68 
THE PAN-PACIFIC ENTOMOLOGIST 
Conclusion 
The behavior of male Dynatus nigripes spinolae is much like the be¬ 
havior of some Trypoxylon (Rau, 1928) and Oxybelus (Bohart and Marsh, 
1960) males where the male remains at the nest while the female is 
out foraging. The male remains at the nest for as long as it takes for 
the female to complete it, except for occasional feeding excursions. 
The result is that the male mates repeatedly with a single female until 
the nest is completed, usually three to four days. If that female builds 
another nest nearby the male will stay with her. If she leaves to build a 
nest elsewhere the male will remain at the old nest for a few hours 
and then leave to look for another female. 
Acknowledgements 
I would like to thank Dr. Frank W. Fisk for determining the cock¬ 
roach nymphs, Mr. Roy R. Snelling for determining the species of 
Centris and Dr. R.M. Bohart for comments and criticisms of the manu¬ 
script. Also I would like to thank the Smithsonian Tropical Research 
Institute for allowing me to work on Barro Colorado Island. 
Literature Cited 
Bohart, R. M. and R. M. Marsh. 1960. Observations on the habits of Oxybelus sericeum 
Robertson. Pan-Pacific Entomol. 36:115-118. 
Bohart, R. M. and A. S. Menke. 1976. Sphecid wasps of the world: a generic revision. 
U.C. Press, Berkeley, 695pp. 
Rau, P. 1928. Field studies in the behavior of the non-social wasps. Trans. Acad. Sci. St. 
Louis 25(9):325-489. 
SCIENTIFIC NOTE 
Observations on Monarthrum dentiger (Coleoptera: Scolytidae) and Its Primary Sym¬ 
biotic Fungus, Ambrosiella brunnea (Fungi imperfecti), in California. The ambrosia beetle 
Monarthrum dentiger (LeConte) was collected in California during a study of the ectosym- 
biotic interrelationships of Western ambrosia beetles and their symbiotic fungi. This re¬ 
port records the association of the symbiotic fungus Ambrosiella brunnea (Verrall) Batra 
with M. dentiger for the first time. This fungus had previously been associated with M. mali 
(Fitch) and M. fasciatum (Say) in the Eastern United States (Batra, 1967. Mycologia, 59: 
976-1017) and M. scutellare (LeConte) in British Columbia (Funk, 1965. Can. J. Bot., 43: 929- 
932). Doane and Guilliland (1929, J. Econ. Entomol., 22:915-921) probably observed this 
fungus in their study of the biology of M. dentiger. 
Isolations of A. brunnea from tunnels, larval niches, and the forecoxal mycangia of the 
female beetles, were made on 0.6% malt extract agar and 3% malt extract — 1% yeast 
extract agar using techniques of Batra (1963, Kan. Acad. Sci., 66:213-236). Microscopic ob¬ 
servations of dissected beetle and thin sections of wood from tunnels and larval niches 
were mounted in 1 % KOFI or 0.5% trypan blue stain. 
Upon dissection of adult male (15) and female (20) beetles, fungal cells were found only 
in a forecoxal enlargement of the female beetle. This forecoxal mycangia of M. dentiger 
appeared similiar in structure to those previously described by Batra (1963, Ibid.) for M. 
The Pan-Pacific Entomologist 54:68-69. January 1978 
