1a. Objectives (from AD-416):
Develop or identify environmentally compatible chemical controls to provide immediate, effective management of the invasive Caribbean crazy ant (CCA), Paratrechina pubens, and conduct an initial search for biological organisms that could provide long-term, sustainable control of CCA.
1b. Approach (from AD-416):
1) Identify/develop an ant bait formulation that CCA will distribute among multiple nest sites located beyond the bait application site. 2) Survey CCA populations for the presence of pathogens that can potentially be utilized as biological control agents for long term, sustainable suppression of CCA.
3. Progress Report:
These results directly support and correspond to inhouse project objective 4: Develop integrated pest management plans that utilize available control methods, perform comprehensive risk assessment, and that can be adapted to specific stakeholder needs, including local eradication. It is hypothesized that insect growth regulating (IGR) baits will be more effective against pest ants, like CCA, with large, interconnected colonies. Because IGRs do not affect adult worker ants, bait distribution among multiple colonies should be more efficient than with fast-acting baits. Laboratory evaluations identified three non-insect growth regulating commercial ant baits (2 granular and 1 liquid formulations) that consistently killed small CCA colonies within 3 weeks. Commercial fire ant baits which contain IGR active ingredients (pyriproxyfen or (S)-methoprene) were ineffective probably due to poor bait ingestion. IGR fire ant baits supplemented with powdered protein or baits utilizing cat food lures resulted in brood reductions of over 80%. However, reductions were not consistent across all colonies, hence improvements in formulations are needed. A transcriptome was generated from CCA populations collected across Florida. Analyses of over 1.3 million gene sequences revealed three replicating sequences of viral origin which indicated potential virus infections in the crazy ants. Gene surveys are an efficient method of discovering pathogens that potentially can be utilized as biological control agents for self-sustaining suppression of invasive ants. The gene survey of CCA for pathogens (Approach 2) has been completed and published (PloS One 2012). Research progress was monitored by frequent email communications, telephone communications, and visits/meetings between cooperating laboratories.