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Density-dependent benefits in ant-hemipteran mutualism? The case of the ghost ant Tapinoma melanocephalum (Hymenoptera: Formicidae) and the invasive mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae).

Zhou A, Kuang B, Gao Y, Liang G - PLoS ONE (2015)

Bottom Line: Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density.Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately.These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

View Article: PubMed Central - PubMed

Affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China; Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou 510642, China.

ABSTRACT
Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density. In this study, we tested whether the invasive mealybug Phenacoccus solenopsis is affected by tending by ghost ants (Tapinoma melanocephalum), the presence of parasitoids, mealybug density, parasitoid density and interactions among these factors. Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately. However, there were no interactions among the independent factors. There were also no significant interactions between ant tending and parasitoid density on either mealybug colony growth rate or percentage parasitism. Mealybug colony growth rate showed a negative linear relationship with initial mealybug density but a positive linear relationship with the level of ant tending. These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

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Effect of ant tending, the presence of parasitoids, and initial mealybug density on the percentage of parasitism.(A): Ant tending; (B): Initial mealybug density.
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pone.0123885.g002: Effect of ant tending, the presence of parasitoids, and initial mealybug density on the percentage of parasitism.(A): Ant tending; (B): Initial mealybug density.

Mentions: Our results showed that the growth rate of the mealybug colony was significantly affected by ant tending, parasitoids, and the initial mealybug density, separately (Table 1: Ant tending, Parasitoid, Density). The growth rate was obviously improved by ant tending (Table 1: Ant tending, Fig 1A, and S1 Dataset). In contrast, it showed a notable decrease with the presence of the parasitoid or with a higher initial mealybug density (Table 1: Parasitoid, Fig 1B; Table 1: Density, Fig 1C; and S1 Dataset). No significant interactions were found for ant tending and parasitoids, ant tending and mealybug density, and parasitoids and mealybug density, nor for all three factors together (Table 1). The effect of ant tending and initial mealybug density significantly affected the percentage of parasitism (Table 2: Ant tending, Density). The percentage of parasitism of mealybugs significantly decreased with ant tending but increased with increased mealybug density (Table 2: Ant tending, Fig 2A; Table 2: Density, Fig 2B; and S1 Dataset). However, the effect of interactions between ant tending and mealybug density on percentage of parasitism was indistinct (Table 2: Ant tending × Density).


Density-dependent benefits in ant-hemipteran mutualism? The case of the ghost ant Tapinoma melanocephalum (Hymenoptera: Formicidae) and the invasive mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae).

Zhou A, Kuang B, Gao Y, Liang G - PLoS ONE (2015)

Effect of ant tending, the presence of parasitoids, and initial mealybug density on the percentage of parasitism.(A): Ant tending; (B): Initial mealybug density.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4401700&req=5

pone.0123885.g002: Effect of ant tending, the presence of parasitoids, and initial mealybug density on the percentage of parasitism.(A): Ant tending; (B): Initial mealybug density.
Mentions: Our results showed that the growth rate of the mealybug colony was significantly affected by ant tending, parasitoids, and the initial mealybug density, separately (Table 1: Ant tending, Parasitoid, Density). The growth rate was obviously improved by ant tending (Table 1: Ant tending, Fig 1A, and S1 Dataset). In contrast, it showed a notable decrease with the presence of the parasitoid or with a higher initial mealybug density (Table 1: Parasitoid, Fig 1B; Table 1: Density, Fig 1C; and S1 Dataset). No significant interactions were found for ant tending and parasitoids, ant tending and mealybug density, and parasitoids and mealybug density, nor for all three factors together (Table 1). The effect of ant tending and initial mealybug density significantly affected the percentage of parasitism (Table 2: Ant tending, Density). The percentage of parasitism of mealybugs significantly decreased with ant tending but increased with increased mealybug density (Table 2: Ant tending, Fig 2A; Table 2: Density, Fig 2B; and S1 Dataset). However, the effect of interactions between ant tending and mealybug density on percentage of parasitism was indistinct (Table 2: Ant tending × Density).

Bottom Line: Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density.Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately.These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

View Article: PubMed Central - PubMed

Affiliation: Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, People's Republic of China; Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou 510642, China.

ABSTRACT
Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density. In this study, we tested whether the invasive mealybug Phenacoccus solenopsis is affected by tending by ghost ants (Tapinoma melanocephalum), the presence of parasitoids, mealybug density, parasitoid density and interactions among these factors. Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately. However, there were no interactions among the independent factors. There were also no significant interactions between ant tending and parasitoid density on either mealybug colony growth rate or percentage parasitism. Mealybug colony growth rate showed a negative linear relationship with initial mealybug density but a positive linear relationship with the level of ant tending. These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

Show MeSH