Invasive Species Research

The Invasive Species Research Lab at BFL has led key research into the imported fire ant, Solenopsis invicta, and some prospective biological controls. After the imported fire ant arrived at BFL in 1981, the field station began studying the invader's pattern of expansion and competitive interactions. In the years following the invasion, the lab released several species of phorid flies from South America that are host-specific parasitoids of this invasive ant, and has established a research program into several known pathogens of fire ants. A long-term study of ant community changes at BFL spans the time since the fire ant arrived to the present day. 

In recent years, the lab has begun researching other invasive species that have colonized Texas. One new species of interest is the tawny crazy ant (Nylanderia fulva), which can displace ants in sites that it colonizes. It is unique in that it can neutralize fire ant venom with its own formic acid, giving it the potential to outcompete even the tenacious imported fire ant. 

The lab is also studying invasive grasses like buffelgrass and guinea grass, African grasses that were originally introduced as pasture grass. Researchers at BFL are currently investigating management treatments that will lower the success of these grass species and are also studying the basic population biology of these grasses.  

Another invasive plant, the giant reed, has become established in large patches along the river bank at BFL. Recently, gall-forming wasps and scale insects were released in conjunction with the USDA as biocontrol agents of the reed. The success of this biocontrol at the field lab will be assessed over the next several years.

Research Areas

Publications

Invasive Species Lab Publications

Aron, S., E. L. Vargo, and L. Passera. 1995. Primary and secondary sex ratios in monogyne colonies of the fire ant Solenopsis invicta. Animal Behaviour 49: 749-757.

Brown, B.V., and Morrison, L.W. 1999. A new Pseudacteon (Diptera: Phoridae) from North America that parasitizes native fire ants, Solenopsis geminata (Hymenoptera, Formicidae). Annals of the Entomological Society of America, 92, 308-311.

Brown, B.V., P. Folgarait, and L.E. Gilbert. 2003. A new species of Pseudacteon attacking Solenopsis fire ants (Hymenoptera: Formicidae) in Argentina. Sociobiology 41: 685-688.

Calabi, P. and S. D. Porter 1989. Worker longevity in the fire ant Solenopsis invicta: Ergonomic considerations of correlations between temperature, size, and metabolic rates. Journal of Insect Physiology 35: 643-649.

Callcott, A.M.A., Porter, S.D., Weeks Jr, R.D., Johnson, S.J. and Gilbert, L.E. 2011. Fire ant decapitating fly cooperative release programs (1994–2008): two Pseudacteon species, P. tricuspis and P. curvatus, rapidly expand across imported fire ant populations in the southeastern United States. Journal of Insect Science, 11(19), pp.1-25.

Consoli, F., C. Wuellner, L. Gilbert, S. Vinson. 2001. Immature development of Pseudacteon tricuspis (Diptera: Phoridae), an endoparasitoid of the red imported fire ant, Solenopsis invicta(Hymenoptera: Formicidae). Annals Ent. Soc. Am. 94:97-109.

Disney, R.H.L. 1980. A new species of Apocephalus (Diptera:Phoridae) that parasitises Atta texana(Hymenoptera:Formicidae) in Texas. Zeitschrift fur Angewandte Zoologie 67: 47-50.

Disney, R.H.L. 1982. Three new species of scuttle-fly (Diptera:Phoridae) that parasitize ants (Hymenoptera:Formicidae) in North America. Journal of Zoology, London 197: 473-481.

Estrada, C., R. J. W. Patrock, P. J. Folgarait, and L. E. Gilbert. 2006. Host specificity of four Pseudacteon spp. (Diptera: Phoridae), parasitoids of fire ants in Argentina (Hymenoptera: Formicidae). Florida Entomologist 89:462-468.

Feener, D.H.J. 1978. Structure and organization in a litter-foraging ant community: roles of interference competition and parasitism. University of Texas, Austin.

Feener, D.H.J. 1981. Competition between ant species: outcome controlled by parasitic flies. Science 214: 815-817.

Feener, D.H.J. 1981. Notes on the biology of Pheidole lamia (Hymenoptera: Formicidae) rediscovered at its type locality (Austin, Texas). Journal of the Kansas Entomological Society 54: 269-277.

Feener, D.H.J. 1987. Size-selective oviposition in Pseudacteon crawfordi (Diptera: Phoridae), a parasite of fire ants. Annals of the Entomological Society of America 80: 148-151.

Feener, D.H.J. 1988. Effect of parasites on foraging and defense behavior in a termitophagous ant,Pheidole titanis Wheeler (Hymenoptera: Formicidae). Behavioral Ecology and Sociobiology 22: 421-427.

Feener, D. H., Jr., and B. V. Brown. 1992. Reduced foraging of Solenopsis geminata (Hymenoptera: Formicidae) in the presence of parasiticPseudacteon spp. (Diptera: Phoridae). Annals of the Entomological Society of America 85:80 - 84.

Folgarait, P.J. and L.E. Gilbert. 1999. Phorid parasitoids affect foraging activity of Solenopsis richteri under different availability of food in Argentina. Ecological Entomology 24:163-173.

Feener, D. H., M. R. Orr, K. Wackford, J. Longo, W. W. Benson, and L. E. Gilbert. 2008 in press. Geographic variation in resource dominance, discovery, and parasitoid-mediated competition in the Brazilian range of the red imported fire ant (Solenopsis invicta). Ecology.

Folgarait, P.J., O.A. Bruzzone, and L.E. Gilbert. 2002. Development of Pseudacteon cultellatus(Diptera: Phoridae) on Solenopsis invicta and Solenopsis richteri fire ants (Hymenoptera: Formicidae). Environmental Entomol. 31:403-410.

Folgarait, P. J., O. Bruzzone and L. E. Gilbert. 2003. “Seasonal patterns of activity among species of parasitoid flies (Pseudacteon: Phoridae) in Argentina explained by analysis of climatic variables”. Biological Control 28: 368-378.

Folgarait, P. J., P. D'Adamo y L. Gilbert. 2004. "A grassland ant community in Argentina: the case ofSolenopsis richteri and Camponotus punctulatus attaining high densities in their native ranges". Annals of the Entomological Society of America 97: 450-457.

Folgarait, P. J., O. Bruzzone, S. Porter, M. A. Pesquero, y L. Gilbert. 2005. “Biogeography and macroecology of phorid flies that attack fire ants in southeastern Brazil and Argentina.” Journal of Biogeography 32: 353-367.

Folgarait, P. J., Chirino, M. G., and Gilbert, L. 2005. “Development of Pseudacteon obtusus (Diptera: Phoridae) on Solenopsis invicta and Solenopsis richteri (Hymenoptera: Formicidae)”. Environmental Entomology 34:308-316.

Folgarait, P. J., R. J. W. Patrock, and L. E. Gilbert. 2007. Associations of fire ant phorids and microhabitats. Environmental Entomology 36:731-742.

Folgarait, P.J. R.J.W. Patrock and L.E. Gilbert. 2006. Development of Pseudacteon nocens(Diptera: Phoridae) on Solenopsis invicta and Solenopsis richteri Fire Ants. J.Econ. Entomol. (in press)

Folgarait, P. J., R. J. W. Patrock, and L. E. Gilbert. 2007b. The influence of ambient conditions and space on the phenological patterns of a Solenopsisphorid guild in an arid environment. Biological Control 42:262-273.

Gilbert, L. E., C. L. Barr, A. A. Calixto, J. L. Cook, B. M. Drees, E. G. LeBrun, R. J. W. Patrock, R. M. Plowes, S. D. Porter, and R. T. Puckett. 2007 in press. Introducing phorid fly parasitoids of Red Imported Fire Ant workers from South America to Texas: Outcomes vary by region and byPseudacteon species released. Southwestern Entomologist.

Gilbert, L.E. and L.W. Morrison. 1997. Patterns of host specificity in Pseudacteon parasitoid flies (Diptera, Phoridae) that attack Solenopsis fire ants (Hymenoptera, Formicidae) Environmental Entomology. 26:1149-1154.

Gilbert, L.E. and R.J.W. Patrock. 2002. Phorid flies for the biological suppression of imported fire ants in Texas: Region specific challenges, recent advances and future prospects. Southwestern Entomologist. Suppl. No. 25:7-17.

*Himler A, U.G. Mueller, C. Currie, R. Adams, T. Murakami, T. Mueller. In preparation. Life history of the primitive fungus-growing ant Mycetosoritis hartmanni in central Texas.

Hook, A. W. and S. D. Porter 1990. Destruction of harvester ant colonies by invading fire ants in south-central Texas (Hymenoptera: Formicidae). Southwestern Naturalist 35: 477-478.

Ishak, H.D., Plowes, R., Sen, R., Kellner, K., Meyer, E., Estrada, D.A., Dowd, S.E. and Mueller, U.G. 2011. Bacterial diversity in Solenopsis invicta and Solenopsis geminata ant colonies characterized by 16S amplicon 454 pyrosequencing. Microbial Ecology, 61(4), pp.821-831.

Kaspari, M. and E. L. Vargo 1994. Nest site selection by fire ant queens. Insectes Sociaux 41: 331-333.

Kaspari, M. and E. L. Vargo 1995. Colony size as a buffer against seasonality: Bergmann's rule in social insects. American Naturalist 145: 610-632.

Kaspari, M. 2000. Do imported fire ants impact canopy arthropods? Evidence from simple arboreal pitfall traps. The Southwestern Naturalist 45: 11

Keller, L. and E. L. Vargo 1993. Reproductive structure and reproductive roles in colonies of eusocial insects. In: Queen Number and Sociality in Insects. L. Keller (ed.). Oxford, Oxford University Press. pp. 16-44.

Kronforst, M. R., P. J. Folgarait, R. J. W. Patrock, and L. E. Gilbert. 2007. Genetic differentiation between body size biotypes of the parasitoid flyPseudacteon obtusus (Diptera: Phoridae). Molecular Phylogenetics and Evolution 43:1178-1184.

Lanza, J. 1991. Response of fire ants (Formicidae: Solenopsis geminata and S. invicta) to artificial nectars with amino acids. Ecological Entomology 16: 203-210.

Lanza, J., E. L. Vargo, S. Pulim, and Y. Z. Chang 1993. Preferences of the fire ants Solenopsis invicta and S. geminata (Hymenoptera: Formicidae) for amino acid and 

sugar components of extrafloral nectars. Environmental Entomology 22: 411-417.

LeBrun, E.G., Abbott, J. and Gilbert, L.E., 2013. Imported crazy ant displaces imported fire ant, reduces and homogenizes grassland ant and arthropod assemblages. Biological invasions, 15(11), pp.2429-2442.

LeBrun, E.G., Diebold, P.J., Orr, M.R. and Gilbert, L.E. 2015. Widespread Chemical Detoxification of Alkaloid Venom by Formicine Ants. Journal of chemical ecology, 41(10), pp.884-895.

LeBrun, E.G., Jones, N.T. and Gilbert, L.E. 2014. Chemical warfare among invaders: a detoxification interaction facilitates an ant invasion. Science, 343(6174), pp.1014-1017.

LeBrun, E. G., R. M. Plowes, and L. E. Gilbert. 2007. Dynamic expansion in recently introduced populations of fire ant parasitoids (Diptera: Phoridae). Biological Invasions Online: 10.1007/s10530-007-9177-y.

LeBrun, E. G., R. M. Plowes and L. E. Gilbert (2009). Indirect competition facilitates

widespread displacement of one naturalized parasitoid of imported fire ants by another.

Ecology 90(5): 1184-1194.

LeBrun, E.G., Plowes, R.M. and Gilbert, L.E. 2012. Imported fire ants near the edge of their range: disturbance and moisture determine prevalence and impact of an invasive social insect. Journal of Animal Ecology, 81(4), pp.884-895.

Mackay, W.P., S. Porter, D. Gonzalez, A. Rodriguez, H. Armendedo, A. Rebeles, and S.B. Vinson 1990. A comparison of monogyne and polygyne populations of the tropical fire ant, Solenopsis geminata (Hymenoptera: Formicidae), in Mexico. Journal of the Kansas Entomological Society 63: 611-615.

Mehdiabadi, N.J. and L.E. Gilbert. 2002. Colony-level impacts of parasitoid flies on fire ants. Proceedings of the Royal Society (Lond.). 269:1695-1699.

Mehdiabadi, N.J. and L.E. Gilbert. 2004a Phorid fly parasitoids of invasive fire ants indirectly improve the competitive ability of a native ant. Ecological entomology 29: 621-627.

Mehdiabadi, N.J. and L.E. Gilbert. 2004b. Parasitoids and competitors influence colony-level responses in the red imported fire ant, Solenopsis invicta flies on fire ants. Naturwissenschaften 91:539-543.

Morrison, L.W. 1999. Indirect effects of phorid fly parasitoids on interspecific competition between fire ants. Oecologia 121:113-122.

Morrison, L.W. 2000. Biology of Pseudacteon (Diptera: Phoridae) ant parasitoids and their potential to control imported Solenopsis fire ants (Hymenoptera: Formicidae). Recent Res. Devel. Entomol. 3: 1-13.

Morrison, L.W. 2000. Mechanisms of interspecific competition bewteen an invasive and two native fire ant species. Oikos 90:238-252.

Morrison, L.W. 2000. Mechanisms of Pseudacteon parasitoid (Diptera: Phoridae) effects on exploitative and interference competition in host Solenopsis ants (Hymenoptera: Formicidae). Annals of the Entomological Society of America 93:841-849.

Morrison, L.W. 2000. Biology of Pseudacteon (Diptera: Phoridae) ant parasitoids and their potential to control imported Solenopsis fire ants (Hymenoptera: Formicidae). Recent Res. Devel. Entomol. 3:1-13.

Morrison, L. et al. Long-term effects of the invasion of an arthropod community by the imported fire ant, Solenopsis invicta. In prep.

Morrison, L.W. and L.E. Gilbert 1998 Parasitoid-host relationships when host size varies: the case of Pseudacteon flies and Solenopsis fire ants. Ecological Entomology, 23:409-416.

Morrison, L.W. and L.E. Gilbert. 1999. Host specificity in two additional Pseudacteon spp. (Diptera: Phoridae), parasitoids of Solenopsis fire ants (Hymenoptera: Formicidae). Florida Entomologist 82:404-409.

Morrison, L.W., C.G.D. Holvorcem, and L.E. Gilbert. 1997. Oviposition behavior and development ofPseudacteon flies (Diptera: Phoridae), parasitoids of Solenopsis fire ants (Hymenoptera: Formicidae). Environmental Entomology 26:716-724.

Morrison, L.W., S.D. Porter, and L.E. Gilbert 1999. Sex ratio variation as a function of host size inPseudacteon (Diptera: Phoridae) parasitoid flies. Biol. J. Linnean Soc. 66:257-267.

Morrison, L.W., E.A. Kawazoe, R. Guerra, and L.E. Gilbert. 1999. Phenology and dispersal inPseudacteon flies (Diptera, Phoridae), parasitoids of Solenopsis fire ants (Hymenoptera, Formicidae). Annals of the Entomological Society of America. 92: 198-207.

Morrison, L.W., E.A. Kawazoe, R. Guerra, L.E. Gilbert 2000. Ecological interactions of Pseudacteonparasitoids and Solenopsis ant hosts: environmental correlates of activity and effects on interspecific competition. Ecological Entomology 25:433-444.

Orr, M.R., S.H. Seike, W.W. Benson, and L.E. Gilbert. 1995. Flies suppress fire ants. Nature 373: 292-293.

Orr, M. R., S. H. Seike, W. W. Benson, and L. E. Gilbert. 1996. Host location and attack behavior of parasitoid communities attacking fire ants in Brazil. Bulletin of the Ecological Society of America 77:335.

Orr, M.R., S.H. Seike, and L.E. Gilbert. 1997. Foraging ecology and patterns of diversification in dipteran parasitoids of fire ants in south Brazil, genus Pseudacteon (Phoridae). Ecological Entomology. 22:305-314.

Orr, M.R. and S.H. Seike. 1998. Parasitoids deter foraging by Argentine ants (Linepithema humile) in their native habitat in Brazil. 117:420-425.

Passera, L., E. L. Vargo, and L. Keller 1991. Le nombre de reines chez les fourmis et sa conséquence sur l'organisation sociale. Année Biologique 30: 137-173.

Patrock, R.J.W. andL.E. Gilbert. 2005. Ant midden as an aide in documenting a species inventory. Entomological News 116(3): 173-176.

Patrock, R.J.W. and L.E. Gilbert. In prep. Habitat effects on ant community interactions with native and imported fire ants on the edges of their distributin in the South Texas plains.

Patrock, R. J. W., G. E. Albioni Montenegro, L. E. Gilbert, and P. J. Folgarait. 2006. Possible identification of cryptic species of S. invicta using parasitoid flies: parasitoid host discrimination is population dependent. Pages 164-349 in XV Congress of the IUSSIs, Washington, DC.

Plowes, R.M., Becnel, J.J., LeBrun, E.G., Oi, D.H., Valles, S.M., Jones, N.T. and Gilbert, L.E. 2015. Myrmecomorba nylanderiae gen. et sp. nov., a microsporidian parasite of the tawny crazy ant Nylanderia fulva. Journal of invertebrate pathology, 129, pp.45-56.

Plowes, R.M., Folgarait, P.J. and Gilbert, L.E. 2012. The introduction of the fire ant parasitoid Pseudacteon nocens in North America: challenges when establishing small populations. BioControl, 57(4), pp.503-514.

Plowes, R.M., Folgarait, P.J. and Gilbert, L.E. 2014. Pseudacteon notocaudatus and Pseudacteon obtusitus (Diptera: Phoridae), two new species of fire ant parasitoids from South America. Zootaxa, 4032(2), pp.215-220.

Plowes, R. M., and L. E. Gilbert. 2007. Advances and challenges in biocontrol efforts against fire ants in Texas. Biocontrol News and Information 28:67-68.

Plowes, R.M., LeBrun, E.G. and Gilbert, L.E. 2011. Introduction of the fire ant decapitating fly Pseudacteon obtusus in the United States: factors influencing establishment in Texas. BioControl, 56(3), pp.295-304.

Plowes, R. M., J. G. Dunn, and L. E. Gilbert. 2007. The urban fire ant paradox: native fire ants persist in an urban refuge while invasive fire ants dominate natural habitats. Biological Invasions 9:825-836.

Plowes, R. M., E. G. LeBrun, B. V. Brown and L. E. Gilbert. 2009. A Review of Pseudacteon (Diptera: Phoridae) That Parasitize Ants of the Solenopsis geminata Complex (Hymenoptera: Formicidae). Ann. Entomol. Soc. Am. 102(6): 937-958.

Porter, S.D. 1988. Impact of temperature on colony growth and developmental rates of the ant,Solenopsis invicta. Journal of Insect Physiology 34: 1127-1133.

Porter, S.D. 1989. Effects of diet on the growth of fire ant colonies. Journal of the Kansas Entomological Society 62: 288-291.

Porter, S.D., A. Bhatkar, R. Mulder, S.B. Vinson, and D. Clair 1991. Distribution and density of polygyne fire ants (Hymenoptera: Formicidae) in Texas . Journal of Economic Entomology 84: 866-874.

Porter, S. D., B. V. Eimeren, and L. E. Gilbert 1988. Invasion of red imported fire ants (Hymenoptera: Formicidae): Microgeography of competitive replacement. Annals of the Entomological Society of America 81: 913-918.

Porter, S. D., H. G. Fowler, and W. P. MacKay 1992. Fire ant mound densities in the United States and Brazil (Hymenoptera: Formicidae). Journal of Economic Entomology 85: 1154-1161.

Porter, S. D. and D. Savignano 1990. An invasion of polygyne fire ants decimates native ants and disrupts arthropod community. Ecology 71: 2095-2106.

Porter, S. D. and L. E. Gilbert. 2005. Assessing host specificity and field release potential of fire ant decapitating flies (Phoridae: Pseudacteon). Van Driesche et al eds. Assessing host ranges for parasitoids and predators used for classical biological control: A guide to best practice. FHTET 2004-03 USDA Forest Service, Morgantown, W.V.

Porter, S.D. and L.E. Gilbert, 2005. Parasitoid Case History: An Evaluation of Methods Used to Assess Host Ranges of Fire Ant Decapitating Flies In “Proceedings, 2nd International Symposium of Biological Control of Arthropods” 12-16 September 2005, Davos, Switzerland (M. Hoddle, Ed.), pp.__.

Ross, K. G., E. L. Vargo, L. Keller, and J. C. Trager. 1993. Effect of a founder event on variation in the genetic sex-determining system of the fire ant Solenopsis invicta. Genetics 135: 843-854.

Ross, K.G., E. L. Vargo, and L. Keller. 1996. Simple genetic basis for important social traits in the fire ant Solenopsis invicta. Evolution 50: 2387-2399.

Ross, K. G., E. L. Vargo, and L. Keller. 1996. Social evolution in a new environment: The case of introduced fire ants. Proceedings of the National Academy of Sciences, USA 93: 3021-3025.

Sanchez-Peña, S., R.J.W. Patrock and L.E. Gilbert.2005 The red imported fire ant is now in Mexico: Documentation of its wide distribution along the Texas-Mexico border. Entomological News

Sharma, K.R. and Fadamiro, H.Y. 2013. Fire ant alarm pheromone and venom alkaloids act in concert to attract parasitic phorid flies, Pseudacteon spp. Journal of insect physiology, 59(11), pp.1119-1124.

Smith, C.R. and L.E. Gilbert. 2003. Differential attraction of a parasitoid to dead host ants. Florida Entomologist 86:479-480.

Tennant, L.E. and S.D. Porter 1991. Comparison of diets of two fire ant species (Hymenoptera: Formicidae): Solid and liquid components. Journal of Entomological Science 26: 450-465.

Tschinkel, W. R. and S. D. Porter 1988. The efficiency of sperm use in queens of the fire ant Solenopsis invicta Buren. Annals of the Entomological Society of America 81: 777-781.

Vargo, E.L. 1988. A bioassay for a primer pheromone of queen fire ants (Solenopsis invicta) which inhibits the production of sexuals. Insectes Sociaux 35: 382-392.

Vargo, E.L. 1988. The effect of pleometrosis and colony size on the production of sexuals in monogyne colonies of the fire ant (Solenopsis invicta). In: Advances in Myrmecology. J.C. Trager (ed.) Leiden, The Netherlands, E.J. Brill. pp. 217-225.

Vargo, E L. 1989. On differential reproduction among queens in polygyne colonies of the fire ant, Solenopsis invicta. Actes des Colloques Insectes Sociaux, London, L'Union Internationale pour les Etudes des Insectes Sociaux, Section francaise, Comptes Rendu Colloque Annuel 5: 109-116.

Vargo, E L. 1990. Social control of reproduction in fire ant colonies. In: Applied Myrmecology: A World Perspective. R.K. Vander Meer, K. Jaffe, and A. Cedeno (eds.) Boulder, CO, Westview Press. pp. 158-172.

Vargo, E L. 1992. Mutual pheromonal inhibition among queens in polygyne colonies of the fire antSolenopsis invicta. Behavioral Ecology and Sociobiology 31: 205-210.

Vargo, E.L. 1993. Colony reproductive structure in a polygyne population of the fire ant Solenopsis geminata (Hymenoptera: Formicidae). Annals of the Entomological Society of America 86: 441-449.

Vargo, E.L. 1996. Sex investment ratios in monogyne and polygyne populations of the fire antSolenopsis invicta. Journal of Evolutionary Biology. 9: 783-802.

Vargo, E.L. 1997. Poison gland of queen fire ants (Solenopsis invicta) is the source of a primer pheromone. Naturwissenschaften 84:507-510.

Vargo, E L. 1998. Primer pheromones in ants. In: Pheromone Communication in Social Insects. Ants, Wasps, Bees, and Termites. R. K. Vander Meer, M. Breed, K. Espelie and M. Winston (eds). pp. 293-313. Westview Press, Boulder, Colorado.

Vargo, E.L. 1999. Reproductive development and ontogeny of queen pheromone production in the fire ant Solenopsis invicta. Physiological Entomology. 24: 370-376.

Vargo, E.L. and D.J.C. Fletcher 1989. On the relationship between queen number and fecundity in polygyne colonies of the fire ant, Solenopsis invicta. Physiological Entomology 14: 223-232.

Vargo, E.L. and C.D. Hulsey. 2000. Multiple glandular origins of queen pheromones in the fire antSolenopsis invicta. Journal of Insect Physiology. 46: 1151-1159.

Vargo, E.L. and M. Laurel. 1994. Studies on the physiological mode of action of a queen primer pheromone in the fire ant Solenopsis invicta. Journal of Insect Physiology 40: 601-610.

Vargo, E.L. and L. Passera 1990. Role of overwintering and queen control in caste determination in the Argentine ant, Iridomyrmex humilis. Social Insects and the Environment: Eleventh Congress of International Union for the Study of Social Insects, Bangalore, India, Oxford and IBH Publishing Co., New Delhi pp. 174-175.

Vargo, E.L. and L. Passera 1991. Pheromonal and behavioral queen control over the production of gynes in the Argentine ant Iridomyrmex humilis (Mayr). Behavioral Ecology and Sociobiology 28: 161-169.

Vargo, E.L. and L.L. Passera 1992. Gyne development in the Argentine ant, Iridomyrmex humilis: role of overwintering and queen control. Physiological Entomology 17: 193-210.

Vargo, E.L. and S.D. Porter 1989. Colony reproduction by budding in the polygyne form ofSolenopsis invicta (Hymenoptera: Formicidae). Annals of the Entomological Society of America 82: 307-313.

Vargo, E.L. and S.D. Porter. 1993. Reproduction by virgin queen fire ants in queenless colonies: comparative study of three taxa (Solenopsis richteri, hybrid S. invicta/S.richteri, S. geminata) (Hymenoptera: Formicidae). Insectes Sociaux 40: 283-293.

Vargo, E.L. and K.G. Ross 1989. Differential viability of eggs laid by queens in polygyne colonies of the fire ant Solenopsis invicta. Journal of Insect Physiology 35: 587-593.

Valles, S.M., Oi, D.H., Plowes, R.M., Sanchez-Arroyo, H., Varone, L., Conant, P. and Webb, G. 2013. Geographic distribution suggests that Solenopsis invicta is the host of predilection for Solenopsis invicta virus 1. Journal of invertebrate pathology, 113(3), pp.232-236.

Waller, D.A. 1980. Leaf-cutting ants and leaf-riding flies. Ecological Entomology 5: 305-306.

Waller, D.A. 1982. Leaf-cutting ants and avoided plants: Defences against Atta texana attack. Oecologia 52: 400-403.

Waller, D.A. 1982. Leaf-cutting ants and live oak: The role of leaf toughness in seasonal and intraspecific host choice. Entomologia Experimentalis et Applicata 32: 146-150.

Waller, D.A. 1984. Pholeomyia texensis Sabrosky (Diptera: Milichiidae): Laboratory notes on larval biology. Southwestern Naturalist 29: 356-357.

Waller, D.A. 1986. The foraging ecology of Atta texana in Texas. In: Fire Ants and Leaf-cutting Ants: Biology and Management. C.S. Lofgren and R.K. Vander Meer (eds.) Boulder, Westview Press. pp. 146-158.

Waller, D.A. 1989. Size-related foraging in the leaf-cutting ant Atta texana (Buckley) (Formicidae: Attini). Functional Ecology 3: 461-468.

Waller, D.A. 1989. Foraging behavior of Trachymyrmex turrifex Wheeler (Formicidae: Attini). Southwestern Naturalist 34: 271-275.

Waller, D. and J.C. Moser 1990. Invertebrate enemies and nest associates of the leaf-cutting ant Atta texana (Buckley) (Formicidae, Attini). In: Applied Myrmecology: A World Perspective. R.K. Vander Meer, K. Jaffe, and A. Cedeno (eds.) Boulder, CO, Westview Press. pp. 255-273.

Walter, F., W. Francke, D.J.C. Fletcher, D. Chautems, D. Cherix, W. Fortelius, L. Keller, R. Rosengren, and E. L. Vargo 1993. Identification of the sex pheromone of an ant, Formica lugubris(Hymenoptera, Formicidae). Naturwissenschaften 80: 30-34.

Wilder, S.M., Holway, D.A., Suarez, A.V., LeBrun, E.G. and Eubanks, M.D. 2011. Intercontinental differences in resource use reveal the importance of mutualisms in fire ant invasions. Proceedings of the National Academy of Sciences, 108(51), pp.20639-20644.

Wuellner, C.T. Male aggregation by Solenopsis richteri Forel (Hymenoptera: Formicidae) and associated mating behavior in Argentina. J. Insect Behavior.13:751-756.

Wuellner, C.T., C.G. Dall'Aglio-Holvorcem, W.W. Benson, and L.E. Gilbert. 2002. Phorid fly (Diptera: Phoridae) oviposition behavior and fire ant (Hymenoptera: Formicidae) reaction to attack differ according to phorid species. Ann. Ent. Soc. Am. 95:257-266.

Wuellner, C.T. and J.B. Saunders. Circadian and circannual patterns of activity and territory shifts: comparing a native ant (Solenopsis geminata, Hymenoptera: Formicidae) with its exotic, invasive congener (S. invicta) and its parasitoids (Pseudacteon spp., Diptera: Phoridae) at a central Texas site. Annals Emtomol. Soc. Am. Accepted.

Wuellner, C.T., S.P. Porter, and L.E. Gilbert. Eclosion, mating, and grooming behavior of the parasitoid fly Pseudacteon curvatus Borgmeier (Phoridae). In prep.