Research Service, Bugwood.org
Mike Quinn

14. Blackmargined Aphids
I.J. Park
Aphid Skins
Parasitized blackmargined aphid (do not mistake
for black pecan aphid)
Mike Quinn
Non-Winged Female
“apterous” stem mother
Winged Female
“alate”

15. Blackmargined Aphid
1. Adult females both winged and non-winged
2. Characteristic “black band” on wings
3. All forms “lime green”
4. Lifespan approximately 30 days
5. Produce approximately 150 offspring
6. Populations tend to be uniform across the orchard
7. Feed primarily on underside of the leaflet

16. Blackmargined Aphid Damage
1. Compete with the tree for photosynthates
“sinks”*
2. May reduce nut quality*
3. May reduce # flowers (next year)*
4. Historically considered “secondary pest”
in other pecan growing regions
5. Provide a food source for sooty
mold* (honeydew)
6. Damage not visible
7. Premature defoliation

17. Quick Summary
1. Aphid species
2. Damage differences
3. Difference in fecundity rates

18. Pecan Production Basics
(Aphid Control Considerations)
1. Pecans alternate between “heavy” and “light”
production years.
2. Number and location of flowers are determined
the previous year.
3. Pecans are considered a “high value” crop.

19. Aphid Control Considerations
I. Economic Threshold Levels (internet)
• Black pecan aphid 1-3 per leaf
• Blackmargined aphid 10 per leaf
II. Yield reductions (regional)
• Approximately 2%+ reduction in meat
(“heavy” production year)
• Reduce number of flowers following year
(“light” production year)
• Increase in “husk retention” at harvest
(“heavy production” year)

21. Aphid Control Considerations
(Treat or No-Treat)
I. Scout (insect)
- Species
- Density
- Location (within, proximity to neighboring orchards)
- Aphid forms (winged, stem, nymphs)
- Damage (black)
- Honeydew production (blackmargined)
- History (how many, how long)

22. Aphid Control Considerations
(Treat or No-Treat)
II. Scout (orchard information)
- Yield estimate
- Overall orchard condition
- Foliar requirements (zinc)
- Soil moisture
III. Equipment availability
IV. Dollars
- Expected market price
- Application costs (chemical, labor)
V. Climate (treatment, honeydew, sooty mold)

23. Insecticide Selection & Application
• Number of insecticide active ingredients and activity for
aphid control
– Foliar trans-laminar systemics (neonicitinoids)
– Foliar true systemics (Movento*)
– Soil applied systemics (neonicitinoids)
– Contact (organophosphate, pyrethroids)
• Restricted vs. non-restricted
• Costs $5/acre to $30+/acre
• Resistance issues
• Adjuvants
• Application (coverage, air vs. ground, speed)

24. Status of Conventional Insecticides
Used to Control Pecan Aphids
I. Foliar
•1) Pyrethroids (co-packs)
•2 ) Non-specific feeding blockers (Fulfill)
•3) Neonicotinoids
•4) Chlorpyriphos (Lorsban 4E to Lorsban Advanced)
•5) Pyriproxyfen (Knack)
•6) Spirotetramat (Movento)
•7) 2012 ??
II. Systemic (soil applied)
Carbamates (Aldicarb removed 2010)
Neonicotinoids

25. OMRI Approved Insecticides for Aphids
• Sulfur
• Pyrethrin
• Potassium salts of fatty acids
• Aromatic Oils (i.e. rosemary, peppermint)
• Azadiachtin
• Plant Growth Regulator

26. Decisions

27. Pecan Nut Casebearer Basics
• Most recent pest introduced into western area*
• Overwinter as a diapaused larvae in the base of pecan bud
• Emerge in spring
• Normally three generations throughout the growing season
• Larvae feed on developing pecan nuts (direct impact), or buds
• Smaller the nuts, more nuts damaged by larval feeding
• Populations monitored with pheromone traps and scouting
for eggs and damage
• Economic threshold levels dependent on yield

28. Pecan Nut Casebearer Basics

29. PNC Life Stages
STAGE LOCATION APPROX DURATION
(days)
Egg Nutlet, Bud 5 - 10
Larvae Nutlet, Base of Bud
(overwintering)
25 - 30
Pupae Nutlet, Base of Bud 10 – 15
Adult (100-150 eggs) Omnipresent 7-10

30. Pecan Nut Casebearer
(Western Region)
PNC Infested
Pecan Growing, PNC Uninfested

31. Three Pecan Nut Casebearer Generations
(Moth activity)
10 16 20
DAYS

32. Detecting PNC Adult Populations
(Pheromone Traps)
10 16 20

33. Placement of Pheromone Traps
Wind
1. Location
2. Minimum of two traps
3. Record moths and #
nights since last count
4. Used to time egg
scouting
5. Replace pheromone
every month
6. Consider access
A

34. PNC Economic Decisions
• Economic Threshold Levels: (Internet)
– 1% egg infested clusters for 1st
generation
– 2% egg infested clusters for 2nd
and 3rd
generation
ON-YEAR 1st
GENERATION
-2,500 Lbs/Acre
-65 Nuts/Lb
-$1.80/Lb Market
-40,000 clusters/Acre
-At 1% infested = 400
Clusters/acre
-3 damaged nuts/cluster
=1200 nuts or 18 lbs or $32
Loss
OFF-YEAR 1st
GENERATION
-1,500 Lbs/Acre
-60 Nuts/Lb
-$1.80/Lb Market
-26,000 clusters/Acre
-At 1% infested = 260 Clusters/acre
-3 damaged nuts/cluster =780 nuts
or 13 lbs or $23 Loss
Western PNC may have a high egg mortality (up to 80%)
Used to thin crop load?

35. Pecan Nut Casebearer Management
A. Timing Insecticide
Application
1) Field Scouting
2) Modified Degree-Day Models
(1st
gen. only)
a. Biofix (Texas A&M)
b. Traditional (egg survey)
c. Forecast Model
3) Calendar Based
a. 12 days following accumulation
of 25 moths*
Egg
Egg Hatch, Larvae and Nut Entry
Treatment Decision
MothCatches
TIME

36. PNC Insecticides
(General Characteristics)
Broad Spectrum
• Older chemistries, less
expensive, residual less
than 10 days, high
degree of familiarity,
reduce moth
population, tend to
increase aphid density
Narrower Spectrum
• Newer chemistries,
more expensive,
primarily target
larvae, conserve
beneficials, longer
residual (some),
good OMRI
approved products

37. Alternative PNC Management
Strategy

38. PNC Adult Suppression Program
No Eggs
Countable Moths
Spray
Countable Moths
Spray
1. Not considered IPM
2. Can treat every other row
3. Inexpensive
4. No investment in scouting

39. Addition of Pecan IPM PIPE Website
• Maintained by Texas A&M
• Information contributions by all pecan
belt entomology researchers
• Early development phase
• www.pecan.ipmpipe.org
• Caution: recommendations may not be
appropriate for all growing regions

40. Pecan Weevil
Jerry A. Payne, USDA Agricultural
Research Service, Bugwood.org
H C Ellis, University of Georgia, Bugwood.org
Texas A&M

41. Recently Infested
1998/2002
1999/2003
2000/2003
Weevil Infested
Pecan Weevil
(1st
trapped/Last trapped)
2008

42. Pecan Weevil Prevention
• Restrict the movement of in-shell pecan and
potted pecan nursery stock from pecan weevil
infested areas.
• NMDA , WPGA, NMPG, WTPGA, APGA support
statewide cleaning plant and buying station
inspection programs.
• NMDA, NMSU, WPGA, NMPG support pecan
weevil eradication programs.

43. Primary pest objective is to
prevent the movement of pecan
weevil into, and eradicate
establishing populations in New
Mexico

44. Call