Journal of the Kansas Entomological Society, Apr 1, 1981
The rediscovery of Pheidole lamia at its type lo cality is reported, and several aspects of its b... more The rediscovery of Pheidole lamia at its type lo cality is reported, and several aspects of its biology are clarified: 1) P. lamia is not confined to undisturbed woodlands, but is also found in recently disturbed wooded habitat. 2) P. lamia is not rare in Austin, although its inconspicuous nesting sites and foraging habits make it appear so. 3) It is suggested that the size of Austin colonies is probably near 500-1000 minor workers, the same order of magnitude as colonies found in Florida. In 1901, and more formally in 1908, William Morton Wheeler described Pheidole lamia from a small number of specimens collected in Austin, Tex as. The major workers of this species are strikingly different from the major workers of all other North American members of Pheidole. The heads of P. lamia major workers are elongate, subcylindrical in cross section and obliquely truncated in front, closely resembling the phragmotic heads of Camponotus (Colobopsis) major workers. Wheeler believed colonies of P. lamia to be small, hypogaeic and, at least in the Austin area, very patchily distributed. Furthermore, he suggested that the major workers may serve a dual function. First, like Camponotus (Colobopsis) major workers, they may use their "phragmotic" heads to block the entrances to nest galleries. Second, due to the large size of their gasters and their small numbers (1-4) in a colony, the major workers may also function as the queen caste. Until recently the validity of Wheeler's statements on P. lamia remained unchecked. P. lamia was not collected again until 1931 in Fayette, Missis sippi (Smith, 1931) and for only a third time in 1954 in Decatur County, Georgia (Gregg, 1956). Creighton repeatedly searched for P. lamia in the Austin area without success (Gregg, 1956). These geographically disjunct collecting records led Gregg (1956) to suggest that P. lamia is extremely rare and patchily distributed throughout the southeastern United States. More recently, Buren et al. (1977) collected numerous colonies of this species in Leon County, Florida. Unlike the collections reported by Wheeler (1901, 1908), Smith (1931) and Gregg (1956), these colonies were not small 1 A contribution from The University of Texas Brackenridge Field Laboratory, Austin, Texas. 2 Present address, Department of Zoology, University of Iowa, Iowa City, Iowa 52242. Received for publication 4 June 1980. This content downloaded from 207.46.13.167 on Thu, 21 Jul 2016 06:08:28 UTC All use subject to http://about.jstor.org/terms 270 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY and contained over 200 major workers and 1000 minor workers. Further more, observations by Buren et al. (1977) suggested that the heads of P. lamia major workers are not phragmotic, but, instead, are specialized for subterranean warfare against marauding thief ants, Solenopsis (Diplorhop trum) spp. Thus Wheeler appears to be mistaken on most of his conjectures regarding P. lamia. Buren et al. (1977), following Gregg (1956), suggested that Austin, Texas is a geographical fringe area for P. lamia, and that this fact may account for its apparent rarity and small colony size at the type locality. In this paper I report the rediscovery of Pheidole lamia at its type locality and present evidence that suggests this species is more common than previously thought and may maintain large colonies in this geographical "fringe area." Study Area and Methods I made all observations and collections at The University of Texas Brack enridge Field Laboratory, Austin, Texas. This area, adjacent to the Colo rado River, is a 32 hectare tract of semi-deciduous woodland in various stages of secondary succession. Residential structures stood on some of this land as late as 1960. The woodland is chiefly composed of oak (Quercus fusiformis and Q. texana), hackberry (Celtis reticulata and C. laevigata), cedar elm (Ulmus crassifolia) and post cedar (Juniperus ashei). In general the litter in this woodland is largely composed of U. crassifolia and Q. fusiformis leaves. To determine the composition of the litter-foraging ant fauna I established two 100 m transects and four 10 m x 10 m quadrats in 5 separate areas of the woodland. Transect 1 passed through Quadrat 2. All of these areas were in the same stage of secondary succession. Both transects contained 10 sites 10 m apart with 5 sampling stations per site. The 5 sampling stations were at the corners and center of squares 1.5 m on a side. Each of the 10 m x 10 m quadrats contained 81 sampling stations 1 m apart. In August 1975 I collected one 25 cm x 25 cm litter sample at each sampling station along both transects and extracted the arthropods using Berlese funnels. All litter was then returned to the appropriate stations. In 1976 and 1977, from mid April until late October, I monitored spatial distributions and activity pat terns of ant species along these transects by tunafish baiting at the same stations where litter samples were collected in 1975. In summer 1979…
Annals of The Entomological Society of America, Mar 1, 1987
ABSTRACT Solenopsis geminata (F.) and Solenopsis xyloni McCook, fire ants native to North America... more ABSTRACT Solenopsis geminata (F.) and Solenopsis xyloni McCook, fire ants native to North America, are attacked by at least three species of parasitic phorid flies. Oviposition behavior of one of these parasites, Pseudacteon crawfordi Coquillett, is described. This species inserts its oviscape in a thoracic suture of workers and apparently deposits eggs therein. P. crawfordi does not oviposit on all available workers, but tends to attack larger workers. Several reasons are suggested for size-selective oviposition in parasitic phorid flies, and the implications for host ant species are discussed.
The locomotion and load carriage energetics of the southwestern American harvester ant, Pogonomyr... more The locomotion and load carriage energetics of the southwestern American harvester ant, Pogonomyrmex rugosus, were quantified at several temperatures within their normal foraging temperature range using a voluntary locomotion regime (‘running tube respirometer’). In a metabolic rate (MR) versus running speed regression, the intercepts for the individual ants differed significantly, so data were evaluated using analysis of covariance (ANCOVA) rather than the more common pooling of individuals. Unladen cost of transport was 158 J kg−1 m−1. The mean y-axis intercept did not differ significantly from zero after temperature-corrected standard MR (SMR) had been subtracted from MR; i.e. the y-axis intercept was not elevated above SMR. When the data were pooled, standard tests of the cost of load carriage showed that the costs of load and body carriage were statistically equivalent. However, using ANCOVA to regress MR-SMR against the product of running speed and load ratio showed that the c...
Pheidole morrisi Forel is an omnivorous ant common throughout the eastern United States. Like all... more Pheidole morrisi Forel is an omnivorous ant common throughout the eastern United States. Like all members in the genus Pheidole the worker force is composed of morphologically distinct soldiers and workers. The aggressive ants Lasius alienus (Foerster) and Solenopsis geminata (F.) are frequently abundant in the same habitats occupied by P. morrisi. Experimental introductions of these two enemy species indicate that Florida col onies of P. morrisi alarm-recruit soldiers and workers against L. alienus but not against S. geminata. These enemy-specific defense responses are compared with defense responses in other Pheidole species and a general model of defense behavior is presented. Recent studies on Pheidole dentata Mayr and Pheidole militicida Wheeler in dicate that the soldier castes, which differ markedly in these two species, are specialized to defend nest sites and food sources against a small subset of potential enemy ant species (Feener, 1981, 1986; Wilson, 1975, 1976a, b). In particular, workers of both these species alarm-recruit soldiers against ants in the genus Solenopsis but do not alarm-recruit soldiers against a variety of other ant species. Carlin and Johnson (1984) discovered that the alarm-recruit response of P. dentata soldiers against Solenopsis is innate, however colonies can also learn to alarm recruit soldiers against other ant species, including species with no previous contact with P. dentata. The discovery of such enemy-specific defense behavior is of general interest for two reasons. First, it demonstrates that caste division of labor can be unexpectedly specific. Moreover, these studies indicate that morphology and behavior are not necessarily closely associated (Feener, 1986). Second, enemy-specific defense be havior clearly shows that ant colonies not only distinguish between nestmates and alien workers, but also among different species of ants. Differences among species in the expression of this behavior presumably reflect differences in the evolutionary and ecological history of interspecific interactions. In this paper, I examine the defense behavior of Pheidole morrisi Forel against two species of enemy ants, Lasius alienus (Foerster) and Solenopsis geminata (F.). P. morrisi is broadly distributed throughout the eastern United States. It prefers to nest in sandy soil in blow-outs, pastures and open woodlands. The diet of this species consists mostly of insects and other arthropods, and workers occasionally collect seeds. Most of the prey items returned to nests are retrieved by single workers, but nestmates can also effectively cooperate to retrieve prey items that are too large for individual workers. 1 Present Address: Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama. Accepted for publication 4 February 1987. This content downloaded from 207.46.13.73 on Thu, 11 Aug 2016 06:01:58 UTC All use subject to http://about.jstor.org/terms 570 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY L. alienus and S. geminata are aggressive species that nest in the same habitat as P. morrisi. L. alienus is geographically widespread, but is most abundant in the north and central eastern United States (Wilson, 1955). S. geminata, in con trast, does not occur in the northeastern United States, but it is abundant in the southeast (Creighton, 1950). The diet of L. alienus consists of arthropod prey and honeydew, whereas the diet of S. geminata consists of arthropod prey and seeds. Both species employ efficient mass recruitment systems to usurp and defend large or persistent food sources. Where they occur, these species are frequently nu merically and aggressively dominant and present a significant competitive threat to other ant species. Materials and Methods Field work was conducted between 29 July and 4 August 1983 in open hard wood-pine woodland in the Apalachicola National Forest, 25 km south of Tal lahassee, Leon Co., Florida. P. morrisi and S. geminata were the most abundant soil-nesting species at this locality. Other species present included Conomyrma sp., Pheidole dent ata Mayr, Pheidole metallescens Emery and Pogonomyrmex badius (Latreille). L. alienus did not occur at this locality and, in fact, is rare in northern Florida, the southern limit of its range. I did not find the imported fire ant, Solenopsis invicta Buren, in this study site, although it was very abundant in surrounding areas. Presumably P. morrisi colonies at this locality had no previous contact with either L. alienus or S. invicta. S. geminata workers used in the experiments described below were collected from colonies in the study area. L. alienus workers were collected from captive queenless colonies collected in Iroquois Co., Illinois and transported to Florida for the present study. P. morrisi was common at this Illinois locality, but S. geminata was absent. Responses of P. morrisi colonies to contact with L. alienus and S. geminata were assessed using the following experimental…
Pyrazines are an important group of natural products widely used as food additives and fragrants.... more Pyrazines are an important group of natural products widely used as food additives and fragrants. Gas chromatography-mass spectrometry (GC MS) is the most widely applied analytical technique for characterization of alkylpyrazines. However, mass spectra of many positional isomers of alkylpyrazines are very similar. Consequently, an unambiguous identification of each positional isomer by spectral interpretation or database search protocols is practically unfeasible. In fact, there are many misidentifications in literature. To identify alkylpyrazines, chemists often resort to gas chromatographic retention indices (RIs). Although there are many compilations of retention indices of alkylpyrazines, these databases are often incomplete and the values reported are sometimes inconsistent. Herein, we present retention indices of fifty-six alkylpyrazines recorded on DB-1, ZB-5MS, DB-624, and ZB-WAXplus stationary phases, and compare them with those available in the NIST-2017 MS-RI database. Furthermore, we demonstrate how RI values can be used, together with mass spectral interpretations, to identify certain alkylpyrazines unambiguously.
For workers at 28 C, standard Vo2 = 0.166 M.84 where Vo2 is ml h-' and M is mass in g. At th... more For workers at 28 C, standard Vo2 = 0.166 M.84 where Vo2 is ml h-' and M is mass in g. At the same temperature, pupal o02 = 0.156 M.83. Gross cost of transport (GCOT) and net cost of transport (NCOT) decreased with body mass and running speed, log GCOT = 0.87 - (1.05 log s) - ( ...
Standard rates of 02 consumption (Vo2) and net, gross, and minimum costs of transport (NCOT, GCOT... more Standard rates of 02 consumption (Vo2) and net, gross, and minimum costs of transport (NCOT, GCOT, and Mm) were measured in the leaf-cutting ant Atta co-lombica. Both closed (running wheel respirometer) and flow-through (treadmill) systems were used. The ...
Allometric scaling in ants with polymorphic castes often remains curvilinear after logarithmic tr... more Allometric scaling in ants with polymorphic castes often remains curvilinear after logarithmic transformation. A technique for comparing non-linear scaling is developed and used to compare caste polymorphism in the leaf-cutting ant Atta colombica Guerin and the army ant Eciton hamatum (Fab.). Of the five morphological characters compared, the scaling of leg length to the cube root of body mass (M1l3) differed the most: relative leg length increased with M1l3 in E. hamatum and decreased with M1l3 in A. colombica. This difference reflected species differences in the energetics and foraging behaviour. Key-words: Atta colombica, Eciton hamatum, leafcutters, army ants, curvilinear allometry, foraging ecology
Background/Question/Methods The factors driving the assembly of communities along spatial and env... more Background/Question/Methods The factors driving the assembly of communities along spatial and environmental gradients are actively debated among ecologists. Using an ant assemblage in a spatially heterogeneous region in Florida, we analyzed evidence for species segregation along spatial, temporal, and dietary axes that potentially promote species coexistence. We first examined species and functional group spatial co-occurrence patterns at local and regional scales, utilizing null models that incorporate abundance data and spatial/environmental constraints. To complement null model analyses, we analyzed ant species-environment relationships to examine whether habitat suitability represents a potential mechanism underlying regional co-occurrence patterns. To examine temporal segregation at the local scale, we assessed a suite of interspecific trade-offs associated with resource use and temperature stress in habitats spanning a temperature gradient. Finally, we used stable-isotope anal...
fore energy savings are actually c,onsiderably less than 10%. Leaf-cutting ants in the genera A u... more fore energy savings are actually c,onsiderably less than 10%. Leaf-cutting ants in the genera A u a and Acrornyrrnex are attacked by over 20 species of parasitic phorids. In the discussion we review what is known about these associations and suggest that these parasites have influenced the ecology and evolution of polyethism in leaf-cutting ants.
▪ Parasitoids in the insect order Diptera include an estimated 16,000 species, or approximately... more ▪ Parasitoids in the insect order Diptera include an estimated 16,000 species, or approximately 20% of the total number of species with this life-style. Parasitoids in this order are exceedingly diverse in both their habits and evolutionary origins, which makes them an underutilized but highly suitable group for quantitative studies of character convergence and adaptive radiation. This review focuses on several aspects of the bionomics of dipteran parasitoids that have received little comprehensive treatment, including processes associated with host location and attack, patterns of host use, and the evolutionary and ecological consequences of host-parasitoid interactions. Throughout the review we contrast the patterns found within the parasitic Diptera against those found in the better studied parasitic Hymenoptera. We conclude that more intensive study of dipteran parasitoids is required before we can understand the general conditions that favor the evolution of insect parasitoid...
Foraging activity of ants in xeric areas may be limited by desiccation stresses. To assess the ex... more Foraging activity of ants in xeric areas may be limited by desiccation stresses. To assess the extent of such stresses on a polymorphic ant species [Messor pergandei (Mayr), body mass range 1-12mg1, we measured body water reserves, absolute rates of water loss, and cuticular permeability over the species' foraging temperature range (15-45°C). Cuticular permeability of M.pergundei was typical of xeric arthropods (17 vg h-l mmHg-I). However, the effect of polymorphism on both absolute and relative rates of water loss was unexpected. Large workers lost water more slowly than small workers, even after adjusting for cuticular surface area. In addition, the body water reserves of large workers were larger, even after adjusting for body mass. Small workers of this ant species are therefore disproportionately prone to dehydration, yet, in spite of this, constitute a large and important component of the foraging force. To assess the practical relevance of desiccation to polymorphic ants, we developed a 'worst-case' model of desiccation-limited foraging parameters (time to complete loss of locomotor coordination in 5% of the foraging force). In this model, average actual foraging duration was substantially less than would be required to incapacitate the ants by dehydration. We discuss direct and indirect evidence suggesting that desiccation may, nevertheless, impose limitations on the foraging activity of ants.
This data file includes details of species richness and PIE from pitfall-trapped ant assemblages ... more This data file includes details of species richness and PIE from pitfall-trapped ant assemblages across the globe. The data includes the following information for 1128 assemblages: Locality_ID - A unique code for each locality; Source - Details of reference source for each dataset; Cluster - Geographic cluster used as a random factor in analyses; Latitude - Latitude provided by authors; Longitude - Longitude provided by authors; Mean annual temperature - Derived from WorldClim; Total annual precipitation - Derived from WorldClim; Temperature range - Derived from WorldClim; Disturbance - Disturbance described by authors; Hemisphere - Derived from Latitude; Continent - Continent provided by authors; Pitfall days - Number of pitfalls multiplied by trapping days; Transect length - Distance from first to last trap in transect; Species richness - Total number of species collected; PIE - Probability of Interspecific Encounter, a measure of species evenness. Further details are provided in the paper
Annals of the Entomological Society of America, 1992
... yr, the area oc-cupied by imported fire ants increased from 10 to 93 million ha in the southe... more ... yr, the area oc-cupied by imported fire ants increased from 10 to 93 million ha in the southeastern United States, an area which ... Presence of phorid parasitoids was easily assessed by direct obser-vation of the flies or indirectly by the distinctive defense posture assumed by the ...
What forces structure ecological assemblages? A key limitation to general insights about assembla... more What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships betwee...
Although water-loss rates and cuticular permeabilities have been investigated in several xeric ar... more Although water-loss rates and cuticular permeabilities have been investigated in several xeric arthropods, they are little known in ants, which are abundant and ecologically important in many arid regions. We report here the water-loss characteristics of Pogonomyrmex rugosus foragers; this harvester ant species (mean mass ca. 15 mg) is widespread in the deserts of the southwestern United States. Cuticular permeability at 25° C was 11.6μgH₂O cm−2 Torr−1 h−1, less than half the value calculated from published data for mesic ants. Cuticular permeability rose approximately exponentially with temperature, without a sharp transition point, and was not afected irreversibly by brief exposure to temperatures up to 60° C. Mean body water content was 65.9% of live body mass. Ants lost coordination at a body water content of 4.88 mg. This value did not scale with body mass. A predictive model is developed that allows the water balance and maximum exposure time of P. rugosus foragers to be calculated from environmental variables. Such models may aid in evaluating the physiological constraints imposed by the environment on foraging behavior.
Journal of the Kansas Entomological Society, Apr 1, 1981
The rediscovery of Pheidole lamia at its type lo cality is reported, and several aspects of its b... more The rediscovery of Pheidole lamia at its type lo cality is reported, and several aspects of its biology are clarified: 1) P. lamia is not confined to undisturbed woodlands, but is also found in recently disturbed wooded habitat. 2) P. lamia is not rare in Austin, although its inconspicuous nesting sites and foraging habits make it appear so. 3) It is suggested that the size of Austin colonies is probably near 500-1000 minor workers, the same order of magnitude as colonies found in Florida. In 1901, and more formally in 1908, William Morton Wheeler described Pheidole lamia from a small number of specimens collected in Austin, Tex as. The major workers of this species are strikingly different from the major workers of all other North American members of Pheidole. The heads of P. lamia major workers are elongate, subcylindrical in cross section and obliquely truncated in front, closely resembling the phragmotic heads of Camponotus (Colobopsis) major workers. Wheeler believed colonies of P. lamia to be small, hypogaeic and, at least in the Austin area, very patchily distributed. Furthermore, he suggested that the major workers may serve a dual function. First, like Camponotus (Colobopsis) major workers, they may use their "phragmotic" heads to block the entrances to nest galleries. Second, due to the large size of their gasters and their small numbers (1-4) in a colony, the major workers may also function as the queen caste. Until recently the validity of Wheeler's statements on P. lamia remained unchecked. P. lamia was not collected again until 1931 in Fayette, Missis sippi (Smith, 1931) and for only a third time in 1954 in Decatur County, Georgia (Gregg, 1956). Creighton repeatedly searched for P. lamia in the Austin area without success (Gregg, 1956). These geographically disjunct collecting records led Gregg (1956) to suggest that P. lamia is extremely rare and patchily distributed throughout the southeastern United States. More recently, Buren et al. (1977) collected numerous colonies of this species in Leon County, Florida. Unlike the collections reported by Wheeler (1901, 1908), Smith (1931) and Gregg (1956), these colonies were not small 1 A contribution from The University of Texas Brackenridge Field Laboratory, Austin, Texas. 2 Present address, Department of Zoology, University of Iowa, Iowa City, Iowa 52242. Received for publication 4 June 1980. This content downloaded from 207.46.13.167 on Thu, 21 Jul 2016 06:08:28 UTC All use subject to http://about.jstor.org/terms 270 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY and contained over 200 major workers and 1000 minor workers. Further more, observations by Buren et al. (1977) suggested that the heads of P. lamia major workers are not phragmotic, but, instead, are specialized for subterranean warfare against marauding thief ants, Solenopsis (Diplorhop trum) spp. Thus Wheeler appears to be mistaken on most of his conjectures regarding P. lamia. Buren et al. (1977), following Gregg (1956), suggested that Austin, Texas is a geographical fringe area for P. lamia, and that this fact may account for its apparent rarity and small colony size at the type locality. In this paper I report the rediscovery of Pheidole lamia at its type locality and present evidence that suggests this species is more common than previously thought and may maintain large colonies in this geographical "fringe area." Study Area and Methods I made all observations and collections at The University of Texas Brack enridge Field Laboratory, Austin, Texas. This area, adjacent to the Colo rado River, is a 32 hectare tract of semi-deciduous woodland in various stages of secondary succession. Residential structures stood on some of this land as late as 1960. The woodland is chiefly composed of oak (Quercus fusiformis and Q. texana), hackberry (Celtis reticulata and C. laevigata), cedar elm (Ulmus crassifolia) and post cedar (Juniperus ashei). In general the litter in this woodland is largely composed of U. crassifolia and Q. fusiformis leaves. To determine the composition of the litter-foraging ant fauna I established two 100 m transects and four 10 m x 10 m quadrats in 5 separate areas of the woodland. Transect 1 passed through Quadrat 2. All of these areas were in the same stage of secondary succession. Both transects contained 10 sites 10 m apart with 5 sampling stations per site. The 5 sampling stations were at the corners and center of squares 1.5 m on a side. Each of the 10 m x 10 m quadrats contained 81 sampling stations 1 m apart. In August 1975 I collected one 25 cm x 25 cm litter sample at each sampling station along both transects and extracted the arthropods using Berlese funnels. All litter was then returned to the appropriate stations. In 1976 and 1977, from mid April until late October, I monitored spatial distributions and activity pat terns of ant species along these transects by tunafish baiting at the same stations where litter samples were collected in 1975. In summer 1979…
Annals of The Entomological Society of America, Mar 1, 1987
ABSTRACT Solenopsis geminata (F.) and Solenopsis xyloni McCook, fire ants native to North America... more ABSTRACT Solenopsis geminata (F.) and Solenopsis xyloni McCook, fire ants native to North America, are attacked by at least three species of parasitic phorid flies. Oviposition behavior of one of these parasites, Pseudacteon crawfordi Coquillett, is described. This species inserts its oviscape in a thoracic suture of workers and apparently deposits eggs therein. P. crawfordi does not oviposit on all available workers, but tends to attack larger workers. Several reasons are suggested for size-selective oviposition in parasitic phorid flies, and the implications for host ant species are discussed.
The locomotion and load carriage energetics of the southwestern American harvester ant, Pogonomyr... more The locomotion and load carriage energetics of the southwestern American harvester ant, Pogonomyrmex rugosus, were quantified at several temperatures within their normal foraging temperature range using a voluntary locomotion regime (‘running tube respirometer’). In a metabolic rate (MR) versus running speed regression, the intercepts for the individual ants differed significantly, so data were evaluated using analysis of covariance (ANCOVA) rather than the more common pooling of individuals. Unladen cost of transport was 158 J kg−1 m−1. The mean y-axis intercept did not differ significantly from zero after temperature-corrected standard MR (SMR) had been subtracted from MR; i.e. the y-axis intercept was not elevated above SMR. When the data were pooled, standard tests of the cost of load carriage showed that the costs of load and body carriage were statistically equivalent. However, using ANCOVA to regress MR-SMR against the product of running speed and load ratio showed that the c...
Pheidole morrisi Forel is an omnivorous ant common throughout the eastern United States. Like all... more Pheidole morrisi Forel is an omnivorous ant common throughout the eastern United States. Like all members in the genus Pheidole the worker force is composed of morphologically distinct soldiers and workers. The aggressive ants Lasius alienus (Foerster) and Solenopsis geminata (F.) are frequently abundant in the same habitats occupied by P. morrisi. Experimental introductions of these two enemy species indicate that Florida col onies of P. morrisi alarm-recruit soldiers and workers against L. alienus but not against S. geminata. These enemy-specific defense responses are compared with defense responses in other Pheidole species and a general model of defense behavior is presented. Recent studies on Pheidole dentata Mayr and Pheidole militicida Wheeler in dicate that the soldier castes, which differ markedly in these two species, are specialized to defend nest sites and food sources against a small subset of potential enemy ant species (Feener, 1981, 1986; Wilson, 1975, 1976a, b). In particular, workers of both these species alarm-recruit soldiers against ants in the genus Solenopsis but do not alarm-recruit soldiers against a variety of other ant species. Carlin and Johnson (1984) discovered that the alarm-recruit response of P. dentata soldiers against Solenopsis is innate, however colonies can also learn to alarm recruit soldiers against other ant species, including species with no previous contact with P. dentata. The discovery of such enemy-specific defense behavior is of general interest for two reasons. First, it demonstrates that caste division of labor can be unexpectedly specific. Moreover, these studies indicate that morphology and behavior are not necessarily closely associated (Feener, 1986). Second, enemy-specific defense be havior clearly shows that ant colonies not only distinguish between nestmates and alien workers, but also among different species of ants. Differences among species in the expression of this behavior presumably reflect differences in the evolutionary and ecological history of interspecific interactions. In this paper, I examine the defense behavior of Pheidole morrisi Forel against two species of enemy ants, Lasius alienus (Foerster) and Solenopsis geminata (F.). P. morrisi is broadly distributed throughout the eastern United States. It prefers to nest in sandy soil in blow-outs, pastures and open woodlands. The diet of this species consists mostly of insects and other arthropods, and workers occasionally collect seeds. Most of the prey items returned to nests are retrieved by single workers, but nestmates can also effectively cooperate to retrieve prey items that are too large for individual workers. 1 Present Address: Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama. Accepted for publication 4 February 1987. This content downloaded from 207.46.13.73 on Thu, 11 Aug 2016 06:01:58 UTC All use subject to http://about.jstor.org/terms 570 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY L. alienus and S. geminata are aggressive species that nest in the same habitat as P. morrisi. L. alienus is geographically widespread, but is most abundant in the north and central eastern United States (Wilson, 1955). S. geminata, in con trast, does not occur in the northeastern United States, but it is abundant in the southeast (Creighton, 1950). The diet of L. alienus consists of arthropod prey and honeydew, whereas the diet of S. geminata consists of arthropod prey and seeds. Both species employ efficient mass recruitment systems to usurp and defend large or persistent food sources. Where they occur, these species are frequently nu merically and aggressively dominant and present a significant competitive threat to other ant species. Materials and Methods Field work was conducted between 29 July and 4 August 1983 in open hard wood-pine woodland in the Apalachicola National Forest, 25 km south of Tal lahassee, Leon Co., Florida. P. morrisi and S. geminata were the most abundant soil-nesting species at this locality. Other species present included Conomyrma sp., Pheidole dent ata Mayr, Pheidole metallescens Emery and Pogonomyrmex badius (Latreille). L. alienus did not occur at this locality and, in fact, is rare in northern Florida, the southern limit of its range. I did not find the imported fire ant, Solenopsis invicta Buren, in this study site, although it was very abundant in surrounding areas. Presumably P. morrisi colonies at this locality had no previous contact with either L. alienus or S. invicta. S. geminata workers used in the experiments described below were collected from colonies in the study area. L. alienus workers were collected from captive queenless colonies collected in Iroquois Co., Illinois and transported to Florida for the present study. P. morrisi was common at this Illinois locality, but S. geminata was absent. Responses of P. morrisi colonies to contact with L. alienus and S. geminata were assessed using the following experimental…
Pyrazines are an important group of natural products widely used as food additives and fragrants.... more Pyrazines are an important group of natural products widely used as food additives and fragrants. Gas chromatography-mass spectrometry (GC MS) is the most widely applied analytical technique for characterization of alkylpyrazines. However, mass spectra of many positional isomers of alkylpyrazines are very similar. Consequently, an unambiguous identification of each positional isomer by spectral interpretation or database search protocols is practically unfeasible. In fact, there are many misidentifications in literature. To identify alkylpyrazines, chemists often resort to gas chromatographic retention indices (RIs). Although there are many compilations of retention indices of alkylpyrazines, these databases are often incomplete and the values reported are sometimes inconsistent. Herein, we present retention indices of fifty-six alkylpyrazines recorded on DB-1, ZB-5MS, DB-624, and ZB-WAXplus stationary phases, and compare them with those available in the NIST-2017 MS-RI database. Furthermore, we demonstrate how RI values can be used, together with mass spectral interpretations, to identify certain alkylpyrazines unambiguously.
For workers at 28 C, standard Vo2 = 0.166 M.84 where Vo2 is ml h-' and M is mass in g. At th... more For workers at 28 C, standard Vo2 = 0.166 M.84 where Vo2 is ml h-' and M is mass in g. At the same temperature, pupal o02 = 0.156 M.83. Gross cost of transport (GCOT) and net cost of transport (NCOT) decreased with body mass and running speed, log GCOT = 0.87 - (1.05 log s) - ( ...
Standard rates of 02 consumption (Vo2) and net, gross, and minimum costs of transport (NCOT, GCOT... more Standard rates of 02 consumption (Vo2) and net, gross, and minimum costs of transport (NCOT, GCOT, and Mm) were measured in the leaf-cutting ant Atta co-lombica. Both closed (running wheel respirometer) and flow-through (treadmill) systems were used. The ...
Allometric scaling in ants with polymorphic castes often remains curvilinear after logarithmic tr... more Allometric scaling in ants with polymorphic castes often remains curvilinear after logarithmic transformation. A technique for comparing non-linear scaling is developed and used to compare caste polymorphism in the leaf-cutting ant Atta colombica Guerin and the army ant Eciton hamatum (Fab.). Of the five morphological characters compared, the scaling of leg length to the cube root of body mass (M1l3) differed the most: relative leg length increased with M1l3 in E. hamatum and decreased with M1l3 in A. colombica. This difference reflected species differences in the energetics and foraging behaviour. Key-words: Atta colombica, Eciton hamatum, leafcutters, army ants, curvilinear allometry, foraging ecology
Background/Question/Methods The factors driving the assembly of communities along spatial and env... more Background/Question/Methods The factors driving the assembly of communities along spatial and environmental gradients are actively debated among ecologists. Using an ant assemblage in a spatially heterogeneous region in Florida, we analyzed evidence for species segregation along spatial, temporal, and dietary axes that potentially promote species coexistence. We first examined species and functional group spatial co-occurrence patterns at local and regional scales, utilizing null models that incorporate abundance data and spatial/environmental constraints. To complement null model analyses, we analyzed ant species-environment relationships to examine whether habitat suitability represents a potential mechanism underlying regional co-occurrence patterns. To examine temporal segregation at the local scale, we assessed a suite of interspecific trade-offs associated with resource use and temperature stress in habitats spanning a temperature gradient. Finally, we used stable-isotope anal...
fore energy savings are actually c,onsiderably less than 10%. Leaf-cutting ants in the genera A u... more fore energy savings are actually c,onsiderably less than 10%. Leaf-cutting ants in the genera A u a and Acrornyrrnex are attacked by over 20 species of parasitic phorids. In the discussion we review what is known about these associations and suggest that these parasites have influenced the ecology and evolution of polyethism in leaf-cutting ants.
▪ Parasitoids in the insect order Diptera include an estimated 16,000 species, or approximately... more ▪ Parasitoids in the insect order Diptera include an estimated 16,000 species, or approximately 20% of the total number of species with this life-style. Parasitoids in this order are exceedingly diverse in both their habits and evolutionary origins, which makes them an underutilized but highly suitable group for quantitative studies of character convergence and adaptive radiation. This review focuses on several aspects of the bionomics of dipteran parasitoids that have received little comprehensive treatment, including processes associated with host location and attack, patterns of host use, and the evolutionary and ecological consequences of host-parasitoid interactions. Throughout the review we contrast the patterns found within the parasitic Diptera against those found in the better studied parasitic Hymenoptera. We conclude that more intensive study of dipteran parasitoids is required before we can understand the general conditions that favor the evolution of insect parasitoid...
Foraging activity of ants in xeric areas may be limited by desiccation stresses. To assess the ex... more Foraging activity of ants in xeric areas may be limited by desiccation stresses. To assess the extent of such stresses on a polymorphic ant species [Messor pergandei (Mayr), body mass range 1-12mg1, we measured body water reserves, absolute rates of water loss, and cuticular permeability over the species' foraging temperature range (15-45°C). Cuticular permeability of M.pergundei was typical of xeric arthropods (17 vg h-l mmHg-I). However, the effect of polymorphism on both absolute and relative rates of water loss was unexpected. Large workers lost water more slowly than small workers, even after adjusting for cuticular surface area. In addition, the body water reserves of large workers were larger, even after adjusting for body mass. Small workers of this ant species are therefore disproportionately prone to dehydration, yet, in spite of this, constitute a large and important component of the foraging force. To assess the practical relevance of desiccation to polymorphic ants, we developed a 'worst-case' model of desiccation-limited foraging parameters (time to complete loss of locomotor coordination in 5% of the foraging force). In this model, average actual foraging duration was substantially less than would be required to incapacitate the ants by dehydration. We discuss direct and indirect evidence suggesting that desiccation may, nevertheless, impose limitations on the foraging activity of ants.
This data file includes details of species richness and PIE from pitfall-trapped ant assemblages ... more This data file includes details of species richness and PIE from pitfall-trapped ant assemblages across the globe. The data includes the following information for 1128 assemblages: Locality_ID - A unique code for each locality; Source - Details of reference source for each dataset; Cluster - Geographic cluster used as a random factor in analyses; Latitude - Latitude provided by authors; Longitude - Longitude provided by authors; Mean annual temperature - Derived from WorldClim; Total annual precipitation - Derived from WorldClim; Temperature range - Derived from WorldClim; Disturbance - Disturbance described by authors; Hemisphere - Derived from Latitude; Continent - Continent provided by authors; Pitfall days - Number of pitfalls multiplied by trapping days; Transect length - Distance from first to last trap in transect; Species richness - Total number of species collected; PIE - Probability of Interspecific Encounter, a measure of species evenness. Further details are provided in the paper
Annals of the Entomological Society of America, 1992
... yr, the area oc-cupied by imported fire ants increased from 10 to 93 million ha in the southe... more ... yr, the area oc-cupied by imported fire ants increased from 10 to 93 million ha in the southeastern United States, an area which ... Presence of phorid parasitoids was easily assessed by direct obser-vation of the flies or indirectly by the distinctive defense posture assumed by the ...
What forces structure ecological assemblages? A key limitation to general insights about assembla... more What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51,388 ant abundance and occurrence records of more than 2693 species and 7953 morphospecies from local assemblages collected at 4212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type and degree of disturbance. The aim of compiling this dataset was to provide comprehensive species abundance data in order to test relationships betwee...
Although water-loss rates and cuticular permeabilities have been investigated in several xeric ar... more Although water-loss rates and cuticular permeabilities have been investigated in several xeric arthropods, they are little known in ants, which are abundant and ecologically important in many arid regions. We report here the water-loss characteristics of Pogonomyrmex rugosus foragers; this harvester ant species (mean mass ca. 15 mg) is widespread in the deserts of the southwestern United States. Cuticular permeability at 25° C was 11.6μgH₂O cm−2 Torr−1 h−1, less than half the value calculated from published data for mesic ants. Cuticular permeability rose approximately exponentially with temperature, without a sharp transition point, and was not afected irreversibly by brief exposure to temperatures up to 60° C. Mean body water content was 65.9% of live body mass. Ants lost coordination at a body water content of 4.88 mg. This value did not scale with body mass. A predictive model is developed that allows the water balance and maximum exposure time of P. rugosus foragers to be calculated from environmental variables. Such models may aid in evaluating the physiological constraints imposed by the environment on foraging behavior.
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Papers by Donald Feener