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.
Whitefly Control with Natural Solutions: Often confused with aphids, whitefly feed on the underside of leaves. Both adult and nymph stages feed by sucking the plant juices. Large populations or heavy feeding by whitefly can give plants a mottled look, cause yellowing and eventually death to the host plant.