Pests
Arthropod and invertebrate pests, identification, life cycles, damage patterns, monitoring, and intervention context.
Published lessons
These pages are organized here by subject. The permanent THC-ENC IDs remain stable behind the scenes even when a clearer display title is used.
Pest Identification by Life Stage and Injury Pattern
Build a repeatable arthropod-identification workflow that combines life stage, body form, feeding injury, location, magnified evidence, and population trend before assigning a pest identity or control response.
Two-Spotted Spider Mites
Identify two-spotted spider mite life stages and feeding injury on cannabis or hemp, distinguish active infestation from old damage and other stippling causes, and document population change without relying on a universal action threshold.
Hemp Russet Mites
Recognize hemp russet mite as a microscopic cannabis-associated eriophyid, distinguish its life form and injury from spider mites, broad mites, disease, and abiotic stress, and document confirmation at an evidence level appropriate to its minute size.
Broad Mites
Identify broad mite life stages and characteristic growing-point injury, distinguish Polyphagotarsonemus latus from hemp russet mite, spider mite, herbicide, nutrient, viral, and environmental differentials, and document confirmation at appropriate magnification.
Western Flower Thrips and Related Thrips
Identify western flower thrips and related thrips using life stage, body form, feeding injury, fecal evidence, tissue location, and specimen-level characters while distinguishing thrips injury from mites, abrasion, phytotoxicity, nutrient disorders, and plant disease.
Cannabis Aphids
Identify cannabis aphid, Phorodon cannabis, from life stage, colony pattern, honeydew, host association, and specimen characters while separating aphid presence from virus diagnosis or an automatic treatment decision.
Other Aphid Species on Hemp and Cannabis
Distinguish cannabis aphid from other aphids that may probe, colonize, or be recovered from hemp and cannabis, and document host suitability, colony persistence, and identification confidence before assigning pest significance.
Whiteflies
Identify whiteflies on hemp or cannabis from adults, immature stages, honeydew, and leaf-location evidence while distinguishing feeding injury from whitefly-transmitted disease and avoiding unsupported universal thresholds.
Fungus Gnats
Identify dark-winged fungus gnats by adult and larval morphology, separate nuisance adult activity from root-zone larval risk, and use moisture, media, and direct larval evidence to interpret plant injury.
Shore Flies
Identify shore flies and separate their algae-associated nuisance biology from fungus-gnat root feeding, while documenting moisture, algae, fecal spotting, and possible pathogen-association evidence without assuming direct plant feeding.
Leafminers
Recognize leaf-mining injury on hemp or cannabis, distinguish agromyzid fly mines from caterpillar or beetle mines and early skeletonization, and document the organism responsible before assigning pest significance.
Caterpillars and Bud-Feeding Larvae
Identify important lepidopteran larval injury on hemp or cannabis by larval morphology, feeding site, frass, boring pattern, and adult-monitoring evidence while distinguishing defoliators, stem borers, and flower-feeding larvae.
Beet Leafhoppers and Virus Vectoring
Identify beet leafhopper risk in hemp by separating vector detection, host use, and Beet curly top virus confirmation, and use current hemp research to interpret vector presence without equating insect capture with disease.
Root Aphids and Soil-Dwelling Pests
Recognize root-associated aphids and other soil-dwelling invertebrates on hemp or cannabis by sampling the root/media zone, distinguish them from canopy aphids and non-pest soil organisms, and separate pest evidence from root-disease diagnosis.
Slugs, Snails, and Outdoor Seedling Injury
Recognize slug and snail feeding as one cause of outdoor seedling injury by combining chewing pattern, slime trails, shelter/moisture conditions, and direct nocturnal evidence while separating mollusk injury from caterpillars, earwigs, beetles, damping-off, and mechanical damage.
Ants, Wasps, and Secondary Pest Indicators
Interpret ants, wasps, and other conspicuous insects in hemp or cannabis as possible pests, natural enemies, scavengers, or indirect indicators, and confirm their ecological role before assigning damage or control significance.
Sticky Cards, Tap Tests, and Leaf Sampling
Use complementary pest-monitoring methods correctly by defining what sticky cards, tap or beat samples, direct leaf inspection, and root/media samples can and cannot measure, and standardize observations so trends are comparable over time.
Action Thresholds and Crop-Value Context
Use action thresholds as evidence-based decision tools rather than universal pest numbers by linking monitoring data to crop stage, market, injury tolerance, pest biology, natural enemies, and local historical outcomes.
Biological Control Compatibility
Evaluate whether pest-management actions, prior residues, environmental conditions, and scouting tools are compatible with predators, parasitoids, and microbial biological-control agents without assuming that any product or beneficial organism is universally compatible.
Pest Records, Mapping, and Trend Analysis
Turn scouting observations into comparable records, spatial maps, and time-series trends that distinguish hotspots, spread, treatment response, and sampling artifacts while preserving uncertainty and diagnostic traceability.