TITLE:
Outbreak, Distribution and Damage Characteristics of Cocoa Stem Borer, Eulophonotus myrmeleon Felder 1874 (Lepidoptera: Cossidae) in Major Cocoa Producing States in Nigeria
AUTHORS:
Emem Basil Kingsley-Umana, Uche Evarestus Asogwa, Idongesit Mokwunye
KEYWORDS:
Cocoa, Stem Borer, Survey, Infestation, Exudates, Damage
JOURNAL NAME:
Advances in Entomology,
Vol.10 No.2,
April
6,
2022
ABSTRACT: This study aims to ascertain the extent of the cocoa stem borer Eulophonotus myrmeleon distribution,
outbreak, and damage to the cocoa plantations in six cocoa growing states in
Nigeria. Three local government areas were selected from each of the six major
cocoa states and three farms from each local government area. In each farm, 100
cocoa trees were randomly selected and inspected for symptoms and damages of E. myrmeleon. The result revealed that E. myrmeleon infestation has increased
significantly (p = 0.01, df = 1, F =
41.77) in 2019 by 10% from the 2014 inspection. It also showed that the
infestation level was significantly different from state to state. Symptoms of
infestation include presence of entry/exit holes, woody exudates around the
trees, yellowing and browning of the leaves. Damages caused by E. myrmeleon infestation are, loses of
pod on the affected branch and tree and death of tree. Field observations
showed clearly that stem borer is now becoming a serious problem and limiting
considerably the production of cocoa in the region. It is time to give more
attention to the biology and management of the pest. This is the first report
detailing the symptoms and damage done by cocoa stem borers in Nigeria.