Resistant Cultivars

At the moment, the cultivar Forastero has really good disease resistant but there no indication on how will it handle pest pressures, such as the cocoa pod borer.

 

The focus is to create a cultivar with a harder pod wall for cocoa pod borer resistance. This hard wall is caused by a sclerotic layer and varies greatly across cocoa cultivar. Some of the earlier harder-pod cultivars created in the mid-1980’s were susceptible to other diseases, such as vascular streak dieback caused by Oncobasidium theobromae. In addition, there as a general lack of interest by growers for cocoa prices were falling at that time. Today there is still interest in resistant cultivars and ongoing cultivar selection taking place in Sulawesi, an Indonesian island, looking for resistance.
 

Variation of the Response of Clonal Cocoa to Attach by Cocoa Pod Borer in Sabah

 

 

Natural Enemy

Predators

Natural predation levels are between 40-60% and occur most in the pupal life stage. Two of major predator of cocoa pod borer is Oecophylla smaragdina and Dolichoderus thoracicus. Both are ant specie common throughout Asia and Oceanic range. There is been recent research in increasing the biocontrol provided by ant species but there has been limited success. There has been some intersted in using nematodes as well to cotnrol cocoa pod borer.

 

Uses of Ants to Control for Cocoa Pod borer

 

 

Parasitoids

There are roughly sixteen different parasitoid species that are documented attacking cocoa pod borer, mainly in the egg, larval or pupual life stage (see table below). However, it is not an effect control method; because it does not occur until cocoa pod borer populations are significantly high. There have been two attempts to use exotic parasitoid species, but both were mostly unsuccessful. It was found that large-rearing of parasitoids was more expensive compared to spraying, and therefore discontinued.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pathogens

There is a handful disease agents that attack cocoa pod borer (see table below). Several articles have explored the topic in terms of cocoa pod borer control but there are no commercial practices involving them being used to date.
 

Bacillus thuringiensis is a very common entomopathogenic fungal pathogen used against a wide range of insects. There are few commercial product containing Bacillus thuringiensis and provide very good control of pest insects. However, there is no indication that they have been used commercially to control cocoa pod borer. 

 

 

 

 

 

 

 

 

 

 

 The Study on the role of entomopathogenic fungal endophytes in controlling the cocoa pod borer (conopomorpha cramerella (Snellen)) (Lepidoptera: Gracillariidae) on cocoa plant

 

Activity of Bacillus thiringiensis toxins against cocoa pod borer larvae

 

Establishment of the fungal entompathogen Beaveria bassiana (Ascomycota: Hypocreales) as an endophtye in
cocoa seedlings (Theobroma cacao)

 

 

Pesticide

Insecticide sprays are not commonly used to control cocoa pod borer because of a range of different factors.

 

Board cast sprays for cocoa pod borer were found to cause very sever secondary pest outbreak in the 1950’s and 1960’s. These outbreaks were caused by the loss of natural enemies for the secondary pest. In addition, environmental factors such as rain and sun break down the chemicals in the spray quickly, reducing their effectiveness.
 

The timing and placement of the insecticide application is very important. Spraying at peak crop period through harvest has very little impact on population densities. Branch sprays can be applied at low crop period (such as early season) for they provide a long lasting protection period. Targeted sprays to the underside of leaves, for this were the adult like to reside, can be efficient to keep population below economic damage threshold level. Often a contact insecticide, such as pyrethroid and carbamate, are used.

 

Another factor that limits insecticide sprays as a control method is that they are very expensive for growers. Low cocoa prices and the limited control they provide results in grower only chemical sprays as a last restort.   

 

If sprays are used it is important to follow product instruction. This results in maximum control and no harmful side-of-effects to humans or the ecosystem.

 

Pheromone Control

There has been some interest in using pheromones to control and monitoring cocoa pod borer, since it has been very successful with other moth species. Many studies have focused on the area to identify pheromones to field trails to test them. One study found that the traps could track moth from up to 800 m away. However, it was found that some races of cocoa pod borer do not respond to the found pheromones. As a result, pheromone traps are not used commercial at the moment.

 

 

Culture Control Methods

One the most predominate cultural control method for the cocoa pod borer is to remove alternative host material (see list) in and around the cocoa field. This method can reduce cocoa pod borer populations in an area and limits pest build up. This method contributed to the only known case of eradication.

 

Satiation is a very important factor in control. It is important to remove damage or infested pods from the field to disrupt the life cycle during the season before harvest.  When harvest is conducted all pods should be removed, this includes ripe, damage, and unripe pods. Once the harvest is complete any remains of the pods and damage or infect pods should be destroyed or buried.

 

Maintaining an open and structured canopy may help control cocoa pod borer. An open canopy a deter adults since they like the hang out on the underside of leaves. Keeping the canopy less than 4 m/ 12 ft. height helps keeps the pod within reach for harvest and allows them the be monitor for infection.

 

There has been some research into plastic sleeves that cover the developing pod to prevent the larvae of the cocoa pod borer from boring into the pod. However, there are some drawbacks to the sleeves. They must be applied individual to the pods, which can be timing consuming and labor intense. In addition, it may be hard to get a sleeve on the all the pods of a mature tree so it often done when the trees are younger.  It is important to know how to and when to apply the sleeves. Far too often they are applied to late. In addition, it is important that the selves are properly vented of they can cause rot.

 

Control of Cocoa Pod Borer and Phytophthorea Pod Rot Using Degradable Plastic Pod Sleeves and a Nematode

 

 

Eradication
The only successful eradication of the cocoa pod borer took place in Queensland Australia. It is not native to the area. Several different control methods were used to successful eradicate it, including sprays, removal of host planter material, and other.