Effect of feeding on conspecific and heterospecific prey on the fitness of two species of phytoseiid mites
Author of the article:LI Yu-Jing；TIAN Yu；YIN Yun-Fei；CHI Yuan-Ming；ZENG Ke-Ke；QI Hui；MENG Rui-Xia
Author's Workplace：College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China；College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China；College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China； College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China；College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China；College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China；College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot 010019, China
Key Words：predatory mite; reciprocal intraguild predation; intraspecific predation (ISP); fitness; risk assessment
Abstract：
[Objectives] To investigate conspecific and heterospecific
predator-prey interactions between two exotic phytoseiid mites, Amblyseius (Typhlodromips) swirskii and Neoseiulus cucumeris in order to assess the risk of using A.
swirskii, either alone, or in combination with other phytoseiid
species, as a biocontrol agent. [Methods] The prey preferences and predation rates
of these two phytoseiid mites were determined by offering either conspecific or
heterospecific eggs, larvae or protonymphs, to female adults. The effect of
feeding on either conspecific or heterospecific prey on the fitness
(oviposition rate and adult female survival) of females of each species was
measured and compared. [Results] A. swirskii and N. cucumeris both preyed on each other but A. swirskii was more likely to be the IG-predator than N. cucumeris. There was no significant difference in
the likelihood of cannibalism by each species (χ2=0.118, df=1, P=0.732). Both species of predatory mites
displayed statistically higher predation on larvae than on protonymphs or eggs (A. swirskii: F2,114=66.27, P<0.000 1; N. cucumeris: F2,114=50.39, P<0.000 1). Both phytoseiid predators preyed
significantly more on heterospecific larvae and protonymphs than on conspecific
larvae and protonymphs. The
oviposition rate of females of both species was significantly higher when females
fed on larvae than when they fed on protonymphs (A. swirskii: t=5.774, df=26, P<0.000 1; N. cucumeris: t=3.334, df=26, P=0.002 6) and A. swirskii had
significantly higher oviposition rates after feeding on heterospecific larvae
than conspecific larvae (t=2.854, df=26, P=0.008 4). There was no significant difference in
the survival of the two species when they fed on either larvae or protonymphs. However, the survival of A.
swirskii was significantly higher when
fed heterospecific prey than when fed conspecific prey (t=2.196, df=26, P=0.037 2). [Conclusion] A. swirskii and N. cucumeris preferentially engage in reciprocal IGP rather than cannibalism. Females of
either species that fed on larvae laid more eggs than those that fed on
protonymphs. Heterospecific prey appears to be more suitable than conspecific
prey for A. swirskii.