Location: Biological Control of Pests ResearchTitle: Red imported fire ants (Hymenoptera: Formicidae) cover inaccessible surfaces with particles to facilitate food search and transportation
|WEN, CHAO - South China Agricultural University|
|QIN, WENQUAN - South China Agricultural University|
|CHEN, XUAN - Salisbury University|
|WEN, JUNBAO - Beijing Forestry University|
|WEN, XIUJUN - South China Agricultural University|
|WANG, CAI - South China Agricultural University|
Submitted to: Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/16/2020
Publication Date: 12/30/2020
Citation: Wen, C., Chen, J., Qin, W., Chen, X., Wen, J., Wen, X., Wang, C. 2020. Red imported fire ants (Hymenoptera: Formicidae) cover inaccessible surfaces with particles to facilitate food search and transportation. Insect Science. 0:1-13. https://doi.org/10.1111/1744-7917.12891.
Interpretive Summary: The red imported fire ant is a significant pest in the world. As a social insect, fire ants have evolved a rich array of social behaviors. Knowledge in these social behaviors is important in not only understanding the biology of fire ants, but also developing novel control methods for their management. In an earlier study, it was found that fire ants deposited soil particles on the substance treated with a repellent. We hypothesized that fire ants can modify surface properties to facilitate their forage. In this study, the particle-covering behavior of fire ants reacting to unfavorable surfaces, such as sticky and repellant surfaces, was investigated in the laboratory and field. It was found that the particle covering behavior helped ants reach the food sources that were otherwise unreachable. Ants deployed particle covering behavior to overcome the negative effect of sticky or repellant surfaces. The ant particle covering behavior will have a far-reaching implication in the development of both fire ant repellant and bait products. For example, suppressing particle covering behavior may improve the efficacy of a fire ant repellant. If particle covering behavior is unique to fire ants, it can also be potentially exploited to improve the selectivity of fire ant bait products. For example, surrounding a bait with stick surface may make the bait only accessible to fire ants.
Technical Abstract: 1. Eusocial insects have evolved diverse and complicated tool-use behaviors involved in foraging processes. A previous study by Wen et al. (2016) reported that the red imported fire ants, Solenopsis invicta Buren, deposited soil particles on the substance treated with essential balm, a repellent against fire ants. We hypothesized that S. invicta modify the inaccessible surfaces by covering them with soil particles to facilitate food search and transportation. 2. In the present study, the laboratory experiments were first conducted to investigate the particle-covering behavior of S. invicta reacting to the viscose surface, or surface treated with essential balm or liquid paraffin, when real food (sausage) or non-food object (acrylic plates) was provided. Result showed that S. invicta workers transported significantly more soil particles onto these three types of treated surfaces than untreated ones. In addition, significantly more particles were relocated when food was placed on the viscose or paraffin-smeared surfaces compared with non-food conditions. 3. The particle-covering behavior on viscose surface was then investigated in the field. Under field conditions, S. invicta transported significantly more particles onto viscose surfaces as they did in the laboratory. Interestingly, in a condition that no soil particles were available, ants could search and transport food on viscose surfaces only if the surfaces were artificiality covered with a certain amount of soil particles but couldn’t do so on viscose surfaces without soil particles or with a deficient amount of soil particles. 4. In addition, ants actively relocated particles to cover viscose surfaces if the transport distance was within 20 cm, whereas significantly less particles were relocated if a longer transport distance (40 cm) was enforced. Our study provides a novel example of tool-use by fire ants during foraging.