AgroPages-Philippine researchers to develop biocontrol agents against cacao pests and diseases-Agricultural news

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BioControl Agents Market Forecast (2015 - 2020)
Bacteriocide Market in Agriculture by Type (Copper-based, Dithiocarbamate, Amide, Antibiotic), Crop Type (Cereals & Grains, Oilseeds & Pulses, Fruits & Vegetables), Mode of Application (Foliar Spray and Soil Treatment), Form, and Region - Global Forecast to 2022

The Philippines’ strategic location and favorable soil and climatic conditions make the country suitable for planting cacao. The current estimate of cacao produced in the country is 12,000 metric tons (MT). According to the Philippine Cacao Road Map developed by the Department of Agriculture (DA) and the Cocoa Foundation of the Philippines, Inc., it is projected that the Philippines has the potential to produce 100,000 MT by 2020.

In 2015, the International Cocoa Organization estimated a 30 to 40% loss in cacao production due to insect pests and diseases. In the Philippines, the pod borer and mirid bug are the more serious ones among the pests of cacao. To address the prevalence of these pests, the De La Salle University (DLSU) spearheaded the study to explore, identify, mass rear, and release biological control agents against cacao pod borer (CPB) and cacao mirid bug (CMB). CPB feeds on the cacao bean pulp and the pod’s placenta, causing malformed and undersized beans. Severe infestation results in small flat and stuck together beans; yellowing, uneven or premature ripening of pods.

The project is being funded by the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD).

Surveillance for Trichogrammatoidea cojuangcoi, a possible egg parasitoid of cacao pod borer in Mindanao (Image credit: Dr. Albert T. Barrion, DLSU)

The use of biological control has become a very promising alternative to the more traditional use of chemical pesticides in agricultural pest management according to the researchers, Dr. Divina Amalin and Dr. Alberto T. Barrion, both of DLSU. Biological control uses other organisms in controlling pests, which can be insects, mites, weeds, and plant diseases, through predation (i.e., organism preying on the pest), parasitism (i.e., smaller organism causing harm on its host organism), or other natural mechanisms.

The project surveyed cacao-growing areas in Quezon, Bicol, and Davao regions previously reported with the insect pests as well as the insects and spiders that can be natural enemies or biological control of these pests.

An egg parasitoid, Trichogrammatoidea cojuancoi Nagaraja, was reported to be active against CPB in Davao del Sur, particularly in areas where there has been no insecticide spraying for a long time. However, it was not collected during the survey as bananas replaced cacao.

Another possible natural enemy, Paraphylax sp. was found parasitizing CPB in some of the cacao-growing areas in Davao del Sur. Both of these biological control agents are currently being attempted to be retrieved and collected.

Meanwhile, cacao mirid bug feeds on cacao pods and shoots, inducing tissue decay resulting in non-productive cacao trees. CMB’s natural enemies include a variety of wasps and spiders, such as the lynx spider, Oxyopes javanus Thorell. A new species of Erythmelus has been found as a parasitoid of CMB. Currently, researchers are mass rearing cacao mirid bug for efficiency testing of natural enemies. Also, a diet is being developed to mass rear lynx spider.

The study being conducted by Dr. Alberto T. Barrion is under the Cacao Pest Management Program: Biological-Based Approaches being led by Dr. Divina Amalin of DLSU is expected to run for two years.