Trojan Horse Microbes: Future of Biological Pesticides?

Researchers from AIST, UEC, and Akita Prefectural University discovered a new insect pathogen that mimics bug symbionts to invade their gut symbiotic organ and kill the host.

Many pests depend on internal symbiotic microorganisms for vital functions, including nutrients missing from their diets.

The pathogen enters from soil, uses the same “wrapping motility” as symbionts to reach the symbiotic organ, then proliferates, breaches the organ, spreads into the hemolymph, causes sepsis, and kills nearly all host bugs within 10 days. This is the first known insect pathogen to kill by colonizing a symbiotic organ while posing as a symbiont, suggesting potential for eco-friendly pest control.

Background

Pests harm crops, food, and sanitation. While chemical pesticides are widely used, concerns about biodiversity and resistance have increased interest in biological pesticides, which target pests more specifically and with less environmental impact.

Many pests rely on symbiotic microorganisms for nutrition, digestion, survival, growth, and reproduction. Some insects evolved symbiotic organs to maintain these microbes.