Important Dates zDecember 6th – Last lecture. zDecember 12th – Study session at 2:30? Where? Fungi-Insect zDecember 13th – Final Exam: 12:00-2:00

Fungi-Insect Symbiosis Fungi-Insect Symbiosis zMany examples of fungi-insect zMany examples of fungi-insect symbiosis. symbiosis (continue). zCover the following examples zInsects that cultivate fungi: „ – Class of „Attine Ants . Mostly on insects. „Septobasidium – of „Mound Building Termites „Ambrosia

Laboulbeniomycetes Laboulbeniomycetes zAscocarps occur on very specific zVery poorly known example. localities in some species: zRelationship between fungi and insects unclear. One species parasitic? „Species of this probably occurs on all insects „Fungus is a member of Ascomycota

zRickia dendroiuli Only found on forelegs of millipedes

1 dendroiuli Rickia dendroiuli

Mature ascocarp

zLow magnification showing three ascocarps zHigh magnification showing two ascocarps, as seen through the microscope. left is mature

Laboulbeniomycetes Laboulbeniomycetes zIn some species specific localities zVariations were based on mating habit misleading. For example: of insects involved. „In some insects, “species A” may have ascocarps arising only on front, upper pair of legs of males „However, “Species A” have ascocarps arising only on the back, lower pair of legs of females of same insect species.

Peyritschiella protea protea

zAscocarps not zHigh magnification always in specific of ascocarps and localities. ascospores.

ascocarps and ascospores

2 majewski Stigmatomyces majewskii

zLow and high z Ascocarps occur magnification mostly on of ascocarps. segment. zNote one on wing.

Laboulbenia cristata cristata zAscocarps occur on zHigh magnification middle segment of ascocarp with legs. ascospores.

SeptobasidiuSeptobasidiumm SeptobasidiuSeptobasidiumm zGenus of Basidiomycota that forms a zMore examples: symbiotic relationship with scale insects. zSuperficially, appears to be a wood decomposing fungus.

3 SeptobasidiuSeptobasidiumm SeptobasidiuSeptobasidiumm zMore examples: zMore examples:

Septobasidium zMuch more complex. Septobasidium

„Scale insects live within fungus Scale insect fruitbody. Suctorial Tube „Scale insects are “sap suckers”, parasitic on tree that they live. Branch „Suctorial tubes enter wood and food conducting tissue.

L-section through branch, insect and fungus

Development of Symbiosis Septobasidium zFungus and insect can over winter. zFungus growth surrounds scale insects. zSpring time female lays eggs zFungus obtains food from insects with z haustoria. Larvae produced can do three things: zBut…Not just a parasitic relationship: „Go to adult stage and stay within „Fungus protects and houses original colony. „ insect from harsh environment. Leave and join another colony „Insect protected from predator, „When leaving colony, basidiospores i.e. birds. will attach to insect and new colony „Scale insects in relationship live will start if it does not join a pre- longer than free counter-parts. existing one

4 Emerging insect Colonial Insects and Fungi

zSome social insects cultivate fungi as source of food. „Evolution of fungi cultivation parallels that of origin of agriculture: Insects once gathered their food. Evolved means of cultivating fungi. Insects gather plant material to cultivate fungi and eat fungus.

L-section through branch, insect and fungus

Colonial Insects and Fungi Attine Ants zSeveral species of ants that cultivate zWill look at two examples: fungi, Attine Ants most highly evolved. „ Attine Ants (Leaf Cutting Ants) zAttine ants can devastate landscape „Mound Building Termites that is in their path of travel. zBoth examples have complex society. „Often strip bare area that they are going through: zFungus is always a Basidiomycota and Makes taking food back to colony usually a mushroom species. easier. zMycelium is utilized for food and not Strip all leaves on trees for mushroom. cultivating fungus.

Attine Ants Attine Ant

zAttine ants cleared path.

ants by ared cle Path zCalled Cutter Ants because they cut leaves into pieces before carrying them back to colony.

5 Attine Ants Attine Ants zComplex caste system exist in this zWorkers cut up plants and carry them species of ants. back to colony. zThere are several classes of soldiers.

„From l-r: Soldier, and major, media and minor workers. Minim not shown.

Attine Ants Attine Ants zWorker carrying a leaf back to colony. zMinim Workers protects larger workers from parasitic fly

Attine Ants Attine Ant zColony may consist of millions to tens of million workers. zColony several cubic meters, extending 100 to 200 meters along trails. zPlant material taken to fungus farm and packed with ant feces onto fungus. zFungus farm is “pure culture” and kept clean by: „Workers weeding farm. „Antibiotics produced by gland on z worker evolved to keep out weed fungi. Workers caring for fungus farm.

6 Attine Ants Attine Ant zWhy grow a fungus garden? „Plant material cannot be used for food. Why? Bromatia: nutritional bodies formed by „Fungus can utilize plant material for fungus food and ants can then eat fungus. „Fungus produce nutritional bodies called gongylidia or bromatia that are eaten by ants. zFungus evolved bodies for feeding ants.

Attine Ant Attine Ants zThe queen stays in the fungus farms Queen where she lays her eggs. zWhen eggs hatch and larvae emerge, nurse workers feed larvae bromatia of fungus. zEggs hatch mostly into workers, but some reproductive males and new queens also produced.

z Queen (top-left), New queen and male right.

Attine Ants Mound Building Termites zFungus does not produce mushrooms zThe mound building termites play an while colony active. important role in recycling. zAfter colony abandons nest, mushrooms zUnlike Attine Ants, termites have can form: symbiotic in gut that allows them to digest wood and other plant material. zNative to old world tropic. zCommon name is from the large mounds they build. Lepiota cristata zImportant for maintaining temperature Leucocoprinus luteus control.

7 Mound Building Termites Mound Building Termites zTermite mound, note size comparison to people.

L-section of termite mound

Mound Building Termites Mound Building Termites

zAs in case of Atta Ants, complex social system also exist. z Queen surrounded by many workers. zSoldiers and workers shown above.

Mound Building Termites Mound Building Termites zFormation of new colonies same as in ants: zAlthough they can eat wood, they „ grow fungi for additional food. Most eggs will give rise to workers. They are females, blind and wingless „Fecal material is saved in chamber „ for fungus growth. Some will be soldiers can see, „Some cellulose remains in feces. females, but wingless and can produce acid in mandible areas „Fungus utilize remaining cellulose in feces and termites will eat fungus. „Reproductive have wings, can see and are male and female. zMale and females, with fungus, swarm and start new colony

8 Ambrosia Fungi Ambrosia Fungi zSo called ambrosia fungi symbiotic with zFungus (ambrosia) provides food for scolytid beetles. beetles as well as larvae that will hatch zFemale beetles bore into living trees from eggs. and take with them ambrosia fungus. zFungus species may be specific for zFungus is carried in specialized species of beetles. structure: mycangium. zSome species have proven harmful to zLocation of mycangia differs in some trees, e.g. Dutch Elm Disease. different species of beetles. zFungus pure when beetles are zBeetle prepares feces and wood litter maintaining it, but contaminated after for growing fungus, along tunnels. leaving.

Ambrosia Fungi Ambrosia Fungi

Asian Ambrosia larvae Adult and eggs and ambrosia fungus

Ambrosia Fungi

Beetle gallery

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