Visiting Insects Species and Behavior Characteristics on Marsdenia tenacissima

PurposeTo explore the reproductive characteristics of “more flowers and less fruit” of Marsdenia tenacissima.

MethodThe species, visiting frequency, residence time, moving distance and carrying capacity with pollen block of potential pollinator from Marsdenia tenacissima (Roxb.) Wight et Arn. were observed during the daytime from May to June in Honghe Prefecture, Yunnan Province.

ResultThe flower-visiting insects from 11 families and 20 species of M. tenacissima were found, and the dominant species were from lepidoptera. The main flower-visiting insects were the Catopsilia pomona and the Danaus genutia, the proportion of visits was 38.54% and 15.69% respectively, accounting for 54.23% of the total number of visits. The visiting activity number of insects reduced before 9: 00 or after 17: 00 when the temperature was lower than 23 ℃ and the humidity was higher than 70%. The visiting frequency of flower visiting of insects showed a trend of increasing at first and then decreasing. The visiting frequency of most insects was less than 5 flowers in a visiting activity. Only 40% of the total number of flower visiting insects stayed for more than 50 s. 35% of the total number of flower visiting insects had a maximum moving distance of more than 5 m. Pollen blocks were not found on the mouthparts of 25% of all the flower visiting insects.

ConclusionThere were many kinds of insects visiting flowers, but the pollination efficiency was very low, which might be the reason of “more flowers and less fruits”.