There are multiple metric units to choose from! This tutorial goes through the process of choosing the best metric unit to use for measuring the mass of a given object.
The most common aphids on houseplants are the light green ones (pear aphids), but aphids can also be found colored pink, white, grey and black. Additionally, winged aphids can appear when colonies are established and fly to infect new plants. Juvenile aphids (nymphs) look like smaller versions of the adults.
These small white flies resemble tiny moths. There are different types of these insects including the silver leaf white fly and the green house white fly. When an infested plant is disturbed, the small white flies will be seen flying out before settling back on the underneath of the leaves.