by Matt Gibson
The pepper weevil (or Anthonomus eugenii) is the pepper plant’s single biggest enemy, and no pepper is safe from its grasp. Though weevils are not the only enemy of the pepper plant, they are by far the most prolific and the hardest to eradicate. From bell peppers to jalapenos, all known commercially grown peppers are susceptible to attacks from the pepper weevil.
Don’t let the threat of weevils threaten your pepper growing green thumb, however, as there are ways to fight them off, as long as you catch them early enough in the process. Peppers are a great crop to grow for use in the kitchen. They are low maintenance and incredibly healthy. So, by all means, grow a whole lot of peppers, just look out for weevils.
Though peppers are the primary host for the pepper weevil, they also tend to prey on any members of the Solanaceae family, so be sure to rotate your crops each season and go in a different direction other than Solanaceae every other year. (That means to also stay away from tomato and eggplant crops when rotating.)
Aside from other members of the Solanaceae family, pepper weevils can also prey on nightshade plants, especially silver nightshade, but also black nightshade and horsenettle. Nightshade plants are basic weeds, so you will want to take care to pull up all known weeds that are anywhere near your pepper crops to keep weevils from gaining easy access.
Even nightshade plants on the outermost margins of your pepper field could be the reason why you got an infestation, so be diligent in ridding your property of nightshade weeds before planting your peppers.
Pepper weevils are the primary pest to pepper plants in Mexico, Central America, The Caribean, and The United States, primarily seen in southern states such as Florida, California, Texas, Arizona, and New Mexico. They can sometimes spread much further north, however, and have been spotted as far as New Jersey.
Identifying Pepper Weevils
Though smaller than a match head, the pepper weevil is a big problem when an infestation occurs. The oval-shaped pest is about ⅛ inch long and have a large snout. Adult weevils have a dark- colored body that has a brassy sheen to it. Larvae look similar to adults, but are smaller and have no wings. They are off-white to gray grub worms with brown heads, and are about half of the size of the adult weevil when they are fully matured.
Pepper Weevil Life Cycle
In order to successfully control the pepper weevil, it’s necessary to know about its life cycle. Adult weevils gorge themselves on the fruit and flower buds of your precious peppers. They also bore a hole, most often near the calyx of the fruit, where they deposit their eggs. In just a few short days, the larvae hatch and begin to eat the fruit of the pepper, working their way towards the seed pods.
The pepper weevil larvae are messy eaters, and depending on the size of the pepper they are infesting, and the amount of weevil larvae inside of it, the result is usually pretty obvious at first glance. The fruit, more often than not, falls off of the plant before it can be harvested. Now, you may not think so at the time, but this is actually a blessing, as it lets you know that your pepper plants are infested with weevils. The last thing you want is to harvest all of your peppers and find out about the infestation from taking a big bite.
The larvae grows quickly, molting three times before it stops chowing down. The weevil larvae then pupates inside the fruit and emerges as a full grown adult when it has the strength to chew its way to freedom.
If you aren’t seeing any fruit on the ground, it doesn’t mean that you are home free. Sometimes the larvae doesn’t have the numbers to do enough damage to cause the fruit to fall, and sometimes the peppers are too big for them to eat enough away to cause the fall. Another way to check for a pepper weevil infestation is to check the calyx of your pepper plants. If the calyx is yellow, there is a good chance that there is a weevil inside.
Pepper growers can also use an aggregation pheromone trap to determine the presence of pepper weevils in your field. Use these traps at the margins of your pepper field, as that’s where the weevils come from, that way you catch them before they do too much damage.
It’s absolutely essential to catch the pepper weevil as early as possible if you want to save your peppers, as only the adult weevils are vulnerable to insecticidal treatments. Once the weevil has laid its eggs in the peppers, it’s too late to save the crop. The only thing you can do at that point is to clean up the mess and take preventative measures to insure that they don’t return for future infestations.
Pepper Weevil Damage
Adult weevils feed on the fruit and leaf buds. Larvae feed on the inside of the pods, often causing immature fruit to drop before ripening. Larger peppers oftentimes do not drop from the plant, causing crop contamination.
How To Prevent, Control, and Kill Pepper Weevils
Step One: Preventative Measures
The best way to prevent pepper weevils is preventative tactics. Growers who are proactive in their fields can oftentimes prevent an infestation by cleaning up crop residue, limiting the length of time a pepper crop is in the field, and by reducing pepper weevil access to the crop in the first place. Here are a few other preventative measures that you can take:
- Inspect all transplants to make sure you are not bringing an infested pepper plant into your crop.
- Remove all damaged or dropped fruit from the field as soon as you notice it.
- Immediately following a pepper harvest, remove and destroy all fruit from the field and surrounding areas. Shred and discard any pepper plant residue
- If you had issues with pepper weevils during the most recent harvest, rotate to another, non-Solanaceous family crop next season
- Remove all nightshade plants and other weeds from your pepper field and the areas around the pepper field.
- Keep pheromone-baited yellow sticky traps on hand to keep a close eye out for infestations.
Step Two: Identify The Problem
Estimate adult pepper weevil numbers by using visual examination and pheromone-baited yellow sticky traps.
Before blooming occurs, put your traps out to detect any sign of adult pepper weevil emergence. Mount the traps on poles that can be raised or lowered during crop growth, keeping the bottom of the traps right at or just below the tops of the pepper plants. Check traps twice per week in the morning, or even more vigilantly if you already know that there are adults in the field. Apply treatments as soon as you know that they are present.
You can also catch pepper weevils in the act by keeping an eye on the terminal buds of the pepper plant. Check the two buds on each plant for adults and treat when one or more adults are identified per 400 buds.
Step Three: Treatment
Insecticides can be applied in short intervals once adult weevils are spotted. There are many insecticides that supposedly work on pepper weevils, but most only suppress the activities of the pest, and do not completely eradicate them from your land. Check your local pest management guides to find a list of your available options. To fight against insecticide resistance, rotate the insecticides used for treatment.
As many of the recommended insecticides are toxic to bees, care should be taken to avoid directly spraying blooming crops where bees are foraging. Alternatively, you could use a bee friendly pesticide to fight your weevil problem.
Some insecticides that have had success treating pepper weevils are:
- Neonicotinoids Belay and Actara
- A carbamate known as Vydate is another tool available to growers in most areas.
- Rotate insecticides between neonicotinoids and carbamates for best results.
- For organic gardeners, Pyrethrin spray, Dipel or Thuricide, preferably a combination of two or more, on rotation.
Step Four: Clean up and Rotate
After each round of pepper growing, discard all leftover fruit and pepper plant residues thoroughly. Rotate the crop that you grow in the place of your pepper crop next season, avoiding Solanaceae family plants.
Biological Control of Pepper Weevils:
Parasitic wasps do attack the pepper weevil, but they do not seem to be a reliable way to stop the problem altogether. Observations have shown that the wasps do very little to control the pest in the face of infestations that have advanced to the point of being serious.
Want to Learn More About Fighting Pepper Weevils?
Pepper Joe’s has a cheap method to help you fight against pepper weevils in this short video:
Want to see a pepper weevil in action? This film shows a close-up of a pepper weevil larvae eating a pepper from the inside out:
For organic gardeners, check out this insecticide tutorial: