✅ These diseases are common in insect farms.
🚩 Nudivirus Infection (Photo courtesy of a Korean website)
Pathogen: Oryctes rhinoceros nudivirus
Cause: Occurs when larvae ingest contaminated substrate.
Characteristics: Has a long incubation period before death.
Symptoms:
▪ Early stage: The skin turns milky white, and the lower abdomen becomes swollen.
▪ Mid/Late stage: The swollen abdomen becomes soft, and the larva climbs to the surface and dies.
▪ After death: The body turns dark brown as internal decay begins.
Action: Remove and incinerate infected larvae immediately to prevent spread. Disinfect containers and tools thoroughly, replace with a clean substrate,
and maintain good hygiene to prevent further infections.
🚩 Bacterial Disease (Soft Body Syndrome) (Photo courtesy of a Korean website)
Pathogen: Serratia entomophila
Cause: Occurs when larvae ingest contaminated substrate.
Characteristics: Highly lethal, almost always fatal once infected.
Symptoms:
▪ Early/Mid stage: The body becomes transparent and loses its shine.
▪ Late stage: The body softens, becomes jelly-like, and the larva climbs to the surface and dies.
▪ After death: The body turns dark brown and starts to rot internally.
Action: Remove and burn infected larvae immediately. Disinfect the container and all equipment with disinfectant and replace with clean substrate to stop the spread.
🚩 Green/White Mold Disease (Metarhizium Infection) (Photo courtesy of korean website)
Pathogen: Metarhizium anisopliae / Beauveria bassiana
Cause: Poor hygiene, leftover food, or high-heat/high-humidity environments, above 28°C (82.4°F) and 70% RH
Characteristics: Longest incubation period among mold-related diseases.
Symptoms:
▪ Around day 8 post-infection, large dark patches appear on the larval skin, followed by death.
▪ Dead larvae become stiff and develop deep green mold spores (conidia) on the skin.
Action: As soon as infection is confirmed, seal the container and remove it from your rearing area to avoid spore spread. Disinfect the entire container and contents thoroughly and dispose of it by incineration.
📌 Even if other larvae in the same container show no symptoms, do not reuse the substrate or raise them further, discard everything.
🚩 Black Spot Disease (Photo courtesy of Japanese website Queen Beetles)
Cause: Exact cause is unknown. Suspected factors include excessive stress,
fungal infection (Metadium-type mold), or even genetic predisposition.
Symptoms:
▪ Black spots appear on the body.
▪ In severe cases, the spots may spread throughout the body and lead to death.
▪ Survival depends on the individual's physical strength or immunity. If it occurs in the head capsule or L1 larvae, it is fatal.
But in most cases, larvae grow and pupate normally.
Action: Keep larvae individually housed on clean substrate to prevent the spread of infection. 
🚩 Mites (Photo courtesy of korean and Japanese websites ドルクス赤羽＆ダイナステス赤羽 / shiho)
Cause: Unhygienic substrate or contaminated rearing environment.
Symptoms:
Mites feed on the insect’s bodily fluids, which can result in.
▪ Stunted growth
▪ Weight loss
▪ Reduced activity
▪ Shortened lifespan
Action: Remove visible mites from the body using a soft brush or rinse them off gently with water. As mites often originate from the substrate, make sure to sterilize or freeze the substrate before use to kill any eggs or mites hiding within.
