548 
Psyche 
[Vol. 92 
In cultivation, plants of M. incana have been found to be self- 
compatible and all have had a chromosome number of 2n = 14 
while plants of M. implicata have all been self-incompatible and 
have had a chromosome number of 2n = 18. The one hybrid plant 
propagated from wild fruit was sterile and 16 univalents were found 
in meiosis. Tests using long and short wave UV light (366nm and 
245nm) on flower heads of plants in cultivation indicate that the 
reflective pattern of M. incana is quite different from that of M. 
implicata, and that the hybrid has the same pattern as in M. incana. 
Because of the differences between M. incana and M. implicata in 
flower color, breeding system, and UV reflectance it was clear that a 
study of the pollinators of the two species would contribute to a 
general study of the causes of interspecific hybridization. 
The only mention in the literature of insects on Malacothrix on 
San Miguel Island are the records of six native bee species at flowers 
of M. implicata by Cockerell (1937), the recent synonomy of one of 
these bees by Rust (1984), and there were no data on pollinator 
choice among the three flower types (Miller and Menke, 1981; 
Miller, 1985b). 
Methods 
The present preliminary report is based on collections made on 
San Miguel Island, 24-27 May 1984, and data from Cockerell 
(1937), supplemented by earlier observations on this and other of 
the California Islands. On the May, 1984 trip most of the island was 
surveyed, with concentrated efforts on the slopes above Cuyler 
Harbor and Tyler Bight. Insect specimens are deposited in Santa 
Barbara Museum of Natural History, Natural History Museum of 
Los Angeles County, U.S. National Museum of Natural History, 
and California Department of Food and Agriculture collections. 
Our collecting emphasized sampling the diversity of insects present; 
time did not allow detailed observation of the abundance and activi- 
ties of each species. Although our data are only preliminary, we feel 
that they are adequate to infer general patterns and suggest direc- 
tions for future research, which should address seasonal and diurnal 
activity patterns of the insects, insect-flower interactions, and flower 
constancy of the insects (e.g. Hurd and Linsley, 1975; Hurd et al., 
1980). 
