Spatial relationships between Frankliniella intonsa and its natural enemies in four tea gardens
Abstract:
[Objectives] To make rational use of, and protect, the natural
enemies of Frankliniella intonsa and clarify the natural enemies that
exist in close proximity to this pest. [Methods] Using grey correlation, geostatistics and
a closeness index, the spatial relationships between F. intonsa and its
predatory natural enemies were systematically analyzed in four tea gardens.
The three natural enemies with the closest spatial relationship to F.
intonsa were comprehensively evaluated. [Results] According to the closeness index, in a ‘Huangshan large
leaf’ tea garden, the three natural enemies with the closest spatial
relationship to F. intonsa were Tetragnatha squamata (1.000 0), Clubiona
japonicola (0.987 6) and Oxyopes sertatus (0.976 8). In a ‘Agricultural anti-zao’ tea garden, the first three natural
enemies with the closest spatial relationship to F. intonsa were T.
squamata (1.000 0), O. sertatus (0.976 3) and C. japonicola (0.968
2). In a ‘Pingyangtezao’ tea garden, the first three natural enemies with the
closest spatial relationship to F. intonsa were O. sertatus (1.000
0), T. squamata (0.995 5) and C. japonicola (0.992 8). In a
‘Baihaozao’ tea garden, the three natural enemies with the closest spatial
relationship to F. intonsa were O. sertatus (1.000 0), T.
squamata (0.989 8) and T. maxillosa (0.986 3). The same three
natural enemies had the closest spatial relationship to F. intonsa in
all four tea gardens, however, their ranking in terms of spatial relationship
differed from garden to garden. In terms of the ratio of numbers of individual F. intonsa to specific natural
enemies, the species with the closest spatial relationship to F. intonsa in the ‘Huangshan large
leaf’ tea garden was T. squamata, and the sixth was T. maxillosa,
with ratios of 37.29 and 83.90, respectively. The natural enemy with the
closest spatial relationship to F.
intonsa in the ‘Agricultural
anti-zao’ tea garden was T. squamata, and the sixth was Erigonidium
graminicolum, with ratios of 8.84 and 22.11, respectively. The natural
enemy with the closest spatial relationship to F. intonsa in the ‘Pingyangtezao’ tea garden was O.
sertatus, and the sixth was E. graminicolum with ratios of 8.24 and
34.68, respectively. The ratio of the first natural enemy is an order of
magnitude less than that of the sixth. The first natural enemy with the closest
spatial relationship to F. intonsa in
the ‘Baihaozao’ tea garden was O. sertatus, and the sixth was C.
japonicola, with ratios of 19.67 and 88.50, respectively. [Conclusion] The factors responsible for a close
spatial relationship between F.
intonsa and its natural enemies appear to be those that promote an
abundance of F. intonsa.
These results provide an important scientific basis for the rational protection
and utilization of natural enemies of F. intonsa.