Why isn’t the Asian ladybug also killed by this fungal parasite? Currently, the best hypothesis that accounts for their resistance is the high concentration of a chemical called “harmonine” in the hemolymph (blood) of this bug. Harmonine is a broad spectrum anti-microbial agent and it may be this chemical that enables the Asian ladybug to survive most new pathogens it comes in contact with in its new habitats. Indeed the organisms that cause tuberculosis and malaria are both inhibited by this drug making it potentially useful in our efforts to design better therapeutic drugs to combat these widespread and difficult to treat human diseases.
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