1. Beauvaria bassiana (Botanigard) Gill 2001 Highly effective
Metarhizium anisopliae (Met-52) Gill 2013 Highly effective
Metarhizium flavoviride Chandler 1992 Highly effective
Carbofuran (Furadan, Curater) Harding 1971, Alleyne 1975 Highly effective
Aldicarb Harding 1971 Effective
Aphistar (triazimate) Cowles 2004 Effective
Bendiocarb (Dycarb) Gill 2001 Effective
Methomyl (Lannate) Harding 1971 Moderate efficacy
Toxaphene Harper 1961 Ineffective
Imidicloprid (Merit, Marathon) Cowles 2004, Gill 2001
Moderate efficacy /
Ineffective
Thiamethoxan Cowles 2004 Ineffective
Clothianidin & beta-cyfluthrin Pretorius 2014 Ineffective
Aldrin Harper 1961 Highly effective
Endrin
Dunn 1960, Harper 1961,
Alleyne 1975
Highly effective
Lindane Harper 1961 Highly effective
Heptachlor Harper 1961 Effective
Dieldrin Harper 1961 Moderate efficacy
Chlordane Harper 1961 Ineffective
DDT Harper 1961 Ineffective
Acephate (Orthene) Gill 2001 Highly effective
Diaziinon Dunn 1960, Harding 1971
Highly effective /
Moderate efficacy
Parathion Harding 1971, Harper 1961
Highly effective /
Moderate efficacy
Dimethoate Harding 1971 Effective
Disulfoton Harding 1971, Alleyne 1975 Effective
Methamidophos (Monitor) Harding 1971 Effective
Monocrotophos Harding 1971 Effective
Azodrin Harding 1971 Moderate efficacy
Ethion Harding 1971 Moderate efficacy
Malathion Harper 1961 Ineffective
Phorate (Thimet) Alleyne 1975 Ineffective
Terbufos (Counter CR)
Seymour et al. 1999, Alleyne
1975
Ineffective
Tebuprimphos & cyfluthrin (Aztec) Seymour et al. 1999 Ineffective
Hexamethylditin Harding 1971 Effective
Fipronil (Regent 4SC) Seymour et al. 1999 Highly effective
Insecticidal soap (M-pede) Gill 2001
Highly effective
(root ball dip)
Bifenthrin (Talstar) Gill 2001 Ineffective
Tefluthrin (Force 3G) Seymour et al. 1999 Ineffective
• Over the past few seasons, root aphids (Pemphigus spp.) have
emerged as a pest of succulents in some Michigan greenhouses.
• Although it remains to be seen whether root aphids have a
measurable impact on succulent growth, other crops have been
known to wilt and die from heavy infestations.
RESULTS - Literature review
Acknowledgements
DISCUSSION
Root aphids in the greenhouse: observations and recommendations
INTRODUCTION
Literature Review:
Study plants were donated by a very generous greenhouse grower in southwest Michigan.
Many thanks to Dr. Jen Lau at Kellogg Biological Station for the use of laboratory space.
• I performed an extensive literature review to find anything related
to managing root aphid populations in greenhouse systems.
• The body of research is tiny, so it was necessary to expand the
literature review to include any study or article regarding the
biology or management of root aphids, regardless of the system.
• Each method was evaluated for efficacy and assigned a rating
(see results section).
METHODS - Literature review
Jeremy J. Jubenville
West Michigan IPM
RESULTS - Root zone sampling
METHODS - Root zone sampling
Commonly Available Options
(recommendations highlighted in green)
Management tactic Source Result Class
Biological
Carbamate
Neonicotinoid
Organochlorine
Organophosphate
Organotin
Phenylpyrazole
Potassium salts
of fatty acids
Pyrethroid
Chlorinated
terpene
Rating
Highly effective
Effective
Moderate efficacy
Ineffective
Reduction in root
aphid population
95 - 100%
80 - 94%
60 - 79%
Under 60%
Management
option Class
Application
method
Relative
toxicity
Success
likelihood
Example
products
• Slower growth — more time to reach marketable size
• Possible death of the plant
• Possible pathogen transfer
• Rejected shipments from other growers
• Regulatory action
Risks include:
• Pertinent management advice was scarce and unsatisfying, so
a study was developed to answer two important questions.
• Question 1: What methods have been used to successfully
manage this pest in the past?
• Question 2: How are these aphids distributed within the root
zone of a typical greenhouse plant?
1. Divide growing medium profile into roughly three equal parts
(top, middle, bottom).
2. Submerge bottom third into water to separate aphids from soil.
3. Collect aphids floating on the surface and count them.
4. Repeat for middle and top thirds of root system.
5. Check the core root structure for any remaining aphids.
6. Differences in abundance determined by Fisher’s Exact Test.
• Sempervivum plants infested with root aphids were acquired
from a commercial succulent grower in southwest MI.
Sampling protocol:
Step 2Step 1 Step 3
• Aphids found in all root zone sections.
• 82% of root aphids found in top 2/3 of root zone
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MeanPercentageofAphidsCollected
Root Zone
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b
b
(P<0.001, four-sample Fisher’s Exact Test)
20
30
40
50
* Bars with the same letters are not significantly different from each other
• There was variability in effectiveness within most chemical classes
-- likely due to variation in systems and application methods.
• Entomopathogenic fungi provided highly effective control in
limited testing.
• Carbamates also provided consistently effective control.
• Pyrethroids and neonicotinoids were largely ineffective.
Root Zone Sampling:
• Root aphids were found in all areas of the root zone.
• Any method with contact activity should should be used in a way that ensures
all of the media in the pot has been treated (i.e. drench until slight leaching).
• Few systemic insecticides actively move into the roots.
• Despite the small sample size, the vertical distribution patterns of
root aphids within the root zone was highly similar to those reported
in other studies (e.g. Alleyne 1975).
• Suggests that root aphid abundance is positively correlated with root density.
• Most studies were not directly comparable to greenhouse
systems, so these results are best used as guidance toward
methods that are more likely to succeed (see recommendations).
• A total of ten studies met the requirements -- most were field studies.
• Foliar sprays were usually ineffective.
• In-furrow banding (granular or drench) was generally more effective.
• Only one study in modern greenhouse systems (Gill 2001)
Questions?
Feel free to contact me via email: jubenvi3@msu.edu
• As always, read the entire label before applying any product.
• Some products have phytotoxic considerations (e.g. Kontos, M-pede).
Perform a test on a small number of plants before applying an
unfamiliar product to a large area.
B. bassiana Botanigard Biological Drench very low High
M. anisopliae Met-52 Biological Drench very low
Potassium salts
of fatty acids
M-pede
Insecticidal
soap
90-second rootball
dip
low
Spirotetramat Kontos Keto-enol
Drench, foliar
spray
moderate
Predatory
nematodes
Biological
Sprench, Drench,
cutting dip
none
Azadirachtin
AzaSol, Azatin,
etc.
Limonoid Drench low
Cyantraniliprole Mainspring Ryanoid
Drench, foliar
spray
low
S-Kinoprene Enstar II JH analog Drench low
Predatory
arthropods
Atheta,
Hypoaspis, etc.
Biological Manual dispersal none
Pyriproxyfen Distance JH analog Drench (top 1.5") low
Imidicloprid Marathon Neonicotinoid Drench moderate
Thiomethoxam Flagship Neonicotinoid Drench moderate
Dinetofuran Safari Neonicotinoid Drench moderate LowLower
Higher