The diet consists mainly of the natural gum of trees in temperate deciduous forests. The Masoala fork-marked lemur has become specialized for harvesting this substance. Like most lemuriform primates, it has a toothcomb; in "Phaner" species, the toothcomb has evolved to be more robust and is used to scrape the gum that exudes from holes on a tree made by insects. This structure consists of a row of lower incisors that are long and forward pointing. The favoured food sources are trees in the genus "Terminalia", but certain other tree species also provide gum, including "Adansonia" spp., and the buds of "Zanthoxylum tsihanimposa". Certain beetle larvae burrow just under the bark of "Terminalia" and leave characteristic galleries that ooze gum. This lemur has also been observed licking the flowers of "Crateva greveana", and feeding on a "syrup" produced by insect larvae on thin branches of "Rhopalocarpus lucidus" trees.