Spider Mites: A Serious Threat to Cannabis Crops Spider mites (especially the two-spotted spider mite Tetranychus urticae) are one of the most destructive pests in cannabis cultivation. These microscopic arachnids feed by piercing plant cells and sucking out the contents, which causes tiny white or yellow “stippling” spots on leaves as an early symptom. As feeding continues, leaves may become bronzed, yellow, or dry and can drop off prematurely . In heavy infestations, fine silk webbing will cover foliage and even buds – a telltale sign that the mite population has exploded. Entire colas (flower clusters) can become shrouded in webbing and speckled with mites and eggs, rendering the buds unsalable. If left unchecked, spider mites can rapidly ruin a cannabis crop, with yield losses up to 40–60% reported in other plants.

The reproductive cycle of spider mites makes them especially dangerous. A single female can lay dozens of eggs in her short lifetime (often 100+ eggs per female), and those eggs hatch in just a few days under warm conditions. At optimal temperatures (around 86 °F), a spider mite can go from egg to egg-laying adult in only about 7 days. This means populations can increase exponentially – studies show mite numbers can 70-fold in under a week during hot, dry weather. In practical terms, just one or two mites can turn into thousands within a month if conditions favor them . Such explosive growth, combined with their tendency to go unnoticed until damage is apparent, makes spider mites a nightmare for cannabis growers.

Infestations often start on the undersides of leaves and at lower parts of the plant, then rapidly spread upward as the plant’s health declines. By the time webbing is visible, the outbreak is severe and immediate action is required.

The Need for Fast, Residue-Free Solutions in Cannabis Unlike food crops, cannabis is typically inhaled or ingested without further processing, so any pesticide residues on buds can pose health risks to consumers and cause products to fail state testing requirements. Cannabis growers therefore face strict regulations and consumer expectations to keep their product free of harmful chemical residues. Many conventional chemical miticides (such as avermectins or pyrethroids) are not approved for use on cannabis due to safety concerns, and spider mites have developed resistance to many of them in any case . Commercial cultivators need solutions that can knock down mites quickly and be used right up to harvest without contaminating the flowers.

Big Time Exterminator (BTE) is an example of a modern cannabis-safe miticide that meets these needs. It is a 99.999% organic contact pesticide designed for use on cannabis plants. BTE leaves no odor, taste, or lasting residue on the buds – it breaks down into inert components within about 48 hours of application. This means it can be applied even in the late flowering stage without fear of contaminating the harvest. In fact, BTE is labeled for daily use right up to the day of harvest if needed. This rapid degradation and lack of residuals are crucial for maintaining compliance with testing and ensuring a clean, safe final product. When spider mites threaten a valuable cannabis crop, growers require a fast-acting, “zero-residue” solution, and Big Time Exterminator is engineered to provide exactly that.

Beyond regulatory concerns, using a residue-free product like BTE also prevents any negative impact on bud quality. Oil-based sprays (e.g. neem oil) or sulfur can leave films, odors, or flavors on cannabis flowers and even “burn” pistils or terpenes late in bloom. By contrast, BTE’s formula contains no oils or heavy solvents – it is water-based and uses natural active ingredients – so it won’t damage trichomes or alter the taste/aroma of the buds when used as directed. For professional growers, this means problems like spider mites can be addressed aggressively without sacrificing product quality or marketability. In short, Big Time Exterminator allows for rapid eradication of mites with minimal downtime and no chemical after-effects, which is exactly what modern cannabis IPM programs demand.

Early Identification of Spider Mite Infestations Detecting spider mites early is critical to preventing full-blown outbreaks. Cannabis growers and IPM scouts should regularly inspect plants for the following tell-tale signs (in roughly the order they appear):

Speckled Leaves – Tiny Dots: The first evidence of spider mites is often faint white, yellow, or rust-colored specks on the tops of fan leaves. These pinpoint spots are mite feeding marks (where cells have been sucked dry) . They often appear in clusters or patches. Growers may mistake this stippling for nutrient deficiencies or heat stress at first, so it’s important to examine any speckling up close.

Mites on Undersides: Using a 10× hand lens or microscope, check the underside of affected leaves. Spider mites are extremely small (adults ~0.4 mm, about the size of a dust speck) and range from translucent yellowish to green with two dark spots (two-spotted mites) or even reddish-brown in color . You might see tiny slow-moving dots and even clear, spherical eggs attached to the leaf undersides or nestled in fine silk webbing . A classic scouting method is to tap or gently shake a leaf over a white sheet of paper – if mites are present, you’ll see tiny specks moving on the paper. Early on, mites tend to cluster on lower leaves and inner canopy where it’s dry and sheltered.

Leaf Discoloration and Damage: As the infestation grows, affected leaves will show increasingly heavy stippling (many specks merging), and may turn pale, yellow, or bronze in color . The foliage starts to look mottled or “rusty”. Edges of leaves might curl and the overall vigor of the plant declines. Heavily infested leaves eventually dry out to a crisp and die.

Webbing: Fine webbing on the plant is a late-stage sign of spider mites. Mites produce silk webbing both for protection and to help disperse to new leaves. You may first notice thin strands of web on the underside of leaves or between leaf petioles. In a severe infestation, a gauzy web can cover large portions of leaves, growing tips, and even buds. Spider mites get their name from this webbing. If you see webs, the mite population is very high – action is overdue. Webs often collect dust and mite droppings, giving the plant a dirty appearance .

“Burnt” or Ruined Buds: In the worst cases (typically if mites explode during flowering), entire colas can become encased in spider mite webs and massive numbers of mites. Buds may appear cobweb-coated, brown, or necrotic. Such flowers are unsalvageable – they will smell and taste foul due to the infestation and must be discarded. The goal is to never let it reach this stage by catching mites early.

Regular scouting is essential. Commercial growers should have an IPM scout or trained staff inspect plants at least once or twice weekly, especially in warmer, drier periods. Focus on high-risk areas: the lower canopy, plants near entrances/vents (mites often enter with incoming air or on workers’ clothes), and any “hot spots” where plants look stressed. Use magnification to check underside of a few leaves per plant. Also inspect any incoming clones or plant material rigorously, as clones are a common source of spider mite introduction . If even a single mite or egg is found, treat immediately and thoroughly – don’t wait for more evidence. Early detection and prompt response can literally save your crop, since minor infestations are far easier to control than outbreaks that are noticed late.

(Tip: Spider mites thrive in hot, dry, stagnant conditions. If you notice your grow room climate trending toward

high temperatures (>80–85 °F) and low humidity (<30% RH), be extra vigilant for mite symptoms, as these

conditions accelerate their reproduction. Also, always quarantine and inspect new clones from other facilities –

assume any incoming plant “has mites” until proven otherwise .)

Applying Big Time Exterminator (BTE) for Spider Mite Control Once spider mites have been identified, rapid and repeated treatment is crucial to eradicate them. Big Time Exterminator should be the centerpiece of your control program, providing a fast knockdown of mites at all life stages. Below is a step-by-step guide to using BTE effectively in a commercial cannabis grow:

1. Preparation and Dilution: BTE is a highly concentrated liquid and must be diluted in water for foliar application. The manufacturer’s recommended dilution for foliar spray ranges from 30 mL to 175 mL of BTE per gallon of water, depending on pest pressure. For an active spider mite infestation, start around the middle-to-high end of this range – a common mix is ~80 mL per gallon of water. (In severe cases with dense canopy or mite webs, some growers go up to 150–175 mL/gal for extra power.) Always mix thoroughly in clean, cold water – using cold water can improve efficacy as mites are sluggish at cooler temperatures. The BTE solution is slightly acidic; ensure the final spray solution is roughly pH 6.0–7.0 for optimal results.

2. Spraying Technique: Apply BTE as a foliar spray to all affected and surrounding plants. For best results, use an atomizer or misting sprayer that can generate a very fine droplet – this helps distribute the product evenly and reach mites hiding on leaf undersides. It’s recommended to spray at lights-off (night cycle) or after natural sunset in greenhouse grows. This prevents the spray from drying too quickly or “burning” leaves under intense light. In indoor facilities, turn off HPS/LED lights and let the area cool slightly before spraying (BTE works best at normal room temps, not when leaves are heat-stressed). Thorough coverage is key: drench every plant from top to bottom, including the undersides of leaves and deep into any buds (if in flower) where mites are present. Mites often hide in crevices, so take time to cover all surfaces. Avoid spraying so heavily that runoff drips, but the foliage should be uniformly wet.

3. Environmental Considerations: After spraying, increase air circulation in the grow area to help plants dry and to avoid excessive humidity (which can invite mold in flowering plants). If you are in mid-to-late flowering (week 5 or later), it’s especially important to use fans or ventilation after spraying to ensure buds dry promptly. BTE leaves no oily residue, so it evaporates cleanly, but the added moisture from spraying large canopies needs to be managed. Do not spray BTE in direct sunlight or with grow lights on, as intense light on wet leaves can cause phototoxic stress. Always wear appropriate PPE (mask, goggles, gloves) when spraying in enclosed spaces, even though BTE is organic – you want to avoid breathing in mist or getting it in your eyes.

4. Frequency of Application: Spider mite eggs hatch fast, so a single treatment is not enough. Plan to repeat the BTE spray once per day (or every 2 days at minimum) for a 10–14 day period to hit multiple mite generations. Consistent daily spraying ensures that as new eggs hatch, the larvae are immediately killed before they can mature and lay more eggs. In practice, many growers do an initial heavy application, then follow up daily for about 1 week, and then continue every 2–3 days in the second week as populations decline. Monitor the plants closely – you should see a dramatic reduction in live mites after the first 1–3 treatments. If any pockets of mites survive, maintain the daily spray regimen for the full two weeks. Do not discontinue early even if you don’t see mites; their eggs or juveniles could be quietly waiting. After two weeks, if no mites are observed, you can taper to a preventative maintenance spray (see IPM section).

5. Late-Flowering and Harvest Considerations: One of BTE’s greatest advantages is that it is safe to use in flowering, even late in bloom. It contains no persistent chemicals and breaks down within 48 hours, so it will not leave residues on buds. The label permits use up to 2–3 days before harvest with no adverse effects on the crop. In emergency scenarios, growers have even used it the day of harvest to knock off mites, then allowed buds to dry, with no residue or flavor carried into the final product. While it’s best to control mites well before harvest, it’s reassuring that BTE can be a “clean-up” spray in final days if needed. After spraying, re-entry interval (REI) for workers is minimal – once the spray has dried (usually within an hour or two), it is safe for staff to work among the plants since BTE’s ingredients are non-toxic to people (only 0.01% of it is a mild food-grade preservative). Always follow any state or local worker safety guidelines, but generally BTE does not require a long wait before re-entry (unlike many chemical pesticides that have 4- hour or 12-hour REIs). 

6. Optional – Pre-Rinse for Heavy Webbing: If plants are completely covered in webbing (e.g. you caught the infestation very late), an effective tactic is to pre-rinse or “knock down” webs with plain water before applying BTE. For example, using an atomizer or garden hose set to a fine mist, spray the plants with icecold water first. Spider mites are stunned by cold water (they hate temperatures below ~45 °F) and many will be physically dislodged. This also helps wash off dust, debris, and some webbing from leaves, improving BTE’s contact with the remaining mites. After letting the water drip dry for ~30 minutes, follow up immediately with a thorough BTE spray as described. This two-step approach (cold water then BTE) can be very useful in extreme infestations or when dealing with microscopic mites like russet mites in addition to spider mites. It essentially “cleans the canvas” for BTE to work most effectively. By following these steps, Big Time Exterminator will act quickly to eliminate active spider mites, nymphs, and eggs on contact. It is both a curative and preventative treatment, meaning that a full course of applications will not only cure the current outbreak but also protect the crop from re-infestation during that period. Always remember to calibrate sprayers, cover all plant surfaces, and maintain the schedule – consistency is key to wiping out mites for good.