Pepper weevil management should be based on sound integrated pest management (IPM) principles. Population levels should be monitored through an acceptable sampling program and the four IPM management principles of cultural efforts, host plant resistance, biological control and use of chemical insecticides should be selected and utilized to maximize economic profit and reduce hazards to the field workers, consumers and the environment.
Cultural Techniques - Sanitation of plants and fields is critical to a successful pepper weevil management program. First, pepper transplants should be free of adult pepper weevils. This can be accomplished by producing seedlings in areas absent of pepper weevils, use of insecticides just prior to transplanting , and the use of covers such as small mesh nets or polyester row covers. To exclude adult pepper weevils, the perimeter of the cover must be completely covered with soil.
Selecting fields free of pepper weevils for transplanting is also important. If a field previously planted to pepper is to be used, efforts should be make to eliminate the pepper plant residue at least one month prior to transplanting. This can be best accomplished by early and deep plowing after the last harvest. Also, any alternate hosts including solanaceous weeds should be removed.
After transplanting, sanitation continues to play a critical role. For example, a single abscised tabasco fruit containing a single female pepper weevil can result in very high pepper weevil numbers later during the season. With tabasco produced in Central America, harvest of a single field can extend for about three months. In the absence of natural or augmented mortality factors, a single female that produces about 200 eggs (100 female) which each have a life cycle of about 21 days (4 complete generations per harvest period), has the potential to result in approximately 100,000,000 female pepper weevils at seasons end. Although population increases to this level are not likely under field conditions, this reproductive potential combined with the short life cycle of the pepper weevil and the extended harvest season provide a clear evidence of the importance of managing pepper weevils early during the production season. Removal of infested fruit prior to emergence of adult weevils can have a substantial impact.
Host Plant Resistance - When given a choice adult pepper weevils may show some tendency to prefer one type of pepper over another. Under field conditions, however, pepper weevils have little choice and will attack most types of pepper. Although breeding peppers with resistance to pepper weevils may be possible, it is unlikely to provide the required levels of protection in the foreseeable future.
Biological Control - Beneficial insects play important roles in the regulation of pest insects, particularly in the tropics in the absence of cold winters. With the pepper weevil, however, the adult is the only stage usually exposed to attack by beneficial insects and adult beetles, particularly those occuring in the canopy of pepper plants, are not easily attacked. The role of vertebrates such as birds, reptiles and amphibians in regulating pepper weevil populations is not known. Pepper weevil larvae have been reported to be attacked by the wasps Catolaccus hunteri (Hymenoptera; Pteromalidae) and Urosigalphus mexicana (Hymenoptera; Braconidae) (Trabanino and Matute ). The impact of these beneficial insects on the pepper weevil, however, appear to be very low. In Honduran Tabasco fields, examination of several hundred infested fruit over a two year period has yet to reveal any larval parasitism.
Regardless of the lack of demonstrated impact of biological control on pepper weevil populations, efforts at preserving beneficials should be made. Although, these efforts may have minimal impact of pepper weevil, other insects such as aphids, whiteflies, and leafminers, may greatly increase in numbers after the beneficials that are regulating their populations are eliminated.
Insecticides - Another common sight in the Central American pepper field is young men equipped with backpack sprayers walking the pepper rows and applying pesticides. Unfortunately, the use of protective clothing is not common. In the absence of respirators, disposable suits, and rubber boots, efforts should be made to educate the applicators to make use of the most available and realistic safety procedures. These include the following:
1. Wash any spills as quickly as possible and completely wash the body and cloths after the application is finished.
2. Ensure that sprayers do not leak. Also, hand pump backpacks sprayers operate at lower pressure and produce less spray drift than the motorized backpacks.
3. If disposable suits are not available, applicators should at least wear rubber gloves. The great majority of dermal exposure to the pesticide applicator is usually through the hands.
4. Applicators should spray down wind and initiate spraying on the field side most down wind.
5. Field rentry, including harvesting, should be delayed as long as possible following pesticide application.
6. Pesticides should be stored in their original container and out of reach of children. Although dermal toxicity of insecticides is much reduced with modern insecticides, many of these chemicals are still highly toxic if ingested and may be fatal to humans, especially children.
Fortunately, the insecticides currently registered for pepper use in the U.S. are now much safer than those used in previous years. Acute dermal toxicity to human has, particularly, been reduced. Long term effects of synthetic chemicals on humans, however, still have many unanswered questions and erring on the side of caution is always warranted.
With the safety issues in mind, it can be said that the backbone of pepper weevil management in Central America is and will continue to be the application of synthetic insecticides. With adult pepper weevils wandering the upper regions of the pepper plant, they are readily accessible with foliar sprays. Adult insects, however, generally feed very little. Their primary role is to mate and reproduce - not to expand in size. Thus, most of the insecticide uptake must be through contact and not ingestion. Also, the hard integument of adult beetles is not as readily penetrated by insecticides as the softer integument of immature stages. These factors make adult pepper weevil management an imperfect system and no insecticides has currently been demonstrated to be completely successful. Finally, the list of insecticides labeled for peppers is constantly changing. Older insecticides continue to be lost because of their applicator and environment hazards and newer insecticides are added once they receive registration from the EPA.
The following table contains a list of the insecticides that have been
shown to be useful in the management of adult pepper weevils. Again,
it should be stated that the effectiveness of these insecticides against
the pepper varies greatly with location and pepper weevil population.
Also, the list is continually changing due to additions and withdraws by
the EPA. The most current list of approved insecticides is available
on the World Wide Web. An excellent site is www.cdms.net
Table 1. Insecticides labeled for pepper March 2002.
Pepper Weevil
| Insecticide | Systemic | Reentry Interval (hours) | Preharvest interval (days) | Remarks |
| Actara
(thiamenthoxam) |
Yes | 0 | 0 | Toxic to honeybees |
| Ambush
(permethrin) |
No | 12 | 3 | Secondary pest, e.g., broad mite, may increase following application. Toxic to honeybees. |
| Asana
(esfenvalerate) |
No | 12 | 7 | Secondary pest, e.g., broad mite, may increase following application. |
| Baythroid
(cyfluthrin) |
No | 12 | 7 | Secondary pest, e.g., broad mite, may increase following application. Toxic to honeybees. |
| Kryocide
(cryolite) |
No | 12 | 14 | Maximum amount per season is 24 lbs. per acre. |
| Pounce
(permethrin) |
No | 12 | 3 | Secondary pest, e.g., broad mite, may increase following application. Toxic to honeybees. |
| Provado(=Confidor)
(imidacloprid) |
Yes | 12 | 0 | |
| Vydate
(oxamyl) |
Some Activity | 48 | 7 | Toxic to honeybees |
Example IPM program for tabasco pepper
1. Produce non-infested pepper seedlings in an area without pepper weevils, in a pepper weevil proof greenhouse or under a row cover.
2. In areas where viral disease and pepper weevils are expected, apply Provado (=Confidor) or Actara to the seedlings two days prior to transplanting.
3. After transplanting and at first flowering, begin to monitor the field by searching 200 terminals for adult pepper weevils. If no weevils are found, avoid spraying. If one or more weevil is found, initiate insecticide application. Early applications should be made with Provado or Vydate. Pyrethroids may be detrimental to beneficials and their applications may result in release of aphids and mites. Pyrethroid use should be delayed until later in the harvest season.
4. If sufficient labor is available, the field should be maintained free of abscised fruit. And this fruit should be removed and destroyed prior to emergence of adult pepper weevils.