Differences in the reproductive behavior of different geographical populations of Rhynchophorus ferrugineus
Author of the article:YAN Jing1** ZHANG Kang1 WANG Qin-Zhao1 XIONG Yang-Ping1 LIU Xing-Ping1 ZENG Ju-Ping1, 2***
Author's Workplace:1. Key Laboratory of Forest Ecosystem Protection and Restoration in Poyang Lake Basin, National Forestry and Grassland Administration, College of Forestry, Jiangxi Agricultural University, Nanchang 330045, China; 2. Observation and Research Station of Forestry Ecosystem in Lushan Mountain, Jiujiang 332900, China
Key Words:Rhynchophorus ferrugineus; invasive pest; geographic population; reproductive behavior; rhythm; adaptation
Abstract:
[Aim] To analyze latitudinal variability in the
reproductive behavior of the red palm weevil, Rhynchophorus ferrugineus,
in order to reveal adaptations that could facilitate the continued northward
invasion of this pest. [Methods] Cocoons of the Nanchang population of R.
ferrugineus were collected in the field, and adult emergence, mating, and
oviposition behavior were recorded to analyze and compare the timing,
frequency, and number of these behaviors. The same data on three other
populations (Wenchang, Nanning and Fuzhou) were collected from the literature.
After sorting and processing the data, the reproductive behavior of these four
populations was compared using statistical tests, such as the Run test and
Mann-Whitney U test. [Results] The
temporal rhythm of mating and oviposition in populations from subtropical
regions (such as Nanchang and Nanning) were significantly different to those of
other populations. A Run test analysis of a non-random 24 h time series
indicates that these populations had a significantly higher mating rate during
the light phase (daytime) than during the dark phase (night). The oviposition
peak of the Nanchang population took place from 13:00 to 19:00, whereas no
significant mating, or oviposition rhythm, was observed in populations from
tropical locations (such as Wenchang). Adult emergence had no significant
temporal pattern. Mating duration ranged from 1 second to 1 325 seconds, with a
75% quantile of 103 seconds. There was a significant positive correlation
between the number of eggs laid by females and the duration of the pre-mating
period and mating. However, there was no significant correlation between mating
frequency and the number of eggs number laid. [Conclusion] Our results
indicate that the red palm weevil is capable of adapting its reproductive
behavior, such as changing its mating or oviposition rhythm, which may
facilitate its establishment at higher latitudes in China. These findings
suggest that the red palm weevil is not confined to tropical, or sub-tropical,
regions and that effective control of this pest will therefore require
monitoring at higher latitudes north of the Yangtze River.