452 FUNGUS-INSECT INTERRELATIONSHIPS 



beetles, and spores either may be regurgitated or may resist diges- 

 tion and then be yoided in the excrement. 



A great deal of interest in ambrosia fungi has centered on those 

 species associated with the staining of wood, since such wood 

 staining is of so much economic importance to the lumber indus- 

 try. The work of Rumbold (1936) shows that Ceratostomella 

 ips, C. pilifera, and C. pint occur in pines, C. piceaperda in spruce 

 in eastern Canada, C. pseudotsugae in Douglas fir and larch in the 

 Northwest, and C. pluriannulata in hardwoods. In white fir 

 damaged by seyeral species of Scolytus, Wright (1935, 1938) 

 noted two wood-staining species, Trichospor'nim symb'wt'icum 

 and Spicaria anomala. 



Ceratostomella ulvii, which attacks elms, is always associated 

 with galleries produced by Scolytus scolytus and 5. vmltistriatus. 



Seyeral other species of fungi are associated with wood staining, 

 but their relationship to insects remains unknown. These species 

 include Endocon'uiiophora coemlescens, E. moniliformis, Diplodia 

 natalensis, Graphiinn rigidum, Lasiosphaeria peziztda, Pemcill'unn 

 divaricatum, P. roseum, P. aureum, Chlorospleminn aeriig'nwsinih 

 Fusarium moniliforme, F. viride, F. roseum, Demathnu pulli/lans, 

 and seyeral species of Cadophora, Hormodendrum, and Alternaria. 

 It seems probable that all of them are not cultivated by wood- 

 boringr beetles. 



Ants and fungi. Approximately a hundred species of tropical 

 and subtropical myrmicine ants have the remarkable habit of culti- 

 vating and feeding upon fungi. These ants live in large colonies 

 in underground nests. They cut out bits of leaves and carry them 

 into these nests. The plant tissues are then built into spongy 

 masses that serve as a culture medium upon which the ants im- 

 plant spores and mycelium. Such inoculum is transported within 

 the infrabuccal pouch, especially by the queens. The fungi grow 

 in these "ant gardens" and produce bromatia, swollen, roundish 

 hvphal tips, which are consumed by the ants. New crops of bro- 

 matia continue to replace those that have been eaten. 



Divergent opinions have been expressed on the identity of the 

 fungi involved. Moller (1893) found in the nests of Acromyrex 

 disciger a gill fungus that he named Rozites gonglyophora (the 

 termination "ites" should be reserved for fossil fungi). Xylaria 

 mi crura was identified in the nest of Acromyrex lundi by Spegaz- 

 zini. Cladosporimn myrmecophilwn is cultivated by Lasius fiilig- 



