Controlling the Andean potato weevil through Integrated Pest Management


Controlling Andean potato weevils while minimizing pesticide use


Peru and other Andean countries

Problem Overview:


Andean potato weevil Photograph by Natasha Wright, Florida Department of Agriculture and Consumer Services, United States From

Controlling Andean potato weevils while minimizing pesticide use

Andean potato weevils, or potato white grubs, are the most severe pest of potatoes cultivated in the high Andean mountains (2,500–4,750 m) of South America. It is a complex of species, most of them belonging to the genus Premnotrypes (Curculionidae). The dominant species are P. latithorax (Pierce) in Bolivia and southern Peru, P. suturicallus Kushel in central Peru, and P. vorax (Hustache) in northern Peru, Ecuador, Colombia, and Venezuela. Species of other genera, Rhigopsidius tucumanus Heller and Phyrdenus muriceus Germar, are largely restricted to Bolivia.

Female weevils lay eggs inside straw debris near the potato plant. Neonate larvae dig into the soil and bore tubers for 11–17 weeks. Full-grown larvae abandon the tuber and pupate in the soil. New adult weevils emerge during the rainy season to infest new potato fields.

Most inhabitants of the high Andes, where this pest is prevalent, are poor peasants with a low level of literacy who receive little, if any, technical assistance. They accept the damage caused by weevils (usually above 50%) as inevitable and occasionally abandon fields because of heavy infestation. The division of land into small units has rendered impractical the traditional system of large communal land rotations that was once used to control weevils and other pests and diseases efficiently.

Farmers living near urban areas are more commercially oriented and use toxic insecticides (carbofuran, parathion, aldicarb, and methamidophos) to control weevils. Despite the use of insecticide, 15–30% tuber infestation is common.

Although all farmers know that potato weevil larvae bore into tubers, they are unaware of other aspects of the insect, such as its life cycle and seasonal history, and are therefore unable to improve their pest control practices.


Making integrated pest management (IPM) a tangible alternative for farmers is a difficult task, particularly when dealing with small farmers living under the conditions of developing countries. Perhaps this explains why most IPM literature, even that related to IPM implementation, includes only general principles and procedures related to the ecological background of IPM philosophy and a list of potential control measures. Extension workers or the farmers themselves must decide which specific measures should be adopted to solve pest problems.

Research has shown that technical arguments or altruistic ecological theories generally play a minor role in farmers' decision-making, particularly when their crops or economic benefits are at risk. Farmers will rarely risk adopting new approaches unless the practical advantages are clearly demonstrated under real conditions.

Therefore, the IPM Program at the International Potato Center (CIP) in Lima, Peru, has devised a strategy to develop and implement IPM based on research and implementation in farmers’ fields.

Based on this strategy, CIP's IPM program comprises five phases:

1. Assessment of the pest problem

2. Development of management components

3. Integration of key components

4. Implementation of IPM in pilot areas or pilot units

5. Implementation of IPM on a large scale

Pest problem assessment

When evaluating pest problems, both technical aspects and farmers’ perspectives must be considered. This combination provides a sound basis for initiating IPM. It does not make much sense to work on a problem that farmers do not recognize as such. Technical aspects include pest damage; cropping systems; farmers’ socioeconomic conditions; characteristics of the agro-ecosystems; and, of course, everything related to the bionomics of key pests and other phytophagous arthropods.

Development of IPM management components

Once key pests are identified, components (control measures) are developed to play vital roles in their management. Potential components already described in the literature should be validated under ambient conditions. Traditional practices used by farmers to control pests are also a good basis for research and verification trials. Finally, new components should be investigated, if necessary. Technological options for the IPM program usually include plant resistance/tolerance, natural enemies, cultural practices, pheromones, and trapping devices. Selective chemicals may also play a temporal role.

Integration of key components

The various potential components are not necessarily compatible. Therefore, ecological, agronomic, and socioeconomic compatibility must be established. The obvious consideration in terms of ecological compatibility is the effect of the selected insecticide on pest natural enemies, but there are many others, such as relative susceptibility of the chosen (key-pest resistant) cultivars to other pests. Agronomic concerns should include interactions between main and rotation crops, types of irrigation, fertilization, hilling, harvest procedures, and other cultural practices. Finally, all IPM components should be compatible with farmers' economic interests, input costs, labor availability, traditions, and the price of their harvested produce. Because of these considerations, IPM programs can not be disseminated as “technological packages.” IPM components should be offered to farmers as a menu of effective alternatives.

Implementation in pilot units

Pilot areas provide farmers with practical opportunities to compare their current plant protection systems with new ones. The active participation of farmers is assured by selecting an appropriate group of participants and by training them in the biology of the pest and in the characteristics of the IPM components.

Together, the technicians and the farmers select compatible components to form programs appropriate for a given agro-ecosystem. The work is conducted in farmers' fields, which become a "pilot unit" (if they share some type of strong organization) or a “pilot area” (if they are loosely organized). Farmers must understand the rationale behind each control measure and must be encouraged to express their thoughts and concerns. Farmers’ reactions to each of the selected components are taken into consideration for future activities. Monitoring insect populations (and/or pest damage) and using action thresholds help farmers better understand pest dynamics and the efficiency of the IPM program. In all cases, efforts should be made to keep the program as simple as possible, no matter how complicated the research.

Actual implementation in the pilot areas often indicates the need to correct, improve, or replace certain components. Only when the practical value of the IPM program has been demonstrated in the pilot areas and the farmers have accepted it as a better alternative is it time to proceed to large-scale implementation and diffusion of the IPM technology.

Pilot areas play other important roles in the development of the IPM program: they serve as demonstration centers for neighboring farmers and for farmers from other localities invited to participate in field days or other activities. Pilot areas also function as training centers for technicians from local institutions, government agencies, and NGOs. IPM communication materials (bulletins, guides, posters, slide-shows, videos, flip-charts, etc.) are then prepared for testing in the pilot units. Finally, through monitoring the evolution of the pilot unit, the research staff gains sufficient experience to improve the methodology for implementing IPM.

Large-scale implementation

During this phase, diffusion of the IPM technology validated in the pilot areas requires special attention. CIP's experience, at least in Latin America, has shown that the conventional approach—where scientists produce technical reports based on their research, and extension workers use this technical information to produce extension bulletins and other training materials to encourage farmers' adoption of IPM programs—does not usually work.

As an international research center, CIP does not have the means or the jurisdiction to perform extension work on a large scale in any given country. However, the Center wants to assure that the technology reaches farmer' fields. Toward this end, CIP helps facilitate the role of those willing to participate in the diffusion of IPM technology, including government agencies, NGOs, universities, rural schools, farmer associations, rural communities, and other institutions directly interested in agriculture, technological progress, and farmer’s welfare. These groups participate in short courses, workshops, and field days, and are exposed to the IPM experience in the pilot units.

CIP itself is involved in three activities related to the diffusion of IPM technology:

Training staff to train farmers ("training the trainers")


Initially, CIP staff trained farmers directly, on a limited scale, to determine appropriate methodologies and materials for IPM implementation. Training courses for trainers followed: along with technical aspects of IPM programs, trainees learn methodologies for training farmers under field conditions. Simple terminology, basic biology (e.g., insect life cycles), and the linkage between new knowledge and farmers' benefit are emphasized.

Production of IPM training materials


For extension work, the most efficient way to disseminate knowledge to farmers is to use training materials that complement field observations and field work. Therefore, CIP produces bulletins, charts, posters, slide-shows, videocassettes, and other training materials. The format and content of these materials are validated under field conditions prior to large-scale production. These materials make training an easy and pleasant activity for most extension workers. The farmers themselves often act as successful extension workers using these materials.



Finally, on a limited scale, CIP staff have acted as technical consultants for NGOs and other groups involved in the large-scale implementation of IPM.

Components for IPM of Andean weevils

The three common species of Andean weevils have similar life cycles: one generation per year (except for P. vorax, which has two generations per year in some parts of Ecuador and Colombia where potato is produced year-round), behavior, and seasonal history.

Research conducted on these characteristics has led to the development of a series of control measures, most of which could be included as components in IPM programs.

All potato cultivars are susceptible to weevil damage. No significant differences in susceptibility (i.e., potential sources of resistance) have been found in primitive cultivars or in wild potato, and no parasitoids have been identified, despite the collection of larvae and adult weevils by the thousands for many years. There is some predatory activity by wild birds and toads, but none of any significance. A fungus pathogen, Beauveria brongniartii (Saccardo), has been found scattered in the soil and could cause epizootics under heavy rain conditions. Without these natural mortality factors, however, management of weevils has been based largely on cultural practices. Since weevils are unable to fly and must crawl out from overwintering places to invade new potato fields, certain cultural practices designed to exploit this vulnerability can be effective control measures


Potential sources of infestation are: abandoned potato fields, fields harvested the previous year, places where potatoes have been piled up during harvest and sorting, rustic stores, and volunteer plants in rotation crops. Most IPM components (control measures) aim at destroying the overwintering population, interrupting migration of the weevil to new fields, and reducing the weevil population in infested fields.

Reducing weevil infestation in the field

There are several ways to reduce potato weevil populations in the field. These include:



  • early planting and the use of early-maturing varieties
  • timely harvest
  • the use of healthy tubers
  • handpicking adult weevils from the crop
  • and the destruction of volunteer potato plants in rotation crops

Early planting

The emergence of overwintering adult weevils lasts 8–14 weeks and coincides with the onset of the rainy season. Females lay eggs for 12–14 weeks. As more adults emerge, there is a continuous increase in the number of females that use late plantings as places to deposit their eggs. Fields planted early are 4 to 5 times less infested than those planted late. Therefore, early planting reduces weevil infestation and damage by 88%. By the same token, early-maturing varieties are less exposed to weevil infestation than late varieties, and therefore their use accomplishes similar results.

Timely harvest

Farmers sometimes delay harvest in hopes of getting higher prices for their crop. However, delayed harvest extends tubers' exposure to weevil infestation. In one field test, delaying harvest by 10 days resulted in an increase in tuber damage of 6.8 to 29.5%.

Healthy planting materials

In general, unhealthy tuber seed diminishes potato plant growth. For example, seed tubers damaged by Andean potato weevil rot readily, which results in poor plant stand establishment. Planting seed bored by the Andean weevil reduced yield by 31% compared with non-infested seed.

Handpicking weevils

Adult weevils in the potato field become active in the evening, climbing the foliage for feeding and mating. They can be captured easily by shaking the foliage over a container. Farmers have accepted this practice readily. Collecting weevils six times during the growing season reduced damage by 34%.

Destroying volunteer plants

Volunteer potato plants in rotation crops are significant sources of weevil infestation and should be destroyed as early as possible. Initially, some farmers were reluctant to accept this practice because they were reluctant to sacrifice the harvest of early potatoes from these volunteer plants. But demonstrating the effect of one rotation field with 6500 volunteer plants/ha--more than 30,000 weevils--provided solid arguments in favor of destroying volunteer plants. Today, farmers organize teams to destroy volunteer plants in neighboring fields.

Interrupting adult migration and larval movement for pupation

Because adult weevils cannot fly, mechanical barriers effectively halt their migration from overwintering places to new potato fields, as do peripheral trenches, which facilitate the capture of migrating weevils. Weevil larvae penetration of the soil for pupation during harvest, sorting, or storing can be prevented by using plastic sheets and storing seed tubers in diffused-light stores. Weevil larvae and pupae can then be fed to chickens.


Migratory weevils can be intercepted in flat lands by digging field peripheral trenches. Weevils can then be captured or killed with insecticides. Spraying a 3-m-wide band with insecticide around the perimeter of the field kills immigrating weevils. Planting field borders with non-host plants (tarwi, Lupinus mutabilis, or oca, Oxalys tuberosa) also disrupts the migratory process and, when possible, is preferable to chemical control.

Shelter traps

Weevils hide in the shade during the day. Straw bundles, pieces of jute (sisal), or plastic sheets and other materials can be used to provide shelter to weevils during the day, facilitating their capture. An alternative is to treat potential shelters with insecticide (potato foliage collected from volunteer plants can be sprayed and placed under the shelter). These shelter traps are particularly effective just prior to the emergence of potato plants in new fields.

Ground sheeting

At harvest, many full-grown larvae abandon the tubers and penetrate the soil to pupate. Larvae can be intercepted on their way to the soil using barriers of plastic sheets or other materials. The collected larvae can then be fed to chickens.

Diffused-light stores

Seed tubers kept in diffused-light stores maintain better quality. Seed tubers should be kept in racks that are not in contact with the soil. Weevil larvae abandoning the tubers can then be destroyed or fed to chickens.

Reducing overwintering populations

Measures to reduce overwintering weevil populations can be carried out in the field or in stores. When it reaches maturity, the weevil larva leaves the infested tuber, digs into the soil, and constructs the pupation cell. The insect remains there, as larva or pupa, most of the winter, then transforms into an adult and waits for the spring rain before emerging from the soil through exit holes. The larvae leave infested tubers before harvest, during harvest, during tuber sorting prior to storage, and during the first 30 days of storage. Thousands of insects overwinter in these places, which are recognized as “sources” of new weevil infestation. However, larvae and pupae can be damaged easily by breaking up the surrounding soil.

Winter plowing

Many larvae reach maturity before harvest and leave the tubers to overwinter underground as pupae. Therefore, large numbers of pupae can be destroyed by plowing the field two or three months after harvest. At least 50% of the larvae and pupae in the soil are killed if plowing is done with oxen. Chickens can also help destroy exposed larvae and pupae. Since abandoned potato fields are another major source of weevil reproduction and migration, they should be plowed at least twice during winter.


Breaking up winter soil near harvest or sorting potato piles

If sheets are not used when piling potatoes at harvest, large numbers of larvae abandon the potato and dig into the soil. The same thing occurs during sorting, prior to storage. Sites where potatoes have been piled should be indicated by a wooden post, and two to three months later (in winter) the soil should be broken up to destroy underground larvae and pupae. More than 90% of the overwintering population can be destroyed using this practice.

Use of Beauveria brongniartii in rustic stores

In many peasant communities, potatoes are stored under rustic conditions. Tubers are piled up and covered with straw, and the cold conditions prevalent in the high mountains preserve the tubers well. But during the first 30 days of storage, large numbers of weevil larvae abandon the infested tubers and dig into the soil to overwinter. Before storing tubers, the soil can be treated with the parasitic fungus, Beauveria brongniartii. Using this method, larvae mortality should exceed 80% and the soil should remain infective as long as it is kept slightly moist.



The evolution of a participatory approach

In general, the farmer’s decision to adopt IPM rather than continue his traditional methods depends on his interests and perceptions. Farmers' interests are related to economics (less pest damage, better yields, lower production costs, less labor demand, better prices); health considerations; and the reduction of risk in general. Farmers' perceptions are more difficult to generalize, but most likely are related to cultural traditions.


First Pilot Units in Peru

The first IPM pilot unit in farmers’ fields was established in the peasant community of Chinchero, near Cusco, south of Peru, in 1990. In that locality, infested tubers averaged 44% at harvest, despite the use of insecticide. Infestation was reduced to 11% in three years with minimum, if any, use of insecticide. Local organizations—including the Municipality of Chinchero, the local governmental agency (INIA-Cusco), the local University (San Antonio Abad) and NGOs—showed interest and participated in the experience. During the following two years, new pilot units were established. One was in Cajamarca, north of Peru, where insecticide was not used and 60% of tubers showed damage; and another was in Huancayo, in central Peru, where infested tubers averaged 25% despite the intensive use of insecticide. In two years, farmers in these two localities adopted more than 6 IPM components and reduced infestations down to 8 - 12 % with minimum or no use of insecticide.

Expanding the experience: The MIPANDES Program of CARE-Peru

Based on CIP’s success in implementing IPM in pilot units (farmers’ fields), CARE-Peru initiated a relatively large-scale, three-year IPM program called MIPANDES in September 1993. The project, which was financed by USAID and technically supported by CIP, addressed potato pest problems (Andean weevil and the tuber moth) in four departments of Peru (Puno, Ancash, Cajamarca, and La Libertad). There were 3500 rural Andean families participating in the program.

CIP’s IPM staff trained CARE staff and helped implement the program; IPM communication materials were prepared jointly. The following excerpts from the final external evaluation of the project (Chiri et al., 1996) describe the success of this program:

…“MIPANDES has been highly successful in achieving most of its stated aims”… “Its training materials and methods have proven to be remarkably effective”...“MIPANDES farmers have now at their disposal a menu of IPM practices that can be used to reduce populations of the Andean weevil and the potato tuber moth” … “A great deal of pest life cycle and IPM information has already been internalized in most project implementation areas” … “In the opinion of most farmers interviewed, a greater proportion of non-infested or lightly-infested potato is being harvested as a result of MIPANDES activities” … "Most farmers interviewed felt the MIPANDES project did generate savings associated with decreased insecticide inputs costs”.


Further expansion of CARE’s IPM work: The ALTURAS project

With the conclusion of the MIPANDES project, CARE-Peru and PRONAMACHS, a para-governmental agency with activities in most of the poor rural areas of the mountains agreed to continue implementation of IPM in the Peruvian Andean area. This new project, ALTURAS, aims to implement IPM on 7500 additional peasant farms in 10 departments of Peru. This is a joint, autonomous endeavor of CARE and PRONAMACHS. The only link with CIP is the continued use of its IPM technology and methodology. CIP continues to offer IPM training activities to all interested organizations.

Initiation of a new experience with an NGO: ARARIWA, Cusco, Peru

One of CIP’s close collaborators in the first IPM pilot unit in Chinchero, Cusco, Peru, was the technical staff of an NGO called ASOCIACION ARARIWA. This NGO promotes agricultural technologies among farmers in two important agricultural provinces of Cusco (Calca and Urubamba) where potato is the main crop. ARARIWA maintains a policy of open collaboration with local institutions, including district municipalities and other NGOs (as part of the COINCIDE network that comprises all local NGOs). With technical assistance from CIP’s IPM project and financial support from the Inter-American Foundation, ARARIWA has initiated an IPM program that will benefit about 4000 peasant families and will train about 90 technicians from local, governmental, and non-governmental organizations working in the Department of Cusco.

Expansion of potato IPM to other Andean countries

CIP’s IPM Program has expanded the experience of Andean potato weevil management in Peru to Bolivia, Ecuador, and Colombia through the implementation of new pilot units. The program was initiated in July 1995 and completed in June 1998, with the financial support of the Inter-American Development Bank. Pilot units were implemented in the Community of Taracollo, La Paz, Bolivia; the communities of Chuamba and Casabamba in Central Andean Peru; the central coast of Peru (for management of the leafminer fly, Liriomyza huidobrensis); the communities of Chaupi-Contadero, Palopo, and Chanchaló in the province of Cotopaxi; the communities of Cahuají, La Merced, Las Delicias, and Santa Isabel in the province of Chimborazo, Ecuador; the Municipality of Motavita; and the municipality of Ventaquemada in the Department of Boyacá, Colombia (for management of the potato tuber moth, Tecia solanivora).

These pilot units had the same purpose as those established in Peru: (a) to demonstrate that IPM was a valid and better alternative for management of the Andean weevil (as well as potato tuber moth and leafminer fly); (b) to train farmers and technicians in IPM implementation; and (c) to make these pilot units centers of IPM dissemination for other areas. The adoption of IPM technologies by farmers and the active participation of local institutions ensured the sustainability of the IPM program beyond the limits of the project.


Training Activities

IPM implementation requires the identification of farmers looking for better solutions to their pest problems—that is, ready to accept new knowledge, new, efficient solutions, and the collaboration of local institutions interested in farmers' productivity and/or farmers' welfare. IPM activities must address these issues.

Training activities were directed to farmers, local coordinator technicians, and national coordinators.

Farmers learned the life cycle and seasonal history of key pests, the rationale of control measures, and the ecological principles of insect management. Training activities included a short course at the beginning of the program, field days during the cropping season, and a workshop at the end of each season. At this time, the positive and negative aspects of IPM implementation work were analyzed and adjustments were proposed for the following season.

Local coordinators (farmer leaders, NGO technicians, and governmental staff) learned the principles of IPM, the rationale of developed alternatives, training methodologies, and monitoring methods. Training activities included short courses, visits to the pilot units, and field days with farmers.

National coordinators (governmental staff) learned about the philosophy of IPM, the strategy for IPM implementation, the economic and health benefits for farmers at the local and national level, and previous experiences in the region. Training activities include short courses and workshops.

Training activities included field observations (this component was increased if the farmers themselves were participating. Production of training materials was also important, as it facilitated the diffusion of the work not only among farmers but also to other members of the rural community (schools, associations, municipalities, etc). Full color posters, bulletins, manuals, videocassettes, flip-charts, insect samples, and slide-shows were used in communication activities.

The Results

The results of integrated pest management of the Andean potato weevil are summarized for each of the various countries, including the reduction of pest damage, the improvement of farmers' knowledge, the adoption of IPM components, the number of farmers participating, and the collaboration of local organizations.


Bolivia. Community of Taracollo, Province of Aroma, La Paz (3900 m)

Reduction of weevil damage: Prior to the initiation of the Project (1995), 48 to 100% of harvested potato was infested by weevils. In monitored areas, tuber damage was 48.9%, despite the use of insecticide. After three years of IPM implementation, tuber damage was reduced to 15%.

Reduction of insecticide use: Prior to the IPM program, all farmers made broad-based applications of insecticide (parathion and methamidophos), two to four times a season. In three years, the farmers discontinued these applications completely. However, in 1998 some farmers (30%) made localized applications to their field borders when weather conditions caused by El Niño favored the migration of weevils to potato fields.

Improvement of farmers’ knowledge: At the beginning of the program all farmers recognized the larval form of the pest, but very few—if any—connected the larvae to the adult weevils. None of the farmers knew about the weevil's seasonal history, its behavior, or its overwintering areas. Three years later, all farmers knew these aspects of the weevil and used them as a basis for adopting better control measures.

Adoption of IPM components: Field border trenches covered with plastic sheets; destruction of volunteer plants; destruction of weevil larvae in rustic stores (using Beauveria brongniartii); weevil hand-picking; use of sheets for piling potatoes at harvest; use of chickens as predators; and occasional applications of insecticide along field borders (band spraying) .

Farmer participation: Two hundred families were directly involved and about 3000 peasants were partially involved, or had requested IPM training.

Local collaborating institutions: The main local counterpart was PROINPA-IBTA. But many other institutions were active participants, including VISION MUNDIAL, Oficina y Laboratorio de Semillas La Paz (OLS-LP), PROSUKO, Proyecto Irpa Tayca de Radio San Gabriel, the Methodist Church, CESA, KURMI, and INTERVIDA.


Peru: Communities of Chuamba and Casabamba, Huancayo (3000–3950 m)

Reduction of weevil damage: At the beginning of the program, 40 to 53% of harvested tubers in the community of Casabamba were infested, and some potato fields had been abandoned because of high weevil damage. After three consecutive cropping seasons, damage was reduced to 8%. In the community of Chuamba, where insecticide was used intensively, average tuber damage was 19% in 1995. In 1998, damage was reduced to 4.1%.

Reduction of insecticide use: Prior to the IPM program, all farmers of the Community of Chuamba used broad-based applications of insecticide (aldicarb, carbofuran, methamidophos, parathion, and tefluthrin) 3 to 4 times per cropping season. After three years, many farmers did not use any insecticide. Those who chose to use insecticide limited their application to bands along field borders (band-spraying).

Improvement of farmers’ knowledge: At the beginning of the program, farmers did not know about the life cycle, seasonal history, overwintering places of the pest, adult weevil behavior, or the occurrence of Beauveria brongniartii. Farmers learned all these aspects and related them to the management of the pest.


IPM components adopted: Most peasants from Casabamba adopted 8 IPM components, while those from Chuamba adopted 10 IPM components. Preferred measures were weevil hand-picking, use of sheets at harvest, improved harvest timing, winter plowing of harvested potato fields, crop rotation, use of chickens as predators, diffuse-light storage for seed tubers, and use of Beauveria brongniartii in rustic stores. When needed, insecticide was applied along field borders (band-spraying).

Farmer participation: In this program there were 580 peasant families. Seventy-four peasants qualified as “trainers by experience,” according to standards set by TALPUY, a local collaborating NGO that managed an adult education project.

Local collaborating institutions: The national agricultural institution (INIA) and an NGO (ASOCIACION TALPUY) were the main local collaborators.


Ecuador: Four communities in the province of Chimborazo and three communities in the province of Cotopaxi (2900–3400 m).

Reduction of weevil damage: Weevil damage in communities practicing IPM in Chimborazo was 3.0 to 7.3% in 1998, as compared to 23–32% damage in other communities. In Cotopaxi, the initial average tuber infestation at harvest was 58–80%. Infestation in the participating communities was reduced to 2–15% in a three-year period.

Reduction of insecticide use: At the beginning of the program, farmers applied Insecticide (methamidophos, carbofuran, methomyl, dimethoate, and profenofos) 2 to 4 times per season in Chimborazo. Three years later, 92% of farmers applied 1 to 2 times per season, with a trend toward use of less toxic products (acephate).

Improvement of farmers’ knowledge: At the beginning of the program about 35% of farmers had some idea about the life cycle of the weevil. Three years later, all farmers knew the biology, behavior, and seasonal history of the weevil and related the new knowledge to management of the pest.


IPM components adopted: Preferred IPM components were the use of weevil shelter traps, the elimination of volunteer plants, early harvest, and better use of insecticide.

Farmer participation: There were 350 peasant families in the program. Another 700 families benefited from the program indirectly through local IPM dissemination activities.

Local collaborating institutions: The governmental INIAP (Instituto Nacional de Investigaciones Agropecuarias), through the Plant Protection Department and Root and Tubers Program, was the local collaborator.


Colombia: Municipality of Motavita, Department of Boyacá (2990–3240 m)

Reduction of weevil damage: Prior to the IPM program, 60% of the farmers reported 21–60% infested tubers at harvest. After three years of IPM implementation, average infestation was 9.4%.

Reduction of insecticide use: At the beginning, all farmers used insecticide (mainly aldicarb and carbofuran) 2 to 4 times per season. At the end of the program 50% of farmers applied insecticide 1 to 2 times; the other 50% applied it 3 times per season.

Improvement of farmers’ knowledge:

Farmers improved their knowledge of the life cycle, seasonal history, and behavior of the weevil, and 70% of the farmers indicated the new knowledge had improved their understanding of control measures.


IPM components adopted: Most farmers adopted the elimination of volunteer plants, the elimination of crop residues, weevil hand-picking, and winter plowing of infested fields. Farmers decreased their use of insecticide.

Farmer participation: There were 300 peasant families directly involved in the program. Another 1875 participated in training activities.

Local collaborating institutions: The governmental agency CORPOICA-Regional 1 and the Municipality of Motavita.


Concluding comments

The adoption of IPM technologies for the management of the Andean potato weevil in Andean communities demonstrated that the strategy used was appropriate. Similar experiences using CIP’s IPM methodology to manage the potato tuber moth (Tecia solanivora) in Ventaquemada, Colombia; the leafminer fly (Liriomyza huidobrensis) in the Central coast of Peru, and the sweetpotato weevil (Cylas formicarius) in Cuba confirm this assertion.

Characteristics common to all these cases were: the occurrence of a real pest problem; farmers’ perception that such a problem required a better solution; the availability of an array of effective IPM components; farmers' desire to participate in the training; an adequate but simple program for both farmers and technicians; the active participation of local institutions (governmental and non-governmental); the production of adequate extension materials; and CIP’s commitment to maintain IPM research and implementation.

There are certainly other approaches to IPM development and implementation. The purpose of this presentation is to describe a successful experience and present additional alternatives for those wishing to implement IPM.

Submitted by:

Dr. Fausto Cisneros, Program Leader
Integrated Pest Management
International Potato Center - CIP (Centro International de la Papa)
Apartado 1558
Lima 12, PERU
Tel: (51-1) 436-6920, 435-4354, 435-4283, 435-9380/81
Fax: (51-1) 435-1570
IVDN USA (direct phone): 1-415-833-6636
IVDN USA (direct fax): 1-415-833-6636

International Organizations:

Cooperative Research Centre for Tropical Pest Management
The University of Queensland
Tel: 61 (0)7 3365-1851
Fax: 61 (0)7 3365-1855
Web site:

Consortium for International Crop Protection
N.Y.S. Agricultural Experiment Station
Geneva, New York 14456-0462 USA
Tel: (315) 787-2252
Fax: (315) 787-2418
Web site:

Information Date: 1999-03-04
Information Source: International Development Research Centre

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