The Pest and Pathogens Glossary

Growing high quality bud takes expertise, knowledge and the right approach. It’s not something that’s learned overnight, and it’s very difficult to achieve on the first grow. Much of that is lack of experience, but for many new growers the problem is lack of knowledge as well. That’s why we’re developing resources for new, or even experiences growers looking for better results. This Pathogen’s Glossary is designed to warn you about the potential conditions your plants could face, and help you prepare to recognize and counteract those issues as they arise. Read through the entries to familiarize yourself with each issue, and to get your research about effective growing started off in the right way.


These little insects rely on the sap and juices of plants as their main food source. They are found in clumps on a range of plants, and are common on new growth especially. Often known as blackfly or greenfly, these little pests blend right into green plants. They re-produce a-sexually, which makes them especially problematic to deal with because they can reproduce quickly and in high number. Aphids must be removed completely and quickly to stop their damage, and even one left behind can be a serious problem over time.

Barnacles (Scale Insects)

Closely-related to lobsters, these tough little insects hide and lock on to the leaves and stems of plants, taking energy from them gradually over time. Some are soft to the touch, while others are much harder. They can significantly weaken a plant over an extended period and will result in a lower harvest overall if left untreated. They rarely move and can be difficult to notice until a large infestation has formed.

Broad Mites

These tiny mites commonly gather on the lower side of new leaves and lay eggs that leave behind a toxic substance on the leaves over time. This substance can stunt plant growth and really impact bud yields over time. These pests are too small to see with the unaided eye, and can be identified using magnification to make the right treatment plan.

Bud Rot

A seriously dangerous condition that forms on plant bud during its growth. It starts out white and wispy in formation and spreads from inside on the step to the outside sections of the bud. Bud rot can ruin a plant within a single week if untreated. It also develops spores and will spread rapidly. Bud rot is common in cool humid locations.

Caterpillars (Inchworms)

Caterpillars and inchworms both cause similar problems on most plants. Moths or caterpillars lay eggs on the leaves and buds of plants, then those eggs hatch unleashing hungry caterpillars and inchworms to do their damage. These pests eat through leaves at an alarming rate and will eat through stems as well. Buds with dark areas or black sections are common with caterpillar or inchworm infestations.


These little omnivores live underground and will burrow up to munch on plants that are accessible. Their arrival is signaled by a series of tunnels that in turn can let rodents into your growing space as well. Crickets will eat at plants rapidly and can do serious damage if no treatment action is taken.

Fungus Gnats

These tiny pests reproduce it an incredible rate and terrorize the bottom part of healthy plants. They are about 2 millimeters in size or less, and these little dark insects do serious damage to plants as their number grows.


These powerful pests lay eggs that can last all throughout summer creating a common problem all throughout the growing season. Grasshoppers will eat plants quickly, and can seriously hinder bud yields if left unchecked.


These tiny multi-colored pests live on plant sap and excrete honeydew, causing serious damage to their hosts. Leafhoppers can green, yellow, blue, black or brown in color, and are common in farms and greenhouses with leafy plant growth. Their excreted honeydew causes mold growth and over time plant discoloration and sagging are both common side-effects of these pests.


Leafminer infestations are easy to recognize because they leave behind white zig-zag patterns on the leaves they feast on. They are fly larvae and can significantly limit yields over time if they aren’t taken care of.

Leaf Septoria (Yellow Leaf Spot)

This damaging disease diminishes plant yields over time, and effects foliage specifically. It can be characterized by yellowing and spotty leaves, white lesions and the destruction of plant cells – also known as chlorosis.

Mealy Bugs

These compact but tough bugs can pose a serious risk to most plant types. They are normally white and fluffy looking. The males aren’t a real issue, because they just mate with females. The female mealy bugs attach to plant stems and can cripple plants over time. They cause defoliation, yellowing and dropping if left untreated.

Root Rot

Caused by overwatering, plant roots begin to decay because they don’t have access to proper aeration. This is especially common with indoor gardening. Avoid this issue by only watering as soil surrounding the plant becomes dry.

Russet Mites

Similar in size to Broad Mites (mentioned above) these compact pests start at the bottom of plants and work their way up, doing serious damage to the stem and leaves on their way up. They feed on sap and drain nutrients leading to stunted growth over time. They are not visible to the naked eye, and should be identified using magnification for accurate treatment.

Slugs or Snails

They feed on new foliage especially and cause the same sort of damage as caterpillars and inchworms. Snails have shells that vary in color but their bodies are normally gray. Snails have a neck, head, hump, foot and a shell. Slugs look similar to snails but without the shell.

Spider Mites

These small pests feed on the inner cells of a plant using a piercing mouth. They have four legs and aren’t insects. They multiply rapidly and can do serious damage in high numbers.


These long slend pests have wings when mature and eat through plants. They have no wings in their larva and nymph stages. They can be found in many different colors, including translucent, white, dark brown and black among others.

Tobacco Mosaic Virus (TMV)

This rod-shaped virus affects the RNA of plants. It causes a pattern of discoloration on leaves and will significantly reduce the growth rate of most plants. It is transmitted mechanically  by contact with plants.

Whiteflies (White Fly)

Characterized by their wings and soft bodies, these pets are related to aphids. They are found in many different regions and are about 1/12 of an inch in size. They have a triangular structure and can be found on the bottom of leaves regularly. They are active during the day, and will reproduce when it’s warm out, which means year-round in warmer areas of the country.

White Powdery Mold

This fungal disease is also called powder mildew. It is common in warm dry climates and spreads through the air via spores. It can kill off plants and move from one plant to the next rapidly if left untreated.

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