Dr Reid Ipser E: [email protected] T: +1 800 264 0870 W: https://nisuscorp.com/

Different bait sizes could lead to better ways to control invasive

Research Objectives References

Dr Ipser determines bait particle size preferences of invasive Ipser, R. and Gardner, W. (2019). Particle Size Preference and native American ant species. of Six Ant Species (: Formicidae). J. of Entomological Science, 54(4), 370-377. Available at: https://doi.org/10.18474/JES19-16 Detail Personal Response Reid Ipser 100 Nisus Drive Rockford, TN 37853 What inspired you to conduct this research? USA Historically, Integrated Pest Management (IPM) consisted of using only residual insecticides. Now, IPM Bio is the use of a multitude of tactics to control the pest Reid Ipser has more than 16 years of practical experience population level(s). What better way to ensure proper in the pest control industry and holds multiple degrees management than to tailor particle baits foraging in Entomology, including a PhD from the University patterns and strategies of invasive species? This ensures of Georgia, and has authored numerous scientific efficacy in addition to prolonging effectiveness, whereby publications in peer-reviewed journals. He has been with conserving and enhancing native ant populations that per se help control the invasive species. are a Nisus Corporation for six years. bioindicator and need to be preserved.

Funding Can these results lead to better ways to control This work was supported by Hatch project: Enhancing the invasive ant species? biological management of selected invasive and non- invasive pests [project accession no. 1008717] from Absolutely. However, not just ant species but a broad the USDA National Institute of Food and Agriculture. spectrum of other invertebrates. The more diversity the better. I feel using these tactics will help enhance Collaborators diversity, and that they can be used in the urban and Wayne Gardner, agricultural environs as well. Professor-Emeritus, University of Georgia Biology︱Reid Ipser

Different bait sizes pallidefulva Pheidole dentata

Argentine ants – choose a specific size Studio/Shutterstock.com Stock Creative could lead to better of food particle that is different from four local species. “If bait particle size could be matched to a specific Argentine ants are just as aggressive as fire target ant species”, then it would ants, and easily displace most native species. ways to control be possible to “increase the efficacy of the bait to the target pest while decreasing impact on non-target ant invasive ant species species”, says the researcher. To improve the efficacy of granular baits, The four native species included in particle size should be tailored to include Current pest control protocols rowing commercial trade has led for short – is native to South America, the study were Aphaenogaster fulva those sizes preferred by the targeted do not allow to differentiate to the accidental transport of but it has been accidentally introduced Roger, Aphaenogaster lamellidens between invasive and native Gmany species of ants across the in Asia, Australia, New Zealand, some Mayr, Formica pallidefulva Latrielle, pest ant species. ant species. Dr Reid Ipser, world. These unintended passengers can Caribbean countries and the United and Pheidole dentata Mayr. The team when a graduate student at easily hitchhike on cargo containers in States. In these locations, this ant is around Dr Ipser chose these particular displacing other species from food opposite colonies’ nest to steal food. the University of Georgia, US, planes and ships. Food items, plants, and viewed as an annoying and unwelcome species because they are common to resources”, explained Dr Ipser. Eventually, all brood was moved to the wanted to find out whether timber are just a few of the items that can pest, responsible for billions of dollars in Georgia, easy to handle and maintain in fire ant’s nest, and all remaining workers invasive species, like fire ants carry ants to their new destinations. damages. Red imported fire ants quickly the laboratory. SIZE OF THE HEAD AND and queens were killed. and Argentine ants, chose become the dominant ant species COMPETING BEHAVIOUR different sizes of food particles Not all succeed in their new homes, where they decide to live, effectively IT’S ALL DOWN When analysing the results, the team FINDING A BETTER WAY TO compared to native American but some of these ants – the most displacing native species out of their TO PERSONAL TASTE noticed a curious relationship: the CONTROL INVADING ANTS species. If so, this would help aggressive and competitive – have the homes and blocking access to food. All six ant species included in this study size of the bait particle selected was For Dr Ipser, the main goal in this study develop more effective ways to ability to establish and spread rapidly. This domination is typically achieved were happy to forage in lab conditions. positively correlated with the size of was to find out whether particle size eliminate these invasive species Researchers know what qualities with a large army of worker ants and The researchers used four bait sizes, the ant’s head. This should not be could be matched to a specific target without affecting native ants. are ideal to become global invasive poison against competing ant species. 2.36mm, 2mm, 1.44mm, and 0.85mm, surprising, as for optimal foraging, ants species. If possible, this approach The research results indicate species: a broad diet, the ability to made from freeze-dried crickets. need to choose the largest particle they would increase the efficacy of the bait that the best options would be breed quickly and resilience to adapt The Argentine ant too is native to can possibly carry in order to maximise treatment and limit the impact on non- to go for large particle bait for to different habitats. The red imported South America, but it has established Ants tried all sizes provided, but there food collection for the colony. target species. fire ants and medium particles fire ant (Solenopsis invicta Buren) itself in many areas including South were definitely some favourites. Three for Argentine ants. and the Argentine ant (Linepithema Africa, Australia, New Zealand, Japan of the four native species focused The champions, in this case, were the This division was not very clear cut, humile Mayr) are two such examples. and the United States. Argentine ants mostly on the largest size, and rarely Argentine ants, who managed to forage but there were some preferences that In fact, these species are so good at are just as aggressive as fire ants, and touched the others. In contrast, the almost 400 particles over three hours, might be useful to develop new ways invading new territories that they have easily displace most or all native ants. remaining species went for the smaller and second place went to the fire ants, to control invasive ant species. For made it into the top 100 most invasive Furthermore, they can even threaten size and ignored the larger particles. with around 300 particles gathered. the native ants, particle size was very species in the world. Native to South other invertebrates. This is because On the other end of the scale, most similar for three out of four species, with America, both species have travelled they often control foraging areas and As for the invading species, fire ants native species managed less than 200 most preferring the large crumbs and north and expanded their ranges into effectively find food resources before and Argentine ants clearly showed how particles over the same period. The only one going for the smaller pieces. North America where they have started other species do. they become the dominant species. one exception was the species with a In contrast, the invasive fire ants and competing with native species. While the native ants opted for one preference for smaller particles, who Argentine ants could forage a broader Pest control for ants typically involves size and tended to stick to that, the hoarded over 300 pieces, but 94% were range of particles. Based on these The fire ant is native With the pest control methods available exploiting their food habits, using invasive ants attempted to forage either 1.44mm or 0.85mm. results, the best options would be large to South America, now, it’s virtually impossible to target slow-acting poison bait. This is collected everything. Fire ants preferred the bait particles (2.36mm) to attract fire but has been introduced to other these two specific species. Inevitably, by the workers, and taken to the larger size (2.36mm) and Argentine In addition, to test the fire ants’ ants, and medium-size particles (2mm) regions including other species of ants will also be affected. nest, eventually killing every ant in ants favoured the second largest aggressive and territorial behaviour, Dr to catch Argentine ants. “These results the US, where this Dr Reid Ipser, previously based at the the colony, including the queen. This option (2mm), but they still removed Ipser placed this colony on a head- indicate that in order to improve the ant is regarded as an unwelcome pest. University of Georgia, US, is keen to approach, however, is not designed to more than half of the other sizes. to-head with each of the native ants’ efficacy of granular baits, particle size develop a way to aim for fire ants and target a specific species, as bait is also “These results indicated that these colonies. In every single case, fire should be tailored to include those Argentine ants while at the same time appealing to non-target species. two invasive species could effectively ants dominated the foraging arena by sizes preferred by the targeted pest protecting local native ant species. forage the range of bait particle sizes arriving before the competition and ant species”, concluded the researcher. To find a solution for this problem, included in this study, an attribute with a larger army. Not satisfied with “This will increase bait uptake and could CHOOSING PARTICLE SIZES Dr Ipser’s objective was to find out that likely contributes to the success getting most of the available resources, potentially allow for less bait to be The red imported fire ant – or fire ant whether invasive species – fire ants and of these species in competitively fire ants would also resort to raiding the applied to achieve the desired result.”

researchoutreach.org researchoutreach.org The public outreach magazine for the research community

researchoutreach.org

Partnership enquiries: [email protected]