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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.

Show MeSH
Effect of ant tending and parasitoid density on the percentage of parasitism.(A): Ant tending; (B): Parasitoid density.
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pone.0123885.g004: Effect of ant tending and parasitoid density on the percentage of parasitism.(A): Ant tending; (B): Parasitoid density.

Mentions: The results showed that the effects of ant tending and parasitoid density on the colony growth rate of mealybugs were significant (Table 3: Ant tending, Parasitoid density). Specifically, the colony growth rate with ant tending was obviously greater than without ant tending (Table 3: Ant tending, Fig 3A, and S2 Dataset). The colony growth rate under low parasitic pressure was significantly greater than that under high parasitic pressure (Table 3: Parasitoid density, Fig 3B, and S2 Dataset). No significant effects on the colony growth rate of mealybugs were found for the interactions between ant tending and parasitoid density (Table 3: Ant tending × Parasitoid density). In addition, ant tending and parasitoid density also significantly affected the percentage of parasitism (Table 4: Ant tending, Parasitoid density). The percentage of parasitism without ant tending was obviously greater than that with ant tending (Table 4: Ant tending, Fig 4A, and S2 Dataset). The percentage of parasitism under high parasitic pressure was significantly greater than that under low parasitic pressure (Table 4: Parasitoid density, Fig 4B, and S2 Dataset). However, the effect of the interactions between ant tending and parasitoid density on the percentage of parasitism was not significant (Table 4: Ant tending × Parasitoid 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 and parasitoid density on the percentage of parasitism.(A): Ant tending; (B): Parasitoid density.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0123885.g004: Effect of ant tending and parasitoid density on the percentage of parasitism.(A): Ant tending; (B): Parasitoid density.
Mentions: The results showed that the effects of ant tending and parasitoid density on the colony growth rate of mealybugs were significant (Table 3: Ant tending, Parasitoid density). Specifically, the colony growth rate with ant tending was obviously greater than without ant tending (Table 3: Ant tending, Fig 3A, and S2 Dataset). The colony growth rate under low parasitic pressure was significantly greater than that under high parasitic pressure (Table 3: Parasitoid density, Fig 3B, and S2 Dataset). No significant effects on the colony growth rate of mealybugs were found for the interactions between ant tending and parasitoid density (Table 3: Ant tending × Parasitoid density). In addition, ant tending and parasitoid density also significantly affected the percentage of parasitism (Table 4: Ant tending, Parasitoid density). The percentage of parasitism without ant tending was obviously greater than that with ant tending (Table 4: Ant tending, Fig 4A, and S2 Dataset). The percentage of parasitism under high parasitic pressure was significantly greater than that under low parasitic pressure (Table 4: Parasitoid density, Fig 4B, and S2 Dataset). However, the effect of the interactions between ant tending and parasitoid density on the percentage of parasitism was not significant (Table 4: Ant tending × Parasitoid 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