The black "Bean Aphid"

The black bean aphid (Aphis fabae) is a tiny black insect with a broad, soft body, a member of the order Hemiptera. Other common names include blackfly, bean aphid and beet leaf aphid. In the warmer climates like ythe Philippines it is found in large numbers on the undersides of leaves and on the growing tips of host plants, including various agricultural crops and many wild and ornamental plants. 

Both winged and wingless forms exist and  they are all females. They suck sap from stems and leaves and cause distortion of the shoots, stunted plants, reduced yield and spoiled crops. 

This aphid also acts as a vector for viruses that cause plant disease and the honeydew it secretes may encourage the growth of sooty mold.

It breeds profusely by live birth but its numbers are kept in check, especially in the later part of the summer, by various predatory and parasitic insects. Ants feed on the honeydew it produces and take active steps to remove the aphid's enemies. It is a widely distributed pest of agricultural crops and can be controlled by chemical or biological means. Winged forms move to different host plants where both males and females are produced. This can contaminate your entire rapidly..