Organic and Biological Control of Colorado Potato Beetle

Progress report for FNE22-023

Project Type: Farmer
Funds awarded in 2022: $18,228.00
Projected End Date: 08/31/2023
Grant Recipient: Plowshare Farms
Region: Northeast
State: Pennsylvania
Project Leader:
Robert Moynihan
Plowshare Farms
Expand All

Project Information

Project Objectives:

This project seeks to  (1) evaluate the effectiveness of innovative organic pest control methods  (2) determine the economic viability of treatments, and (3) clearly communicate results to farmers.



The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Coleoptera: Chrysomelidae), is more significant insect pests of potatoes and is a major pest within the Northern Hemisphere (Sporleder, 2013). Both adult and larval instars feed exclusively on solanaceous crops and weeds, causing significant damage to potatoes and eggplants (Penn State Extension, 2017).  It is also extremely difficult to control using both conventional and organic chemical (Alyokhin, 2009). Colorado potato beetle is legendary for its capacity to develop insecticide resistance (Forgash, 1981). Colorado potato beetle has developed resistance to all major classes of synthetic insecticidal classes, including the neonicotinoid imidacloprid.  To combat resistance, conventional growers alternate insecticides in a 1–3 year rotation but “for organic growers, there are fewer products available, and cultural control practices should be followed to avoid dependency on a product” (Hazzard, 2021). One cultural control widely used by organic and chemical-free farmers is removing CPB adults and larvae by hand.  This method is effective, but can constitute a significant labor expense.  



Plowshare Farms, in coordination with Bucks County Foodshed Alliance and collaborators, will conduct an on-farm research trial evaluating the economic and agronomic impacts of two organic pest control solutions:

  1. TREATMENT 1 Hand Picking: To improve by-hand removal of CPB adults and larvae, farmers will use handheld, cordless vacuums.
  2. TREATMENT 2 Guineafowl: Organic growers have long used guineafowl as a method of biological pest control, reaping the benefits of the guineafowl’s voracious appetite for insects and arachnids.  Guineafowl will be effective at removing Colorado potato beetles, and may be less detrimental to flying beneficial insects than DE.  Guineafowl will be hatched on a schedule such that they will reach maturity before the emergence of the first-generation CPB adults in early May, and can be processed for meat production after the emergence of second-generation CPB “summer adults.”  By processing the guineas after the CPB season, the flock can pay for itself, covering the cost of the pest control, as well as feed for the young guineas. 
Description of farm operation:

Plowshare Farms has been in business for 9 years, raising produce, lamb, pork, and chickens on approximately 20 acres in a given season. I have farmed full time for 7 seasons, and since the COVID-19 pandemic I devoted more time to parenting and small off-farm jobs. Gross sales of the farm are generally in the range of $40-85,000.


Click linked name(s) to expand/collapse or show everyone's info
  • Dr. Sarah Dohle - Technical Advisor (Researcher)


Materials and methods:

Plowshare Farms will conduct an in-field experiment evaluating  1) economic potential to use guinea fowl to control CPB. The field experiment will compare  plots with guinea fowl against control plots utilizing standard hand-picking techniques with three replicates per treatment. 


CONTROL:  Hand Picking


Farmer will plant two varieties of potato (Red Norland and Banana Fingerling), each variety covering one 100’ row.  At one week-10 day intervals, beginning with the first emergence of CPB adults, farmer will use handheld cordless vacuum to remove CPB adults and larvae from potato plants.  


At one week intervals from the first emergence of CPB adults, farmer and farmhand/student intern will use the UMASS Extension Potato Scouting Form to inventory pests and assess defoliation of potato plants.


At time of harvest, yield of each variety will be assessed and compared to yields in the other treatment.  


TREATMENT:  Guineafowl


Farmer will plant two varieties of potato (Red Norland and Banana Fingerling), each variety covering one 100’ row. Guineafowl will be housed adjacent to the "Guinea Treatment" section, and allowed to forage the potato field free choice.  


At one week intervals from the first emergence of CPB adults, farmer and farmhand/student intern will use the UMASS Extension Potato Scouting Form to inventory pests and assess defoliation of potato plants.


At time of harvest, yield of each variety will be assessed and compared to yields in the other treatment.



The experiment will be replicated at three separate locations on the farm to control for variability in soil type and cultural variations.    

Research results and discussion:

This experiment measured Colorado Potato Beetle(CPB) populations, defoliation of potato plants, and potato yield, and how these variables were affected by the presence of Guineafowl vs. the more traditional cultural control of removing pests by hand.  Guineafowl were allowed free access to segregated potato fields for 1-2 weeks at a time.  To improve handpicking of pests, cordless handheld vacuums were used to remove CPB larvae and adults.  To measure relative effectiveness of each method, we performed regular counts of CPB egg masses, small larvae, large larvae, adults, and defoliation of plants.  We used the UMass Extension Potato Scouting Form to record data.  The experiment was conducted with two potato varieties (Banana Fingerling and Red Norland) and was conducted across 3 replication plots. 

Guineafowl were segregated from handpick/vacuum plots using temporary electric mesh fencing, which along with mobile housing was moved to each replication plot at 1-2 week intervals.  The moving of guineafowl and their fencing was determined to be an added time expense over handpicking/vacuuming.

Initially guineafowl were left on the first research plot for 2 weeks, but their excessive scratching and foraging caused minimal to moderate damage to the potato plants.  After this, guineafowl were moved weekly.

Potatoes were not irrigated, as it was reasoned that rainfall would be more consistent across replication plots than irrigation due to the plots placement around the farm.  The 2022 growing season was unusually dry at key growing periods, and this is believed to have negatively affected yields.  

Pest numbers, defoliation percentage, and yields were somewhat mixed across potato varieties and replication plots, showing no clear winner between the two treatment methods.  We will continue to analyze the data with our collaborator, to see if patterns or trends can be determined.  The use of handheld vacuums, however, was surprisingly effective at removing CPB adults and larvae and keeping them contained without the use of a bucket of soapy water.  Emptying the vacuums in the chicken coop was and easy and effective way to make use of the pests.

Colorado Potato Beetle adult laying eggsDefoliated Potato PlantVacuuming Colorado Potato Beetles to remove from potato plantsFarm Intern displaying a vacuum full of Colorado Potato Beetle larvae

Research conclusions:

While we are still analyzing the data, initial analysis indicates that the use of guineafowl as a cultural control of Colorado Potato Beetle is equally as effective as using handheld vacuums to manually remove the pests.  Use of guineafowl may lead to slightly lower pest counts and defoliation percentage, but also constitutes a greater time investment and the potential for the guineas to damage crops by knocking down foliage and scratching tubers.  We were not able to determine how much of the added time investment was due to moving the guineafowl between replication plots for the sake of the experiment, or how much damage was caused because the guineafowl were kept in a smaller segregation plot.  That is, in practical application, a farmer would likely fence in their entire potato crop allowing guinea owl free access to the field without the need to move more than once or twice throughout the growing season.  If a farmer already had infrastructure for keeping poultry, guineafowl could be added at little added expense, and if given access to potato fields could replace manual removal of Colorado Potato Beetles.  One area of further study we would like to look into is if there are certain CPB lifecycle pinch points where cultural controls could be most effective.  That is, could a well timed cultural control (guineafowl or vacuuming) interrupt CPB lifecycle enough to significantly reduce 2nd and 3rd generation feeding later in the season.

Participation Summary
1 Farmers participating in research

Education & Outreach Activities and Participation Summary

5 On-farm demonstrations
4 Tours
2 Workshop field days

Participation Summary:

6 Farmers participated
4 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

To date we have hosted 6 on-farm demonstrations, 2 field days, and 4 farm tours highlighting our use of guineafowl to control Colorado Potato Beetle.  These events have mostly been aimed at community members, restaurant industry staff, and educators, with limited farmer participation.  Now that all the data is collected, we plan to host on-farm events, workshops, and field days aimed at farmers and agriculture students.  Our on-farm demonstrations had approximately 15 participants, our field days and workshops had approximately 20 participants, and our farm tours had approximately 140 participants. 

Farmer leading a tour in late afternoon sun.

Learning Outcomes

Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

We have not yet shared our results with other farmers.  

Project Outcomes

Project outcomes:

We have not yet fully analyzed the data, or made changes to how we farm based on the study.  

Assessment of Project Approach and Areas of Further Study:

Our research clearly showed that guineafowl are an effective control of Colorado Potato Beetle.  In terms of number of pests, defoliation, and yield, guineafowl proved to be as effective as manually removing CPB with handheld cordless vacuums.  On the other hand, the management of guineafowl, particularly moving them from one treatment plot to another proved to be a much greater time investment than manually removing pests.  Within the confines of this study, it was difficult to assess what the time investment would be if a farmer were using guineafowl in a real world scenario, without the need to move them at regular intervals, or keep them segregated on smaller research plots.  

Due to the scope and timeframe of our study, we were not able to determine the marketability of guineafowl for meat production.  Guineahen eggs were an added benefit this season, but in itself not worth the effort of raising them.  We have had lots of interest in guineafowl from our restaurant customers, but we were not yet able to work out the timing to use them for CPB control and process immediately after.  

We will likely continue to raise guineafowl and encourage other farmers to do so.  They are voracious and efficient insect predators, and would be effective in a number of crops where food safety guidelines allow.  

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.