Nylanderia Fulva Research Articles

Invasions of four South-American tramp ants: a systematic review

The invasion and spread of four native South American ants (Hymenoptera: Formicidae) Linepithema humile, Solenopsis invicta, Wasmannia auropunctata and Paratrechina (Nylanderia) fulva all over the world, their environmental and economic impact, and intended control tactics are documented. Displacement of these invasive species is triggered by human international movement of goods, and in one case, P. fulva, a deliberately introduction as a candidate for biological control of Atta spp. and snakes. These tramp ants displace native ants, attack native birds and reptiles, protect and transport sap sucking insects, cause damage to human commodities, and are able to cause health problems to men and domestic animals. Chemical control, producing negative environmental side effects, has shown poor success and short residual effect. Current tendencies use biological control agents, the natural enemies, parasites, predators and diseases of their original range. Quarantine and eradication programs have been implemented. The success of the tramp ants involves a small size that permits hiding in all types of packing materials, their organization in societies, varied diets, and in many cases to their late detection and initial control.

Effect of Soil Treatments for Cottony Cushion Scale (Hemiptera: Monophlebidae) Control on Nylanderia fulva (Hymenoptera: Formidicae) Survival and Trailing Activity

Nylanderia fulva (Mayr) (Hymenoptera: Formicidae), or tawny crazy ant, is an invasive ant from South America that is spreading in the southern US. Extremely large populations of this ant can inundate urban and natural landscapes, and efficient control methods are lacking. This study was conducted to determine if activity of N. fulva would decline after controlling the hemipteran honeydew-producers they were tending. Potted plants infested with cottony cushion scale (Icerya purchasi Maskell) (Hemiptera: Monophlebidae) were treated with 2 imidacloprid insecticide formulations, and changes in N. fulva survival and foraging behavior were monitored. There were fewer ant trails, lower trailing intensity, less foraging, and less nesting in potted plants treated with either product than in the control pots. The use of low application rates of systemic insecticide to reduce honeydewproducing hemipterans, such as cottony cushion scale, could be an important component of the integrated pest management of N. fulva.

Involvement of heat shock protein 40 in the wing dimorphism of the house cricket Acheta domesticus

Wing dimorphism is a common phenomenon in a wide range of insect taxa. In most insects, the two morphs are macropterous and micropterous, in extreme cases of the latter, wing shedding can occur. Wing dimorphism contributes significantly to the ecological success of many insect species. However, the molecular basis of wing dimorphism is not fully understood, especially for wing-shed. Here, differentially expressed genes over eight developmental stages of the house cricket Acheta domesticus, which undergoes wing-shed dimorphism, were studied. The results revealed a wing-shed peak during adult development in which many DEGs were highly upregulated and it’s influenced by cricket population density. A weighted correlation network analysis (WGCNA) grouped 21,922 DEGs among 141,456 unigenes into 18 modules of different expression patterns. The module in which the gene expression pattern correlated with the wing-shed phenotypic data was selected for further analyses with STEM and Cytoscape, and three candidate genes (AdomHSP40: Heat shock protein 40, AdomCFDP: Craniofacial development protein, AdomDIS3L: DIS3 Like 3′–5′ Exoribonuclease) were identified by gene network analysis as the DEGs most relevant to wing-shed occurrence. The RNA interference of these genes together with an insulin receptor and Nylanderia fulva virus showed that the silencing of AdomHSP40 significantly decreased wing-shed occurrence, whereas the silencing of other candidate genes did not, suggesting that AdomHSP40 plays a crucial role in the wing-shed of Acheta domesticus. These findings provide insights into the molecular mechanisms underlying wing dimorphism in the house crickets, which differ from those found in other insects such as the planthopper.

Supercolonial structure of invasive populations of the tawny crazy ant Nylanderia fulva in the US

BackgroundSocial insects are among the most serious invasive pests in the world, particularly successful at monopolizing environmental resources to outcompete native species and achieve ecological dominance. The invasive success of some social insects is enhanced by their unicolonial structure, under which the presence of numerous queens and the lack of aggression against non-nestmates allow high worker densities, colony growth, and survival while eliminating intra-specific competition. In this study, we investigated the population genetics, colony structure and levels of aggression in the tawny crazy ant, Nylanderia fulva, which was recently introduced into the United States from South America.ResultsWe found that this species experienced a genetic bottleneck during its invasion lowering its genetic diversity by 60%. Our results show that the introduction of N. fulva is associated with a shift in colony structure. This species exhibits a multicolonial organization in its native range, with colonies clearly separated from one another, whereas it displays a unicolonial system with no clear boundaries among nests in its invasive range. We uncovered an absence of genetic differentiation among populations across the entire invasive range, and a lack of aggressive behaviors towards conspecifics from different nests, even ones separated by several hundreds of kilometers.ConclusionsOverall, these results suggest that across its entire invasive range in the U.S.A., this species forms a single supercolony spreading more than 2000 km. In each invasive nest, we found several, up to hundreds, of reproductive queens, each being mated with a single male. The many reproductive queens per nests, together with the free movement of individuals between nests, leads to a relatedness coefficient among nestmate workers close to zero in introduced populations, calling into question the stability of this unicolonial system in which indirect fitness benefits to workers is apparently absent.

Lethal and sub-lethal effects of the insecticide fipronil on juvenile brown shrimp Farfantepenaeus aztecus

Chemical pesticides are widely used around the world, but at the same time, they may cause direct or indirect risks to many non-target organisms. Recent increased use of insecticides in coastal areas, for example to control invasive tawny crazy ants, raises concern that insecticides may affect ecologically and/or commercially important species found in estuaries. Here, we investigated the lethal and sub-lethal effects of fipronil on juvenile brown shrimp Farfantepenaeus aztecus over 29 days at five different nominal concentrations (0.1, 1.0, 3.0, 6.4, and 10.0 µg/L) in a laboratory experiment. Exposure to all of the fipronil treatments resulted in all individuals dying before the end of the experiment; whereas, no individual died in the control (0.0 µg/L). The 96-hour LC50 was determined to be 1.3 µg/L. Shrimp also experienced weight loss under all of the fipronil treatments. Inter-moult interval was increased from 12.2 ± 1.64 day in the control group to 15.5 ± 0.53 day in the 1.0 μg/L treatment. Lipid content of shrimp increased significantly in a concentration-dependent manner. Finally, behavioral and body color changes were also observed under the fipronil treatments. We conclude F. aztecus is very sensitive to fipronil and monitoring is needed in coastal areas.

Suppressing tawny crazy ant (Nylanderia fulva) by RNAi technology.

The tawny crazy ant (Nylanderia fulva) is a new invasive pest in the United States. At present, its management mainly relies on the use of synthetic insecticides, which are generally ineffective at producing lasting control of the pest, necessitating alternative environmentally friendly measures. In this study, we evaluated the feasibility of gene silencing to control this ant species. Six housekeeping genes encoding actin (NfActin), coatomer subunit β (NfCOPβ), arginine kinase (NfArgK), and V-type proton ATPase subunits A (NfvATPaseA), B (NfvATPaseB) and E (NfvATPaseE) were cloned. Phylogenetic analysis revealed high sequence similarity to homologs from other ant species, particularly the Florida carpenter ant (Camponotus floridanus). To silence these genes, vector L4440 was used to generate six specific RNAi constructs for bacterial expression. Heat-inactivated, dsRNA-expressing Escherichia coli were incorporated into artificial diet. Worker ants exhibited reduced endogenous gene expression after feeding on such diet for 9 d. However, only ingestion of dsRNAs of NfCOPβ (a gene involved in protein trafficking) and NfArgK (a cellular energy reserve regulatory gene in invertebrates) caused modest but significantly higher ant mortality than the control. These results suggest that bacterially expressed dsRNA can be orally delivered to ant cells as a mean to target its vulnerabilities. Improved efficacy is necessary for the RNAi-based approach to be useful in tawny crazy ant management.

The microsporidian pathogen Myrmecomorba nylanderiae: Intracolony transmission and impact upon tawny crazy ant (Nylanderia fulva) colonies

AbstractThe microsporidian pathogen Myrmecomorba nylanderiae Plowes et al. infects introduced tawny crazy ants (Nylanderia fulva (Mayr)), and constitutes one of the first natural enemies known to attack this invasive ant. We assess how infection is transmitted within colonies and how infection impacts N. fulva colony fragment growth under carbohydrate‐deficient and carbohydrate‐sufficient dietary conditions. Carbohydrate scarcity is a common source of stress for ant colonies. Infected workers efficiently pass infection to developing larvae but all other potential pathways for within colony transmission are rare or non‐viable. For unknown reasons, queens within infected colony fragments are generally uninfected, limiting the role of transovarial transmission in intracolony transmission. In the laboratory, infection by M. nylanderiae primarily impacts the growth of N. fulva colonies by reducing pupal production. Colony growth showed a substantially greater impact under carbohydrate‐deficient conditions implying that the effect of the pathogen may depend on seasonally variable carbohydrate availability. In the colony growth assay, worker mortality did not differ with infection status under either nutrient regime. However, in a longer, direct test of survivorship, infected worker survivorship was significantly lower. Recently, some established N. fulva populations with high prevalence of M. nylanderiae infection have declined precipitously, though it is unknown if M. nylanderiae is a causative agent in these declines. The combination of chronic impacts, presence in North America, and potential association with population declines makes M. nylanderiae a promising prospect for the biological control of N. fulva.

Insecticides for Suppression of Nylanderia fulva.

Nylanderia fulva (Mayr) is an invasive ant that is a serious pest in the southern United States. Pest control operators and homeowners are challenged to manage pest populations below acceptable thresholds. Contact and bait insecticides are key components of an Integrated Pest Management (IPM) strategy, however, little is known about their efficacy. In repellency and efficacy bioassays, N. fulva were not completely repelled by any insecticide tested, although fewer ants crossed a surface treated with Temprid®. Few insecticides provided rapid control. Termidor® and Temprid® were the best performing with mean mortality of 100% in 13.4 and 19.0 days, respectively. In no-choice bait acceptance studies, it was shown that N. fulva generally had greater acceptance of carbohydrate-based ant baits (Advion®, InTiceTM (gel), and InTiceTM (granular)). However, mortality was low for the InTiceTM baits in a 7-day bioassay. Maxforce® Ant Killer Bait Gel and Advance® 375A in the spring and Maxforce® Complete in the summer and fall required the fewest days to reach 100% mortality. Bait active ingredients that resulted in the highest mortality were hydramethylnon and fipronil. These data on the efficacy of commercially available contact and bait insecticides provide valuable information to manage this invasive pest.

Integrated Pest Management (IPM) of the Tawny Crazy Ant, Nylanderia fulva (Mayr)

The tawny crazy ant infests buildings and greenhouses, attacks crops, domestic animals, and honeybee hives, displaces native ant species, and disrupts electrical equipment. This 8-page fact sheet is a major revision that describes how to identify the ant and monitor for infestations. It explains how to eliminate food sources and harborages and presents an integrated pest management plan and specific approaches to control this pest ant. (Note: the tawny crazy ant is a serious pest that multiplies quickly and can easily become an overwhelming problem. If you suspect you have tawny crazy ants, the best approach is to call a licensed pest-control professional for help). Written by Faith Oi, Dawn Calibeo, John Paige III, and Michael Bentley, and published by the UF Department of Entomology and Nematology, September 2016. ENY-2006/IN889: Integrated Pest Management (IPM) of the Tawny Crazy Ant, Nylanderia fulva (Mayr) (ufl.edu)

Isolation and characterization of Nylanderia fulva virus 1, a positive-sense, single-stranded RNA virus infecting the tawny crazy ant, Nylanderia fulva

We report the discovery of Nylanderia fulva virus 1 (NfV-1), the first virus identified and characterized from the ant, Nylanderia fulva. The NfV-1 genome (GenBank accession KX024775) is 10,881 nucleotides in length, encoding one large open reading frame (ORF). Helicase, protease, RNA-dependent RNA polymerase, and jelly-roll capsid protein domains were recognized within the polyprotein. Phylogenetic analysis placed NfV-1 in an unclassified clade of viruses. Electron microscopic examination of negatively stained samples revealed particles with icosahedral symmetry with a diameter of 28.7±1.1nm. The virus was detected by RT-PCR in larval, pupal, worker and queen developmental stages. However, the replicative strand of NfV-1 was only detected in larvae. Vertical transmission did not appear to occur, but horizontal transmission was facile. The inter-colonial field prevalence of NfV-1 was 52±35% with some local infections reaching 100%. NfV-1 was not detected in limited samples of other Nylanderia species or closely related ant species.

The Thermal Breadth of Nylanderia fulva (Hymenoptera: Formicidae) Is Narrower Than That of Solenopsis invicta at Three Thermal Ramping Rates: 1.0, 0.12, and 0.06°C min-1.

Determining the upper (CTmax) and lower (CTmin) critical thermal limits of invasive ants provides insight into how temperature could shape their distribution, seasonality, and daily activity. Understanding the potential distribution of invasive ants is imperative to improving quarantine and management efforts. Nylanderia fulva (Mayr) (tawny crazy ant) and Solenopsis invicta (Buren) (red imported fire ant) are invasive ants that are established throughout the southeastern United States. Recent studies have found that body size and thermal ramping rate can affect the estimation of critical thermal limits. However, the effects of both variables and their interactions on the thermal limits of N. fulva and S. invicta have not previously been described. Thus, we evaluated the impacts of body size and ramping rate on the critical thermal limits of N. fulva and S. invicta Overall, N. fulva had a narrower thermal breadth than S. invicta (Nf CTmin = 7.3°C and Nf CTmax = 41.3°C vs. Si CTmin = 4.1°C and Si CTmax = 45.3°C). For both species, slower ramping rates resulted in lower CTmax values and ants with smaller head capsules had a narrower thermal breadth than ants with larger head capsules. These data improve our understanding of the critical thermal limits of both species and could be useful for developing predictive models that estimate the future spread of these invasive ants in nonnative ranges.

Local co-occurrence of several highly invasive ants in their native range: are they all ecologically dominant species?

An important goal of invasion ecology is to understand the colonization, establishment, and spread of exotic species. To accomplish this, it is essential to examine the ecology of introduced species in native populations. We examined organization patterns, spatial structure, and competitive abilities of ground-dwelling ants in different habitats of a protected area in east-central Argentina, where several highly invasive ant species naturally coexist, to determine whether all they are ecologically dominant in their native range as in their introduced range. We sampled ant communities at Otamendi Nature Reserve and found 49 ant species co-occurred with moderate separation among habitats, including five species that are global invaders; but only Solenopsis richteri (the most numerically dominant) and Linepithema humile (the best mass recruiter) were ecologically co-dominant along with another three non-invasive species in locally rich assemblages. Their co-occurrence was apparently facilitated by both niche and competitive differences. However, we found no evidence for discovery-dominance trade-offs, and ant diversity and spatial segregation suggested that competition only plays a secondary role in structuring assemblages in arboreal habitats. Despite L. humile and S. richteri were ecologically co-dominant, their hegemony was lower in the reserve than in their introduced range likely due to biotic resistance. The other invasive ants (Wasmannia auropunctata, Brachymyrmex patagonicus, and Nylanderia fulva) were not dominant. It is possible that their establishment, persistence, and high prevalence in anthropic habitats in native and introduced populations to be attributed to their better physiologic adaptations to disturbed habitats rather than to their superior competitive abilities.

Repellent Effect of Formic Acid Against the Red Imported Fire Ant (Hymenoptera: Formicidae): A Field Study.

Previous studies showed that the formic acid secreted by tawny crazy ants not only has fumigation toxicity to the red imported fire ant, Solenopsis invicta Buren (Chen et al. 2013), but also can detoxify fire ant venom (LeBrun et al. 2014). These lead us to a field study to determine if low concentrations of formic acid might be useful in repelling S. invicta. Filter paper discs treated with 1.3% or 5% formic acid (v: v) or distilled water (control) were placed on each of the 46 S. invicta mounds and a disturbance was created. For a minute or less, there were significantly more defending ants on the control discs than that on the paper discs treated with formic acid. After food was added and for the next 40 min, there were significantly more foraging ants on the control discs compared to the treated discs. At 50 min into the test, the number of foraging ants on the control and 1.3% formic acid-treated discs was similar, but both were significantly higher than that on the 5% formic acid-treated discs. In addition, the active foraging (≥10 ants stayed on or around the food) and burying behavior (soil particles were deposited around the food) continued to be inhibited by 5% formic acid. The potential application and ecological significant of this repellent effect is discussed.

Toxicity and Efficacy of Two Emulsifiable Concentrates of 2-Tridecanone against Red Imported Fire Ants

2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is an ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. Two emulsifiable concentrates were prepared using 2-tridecanone as an active ingredient, vegetable oil as a solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. In conclusion, both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous synthetic organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects.

Evidence of niche shift and global invasion potential of the Tawny Crazy ant, Nylanderia fulva.

Analysis of an invasive species' niche shift between native and introduced ranges, along with potential distribution maps, can provide valuable information about its invasive potential. The tawny crazy ant, Nylanderia fulva, is a rapidly emerging and economically important invasive species in the southern United States. It is originally from east-central South America and has also invaded Colombia and the Caribbean Islands. Our objectives were to generate a global potential distribution map for N.fulva, identify important climatic drivers associated with its current distribution, and test whether N.fulva's realized climatic niche has shifted across its invasive range. We used MaxEnt niche model to map the potential distribution of N.fulva using its native and invaded range occurrences and climatic variables. We used principal component analysis methods for investigating potential shifts in the realized climatic niche of N.fulva during invasion. We found strong evidence for a shift in the realized climatic niche of N.fulva across its invasive range. Our models predicted potentially suitable habitat for N.fulva in the United States and other parts of the world. Our analyses suggest that the majority of observed occurrences of N.fulva in the United States represent stabilizing populations. Mean diurnal range in temperature, degree days at ≥10°C, and precipitation of driest quarter were the most important variables associated with N.fulva distribution. The climatic niche expansion demonstrated in our study may suggest significant plasticity in the ability of N.fulva to survive in areas with diverse temperature ranges shown by its tolerance for environmental conditions in the southern United States, Caribbean Islands, and Colombia. The risk maps produced in this study can be useful in preventing N.fulva's future spread, and in managing and monitoring currently infested areas.

North American Invasion of the Tawny Crazy Ant (Nylanderia fulva) Is Enabled by Pheromonal Synergism from Two Separate Glands.

A new invader, the "tawny crazy ant", Nylanderia fulva (Hymenoptera: Formicidae; Formicinae), is displacing the red imported fire ant, Solenopsis invicta (Formicidae: Myrmicinae), in the southern U.S., likely through its superior chemical arsenal and communication. Alone, formic acid is unattractive, but this venom (= poison) acid powerfully synergizes attraction of tawny crazy ants to volatiles from the Dufour's gland secretion of N. fulva workers, including the two major components, undecane and 2-tridecanone. The unexpected pheromonal synergism between the Dufour's gland and the venom gland appears to be another key factor, in addition to previously known defensive and detoxification semiochemical features, for the successful invasion and domination of N. fulva in the southern U.S. This synergism is an efficient mechanism enabling N. fulva workers to outcompete Solenopsis and other ant species for food and territory. From a practical standpoint, judicious point-source release formulation of tawny crazy ant volatiles may be pivotal for enhanced attract-and-kill management of this pest.

Tawny Crazy Ant

As of 2012, tawny crazy ants have invaded 24 counties in Florida, parts of southeast Texas, and other areas of the southeastern U.S. The tawny crazy ant is considered a series pest. This species infests buildings and greenhouses, attacks crops, domestic animals, honeybee hives, displaces native ant species, and disrupts electrical equipment. This 3-page fact sheet covers the tawny crazy ant’s distribution, description, colonies, feeding habits, and pest status and control. Written by S. K. Hill, R. W. Baldwin, R. M. Pereira, and P. G. Koehler, and published by the UF Department of Entomology and Nematology, October 2013.
 SP486D/IN1076: Tawny Crazy Ant (ufl.edu)

Tunneling Performance Increases at Lower Temperatures for Solenopsis invicta (Buren) but not for Nylanderia fulva (Mayr)

Nylanderia fulva (Mayr), the tawny crazy ant, is an invasive pest established in Florida and several other Gulf Coast states. In their invasive ranges in the Southeastern USA, large N. fulva populations have reduced species abundance, even displacing another invasive ant, Solenopsis invicta (Buren). In North Florida, N. fulva populations survive winter temperatures that reach below freezing for extended periods. However, the shallow littoral debris used by N. fulva for nest construction offers little insulation to brood and reproductives when exposed to freezing temperatures. Field populations of N. fulva in North Florida were observed tunneling below ground, a previously undescribed behavior. Other invasive ants exhibit similar subterranean tunneling behavior as a means of thermoregulation. To test the hypothesis that N. fulva has the capacity to construct subterranean tunnels across a range of ecologically relevant temperatures, tunneling performance for N. fulva and S. invicta, another invasive ant that tunnels extensively, were compared at four temperatures (15.0, 18.0, 20.0, and 22.0 °C). Overall, N. fulva tunneled significantly less than S. invicta. Nylanderia fulva tunneled furthest at warmer temperatures whereas S. invicta tunneled furthest at cooler temperatures. However, N. fulva constructed subterranean tunnels at all temperatures evaluated. These data support the hypothesis that N. fulva is capable of tunneling in temperatures as low as 15.0 °C, confirming that this ant can also perform a behavior that is used by other ants for cold avoidance.

Myrmecomorba nylanderiae gen. et sp. nov., a microsporidian parasite of the tawny crazy ant Nylanderia fulva

A new microsporidian genus and species, Myrmecomorba nylanderiae, is described from North American populations of the tawny crazy ant, Nylanderia fulva. This new species was found to be heterosporous producing several types of binucleate spores in both larval and adult stages and an abortive octosporoblastic sporogony in adult ants. While microsporidia are widespread arthropod parasites, this description represents only the fifth species described from an ant host. Molecular analysis indicated that this new taxon is phylogenetically closely allied to the microsporidian family Caudosporidae, a group known to parasitize aquatic black fly larvae. We report the presence of 3 spore types (Type 1 DK, Type 2 DK, and octospores) with infections found in all stages of host development and reproductive castes. This report documents the first pathogen infecting N. fulva, an invasive ant of considerable economic and ecological consequence.

Tawny Crazy Ant (previously known as Caribbean crazy ant) Nylanderia (formerly Paratrechina) fulva (Mayr) (Insecta: Hymenoptera: Formicidae: Formicinae)

Nylanderia fulva is part of a group of ants referred to as “crazy ants” due to their quick and erratic movements. It has been reported from 27 counties of Florida and 27 counties of Texas, as well as from Louisiana, Mississippi, Alabama, and Georgia. Huge number of workers in infested areas can make human activities uncomfortable and difficult. They can infest sidewalks, buildings and gardens, and damage phone lines, air conditioning units and computers. They have killed honey bee larvae and used the hives as their nests, and are even displacing red imported fire ants where the two populations overlap in Texas. This 5-page fact sheet was written by Shweta Sharma, John Warner, and Rudolph H. Scheffrahn, and published by the UF Department of Entomology and Nematology, December 2014. (Photo: Lyle Buss, UF/IFAS) EENY610/IN1071: Tawny Crazy Ant (previously known as Caribbean crazy ant) Nylanderia (formerly Paratrechina) fulva (Mayr) (Insecta: Hymenoptera: Formicidae: Formicinae) (ufl.edu)