Insects Three insect lineages, beetles, ants and termites, independently evolved the ability to farm fungi between 40 and 60 million years ago. In a similar way to the way that human societies became more complex after the development of plant-based agriculture, the same occurred in these insect lineages when they evolved this ability and these insects are now of major importance in ecosystems. The methods that insects use to farm fungi share fundamental similarities with human agriculture. Firstly, insects inoculate a particular habitat or substrate with fungi, much in the same as humans plant seeds in fields. Secondly, they cultivate the fungi by regulating the growing environment to try to improve the growth of the fungus, as well as protecting it from pests and diseases. Thirdly they harvest the fungus when it is mature and feed on it. Lastly they are dependent on the fungi they grow, in the same way that humans are dependent on crops.
Beetles '' split open, with larvae and black fungus
Ambrosia beetles, for example
Austroplatypus incompertus, farm
ambrosia fungi inside of trees and feed on them. The
mycangia (organs which carry fungal spores) of ambrosia beetles contain various species of fungus, including species of
Ambrosiomyces,
Ambrosiella,
Ascoidea,
Ceratocystis,
Dipodascus,
Diplodia,
Endomycopsis,
Monacrosporium and
Tuberculariella. The ambrosia fungi are only found in the beetles and their galleries, suggesting that they and the beetles have an
obligate symbiosis. The fungus grows into this material and soon produces immature mushrooms, a rich source of protein, sugars and enzymes, which the worker termites eat. The nodules also contain
indigestible asexual spores, meaning that the faecal pellets produced by the workers always contain spores of the fungus that colonise the plant material that they defaecate. The
Termitomyces also fruits, forming mushrooms above ground, which mature at the same time that the first workers emerge from newly formed nests. The mushrooms produce spores that are wind dispersed, and through this method, new colonies acquire a fungal strain.
Ants Around 220
described species, and more undescribed species of ants in the
tribe Attini cultivate fungi. They are only found in the
New World and are thought to have evolved in the
Amazon rainforest, where they are most
diverse today. For these ants, farmed fungi are the only source of food on which their
larvae are raised on and are also an important food for adults.
Queen ants carry a small part of fungus in small pouches in their mouthparts when they leave the nest to mate, allowing them to establish a new fungus garden when they form a new nest. Different lineages cultivate fungi on different substrates, those that evolved earlier do so on a wide range of plant matter, whereas
leaf cutter ants are more selective, mainly using only fresh leaves and flowers. The fungi are members of the families
Lepiotaceae and
Pterulaceae. Other fungi in the genus
Escovopsis parasitise the gardens and
antibiotic-producing bacteria also inhabit the gardens.
Humans Gastropods The marine
snail Littoraria irrorata, which lives in the
salt marshes of the southeast of the United States feeds on fungi that it encourages to grow. It creates and maintains wounds on the grass,
Spartina alterniflora which are then infected by fungi, probably of the genera
Phaeosphaeria and
Mycosphaerella, which are the preferred diet of the snail. They also deposit faeces on the wounds that they create, which encourage the growth of the fungi because they are rich in nitrogen and fungal
hyphae. Juvenile snails raised on uninfected leaves do not grow and are more likely to die, indicating the importance of the fungi in the diet of
L. irrorata. == See also ==