Survival of Diaphorina citri on Murraya exotica foliage exposed to different levels of light

Anecdotal evidence indicates that Asian citrus psyllid, vector of the causative agent of citrus greening, is less abundant in shady environments. We wanted to test whether foliage exposed to lower levels of light were less suitable for adult Asian citrus psyllids. Using shade cloths of different densities to vary light levels, we exposed host plants (Murraya exotica) to different levels of photosynthetically active radiation, ranging from full sun to 3% of the photosynthetically active radiation of full sun. Plants were maintained under these conditions for two months. Asian citrus psyllids were reared on foliage from plants exposed to different light levels and their longevity was monitored. 50% of the psyllids reared on foliage exposed to full sunlight for one month lived at least 25 days whereas 50% of the psyllids reared on foliage exposed to the lowest levels of light for one month had died by 19 days. Similarly, 50% of the psyllids reared on foliage exposed to full sunlight for two months lived at least 27 days whereas 50% of the psyllids reared on foliage exposed to the lowest levels of light for two months had died by 15 days. These results indicate that plants grown under lower light levels are less suitable for adult Asian citrus psyllid survival.