Tagged: insect

fungal interactions with insects

Elm Bark Beetle galleries 0

#228: Dutch Elm Disease

Elm trees were once the defining tree of American life, widely planted in cities, suburbs, and farms.  This changed beginning in the early 1900’s when Dutch Elm Disease arrived on the continent.  Caused by the fungi Ophiostoma ulmi and O. novo-ulmi, Dutch Elm Disease blocks off the water transportation tissues in elm trees, leading to wilting and death.  The fungus moves between trees by using elm bark beetles as vectors and by growing from tree to tree, making it a difficult pathogen to control.  The best way to manage Dutch Elm Disease today is by planting resistant cultivars – fortunately, there are many resistant options available.

Massospora cicadina infected cicada 0

#221: Massospora cicadina

It’s hard being an insect. Despite being numerous, insects have many predators, have to deal with human pesticides and cars, and are susceptible to dreadful fungal pathogens. Some of these entomopathogenic fungi take control of their hosts’ bodies in innovative but disturbing ways. One such fungus is Massospora cicadina, which infects periodical cicadas (Magicicada spp., which appear in eastern North America every 13 or 17 years). After spending over a decade in the soil waiting for its hosts to emerge, the fungus infects the cicadas and causes their abdomens to pop off. The cicadas then fly around and try to mate with each other, spreading the fungal infection both through the air and through contact. It’s hard to imagine a more horrific sexually transmitted infection, even in the insect world.

Pleurotus ostreatus 1

#021: Pleurotus ostreatus, The Oyster Mushroom

Pleurotus ostreatus, the “Oyster Mushroom,” is the quintessential pleurotoid mushroom: it is a gilled mushroom with a very short stalk that fruits from the sides of logs. Oyster Mushrooms are some of the best edible wild mushrooms; they are fairly easy to identify, they are meaty, and they appear in large numbers. Additionally, you find them in late fall and winter, when the woods are otherwise boring places for mushroom hunters. Although it grows on hardwood logs in nature, P. ostreatus will decompose pretty much any plant material, which makes it very easy to cultivate. As an added bonus, the Oyster Mushroom attacks nematodes. That’s one cool mushroom, right?

Boletinellus merulioides 1

#143: Boletinellus merulioides, the Ash Tree Bolete

Boletinellus merulioides is an odd mushroom, both in appearance and ecology. The Ash Tree Bolete can be readily identified by its tube surface – which is only a few millimeters thick and looks more like a network of ridges – and by the fact that it fruits under only ash trees. B. merulioides appears under ash because it has a unique symbiotic relationship with a pest of ash trees: the Leafcurl Ash Aphid.

Sirex noctilio female 0

#169: Sirex Woodwasp

Sirex noctilio, known as the “Sirex woodwasp” or “European woodwasp” (sometimes spelled “wood wasp”), is an invasive species that attacks most species of pine trees. Interestingly, the insect is dependent upon the fungus Amylostereum aerolatum to complete its life cycle. The Sirex woodwasp carries the fungus with it to new trees and in return the fungus becomes a meal for the Sirex woodwasp’s larvae.

#143: Boletinellus merulioides, the Ash Tree Bolete [Archived] 0

#143: Boletinellus merulioides, the Ash Tree Bolete [Archived]

Note: This is an archived post. You can find the current version of this post here. Boletinellus merulioides is an odd mushroom, both in appearance and ecology. The Ash Tree Bolete can be readily identified by its pore surface – which is only a few millimeters thick and looks more like a network of ridges – and by the fact that it fruits only under ash trees.  merulioides appears under ash because it has a unique symbiotic relationship with a pest of ash trees: the Leafcurl Ash Aphid.

#116: Scorias spongiosa 1

#116: Scorias spongiosa

This bizarre fungus forms a fuzzy mat of tan to black tissue on the branches, trunks, and ground underneath American Beech trees. Scorias spongiosa belongs to a group of fungi called “sooty molds.”  Sooty molds digest the honeydew (essentially sugar-rich aphid poop) dropped by aphids in the process of feeding on plants.  There are many kinds of sooty molds and if you’ve ever had an aphid (or other insect) infestation on trees in your garden, they you’ve probably seen sooty molds.  Normally, sooty molds form a thin, black film on leaves and branches under places where the aphids are feeding.  spongiosa differs from normal sooty molds because it forms films that can be as thick as a football!

#066: Ophiocordyceps sinensis 1

#066: Ophiocordyceps sinensis

This fungus parasitizes caterpillars in the Himalayas and produces small, spike-like mushrooms. These mushrooms are highly prized for their supposed medicinal properties and have brought a lot of new wealth and new problems to the people living in the Himalayas.  Ophiocordyceps sinensis fruiting bodies are known as “Yartsa Gunbu” in Tibetan and “D­ōng Chóng Xià Cǎo” in Chinese, both of which translate to “winter worm, summer grass.”  The English names for the fungus are much less colorful: “Caterpillar Fungus” or (more recently) “Himalayan Viagra.”  sinensis (Fungi, Ascomycota, Sordariomycetes, Hypocreales, Ophiocordycipitaceae) is native to the meadows of the Himalayas and Tibetan plateau and can be found from 3,000m to 5,000m above sea level.  The parasitic fungus infects a variety of species of ghost moth larvae that live underground.  It initially infects the caterpillars in the late summer.  By winter, the fungus is ready to kill its host.  At that time, it...

#058: Cordyceps militaris: the Scarlet Caterpillar Club 1

#058: Cordyceps militaris: the Scarlet Caterpillar Club

Cordyceps militaris is a fascinating fungus that infects caterpillar and moth larvae. What’s the creepiest thing about this fungus?  It mummifies its insect victims.  I’ve been told that it also makes its subterranean victims crawl to the surface so that it can more effectively release its spores, but I can’t find anything online to back that up.  Instead, everyone seems to want me to buy militaris (more on that later).  The Scarlet Caterpillar Club infects the larvae and pupae of a variety of caterpillars and moths.  Before they emerge as adults, the host insects live either underground or in decaying wood, so C. militaris mushrooms often look like a generic club fungus or earth tongue look-alike.  If you dig beneath the surface, however, you will find the mummified remains of the host insect, which provide the nutrients that C. militaris needs to produce spores.  Like other members of the Cordyceps...