The grub and mature African red mite suck the nutrients from the leaf, upper side and lower side, so it turns pale green. The surface of lower side has the mark of the red mite which looks like dust.

The grub and mature thrips sucks the nutrients from the bud, flowers and young fruit. The burning mark is on the crooked leaf which results in the imperfect flowering and falling flowers, as well as the marked fruit.

Black mold is generally found at the unattended garden. The prevention of sucking insect such as mealybug and coccidae that sucks the nutrients and excretes the syrup on the leaf and bough is required.

Entomopathogenic Fungi prefer damp, especially heavy rain. Swimming spores destroy the leaflets and medium-old leaf so it is rotten and falls and accumulates on the ground. When it gives fruit, wind and rain carry the fungi to the fruit and makes it cracks and be rotten

It generally spreads, particularly in the humid climate. In case of severe epiphytotic, the leaf loses the photosynthesis area and will fall eventually. If it happens to the flower, it will rot and fall during blooming period.