This, along with vectors they can carry, and excrement and secretions lead to telltale damage in new growth. Three types of mites account for almost all infestations of cannabis. Broad mites, Russet Mites and Two-Spotted Spider Mites. They range from difficult to impossible to spot without magnification and reproduce rapidly. This means, with the smaller species particularly, the damage is what you see first and by then there are already multiple generations of mites inhabiting and destroying your plant.
It’s more or less impossible to control a full-blown mite population bloom, so it’s especially crucial to maintain preventative conditions and regularly inspect plants so action can be taken as early as possible if mites do appear. When it comes to greenhouse grows the primary source of mites is infected clones, so in addition to proper sanitation, great care must be taken when sourcing new genetics. Biocontrol of a mite infestation needs to be established before flowering, otherwise the reduced light times will cause a clustering response in the mites, rendering predatory mites all but useless. If mites are detected early enough, before too much damage has been done to the affected plants, their numbers can be effectively thinned by spraying plants with water, but additional control methods are required to fully eliminate them. How common are broad mites and what do they look like? The broad mite or, Polyphagotarsonemus Latus , is a new pest in cannabis gardens and sightings are becoming more common. The most notable thing about the broad mite’s appearance is its diminutive size. They are so small that a 60x loop or stronger is recommended to properly identify them. With the naked eye you will only notice a large infestation, clusters of egg sites and the telltale broad mite damage. Up close the broad mite has a structure and appearance similar to larger mite species.
Its coloration can vary, but often it looks like a pale yellow or clear dewdrop with tiny legs. Broad mites have a large cephelathorax, two pairs of small front legs, one pair in the middle of its body, and a wispy pair of back legs; which are more pronounced in the smaller males. Under a microscope they have a medium-size head with a definitive mandible structure. Broad mite eggs are translucent, round and with white spots. These are actually tuffs of spine-like hair, but appear as spots. Broad mites: How to look for them and what they do to the cannabis plant. They prefer newer growth and the crevices of the cannabis plants. Always inspect the damaged growth areas with magnification, paying close attention to the ribbing of the veins on the underside of the leaves. Broad mites cause two types of damage that are great clues for identifying them. The first is often “stipling,” which is a pattern of yellow dots on the leaves. These are the tiny feeding sites from the infestation. Often stipling is inconspicuous, but the leaves turn darker. As time passes after the initial wounding the sites become yellow to gray or even necrotic. These yellow speckled leaves as well as a twisting and/or yellowing of new growth are the second signs of damage. If you see these two signs in a garden, use a 60x loop to look for broad mites. Mites are vectors for infections, but their main damage is the sucking out of nutrients from the plants’ leaves, which interferes with photosynthesis. Draining liquids and nutrients from the leaves slows down the plants’ growth. This, along with vectors they can carry, and excrement and secretions lead to telltale damage in new growth. It’s difficult to surmise where they came from in many instances. Often they come in the wind, infected plant material, or are deposited by animals. One of the most likely sources of infection is importing infected clones. For this reason, many growers start plants only from seed. A good integrated pest management program is always recommended. A periodic spray with an herbal pesticide is a good start.
To target Spider Mites, Clover Mites, Broad Mites and Cyclamen Mites, Neoseiulus Californicus from Biotactics, is a hearty and effective Type II predator that will lay one egg for every 4-6 units of food (spider mite adult/ nymph/ egg). Effective on almost every plant from roses to strawberries to cannabis and alfalfa. • Citric acid • Herbal oils: • Cinnamon • Clove • Peppermint • Rosemary • Thyme. A product called Nuke Em produced by flying skull is effective at eradicating broad mites.
Debug, a product described in aphid treatment and control, can be used to combat broad mites.