Native Ant Responses to <I>Solenopsis invicta</I> Buren Reduction Using Broadcast Baits

Abstract

A pilot study was conducted to investigate the impact of Solenopsis invicta management with an insect growth regulator bait (s-methoprene) on native ant species and to determine the responses of these species to S. invicta reduction. This invasive species alters the diversity and structure of different trophic levels of arthropod assemblages. Despite advances in S. invicta management using biological control agents, poison baits remain as the primary tool for effective fire ant management. However, the effect of these products on native ants is relatively unknown. Understanding these effects is critical to the development of S. invicta management strategies that include conservation of native ants. Native ants compete with S. invicta to some degree and can bolster efforts to release and establish exotic biological control agents to more effectively manage S. invicta. The study was carried out in Mumford, TX. Two treatments were used: a bait treatment that reduced S. invicta densities and a control. The treatments were randomly assigned to 1.33-ha blocks, replicated four times, and periodically inspected using complementary sampling techniques (pitfall traps, baited vials, manual collections, and nest surveys). Sixteen ant species were found among the two treatments. After S. invicta reduction, significant increases in densities of several other ant species were observed. Species within the assemblage shifted from the dominance by S. invicta to the dominance of the native pyramid ant, Dorymyrmex flavus McCook, which showed the most significant increase in bait treated blocks and was found to persist at densities significantly higher than the control for >2 yr after the last bait treatment. A temporary change in diversity was observed, indicating that use of a poison bait for S. invicta management benefited numerous resident species in the ant assemblage.

Red Imported Fire Ant Impacts on Upland Arthropods in Southern Mississippi

“…Ant species diversity and richness were greater in sites treated with an insect growth regulator; however, the long-term benefits to arthropod communities from chemical treatments are short-lived. Calixto et al (2007) noted that some native ant species can respond to reductions in Solenopsis invicta densities with a selective use of poison baits, though more data are needed to further investigate this issue and fire ant populations will likely rebound to pre-treatment levels (or higher) in 1-2 y after treatment (Markin et al 1974). Chemical treatments are expensive, and the feasibility of using them at large spatial and temporal scales is low.…”

Indirect effects of red imported fire ants on Attwater's prairie‐chicken brood survival

“…Bait products such as Extingush Plus are specific to ants, and have few environmental risks compared to contact insecticides (Barr et al , Knutson and Campos 2008). Although other ant species are susceptible to this product, fire ants dominate the insecticide‐laden bait product to their detriment while allowing native ant population increases (Calixto et al ). During November 2010 and again in late‐September 2011, we treated 527, 294, 204, 259, and 179 ha similarly at APCNWR, Midwell, Texas City, Tivoli, and West Clarkson, respectively.…”

“…Bait products such as Extingush Plus are specific to ants, and have few environmental risks compared to contact insecticides (Barr et al 2005, Knutson andCampos 2008). Although other ant species are susceptible to this product, fire ants dominate the insecticide-laden bait product to their detriment while allowing native ant population increases (Calixto et al 2007).…”

Integrated pest management concepts for red imported fire ants Solenopsis invicta (Hymenoptera: Formicidae)

“…Whereas classical biological control involves very large areas, that is, states or parts of states (Callcott et al ., ), chemical approaches involve relatively smaller nonagricultural or agricultural lands (Drees et al ., ). Selection of appropriate insecticide‐based treatment approaches is influenced by size of the area to be treated.…”