The Laboulbeniomycetes are a unique group of fungi that are apparent external parasites of insects and other arthropods, both terrestrial and aquatic. These fungi are minute; their fruting bodies commonly measure less than one millimeter. They live on the antennae, the mouthparts or other body regions of their arthropod hosts. Although several species of Laboulbeniomycetes have more or less extensive, root-like hyphal systems (haustoria) inside their hosts, as a group these fungi are apparently harmless to the animals they live on. These fungi are usually apparent only on adult hosts; apparently immature arthropods eliminate them during ecdysis (adult arthropods no longer molt). Some fungi in the Laboulbeniomycetes have separate female and male individuals, like Herpomyces. Divisions Chytridiomycota Deuteromycota Zygomycota Glomeromycota Ascomycota Basidiomycota Fungus growing on a tree in Borneo A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... Classes & Orders See taxonomy Insects are invertebrate animals of the Class Insecta, the largest and (on land) most widely-distributed taxon within the phylum Arthropoda. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Haustorium, plural Haustoria, is the hyphal tip of a parasitic fungus that penetrates the hosts tissue, but stays outside the host cell membrane. ... Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). ...

In the micrograph above, two flask-shaped, about 0.3 mm long female fruting bodies of Herpomyces periplanetae can be seen. They are full of ascospores. Between them, there are two short, finger-like male individuals. Below, a part of a striated foot cell is visible. In nature, the fruiting bodies sit on the foot cell, which lays on the insect's antennae. Herpomyces periplanetae is a very widespread parasite on the antennae of adult cockroaches in the genus Periplaneta, like the common American cockroach, Periplaneta americana. An ascospore is a spore contained in an ascus or that was produced inside an ascus. ... Families Blaberidae Blattellidae Blattidae Cryptocercidae Polyphagidae Nocticolidae Cockroaches are insects of the order Blattodea (the name Blattaria is sometimes used). ... Binomial name Periplaneta americana Linnaeus, 1758 The American Cockroach (Periplaneta americana) is a large species of cockroach, winged, and growing to a length of 1-1 1/2. It is very common in the southern United States, and in tropical climates, and can be found in many locations throughout the...