We’ve all heard of human mummies, and even animal mummies such as cats preserved by the Ancient Egyptians. Did you know insects and plants can have mummies too?
Brown rot forms mummies of stone fruits, including peaches, nectarines, and cherries. This fungus causes the fruits to shrivel up, forming a fruit mummy. The pathogen survives in the mummies, which act as the source of inoculum for next year’s infection. A related fungus causes “mummy berry disease” of blueberries, though this is not common in Illinois.
Insects can also be mummified, not by fungi but by other insects. A quick glance at the picture on the left, and it appears that aphids are infesting the plant tissue. However, if you look closer, you’ll notice that the aphids don’t appear to be very healthy. In fact, they’re no longer living. A tiny parasitic wasp laid an egg in the aphid’s body. This egg hatched, and the larvae ate its host from the inside. When it was time for the parasite to emerge, it created a perfectly circular porthole in the host’s exoskeleton as an exit, seen in the picture on the right. Parasitic wasps are a form of natural control of aphids, and no insecticides were recommended for this situation as the aphids were almost all dead, making the insecticides at best unnecessary and at worst harmful the beneficial parasitic wasps.