By far the greatest number of fungi known to be associated with cockroaches belong to the Laboulbeniaceae, genus Herpomyces, the species of which are restricted to parasitizing cockroaches (Thaxter, 1908). Most species are hyaline, small and inconspicuous (Thaxter, 1931) and are usually, but not exclusively, found on the insects' antennae. Species of Herpomyces are highly, but not completely, host specific (Richards and Smith, 1954). While attached to the host, these fungi appear like minute dark-colored, yellow, or white (e.g., H. arietinus) bristles or bushy hairs (pl. 27, A).

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Richards and Smith (1955, 1955a) have studied the life history of Herpomyces stylopygae on the oriental cockroach. The plants grow only on living cockroaches, and the infection is disseminated by contact. The mature plants are found mostly on the antennae (pl. 27, B), either on setae or on hard or soft cuticle. Spores are ejected from perithecia singly or in groups of 2 to 4 spores, although groups as large as 12 spores have been found. The presence of single, paired, or multiple spore groups on the surface of the host was correlated with the presence of single, paired, or multiple plants on infected cockroaches. Development from spore to mature perithecia takes about two weeks. The plant obtains nutriment from the host by means of a tubular haustorium that extends through the cockroach's cuticle and expands into a large bulb in the underlying epidermal cells (fig. 1). Infections on nymphs are lost when the nymph moults, but infections on adults persist throughout life. However, nymphs which have lost the fungus upon moulting are readily reinfected. Collart's (1947) statement that nymphs are never infected with Herpomyces is not true.

Richards and Smith (1956) concluded that there is no evidence of pathogenicity in Herpomyces infections because heavily infected cockroaches appear fully active in laboratory colonies; they can run at the same speed as uninfected cockroaches; they reproduce normally and do not appear to die prematurely. These workers stated that the infections cause a dermatitis which is neither pathogenic nor debilitant. So far as we know there are no comparative data on longevity and reproductive performance of fungus-infected versus normal cockroaches. However, Gunn and Cosway (1938) have shown that the presence of these fungi (identified as Stigmatomyces sp.; see p. 138) on the antennae seemed to interfere with the humidity reactions of Blatta orientalis. Although Richards and Smith (1956) admit that humidity receptors and other sense organs on the antennae may be destroyed by the fungus, they state that "insects possess such a large number of sensilla that the result may well be more distressing to the sensory physiologist than to the insect." Yet it seems to us that the loss of sense organs from fungal infection and concomitant shortening of the antennae (pl. 27, A) might be considerably more of a handicap to free-living cockroaches than those in laboratory colonies.

Bode (1936) studied the flora of Periplaneta americana and cultured Aspergillaceae and Mucorinae from the insect's body surface and intestinal contents; he also found nonsporulating yeasts in P. americana. To prevent fungal growth on oÖthecae of P. americana, Griffiths and Tauber (1942a) autoclaved their rearing containers and dipped the oÖthecae in 70-percent alcohol for 10 seconds.

Mercier (1906) isolated and cultured a pathogenic yeastlike parasite which had invaded the fat body and blood of Blatta orientalis. The abdomens of the infected insects became swollen, distended, and soft. McShan (unpublished MS., 1953) consistently isolated Saccharomycetes from the feces of Periplaneta americana.

FUNGI ASSOCIATED WITH COCKROACHES

The use of the asterisk (*) is explained in footnote 3, page 4.

Phylum THALLOPHYTA

Class FUNGI IMPERFECTI

Order MONILIALES

Family PSEUDOSACCHAROMYCETACEAE

Candida zeylanoides(Castellani) Langeron and Guerra

Natural host.—OÖtheca of Blatta orientalis, Italy (Ronzoni, 1949).

Torulopsissp.

Natural host.—OÖtheca of Blatta orientalis, Italy (Ronzoni, 1949).

Family MONILIACEAE

Spicaria prasina(Maublanc) Sawada

Natural host.—Ischnoptera rufa rufa, Puerto Rico (Wolcott, 1950): A dead specimen of this cockroach was found stuck to a leaf and covered with this fungus.

Aspergillus flavusLink

Natural hosts.—OÖthecae of Blattella germanica and Eurycotis floridana, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): On outer surface. Determination by Miss Mary Downing.

OÖthecae of Periplaneta americana, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): Inside oÖthecae. Determination by Miss Mary Downing.

* Aspergillus fumigatusFresenius

Natural vector.—Blatta orientalis, France (Sartory and Clerc, 1908): From intestine.

* Aspergillus nigervan Tieghem

Natural vector.—Periplaneta americana, U.S.A., Texas (McShan in Roth and Willis, 1957a): From feces.

Experimental vector.—Blatta orientalis, Italy (Cao, 1898): Organism passed unchanged through the gut of the insects.

Aspergillus sydowi(Bainier and Sartory) Thom and Church

Natural host.—OÖtheca of Eurycotis floridana, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): On outer surface. Determination by Miss Mary Downing.

Aspergillus tamariiKita

Natural host.—OÖthecae of Blattella germanica, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): On exterior surface. Determination by Miss Mary Downing.

Aspergillussp.?

Natural and experimental vector.—Blattella germanica, on shipboard (Morrell, 1911): Isolated from feces. Experimentally Morrell also showed that the spores of the fungus could be recovered from feces of cockroaches that had fed on them.

Aspergillus sp.

Natural vector.—Periplaneta americana, England (Bunting, 1956): The fungus was isolated mostly from imperfectly excreted feces.

Beauveria bassiana(Balsamo) Vuillemin

Experimental host.—Blattella germanica and Periplaneta americana, U.S.A. (Dresner, 1949, 1950): The nymphs of American cockroaches became infected when they (1) were injected with a 1-percent suspension of spores, (2) ate rat pellets sprayed with the spore suspension, or (3) were dusted with the fungus spores. The symptoms of the fungus infection were paralysis followed by death; some of the infected insects liquefied, others dried up after the appearance of a subcuticular blackening.

Cephalosporiumsp.

Natural vector.—Periplaneta americana, U.S.A., Texas (McShan, unpublished MS., 1953): From feces of cockroaches collected in the basement of a grain elevator at the docks in Galveston.

* Geotrichum candidumLink

Experimental vector.—Blatta orientalis, Italy (Cao, 1898): Organism retained its pathogenicity after passing through the insect's gut.

Penicilliumsp.

Natural vector.—Blaberus craniifer, U.S.A. (Wedberg et al., 1949): From feces.

Periplaneta americana, England (Bunting, 1956): Mostly from imperfectly excreted feces.

Metarrhizium anisopliae(Metschnikoff) Sorokin

Natural hosts.—Blattidae, Seymour (1929); Charles (1941).

Panesthia australis, U.S.A., Massachusetts (Roth and Willis, unpublished data, 1957): Growing on adult specimens that were found dead in a laboratory colony. Determination by Miss Dorothy Fennell.

Periplaneta americana, England (Bunting, 1956): Growing on genitalia of females where it prevented oÖthecal formation.

Cockroach, Puerto Rico (Johnston, 1915): From a "small roach" in the pathological collection at Rio Piedras (no data).

Family DEMATIACEAE

Memnoniella echinata(Rivolta) Galloway

Natural host.—OÖtheca of Blattella germanica, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): On material that had oozed from a damaged oÖtheca. Determination by Miss Mary Downing.

Torula acidophilaOwen and Mobley

Natural host.—Periplaneta americana, U.S.A. (Owen and Mobley, 1948): The digestive tract of this cockroach is the normal habitat of this yeast which was transmitted to sirup by the insects. The yeast superimposed a foreign taste, suggestive of malic acid, upon the original flavor of the sirup.

Torula gropengiesseriLodder

Natural host.—Blatta orientalis, Germany (Gropengiesser, 1925; Lodder, 1934): Isolated from fat body and oÖthecae. Gier (1947) is of the opinion that the so-called yeasts that supposedly may displace the bacteroids in the fat body (Mercier, 1907b; Gropengiesser, 1925) may actually represent poorly fixed and insufficiently stained bacteroids.

Torula roseaPreuss

Experimental host.—Blaberus craniifer, U.S.A. (Wedberg et al., 1949): Upon repeated feeding of massive doses of this yeast to the cockroach, these workers were able to isolate the organism from the feces up to six days thereafter. There was no evidence that T. rosea was pathogenic for B. craniifer.

Class PHYCOMYCETES

Order MUCORALES

Family MUCORACEAE

Mucor guilliermondiiNadson and Filippov

Natural host.—Periplaneta americana, U.S.S.R. (Nadson and Filippov, 1925; Filippov, 1926): Isolated and cultured from intestine.

Mucorsp.

Natural host.—OÖtheca of Periplaneta americana, U.S.A., Pennsylvania (Roth and Willis, unpublished data, 1952): Inside oÖtheca. Determination by Miss Mary Downing.

Pycnoscelus surinamensis, Germany (Bode, 1936): Isolated from fat body which it had stained red.

Rhizopus nigricansEhrenberg

Natural vector.—Blaberus craniifer, U.S.A. (Wedberg et al., 1949): From feces.

Rhizopussp.

Natural vector.—Periplaneta americana, U.S.A., Texas (McShan, unpublished MS., 1953): From feces.

Syncephalastrumsp.

Natural vector.—Periplaneta americana, U.S.A., Texas (McShan, unpublished MS., 1953): From feces.

Order ENTOMOPHTHORALES

Family BLASTOCYSTIDACEAE

Blastocystis hominisBrumpt

Natural vector.—Blatta orientalis, U.S.S.R. (Zasukhin, 1930): In hind gut in 40 percent of over 3,000 cockroaches.

Blastocystissp.

Natural vectors.—Blatta orientalis, U.S.S.R. (Yakimov and Miller, 1922): Found in the intestinal contents of 29 percent of 124 B. orientalis.

Cockroaches, Venezuela (Tejera, 1926).

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The placement of the following fungus is problematic.

Coccidioides periplanetaeAvrech

Natural host.—Blatta orientalis, Germany (Avrech, 1931): Found in cells lining the lumen of midgut and caeca. The whole upper part of the epithelium was filled with sporangia and spores.

Class ASCOMYCETES

Order ENDOMYCETALES

Family SACCHAROMYCETACEAE

Saccharomyces cerevisiaeHansen

Natural vector.—Blaberus craniifer, U.S.A. (Wedberg et al., 1949): In feces.

Saccharomycessp.

Natural vector.—Blattella germanica, U.S.A. (Janssen and Wedberg, 1952): Found consistently in alimentary tract of B. germanica fed sucrose solutions.

Order HYPOCREALES

Family HYPOCREACEAE

Cordyceps amazonicaHennings

Natural host.—Cockroaches, British Honduras (Mains, 1940).

Cordyceps blattaePetch

Natural host.—Blattella germanica, Ceylon (Petch, 1924): Collected at Hakgala twice. A slight covering of brown mycelium overran the insect and fastened it to the underside of a living leaf.

Order LABOULBENIALES

Family LABOULBENIACEAE

Herpomyces amazonicusThaxter

Natural host.—Nyctibora obscura, Brazil, Natal (Thaxter, 1931): On antennae.

Herpomyces anaplectaeThaxter

Natural hosts.—Anaplecta sp., Venezuela, Caracas (Thaxter, 1905, 1908); Trinidad (Thaxter, 1931): On antennae.

Cockroach, Sumatra (Thaxter, 1931).

Herpomyces appendiculatusThaxter

Natural host.—Platyzosteria scabra, Australia, N.S.W. (Thaxter, 1931): On antennae.

Herpomyces arietinusThaxter

Natural hosts.—Ischnoptera sp., U.S.A., Georgia (Thaxter, 1908).

Parcoblatta uhleriana, U.S.A., Massachusetts (Roth, unpublished data, 1957): The nymphs were in a culture of Parcoblatta virginica which was infected with this fungus; it is possible that these P. uhleriana became infected by contact with P. virginica. Fungus identified by Dr. R. K. Benjamin.

Parcoblatta virginica, U.S.A., Massachusetts (Roth, unpublished data, 1957): Fungus determined by Dr. R. K. Benjamin. Fungus found on antennae, palpi, legs, body surface (pl. 27, A).

Parcoblatta sp., U.S.A., Kentucky, Massachusetts (Thaxter, 1902, 1908): On antennae.

It is likely that Thaxter's host records (certainly those assigned to Temnopteryx and possibly those assigned to Ischnoptera) were species of Parcoblatta. Hebard (1917) has shown that all the species referred to Ischnoptera in the United States, except I. deropeltiformis, now belong in the genus Parcoblatta. All species originally referred to the genus Temnopteryx in the United States are now synonymized with species of Parcoblatta.

Herpomyces chaetophilusThaxter

Natural hosts.—Periplaneta americana, Brazil (Thaxter, 1931).

Periplaneta sp., Zanzibar and Mauritius (Thaxter, 1902, 1908): On spines of legs, antennae, and cerci.

Herpomyces chilensisThaxter

Natural host.—Cockroach, Chile (Thaxter, 1918): On antennae.

Herpomyces diplopteraeThaxter

Natural hosts.—Diploptera punctata, Ascension Island (Thaxter, 1902, 1908): On antennae. This species also was infected experimentally (Richards and Smith, 1954).

Cockroach, Fiji (Thaxter, 1931).

Herpomyces ectobiaeThaxter

Natural hosts.—Blattella germanica, U.S.A., Massachusetts (Thaxter, 1902, 1908); Burma, Tenasserim (Spegazzini, 1915); Argentina, Buenos Aires (Spegazzini, 1917): On antennae. U.S.A., Minnesota (Richards and Smith, 1955): Scattered over entire body, wings. France? (Picard, 1913): On tibial spines. Chile and Philippine Islands (Thaxter, 1931).

"Ectobia" spp., Zanzibar and Saint Kitts, B.W.I. (Thaxter, 1902, 1908): Possibly on species that are now in the genus Blattella rather than in the genus Ectobius as it is known today, because Thaxter also used the synonym Ectobia germanica for the German cockroach, Blattella germanica.

Experimental hosts.—Blattella germanica and Blattella vaga, U.S.A. (Richards and Smith, 1954).

Herpomyces forficularisThaxter

Natural hosts.—Cockroaches, Mauritius? and Fiji (Thaxter, 1902, 1908, 1931): On antennae.

Herpomyces gracilisThaxter

Natural host.—Blattella humbertiana, Philippine Islands, Luzon (Thaxter, 1931): On antennae.

Herpomyces grenadinusThaxter

Natural host.—Cockroach, Grenada, B.W.I. (Thaxter, 1931): On antennae of a "brown wingless blattid."

Herpomyces leurolestisThaxter

Natural host.—Leurolestes pallidus, British Guiana and Trinidad (Thaxter, 1931): On antennae.

Herpomyces lobopteraeThaxter

Natural host.—Loboptera sp., Argentina (Thaxter, 1931): On antennae.

Herpomyces macropusSpegazzini

Natural host.—Blaberus sp.?, Argentina (Spegazzini, 1917).

Cockroaches, Peru, Puerto Rico, Ecuador, and Haiti (Spegazzini, 1915, 1917): Material previously assigned by Spegazzini (1915) to H. paranensis was also placed by him in this new species. However, Thaxter (1931) believed that H. macropus may be synonymous with H. paranensis, but he provisionally retained H. macropus because he had not seen Spegazzini's material.

Herpomyces nyctoboraeThaxter

Natural hosts.—Nyctibora tomentosa, U.S.A., Texas (Thaxter, 1905, 1908): On antennae. This cockroach is not established in Texas, and the specimen may have been misidentified (Gurney, personal communication, 1958).

Nyctibora sp., Argentina (Spegazzini, 1917): On antennae.

Herpomyces panchloraeThaxter

Natural hosts.—Panchlora nivea, Trinidad (Thaxter, 1931): On antennae.

Herpomyces panesthiaeThaxter

Natural host.—Panesthia lobipennis, Ceylon (Thaxter, 1915): On antennae.

Herpomyces paranensisThaxter

Natural hosts.—Blaberus sp.? Brazil (Thaxter, 1902, 1908): On antennae.

Blaberus sp., Brazil and Argentina (Spegazzini, 1917): On antennae.

Cockroaches, Trinidad and Argentina (Thaxter, 1931).

Herpomyces periplanetaeThaxter

Natural hosts.—Blaberus sp.?, Argentina (Spegazzini, 1917).

Blatta orientalis, U.S.A., Massachusetts (Thaxter, 1902, 1908); Locality? (Spegazzini, 1915); France? (Picard, 1913).

Periplaneta americana, Bermuda and U.S.A., Massachusetts (Thaxter, 1902, 1908); Plains of Biajar, Italian Somaliland, and Argentina (Spegazzini, 1915, 1917).

Periplaneta australasiae, Bermuda (Thaxter, 1902, 1908).

Periplaneta brunnea, Brazil (Thaxter, 1931).

Periplaneta sp., Mexico, West Indies, Panama, Brazil, Africa, South Seas, and China (Thaxter, 1902, 1908).

Cockroaches, Belgium (Collart, 1947).

Additional locality records: Grenada, Trinidad, B.W.I., and Tangier (Thaxter, 1931).

The fungus was found growing on spines, tegmina, integument, and antennae, at times abundantly.

Experimental hosts.—All the following data are from Richards and Smith (1954):

Blatta orientalis: A few plants matured.

Neostylopyga rhombifolia: Some development but no mature plants.

Periplaneta americana: Fungus developed prolifically with a density equal to that on original host.

Periplaneta australasiae: Some development but no mature plants.

Periplaneta brunnea: Fungus developed prolifically with a density equal to that on original host.

Herpomyces phyllodromiaeThaxter

Natural host.—"Phyllodromia" sp., Abyssinia (Thaxter, 1905, 1908): On antennae.

Herpomyces platyzosteriaeThaxter

Natural host.—"Eurycotis floridana," Mexico (Thaxter, 1905, 1908): On antennal setae.

Since this cockroach is not found in Mexico (J. A. G. Rehn, personal communication, 1957), E. floridana is undoubtedly not the host for this fungus. W. B. Brown (personal communication, 1957) searched the cockroach collection at the Museum of Comparative Zoology but was unable to find Thaxter's insect for reidentification.

Herpomyces stylopygaeSpegazzini

Natural hosts.—Blatta orientalis, Argentina (Spegazzini, 1917); U.S.A. (Richards and Smith, 1955a).

Experimental hosts.—Neostylopyga rhombifolia (Richards and Smith, 1954): A few plants matured.

Pycnoscelus surinamensis (Richards and Smith, 1954): Some development but no mature plants.

The fungus (fig. 1) is found on antennae (pl. 27, B, C), palpi, cerci, and femurs. Thaxter (1931) believed H. stylopygae to be synonymous with H. periplanetae. However, Richards and Smith (1954) concluded that H. stylopygae would not grow on P. americana under their laboratory conditions although H. periplanetae would grow on B. orientalis. This indicated a strain or species difference between the two fungi. Gunn and Cosway (1938) reported a species of Stigmatomyces on the antennae of B. orientalis; this fungus was probably H. stylopygae (Richards and Smith, 1956).

Herpomyces supellae(Thaxter)

Natural host.—Supella supellectilium, Trinidad (Thaxter, 1931): On antennal spines.

Herpomyces tricuspidatusThaxter

Natural hosts.—Blaberus craniifer, U.S.A., Key West (Richards and Smith, 1955).

Blaberus sp. and Epilampra? sp., Panama (Thaxter, 1902, 1908).

Epilampra sp., Saint Kitts, B.W.I., and Haiti (Thaxter, 1902, 1908).

Leucophaea maderae, Fernando Po (Spegazzini, 1915).

Nauphoeta cinerea, Brazil (Thaxter, 1931).

Cockroaches, China? (Thaxter, 1902); Philippine Islands, Mindanao (Thaxter, 1931).

Experimental hosts.—Blaberus craniifer, U.S.A. (Richards and Smith, 1955).

Infections on the antennae. Richards and Smith (1954) were unable to secure experimental infections in L. maderae with H. tricuspidatus. Experiments with N. cinerea showed some development but no mature plants although identification of the growing fungus was uncertain because of simultaneous exposure to H. ectobiae, H. stylopygae, and H. tricuspidatus.

Herpomyces zanzibarinusThaxter

Natural hosts.—Eurycotis manni, Brazil (Thaxter, 1931): On antennae.

Gyna sp.?, Isle of Nias (Spegazzini, 1915): On antennae.

Cockroach, Zanzibar (Thaxter, 1902): On antennae.

INCERTAE SEDIS

According to Dr. R. K. Benjamin (personal communication, 1957) and Dr. E. G. Simmons (personal communication, 1957), the phylogenetic position of the following genus is uncertain.

Amphoromorpha blattinaThaxter

Natural hosts.—Cockroaches, Grenada, B.W.I. (Thaxter, 1920): On the axis of the antennae of a dark wingless and a pale winged blattid.

Amphoromorphasp.

Natural host.—Cockroach, Grenada, B.W.I. (Thaxter, 1920): On antennal setae.

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