Male and female mealy bugs have distinct functions in the bug world. Adult males' sole purpose is to fertilize the female. Males are winged, whereas females may have legs but no wings. Both grow to be no bigger then the tip of a human fingernail.
Female mealy bugs attach themselves to crevices in the plant and form a waxy coating over their bodies as protection while they suck the juices from the host plant. They prefer the company of ants because they act as little soldiers protecting the mealy bug from predators and parasites. If you have no ants, you probably do not have a mealy bug problem.
The presence of mealy bugs in your marijuana plants is indicated by groups of puffy white cottony looking clumps appearing on stems or in crevices. Small infestations will not do much harm, however they should be controlled in order to avoid leaf drop in your cannabis plants.
Mother Nature's answer to controlling mealy bugs is the ladybug. If you don't have ladybugs present, you can spray the plants with a hard stream of water. This will dislodge the puffy bugs but won't eliminate them. You can also rub them off with a cloth; be sure to crush them in the cloth so they can't find a new home. If you are feeling rather sadistic and have some time, dip a Q-tip in rubbing alcohol or nail polish remover and swab them off the plant.
In addition to the aforementioned physical controls, there some organic treatments you can use to get rid of the pests, in the form of soaps and oils. Spraying with neem oil, cinnamon oil or garlic oil will help to control the population. (Refer to the sections on caterpillars, aphids and whiteflies for the recipes.) Spray the plant thoroughly, especially underneath the leaves. Apply on overcast days or after the sun has started setting in order to achieve the full effect.
To make your own batch of insecticidal soap, add five tablespoons pure castile soap and two tablespoons olive oil to one gallon water. Adding the oil helps the solution stick to the plant a while longer. If you have hard water, use bottled water to avoid ugly water spots from forming on your plants. You can also add a teaspoon of garlic or ground red pepper to further repel these chewing bugs. Fill a spray bottle and go to town on your marijuana plants.