Natural distribution, impact and host range in the field.
In order to know the natural distribution and the impact of the
leaf rolling moths, 3 years of surveys were conducted in the field at
28 sites in three provinces in southwestern China from September
2008 to July 2010 (see Fig. 1). In each year, surveys were conducted
during the first week of April, June and October. Because the larvae
cannot be distinguished in the field, the two species were treated
as a single entity. Two survey methods were used: permanent plots
and direct collecting. In the permanent plots (100–300 m2
), 7–20
R. ellipticus clone clusters were set at random for surveys. The clusterswere usually set 5 m apart and there were no more than five main
canes in each cluster. Because the lengths of canes correlate highly
with biomass (unpublished results), the length of the main cane
was measured and the number of leaf-rolls on each was counted.
We also checked Rubus spp. other than R. ellipticus for the rolls
in non-permanent sites (70–200 m2
) in 2008 (Table 5). Leaf rolls
were collected from each site, labeled and kept in bottles
(20 15 cm2
) covered by fine mesh gauze. The samples were kept
cool and transported back to Wuhan Botanical Garden for rearing
and identification when the larvae pupated.