A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
A survery was conducted to assess the present status of infestation caused by
the beehole borer, Zeuzera conferta Walker(Cossidae: Lepidoptera) in keora (Sonneratia
apetala Buch.-Ham.) plantations along the coastal belt of Bangladesh. The survey
covered plantations raised in the four Coastal Afforestation Divisions, namely
Patuakhali, Bhola, Noakhali and Chittagong of the Forest Directorate. The survey
revealed an overall infestation of 20.9% with an average of 15.6,16.6, 26.3 and 25.2%
in the four Divisions respectively. A number of plantation attributes, such as age
(3-20 years), inundation duration (very low to very high levels with which the keora
stand got tidally inundated in a year), canopy closure (open and closed), and stand
composition (single species and mixed species), were evaluated for their correlation/
association with the degree of infestation. The correlations between the degree of
infestation and plantation age in Patuakhali (r = -0.28 ) and Bhola (r = -0.31) were
non-significant, whereas those in Noakhali (r = -0.71) and Chittagong (r = -0.53) were
significant. The infestation trend reached its peak at around the age ofseven years and
then decreased slowly. Infestation was higher in highly inundated (> 9 months
inundation), open canopy and single species stands.