Influence of microhabitat temperature on Coelaenomenodera Elaeidis and its natural enemies in Nigeria

Abstract

Insect infestations are expected to increase in Sub-Saharan Africa with climate change, to levels that may cause rapid changes in vegetation with concomitant changes in microclimate. Microhabitats are niches whose dimensions are smaller than those of the macrohabitats in which they occur. The physical presence of many oil palm stands leads to existence of microhabitats within the macro-environment. This study examined the direct effects of microhabitat temperature on a major pest of the oil palm, Coelaenomenodera elaeidis, its parasitoids and predatory ants. Field plots for observations of microhabitat temperature were established to run through January 2009 to December 2010 at the main station of the Nigerian Institute for Oil Palm Research in Nigeria. The C. elaeidis and microhabitat temperatures were statistically analysed. In 2009, leaf miners were significantly different in the dry season; while in 2010 the predatory ants had the highest significant (P < 0.05) relationship in the rainy
season. Generally, the dry season recorded greater abundance of leaf miners and predatory ants; while the rainy season recorded more of the parasitoids in both 2009 and 2010. This study has demonstrated that the oil palm ecosystem is becoming vulnerable to insect pest attack as a result of increasing temperature. We thus advocate for the strengthening of pest management systems to cope with increased threats.