56 
Newsletter of the Hawaiian Botanical Society 
In September of 1999, following my visit, Mr. 
Qin Qingming, a research colleague of Mr. Chen 
of the Chinese Academy of Agricultural Sciences, 
Beijing, made a separate visit to Yunnan Province 
in behalf of the YHR biocontrol project. He 
carried out fieldwork at sites that we had not 
visited and collected additional beetles species in 
addition to those Mr. Chen, Dr. Duan, and I had 
found. 
Discussion 
Of the insects and disease agents found in 
literature reviews of YHR from the Himalayan 
region of northern India, fungal pathogens appear 
to be the most prominent. Of these, some well- 
known groups of significant agricultural pathogens 
are represented, and host specificity cannot be fully 
ascertained until specific isolates are host range- 
tested. Thus, whereas the current field studies 
were conducted in China, other areas of the 
apparently extensive range of YHR should not be 
overlooked. Among the disease agents mentioned 
from India, however, viruses are generally 
considered the least desirable to work with as 
biocontrol agents because of the frequent 
requirement for specific arthropod vectors and 
because of their submicroscopic, obligate-parasitic 
nature. Quarantine facilities in Hawai'i are not 
currently equipped to support studies of this 
complexity. 
From our observations thus far, it is evident that 
YHR occupies a wide variety of habitats in China. 
Near Jinghong we found it was growing among a 
number of other under story species in a rubber 
plantation on an otherwise forested hillside. Near 
Menghai it occupied a wet habitat on the low dikes 
of fishponds, but also occurred in nearby drier 
waste places. At the Rock Forest site it was found 
in dry rocky soil, but also occurred on a pond bank. 
At the Shuren site near Fengdu we found it on 
steep, open or heavily wooded mountain slopes 
and terraced agricultural lands that appeared to 
receive considerable rainfall. On the other hand, it 
occurred in dry, rocky mountainous habitats and on 
the borders of terraced agricultural plots. 
Geographically, it appears that YHR is widespread 
throughout southern and central China, probably 
occupying a latitude range from the southernmost 
extent of the country (about the 22'"' latitude) north 
to the 30"" latitude or beyond. Furthermore, its 
range probably occurs as a continuous band 
extending westward into southern Tibet and Burma 
to the Himalayan region of Northern India. 
Despite its purported medicinal uses, none of the 
local farmers we spoke with indicated that it had 
any value, whether as a food source or for healing 
purposes. Based on these contacts, whatever 
cultural or medicinal uses YHR might have in 
northern India and elsewhere, as noted above, do 
not seem to have universal application throughout 
the Chinese range of this species. 
Notwithstanding the wide geographic 
distribution of the species, YHR occurred as 
scattered individual plants, usually not more than 2 
meters tall, wherever we found it, and the species 
could not be considered common at most sites 
visited. Thus, in contrast to its invasive nature in 
Hawai'i, we never found YHR in China forming 
tall, robust thickets and obviously colonizing 
habitats. Such lack of aggressiveness of invasive 
weeds in Hawai'i when observed in their native 
habitats has been noted in other biocontrol 
programs (Lutzow-Felling et al., 1995; Ellshoff et 
al., 1995). Aside from the obvious effects of 
removal by local farmers, factors accounting for 
this difference are not readily apparent. Even 
taking into account the number of insects attacking 
YHR in China that are not present in Hawai'i, this 
predation alone did not seem to fully account for 
its relative lack of aggressiveness in areas where it 
had not been physically controlled. 
As noted above, Hawai'i has no commercial 
blackberry or raspberry production, and all 
introduced species of Rubus are weedy. Host 
specificity testing must focus on Hawai'i's two 
endemic species of 'akala, R. hawaiemis and R. 
macraei (the latter a "Species of Concern"), 
thereby insuring protection from any adverse 
effects of introduced biocontrol agents. Under the 
cooperative agreement, identification and initial 
host specificity screening is to be carried in China, 
reducing the pressure on the permitting process 
and the quarantine facilities in Hawai'i. 
Although rust fungi have proven to be effective 
biocontrol agents for other weeds, including 
species of Rubus (e.g., Phragmidium violaceum on 
R. fruticosus in Australia [Bruzzese and Hasan, 
1986]), H. rubi-sieboldii unfortunately did not 
systemically infect YHR and the local leaf lesions 
appeared to have minimal impact on plant health. 
It is possible that the rust may be capable of more 
severe infection under other environmental 
