Coffee Bean Weevil Control: Proven Methods to Protect Beans and Prevent Losses

The quality of coffee is usually evaluated based on the events in the field and seasoned farmers realize that what occurs after harvesting is also important. The coffee bean weevil is one of the least discussed pests when it comes to storage as it can silently kill both the harvested beans and standing crops. Are there bugs in coffee beans is a common question posed by many growers and, unfortunately, the answer to this question is yes unless we take appropriate measures.

The infestation may also start in the field and proceed in storage resulting in serious losses after harvest. Existence of some pests that cannot be detected lowers yield, as well as, influences taste, smell and market value. This necessitates early infestation and incorporated coffee bean weevil control tools as a quality control measure.

As world trade and storage time expands, this pest is turning to be a significant issue in the contemporary coffee supply chains. It needs awareness, monitoring, and sustainable management practices to address it.

Knowledge about Coffee bean Weevil (Araecerus fasciculatus)

The coffee bean weevil is a flexible insect pest with a very high tendency to infest a large variety of stored products. It has been regarded as a cosmopolitan pest, i.e. an organism that can flourish in different environments and climates.

This beetle belongs to one of the families of beetles that are particularly dangerous because of their infestation of not only field crops, but also stored products. The hatching of the larvae occurs within coffee beans and hence the infestation is difficult to detect before the damages are too serious to handle.

This pest can be easily confused by many growers with other coffee beans insects or smaller storage pests. But, in contrast to the surface feeders, this weevil cuts the bean and feeds inside. This feature causes it to be more destructive than many other coffee beans bugs because the damage is not obvious until it is too late.

Coffee bean weevil life cycle and behavior

One should be aware of coffee bean weevil life cycle so that they can be controlled. The pest has four life cycles that include egg, larva, pupa and adult. The larval stage is the most destructive, taking place in its entirety in the coffee bean.

Weevils of the female species lay eggs directly on, or inside the coffee beans. After the eggs are hatched, the larvae minces into the bean and starts feeding. This feeding goes on until the larva has grown and pupated in the same bean.

Depending on particular conditions of the environment: temperature and humidity, the whole life cycle can be finished within 30-56 days. This high rate of reproduction can lead to high growth of a population unless controlled.

Of particular importance is the presence of coffee bean weevil larvae, which inflict most of the internal harm that lowers the quality of the beans.

Damage Symptoms and Economic Impact

Small entry holes on coffee beans are one of the first signs of infestation. These holes are where the adult beetle has drilled in the bean. Indoors, the larvae consume the bean tissue causing serious structural destruction. The obvious consequences are less weight on beans, low quality, and contamination. There is usually a hollow or powdery interior of infested beans. This has a direct influence on yield and market value.

Studies have found that up to 20-30 storage losses may be incurred by the infestations caused by the coffee bean insects and thus it is a significant economic problem to the growers and traders of this crop.

Note: Coffee bean weevil damage should be detected to be able to intervene. Slowness in action may lead to extensive infestation, and the coffee bean weevil treatment becomes more challenging and less efficient.

Traditional and Folklore Coffee bean Weevil Control practices

Detection and prevention methods are subjected to traditional control procedures and adequate coffee bean weevil treatment. One of the best methods of preventing infestation is to maintain low moisture levels in stored coffee beans. The presence of high humidity provides a good environment to develop a pest.

Hygiene matters as well. Culling of infested beans and washing storage premises would help curb the population of the pest and avoid re-infestation. Aaracercus fasciculatus control programs can also be monitored using traps to identify early infestation. These devices assist growers to take immediate action to prevent proliferation of the pest.

Although in the past, chemical fumigation has been applied, the application is subject to limitations like resistance, residue and environmental effects. This has resulted in an increased need of safe and more sustainable coffee bean weevil control measures.

Met Zone (Sustainability) Control Biological

Alternative biological coffee bean weevil control can be a valuable alternative to the traditional methods. Met Zone, a product based on Metarhizium anisopliae, an entomopathic fungus is one such solution. Having a positive effect, this type of useful fungus clings the spores to the outside of the coffee beans insects. Once attached, the spores germinate and penetrate the body of the insect where they multiply until they kill the pest.

This method does not affect the environment, as the pest is targeted and there are no harmful residues or damaging chemicals as with chemical pesticides. This renders it a perfect choice in sustainable farming.

Biological solutions such as Met Zone for coffee bean weevil treatment, decrease the reliance on chemical coffee bean weevil and provide an opportunity to control coffee bean weevils. It can also be easily considered part of an integrated pest management system, which promotes friendly farming.

Long-term Coffee Bean Protection and Strategy

The coffee bean weevil has several solutions and not just one to protect against it over a long period of time. Combining biological coffee bean weevil control techniques, monitoring, and sanitation can yield the best outcome.

Profuse monitoring of stored beans and field crops is used to identify early infestations. An early detection of coffee beans bugs will enable growers to take the necessary steps.

A combination of preventive measures and biological controls will lead to the regular control of coffee bean weevils. This method would not only help to decrease the number of pests, but also ensure reduced chances of resistance and impact on the environment. The construction of a sustainable system with adequate provision of storage, hygiene and environmentally friendly treatments provides resistance to pests such as Araecerus fasciculatus control.

With the long term adoption of integrated strategies, it is the most important to safeguard the quality of coffee, sustain the yield and save the sustainability of coffee production systems.

Reference: 

• Verkleij, F. N., PAM van Amelsvoort, and P. H. Smits. "Control of the pea weevil (Sitona lineatus L.)(Col., Curculionidae) by the entomopathogenic fungus Metarhizium anisopliae in field beans." Journal of applied Entomology 113.1‐5 (1992): 183-193.
• Oliveira, Claudio Marcelo Gonçalves de, et al. "Efficiency of Metarhizium anisopliae in the control of Meloidogyne incognita in banana and coffee crops." (2021).