The spiciness of red hot chili peppers is a defense mechanism against a microbial fungus that these fruits through punctures made in the outer skin by insects. The fungus, from a large genus called Fusarium, destroys the plant's seeds before they can be eaten by birds and widely distributed. Now, Joshua Tewksbury, a University of Washington, and colleagues have found that not all individual plants of the same species produce the hot capsaicinoid compounds to the same levels. In the same plant population they found that fruit on one plant could be hotter than a jalapeno while fruit from other plants of the same species might be as mild as a bell pepper. However, the key factor was that the hottest peppers came from plants exposed to larger populations of hemipteran insects that attack the chilies and leave them more vulnerable to fungus. The finding could lead to new ways to control the heat of chilis and perhaps grow even hotter peppers.
Bugging red hot chili peppers