Tag Archives: infestation

Building An Integrated Pest Management Plan – Part 2

By Phil Gibson
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This is the second part of a series of articles designed to introduce an integrated pest management framework for cannabis cultivation facilities. To see Part One, click here. Part Three comes out next week and covers prioritization and preventative measures. Stay tuned for more!

This is Part 2: Pest Monitoring, Record Keeping, & Communications

Begin your pest identification process with a pest scouting document. You have already mapped out your facility with locations and potential access locations. For each of these pest types and room type assignments (mothers, clone, veg, flower), identify your employee scouts, their scouting methods, scouting frequency and the type of likely pest they are to search for and count.

Insect Types and Tracking Methods

Figure 1: Example Sticky Trap Scouting Map

Insect pest types include, but are not limited to, airborne flying or crawling insects, their various egg, lymph, larvae, pupal shells or immature forms. Look for trace remnants, plant damage or feces that let you know they are present in some form. If they are at the mature jumping or flying stage, this can be harder to count, but sticky traps distributed on an even basis around your rooms can make the counting process more consistent from survey to survey.

Note airflows in your rooms and fan locations so migrations can be predicted once an infestation is located.

Insects Can Be Everywhere – Crawlers & Fliers

Insects would like to be everywhere so they come in many types from the obvious flying and crawling types to root-zone microscopic, aquatic, fungal, bacterial or biofilm based. For those of you using soil or media, root-zone insects can be beneficial by digesting and breaking down organic matter into something useful for your plant’s roots (earthworms) or harmful by feeding directly on your plant roots and sucking the life out of your plants from out-of-sight below (nematodes, maggots).

Common pests in a cannabis environment include:

  • White flies – Oval shaped eggs on the underside of leaves, nymphs- oval crawlers that suck on the undersides of leaves, larger stage nymphs with pupae shells as they form wings and mature white flies.
  • Fungus gnats – Clear eggs deposited in overly wet soil or dead plant matter. Clear or white colored larvae in the soil or media, these worm-like critters go through multiple stages of molting as they grow, eventually pupating into brown cocoons and finally small black or dark flies with clear wings that flutter around your plants and suck on your leaves.
  • The dreaded spider mite – Clear, hard to see eggs on the underside of your leaves. These six-legged tiny moving bubbles begin the feeding as larva, add 2 legs in the intermediate and mature nymph stages and finally the oval shaped spider mites that every grower despises, adding their webs around the tops of your plants as their nurseries suck the life out of your flowers.

Insect Transfers of Bacterial Infections

Figure 2: The Dreaded Spider Mite

Many crawlers or fliers you may discover in your grow operation do not generate fungus or bacteria on their own. However, they do routinely pick these up along the feeding way and bring them into your shop. Sap-feeding insects like leafhoppers and aphids use their needle mouths to pierce your leaves to suck on the sap that is nourishing your greenery. These insects consume the fluids and transfer bacteria as they feed. Whiteflies fit into this category of leaf sucking bacteria carrying pests. These pests can make your healthy grow rooms look blotchy with color drained out of your canopy.

Obvious symptoms of these flying/hopping pests are sticky leaves, black fungus mold, or yellowing leaves that show up at the bottom of your plants and work their way upward as the infestation progresses. Leaf curling or plant wilting will be visible in the more advanced stages of these pests.

As if crawlers were not bad enough, invisible fungus and bacteria that get into your water supplies can be the worst challenges of any grow.

Water Sourced Bacteria

Baseline testing of your feed water is critical for any facility. This is true whether you are using surface water, well water or municipal water. Please see the water tutorials on the AEssenseGrows website for details on how to test your water sources and what to look for in the mineral content.

Regardless of your water source, bacteria can be present directly in your water supply, or it can be introduced from infected plant materials from one of your suppliers. Pythium, fusarium and the latest plague, hop latent viroid, are some of the most common threats that attack your plants from your water or soil sources. These can come from your wells, feed lines or plant materials.

Reverse osmosis (RO) is a typical method to clear water of most pathogens and bacteria using water that is pressed through filters with very small membrane apertures. These small openings usually stop impurities, salts and microorganisms. Of course, these systems come in many different types and they have to be maintained to keep their performance quality. Don’t take shortcuts on your RO system.

Once your water source is clean, strict hygiene procedures for tools, equipment and plumbing are the best way to minimize these threats to your plants downstream from your water source. These cleaning efforts are not a guarantee. Pests can still get into even the best facilities. Symptoms of these maladies vary, but root rot, stunted growth, wilting, discolored roots or leaves, and in some cases, the quick death of your plants is possible depending on the critter.

Use your scouting regimen and your data mapping to locate infestations before they expand and damage your facility. Isolate outbreaks and take appropriate measures to address the pests. We will give you suggestions on prioritization and preventative measures to take in the next chapter.

Figure 3: Example Pythium Brown Roots

Pythium is one of the most commonly harbored soil or water carried pests. When it is present and gets into your plants through cuts, natural openings, root surfaces or leaves on weakened plants, it can be devastating. In hydroponic systems, dirty looking brown roots evolve into full root rot if not addressed. Pythium is often the cause. In soil operations, pythium often shows up as wilting or yellowing patches on leaves.

Your lab testing partners are your friends when it comes to bacterial or fungal infections. Many diseases can resemble one another. It is not hard to misdiagnose environmental stress such as overheating or overwatering for a bacterial problem. Test results are necessary to accurately diagnose a problem.

Truly Airborne Molds & Mildews

Pythium and fusarium are not just present in water. They can also be airborne. Grey mold (botrytis) and powdery mildew are also common airborne pests. Proper humidity, air movement, air filtration and sterilization using HEPA (High-Efficiency Particulate Air) filters, activated carbon filters (also filter smells) and UV light sterilization can minimize these problems in your grow. Powdery mildew is the primary evil spore in this category. Airflow and regular cleaning to discourage fungal growth is the best way to limit these pests.

In conclusion, this week

Now that we have talked about identification (and clearly, this is not an exhaustive list), we will move into how to build in the cultural methods to prevent these problems from taking hold and ruining your business. In later chapters, we will dive into prioritization, treatment and control options for infestations, finally moving into control actions and emergency response.

Your integrated management response is how you pull all of this together and use your IPM procedures to increase your profitability. For the complete white paper on Integrated Pest Management Recommendations, download the document here.

Part three comes out next week and will delve into the world of Preventative Measures. Stay tuned for more!

Protect Your Business: Comprehensive Rodent Exclusion

By David Colbert
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Many experts agree that of all pests threatening the cannabis industry, rodents are the most dangerous. Not only do they chew on cannabis plants and ruin crops at an incredible rate, they also contaminate product with their urine and feces. Rodents post a serious threat to cannabis facilities at every level of the supply chain.

Rodents’ incisor teeth never stop growing; left untouched, a rat’s incisor teeth would grow 4 inches in a year*. For this reason, they must constantly gnaw on things around them to wear them down. Unfortunately for cannabis growers, the woody stalks of cannabis plants present a perfect target. The destructive power of rodents cannot be overstated – creatures that can gnaw through plastic, wood, aluminum, brick, cement and even lead will make very short work of cannabis crops.

The notion that growing cannabis indoors will protect it from rodents is a misconception. Their destructive gnawing power makes rodents highly adept at getting inside buildings. Rodents can enter a building through an opening as small as 1/4 inch, and they will use any means necessary to reach the food and shelter that a heated building provides. In addition to squeezing through minuscule openings, rats and mice can climb wires and rough surfaces, jump considerable distances and tread water for several days.

Rodents, easily squeezing through small openings in a facility, will find food and shelter that a heated building provides

And once they are inside, it is already too late. Pest control experts worldwide agree that exclusion – the technical term for using physical barriers to prevent rodents from entering a building vs. trying to remove them once inside – is the safest, most effective approach to rodent control. This is because once rodents have gained entry, they will contaminate – and multiply – at an alarming rate.

In one year, two mice could potentially multiply into more than 5,000 mice and two rats could become 1,250. In that same year, a single rat can shed more than half a million body hairs, and a mouse can produce up to 18,000 fecal droppings. Rodents eat or contaminate at least twenty percent of the world’s food supply each year (according to the Indiana Department of Health) and carry diseases including rat bite fever, hantavirus, leptospirosis, salmonellosis, murine typhus, and even the bubonic plague. According to experts from Total Food Service, “Mice are known to frequently carry salmonella bacteria in their digestive tract, so salmonella can be easily spread through contact with rodent waste. This is true with marijuana [sic]edibles just as it is with other food products.”

Keeping rodents out of cannabis facilities is fundamental to protecting crops and products. The most common rodent entryways include exterior doors, open garage and loading dock doors, windows, air vents, fireplaces and at points where electrical, water, gas, sewer and HVAC lines enter the building. Rats and mice can also gain entry through tiny cracks in the foundation, by gnawing through the standard rubber and vinyl seals on most garage and loading dock doors, and beneath roofing tiles.

Consider the following exclusion best practices highlighted in The Mallis Handbook of Pest Control:

  • Safeguard your doors. Wooden doors are continuously vulnerable to the gnawing of rats. Sheet iron flashing should be installed surrounding the door, and any clearance below the door must be smaller than 3/8 inch. All doors should remain closed when not in use and be fitted with proven, specialized rodent-proof door sweeps.
  • Ventilator grills and windows should be protected with proper and proven exclusion materials, ensuring any voids or cracks are filled.
  • Defective drain pipes provide a transportation pipeline for rodents. A perforated metal cover should be cemented over the drain pipe, and any small openings surrounding the drain where it enters the building should be patched or filled with proven exclusion material.
  • Large sidewalk cracks should be sealed as these crevices allow rodents to access a building’s foundation, enabling them to more easily search for entry points. Foundation walls can be protected with barriers of metal, concrete, or brick around and below the foundation.
  • Circular rat guards should be placed around all vertical wires and pipes.
  • Ensure that cracked or broken roofing tiles are identified and replaced in a timely manner, and utilize proven exclusion material to fill any voids.

It’s also critical that only proven, rodent-proof exclusion materials be utilized to seal entry points. Caulk, mortar and spray foam offer almost zero protection against the gnawing power of rodents. Steel wool is often used for filling cracks and crevices, but will eventually rust and break down, rendering it useless against rodents. All exclusion materials should be made of stainless steel or other permanent elements.

Rodents are not easily deterred, but a well planned exclusion program can save you from costly infestations

Standard rubber door sweeps used for weatherization are not designed to withstand rodent gnawing, making the small gap beneath and around exterior doors a primary rodent entry point. Specialized rodent-proof door sweeps are fundamental to effective rodent exclusion. Xcluder’s Rodent-Proof Door Sweeps feature a core of Xcluder Fill Fabric – a blend of stainless steel and poly-fiber with sharp, coarse fibers that rodents cannot gnaw through – reinforced gaskets for a superior weatherseal and an extended rubber flap to create a flush ground seal against insects and other outdoor contaminants. Installing rodent-proof door sweeps is arguably the single most important step in protecting cannabis facilities from rodent infestation.

Sanitation is also important. Food products of any kind must be stored in sealed containers. Garbage should be collected frequently and stored as far away from the building as possible. Clutter should be avoided in storage areas as crowded shelves and boxes create opportunities for rodent nesting. Roofs and gutters should be free of debris as standing water attracts rodents as well. All trees and landscaping should be trimmed back away from the building to prevent not only rodent burrowing but also access to the roof.

Rodents are not easily deterred, but a well-supported, thorough exclusion plan is the strongest weapon in the fight against rodents. Investing the time and resources to properly safeguard buildings against rodents before a problem is identified is the best way to protect the plants, products and personnel inside cannabis facilities.