PAN-PACIFIC ENTOMOLOGIST 
Vol. 55, No. 1, pp. 1-9 
BEETLES ASSOCIATED WITH SLIME MOLDS (MYCETOZOA) 
IN OREGON AND CALIFORNIA 
(COLEOPTERA: LEIODIDAE, SPHINDIDAE, LATHRIDIIDAE) 
Loren K. Russell 
Dept, of Entomology, Oregon State University, Corvallis, 97331 
Although the slime molds (Mycetozoa, or Myxomycetes) are an abundant 
and remarkably isolated group of organisms (Olive, 1975), there has been 
little recognition in the American literature of a beetle faunule adapted to 
feed on mycetozoan fruiting structures. This omission is likely due to most 
entomologists being unfamiliar with slime molds, which are often minute 
and often resemble certain types of true Fungi. The present paper records 
11 species of beetles found by the author in four genera of slime molds in 
Oregon, and two beetle species found in two slime molds in California. This 
“guild” is compared with previously reported beetle associates of myce- 
tozoans, principally those compiled from the European literature by Benick 
(1952). 
Beetles have been collected in the following mycetozoans: Fuligo septica 
(Gmelin) and Reticularia lycoperdon (Ehrenb.), both occurring as massive 
compound sporangia (aethalia), and Arcyria denudata (L.) and Stemonitis 
spp., which occur as dense and sometimes extensive patches of stalked 
sporangia. Lycogala epidendrum (L.) has been cited as a host for Sphindus 
spp. in Europe, but I have found no beetles in two collections of this puff¬ 
ball-like species (Benton County, Oregon). Andrews (1977) has given the 
only published records of North American beetles from Fuligo and Arcyria 
and I have seen no American records for Reticularia as a host. Only a few 
definite records are available for beetles from other mycetozoan genera 
(Table 1). 
Collections of Fuligo from widely separated Oregon localities have yield¬ 
ed 10 beetle species: Sphindus crassulus Csy. and Odontosphindus clavi- 
cornis Csy. (Sphindidae); Enicmus cordatus Belon (Lathridiidae); Aniso- 
toma confusa Horn, Anisotoma errans Brown, Anisotoma nevadensis 
Brown, Agathidium contiguum Fall, Agathidium pulchrum LeC., Agathi- 
dium brevisternum Fall, and Agathidium californicum Horn (Leiodidae). 
As many as three species of beetles have been found in a single aethalium. 
These collections include the first Oregon records for the family Sphindidae. 
(Collection records are listed separately below.) 
Most of the Fuligo associated beetles were found in mature, dry aethalia, 
