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Vitellogenin (Vg) has been recognized as a co‐opted gene involved in social colonies where it is associated with reproduction in the queen and task transitions in workers. The Solenopsis invicta genome harbours four Vg genes, Vg1, Vg2, Vg3 and Vg4, and this study explored the regional expression of these genes in the brain and head of the worker caste in different subcaste and social contexts. Transcriptomic analyses of the worker brain while in the presence or absence of brood revealed differential expression of genes involved with social behaviours. Among these, we found higher expression of Vg2 and Vg3 in the brains of workers in the absence of brood. The influence of brood on expression of Vg between worker castes was also investigated. RT‐qPCR revealed higher expression of Vg in the head of workers in the absence of brood. Further studies demonstrated that Vg was also differentially expressed in the heads of workers conducting specific tasks and differing between subcastes. Nurses maintained higher Vg expression than foragers. We conclude worker Vg expression may be linked to the brood and/or nutritional state. Vg expression changes when workers are deprived of protein suggesting it is regulated by nutritional signalling and the presence of brood. [ABSTRACT FROM AUTHOR]

Most of the fire ants alien Solenopsis species, major pests of various horticulture crops. We have reported Solenopsis from crop fields and, through traditional taxonomy, these have been identified as Solenopsis geminata. The present investigation was performed to generate the DNA barcode of this species, for the elucidation of genetic structure collected from the Kalaburagi region. The generated DNA barcode of mitochondrial COI was deposited to the International Barcode of Life Database (BOLD: http://www.boldsystems.org). The barcode, along with its related information, are publicly available on the BOLD website with code MZ669889. It is the first such study from Kalaburagi region. Furthermore, DNA barcoding of fire ant's species accomplished from Maharashtra, Aurangabad (KC685060 & KC685063), Kerala, Malappuram (KP994543), Karnataka, Bangalore (KJ486555, KY000665 & JN886028) is in line with our findings. This study provides a detailed support for further wet lab study in support of traditional taxonomy. [ABSTRACT FROM AUTHOR]

AbstractThe present study adds new data on the natural history of Dendrobates tinctorius. We conducted our fieldwork during the rainy season of the years 2018 and 2019 in two protected areas (Parque Natural Municipal do Cancão–PNMC and Reserva Extrativista Beija-Flor Brilho de Fogo–REBFBF) in the state of Amapá, Brazil. Through active visual searches we sampled 22 individuals of D. tinctorius, of which 10 were counted for the population of PNMC and 12 for the population of REBFBF. We calculated the Body Condition Index (BCI) for all individuals and, for dietary data, each frog’s stomach was flushed. Females from the REBFBF were larger than males when compared to the PNMC population. BCI of females from the REBFBF showed higher values than males. Gravid females of both populations showed higher BCI. Retrieved stomachs revealed a total of 290 prey items divided into four main taxonomic categories of Arthropods. The Index of Relative Importance revealed that ants of the genus Solenopsis were the majority of the diet, and mites represented only 4.86%. The niche breadth for both populations was narrow, indicating a specialist diet, as expected for the species. Our study evidences the importance of integration between BCI and dietary aspects. [ABSTRACT FROM AUTHOR]

The populations usually attributed to Solenopsis bivonae (Tineo) M.B.Crespo, Serra & A.Juan are investigated from a taxonomical and morphological viewpoint. Within this species complex, four new subspecies occurring in Sicily and Calabria are recognized, such as subsp. bivonae, subsp. madoniarum, subsp. peloritana and subsp. brutia. In addition, a new species from Cyprus described as S. meikleana and S. bacchettae from Sardinia must be included in this group. The synonymy, typification, description, seed testa morphology, chorology, ecology, illustrations, conservation status, and examined specimens for each taxon are provided. Besides, the analytical keys, distribution maps, and phytosociological arrangement regarding these taxa are given too. [ABSTRACT FROM AUTHOR]

The red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) causes serious damage worldwide as an invasive alien species. The species has expanded its range to the Pacific Rim since 2000s and Japan has faced its multiple introductions since 2017. While colony-level control methods are urgently needed, testing living colonies of the unestablished species is challenging especially due to various restrictions under the COVID-19 pandemic. Here, we proposed alternative long-term toxicity assays using artificial colonies of Tetramorium tsushimae Emery (Hymenoptera: Formicidae), a Japanese native species belonging to the same subfamily (Myrmicinae) as S. invicta. We conducted an acute toxicity test to determine if T. tsushimae is a suitable substitute for S. invicta using fipronil and found the LD50 value in T. tsushimae was close to that in S. invicta. Then, we conducted the long-term toxicity test with fipronil and two insect growth regulators (pyriproxyfen and etoxazole) using artificial colonies of T. tsushimae. All workers and larvae in the fipronil-treated colonies died within 3 days of treatment initiation. Emergence of new workers was observed after 18 days in the etoxazole-treated and control colonies, but not in the pyriproxyfen-treated colonies. We concluded that fipronil was the most promising insecticide for post-establishment control, and pyriproxyfen was effective as a toxic-bait agent for colony-level control. [ABSTRACT FROM AUTHOR]

The ephemeral hygrophilous vegetation occurring in the temporary ponds of Apulia (southern Italy) weres studied following the phytosociological approach. On the base of 153 phytosociological relevés carried out during the period 2015-2018, 19 associations were identified, of which 16 described for the first time. All the associations belong to the Isoeto-Nanojuncetea class. The surveyed associations can be arranged in two orders, such as Isoetetalia, including those with a winter-spring cycle and Nanocyperetalia, regarding those with a summertime cycle. The identified association has been examined in detail, and for each one, we provided a phytosociological table. The communities belonging to the Isoetetalia are 17 and arranged in four alliances (Isoetion, Preslion cervinae, Cicendio filiformis-Solenopsion laurentiae, Agrostion salmanticae); instead, those ones of Nanocyperetalia are two both included in the Verbenion supinae. In order to highlight the relationships among the associations, all the relevés used for this investigation are processed. Overall, this analysis confirms the autonomy of the associations, grouping them according to the syntaxonomic arrangement proposed by the authors. Taxonomic investigations on the flora occurring in these habitats allowed the detection of two new subspecies of Solenopsis laurentia, both with a different autoecology.

The red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae), is a serious invasive alien ant around the world and has expanded its invasive range to the Pacific Rim since the early 2000s. It was first reported in Japan in 2017, and its entry through cargo has been reported numerous times in many ports. Colonies have been found in Tokyo Port since 2019, and now it is an urgent issue to prevent further invasion and establishment. Chemical control is the best tested method of insect control, but we have little information on the efficacy of insecticides against S. invicta in Japan. Here, we conducted acute toxicity assays of six quick-acting pyrethroids (transfluthrin, prallethrin, phenothrin, permethrin, metofluthrin, and pyrethrin) for killing adults and five new-type insecticides (fipronil, thiamethoxam, indoxacarb, imidacloprid, and hydramethylnon) for controlling colonies with toxic baits. We found that the LD50 from six pyrethroids were comparable to each other. The ED50 causing abnormal behaviors were smaller than LD50, but some ants recovered from paralysis within 12 h. Fipronil showed the lowest LD50 suggesting this chemical is the most promising agent for controlling S. invicta. Our results promise to develop a method for the chemical control of S. invicta. [ABSTRACT FROM AUTHOR]

Red imported fire ant (Solenopsis invicta Buren; RIFA) and black imported fire ant (Solenopsis richteri Forel (Hymenoptera: Formicidae); BIFA) are considered distinct species with introgression via a reproductively functional hybrid (HIFA). The RIFA and BIFA common names are based on relative coloration. Due to human color perception variation, using color to identify RIFA, BIFA or HIFA is challenging. Fire ant identification traditionally involves molecular or chemical techniques, but a colorimetric test could allow rapid and low-cost identification. In this study, ant integument coloration was measured by spectrophotometer, and color attributes were compared to a combined gas chromatography (GC) index derived from cuticular hydrocarbon and venom alkaloid indices. Significant Pearson Correlation coefficients were found for colony GC index versus color attributes red to green (a*), blue to yellow (b*), chroma (C*), and hue (h*), but not lightness (L*). The RIFA colonies were distinct from BIFA for four of five color attributes and plots of the a*b* and C*h* horizontal axis of the L*a*b* and L*C*h* color spaces. Color attributes for HIFA indices were not distinct from BIFA and RIFA parental species, but HIFA a*b* and C*h* plots were distinct from RIFA and a*b* plots from BIFA. Color attributes a*, b*, and C* increased and h* decreased with GC index in a sinusoidal pattern. In conclusion, most RIFA and BIFA color attributes were distinct and a*b* and C*h* color axes plots had potential to distinguish HIFA from parental species, but coloration of HIFA indices was variable and complicated identifications among HIFA phenotypes, RIFA and BIFA. [ABSTRACT FROM AUTHOR]

Sardinia is the second largest island in the Mediterranean region, receiving significant attention due to its interesting fauna and flora. The last checklist of Sardinian ants was published more than a decade ago, and, since then, it got outdated by numerous taxonomic and faunistic novelties. As a result of recent collecting efforts across the island, we present the first Sardinian records of Messor ibericus Santschi, 1931, Solenopsis lusitanica Emery, 1915 (new to Italy), Temnothorax aveli Bondroit, 1918 and Tetramorium atratulum (Schenck, 1852), while proposing to consider Solenopsis fugax (Latreille, 1798) and Temnothorax affinis (Mayr, 1855) as absent. We report for the first time a parasite-host association between Tetramorium atratulum and Tetramorium semilaeve André, 1883, and the conspicuous presence of ergatogynes within a Solenopsis colony (S. lusitanica). Morphological insights on the little-known S. lusitanica and S. orbula Emery, 1875 are also discussed. We combined the new findings and previous literature data into an updated checklist of 77 taxa and discuss a first biogeographic analysis of the Sardinian ants aided by chorotypes. Eurasian, European, Euro-Mediterranean and West-Mediterranean taxa are the numerically prevalent groups, while the overall number of species is significantly lower than in the other large Mediterranean islands. Considerable knowledge gaps still remain and some species are known to require additional taxonomic investigation. [ABSTRACT FROM AUTHOR]

Fire ants (Solenopsis spp.) are bothersome insects to both humans and the environment alike. Due to their prevalence in areas near human habitation, we sought to determine a substance that the ants find attractive that could be used in future control methods. To answer our question, we designed a simple experiment in which Solenopsis sp. specimens were each given the opportunity to choose from a variety of sugars and oils that were presented on a piece of paper in front of them. It was determined that fire ants have a stronger attraction to substances higher in fatty acids, such as cooking oils, than carbohydrates. These results have shown that when devising a home remedy for controlling these insects, individuals would have the most success if they were to use an oil-based product in their control method. [ABSTRACT FROM AUTHOR]

Ants are a widespread group of ecologically important insects. Therefore, ants that are important predators of other ants are likely to play key roles by changing the abundance and impacts of their prey. Familiar arthropod predators, like army ants, are known for their overwhelming raids on invertebrate prey but are limited to mostly tropical systems. Thief ants (Genus: Solenopsis Westwood) are a cosmopolitan group of mostly subterranean ants found in a wide variety of ecosystem types. They are known for their extremely small sizes and their specialized predation where they stealthily tunnel into the nests of other larger ant species to capture and consume only immature ants (larvae and pupae). Predation of ant colonies by other ants, and specialized predatory behaviors of presumed top ant predators (e.g., army ants) are well known. However long‐term predation effects, such as across several seasons, are still poorly understood because of a lack of experimental studies. Here we report results of a ~1.5‐year press field experiment where thief ants were reduced in natural ant communities. Potential impacts, such as predator‐release, were quantified by sampling the co‐occurring ant community. Compared to control plots, overall worker abundance and biomass increased where thief ants were reduced, and effects varied among ant species. Results suggest predator release as select aboveground foraging ant species increased in abundance and that thief ants may act as significant predators. Because thief ants are abundant and widespread, similar predatory effects may occur in many ant communities, and our understanding of important predators may need to adjust to include thieving species as well as army ants. Thief ants are very abundant, tiny, specialized to consume immature life stages, equipped with powerful venom, eusocial, and subterranean. This suite of adaptive traits seems unique to eusocial predators compared to animals, where "thieving" predators are usually larger in size compared to their adult‐sized prey. Future work quantifying top‐down regulation of prey and cascading consumptive and non‐consumptive effects will help to understand thief ant predation and potential effects on ecosystem processes. [ABSTRACT FROM AUTHOR]

Ants (Hymenoptera, Formicidae) are an efficient group of insects as predators of various arthropods. Based on records of the predatory ant activity, a survey was carried out on the efficiency in predation of Anastrepha fraterculus (Diptera: Tephritidae) larvae, considering the percentage of removal of larvae using the variables of soil density and moisture content and their effect on the larvae burying. For this, A. fraterculus larvae were released to the soil and observed for 10 min while burying or removed by the ants in a peach (Prunus persica, Rosaceae) orchard. Eight ant species were recorded removing 32.70% of the larvae. Solenopsis saevissima was the most efficient species, with 42.86% of larvae removal. There were no significant correlations between the predation by ants with soil density and soil moisture content. Despite this, the study pointed out that ants belong to genera Pachycondyla, Pheidole, Pogonomyrmex and Solenopsis can be predators on A. fraterculus larvae, with emphasis on the S. saevissima. These ants can contribute as important agents of conservative biological control of the population of A. fraterculus in peach orchard and their conservation becomes interesting to use of combined control methods aiming to reduce insecticides and aggressive soil management methods.

Fire ants (Solenopsis spp.) are bothersome insects to both humans and the environment alike. Due to their prevalence in areas near human habitation, we sought to determine a substance that the ants find attractive that could be used in future control methods. To answer our question, we designed a simple experiment in which Solenopsis sp. specimens were each given the opportunity to choose from a variety of sugars and oils that were presented on a piece of paper in front of them. It was determined that fire ants have a stronger attraction to substances higher in fatty acids, such as cooking oils, than carbohydrates. These results have shown that when devising a home remedy for controlling these insects, individuals would have the most success if they were to use an oil-based product in their control method. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • CHCs play an important role in water proofing of fire ants. • S. richteri , S. invicta and their hybrids had distinctive CHC profiles. • The order of T m-max s of CHCs was S. invicta ≥ hybrid > S. richteri. • T c-CHC significantly correlates to T m-max obtained from the same CHCs sample. • CHC chemistry might have shaped current fire ant distribution pattern in USA. Abstract Two sibling species, Solenopsis richteri and S. invicta , were both introduced into the southern USA from South America in the early 20th century. Today, S. richteri occupies higher latitudes and colder areas, while S. invicta occupies lower latitudes. Between the distributions of the two species, there is a large area of viable hybrid (S. richteri × S. invicta) populations. This study aimed to characterize the forces driving this distribution pattern and the underlying mechanisms. Cuticular hydrocarbons (CHCs) of freshly killed workers of S. invicta , hybrids, and S. richteri were removed using hexane. Both intact and CHCs-extracted workers were subjected to a constant rate of increasing temperature from 10 to 60 °C to obtain relative water loss and the water loss transition temperature (T c-ant). Mass loss and T c-ant were both significantly increased with CHCs removal. We then examined the CHC composition of three species. CHC profiles of S. richteri are characterized by significant amounts of short-chain (C 23 –C 27) saturated and unsaturated hydrocarbons. In contrast, profiles of S. invicta consist primarily of long-chain (C 27 –C 29) saturated hydrocarbons; unsaturated alkenes are completely lacking. Hybrid fire ants show intermediate profiles of the two parent species. We measured the melting point (T m) and water-loss transition temperature of CHC blends (T c-CHC) of different ant species colonies using differential scanning calorimetry (DSC) and an artificial membrane system, respectively. There were 3–5 T m s of each CHCs sample of different ant colonies due to their complex chemistry. The highest T m s (T m-max s) of CHCs samples from S. invicta and the hybrid were significantly higher than that from S. richteri. The correlation between T c-CHC and T m-max obtained from the same CHCs sample was highly significant. These results reveal that species having higher T c and T m-max retain more water under relatively higher temperature, and consequently are able to occupy warmer environments. We conclude that CHC chemistry plays a role in shaping current distribution patterns of S. richteri , S. invicta and their hybrid in the United States. [ABSTRACT FROM AUTHOR]

Many familiar Hymenoptera are brightly colored and can sting painfully–thus, their threat and clinical importance may be exaggerated. Most stinging insects only sting to defend themselves or their colonies from predators. The clinical nature of Hymenoptera envenomations contrasts that of other venomous animals, including other arthropods, primarily because allergic reaction, not direct intoxication, is the usual main concern. This review focuses mainly on the clinical features of direct toxicity to Hymenoptera envenomations, which can induce a high incidence of acute renal failure, liver failure, multiple organ failures, and death. Toxic mass envenomations by honeybees usually entail many hundreds or more stings per victim. In contrast to honeybee toxic envenomations, hornet sting envenomations can be clinically threatening with only 20–200 stings needed to cause kidney and other organ failures. Many lethal envenomations by honeybees occur in rural areas in the New World and Africa and are not recorded or documented. In contrast, deaths by hornets occur mainly to Asia. The most frequent and important envenomating taxa are honeybees, hornets, yellowjacket wasps, paper wasps, fire ants, and jack jumper ants. Occasional envenomating taxa include bumblebees, bullet ants, harvester ants, solitary wasps, solitary bees, and various ants of lesser clinical importance. Envenomations by Hymenoptera usually can be avoided if one considers that bees, wasps and ants “view” us as potential threats or predators, and that with information about the biology of stinging Hymenoptera, humans can minimize adverse incidents. [ABSTRACT FROM AUTHOR]

Myrmicinosporidium durum is an enigmatic fungal parasite of ants with an unclear phylogeny and life cycle. Despite the fact that new records of this fungus have been revealed in the last few years; several countries from Eastern Europe still lack such information. With this study, we reveal the most northerly location of this fungus to date and its first record in Poland a contribution to filling the gaps in data about its European distribution. Additionally, we present an updated compilation of the world distribution of M. durum and its host ant species. [ABSTRACT FROM AUTHOR]

Ant imprints, new and previously known, from Middle Miocene deposits near Kerch (Crimean Peninsula, Russia) are described or redescribed. A new Myrmicinae species, Solenopsis atavinus sp. nov., is described based on a wingless female. A winged female similar to the earlier described Dolichoderus tauricus Dlussky, 1981 is found: due to the excellent preservation of this specimen, the new specimen and the holotype of D. tauricus are redescribed and can be reclassified as Ponerites tauricus (Dlussky, 1981), comb. nov. Oecophylla taurica sp. nov. is described based on a partly preserved imprint of a female thorax with a forewing, the venation of which allows it to be positively identified as a weaver ant. Two other species are transferred from the formal genus Camponotites to Oecophylla based on forewing venation: O. kraussei (Dlussky et Rasnitsyn, 1999), comb. nov. (Early Eocene, United States) and O. macroptera (Dlussky, 1981), comb. nov. (Middle Miocene, Stavropol, Russia). One of the studied forewing imprints is similar in venation to Paraphaenogaster microphthalmus Dlussky, 1981, described from the Middle Miocene of Vishnevaya Balka (Stavropol province, Russia) and so is attributed to this species. Dolichoderus tavridus sp. nov. is described based on a forewing. [ABSTRACT FROM AUTHOR]

The populations usually attributed to Solenopsisbivonae (Tineo) M.B.Crespo, Serra & A.Juan are investigated from a taxonomical and morphological viewpoint. Within this species complex, four new subspecies occurring in Sicily and Calabria are recognized, such as subsp. bivonae, subsp. madoniarum, subsp. peloritana and subsp. brutia. In addition, a new species from Cyprus described as S.meikleana and S.bacchettae from Sardinia must be included in this group. The synonymy, typification, description, seed testa morphology, chorology, ecology, illustrations, conservation status, and examined specimens for each taxon are provided. Besides, the analytical keys, distribution maps, and phytosociological arrangement regarding these taxa are given too., Competing Interests: No conflict of interest was declared., (Salvatore Brullo, Cristian Brullo, Salvatore Cambria, Valeria Tomaselli, Alessandro Crisafulli, Giuseppe Siracusa, Pietro Minissale, Gianpietro Giusso del Galdo.)

RESUMEN. Fóridos del género Pseudacteon Coquillett oviponen en forrajeras del género Solenopsis Westwood y empupan en sus cabezas. Se evaluó la relación entre la viabilidad de los parasitoides, la presencia de cuernos respiratorios y el color en los opérculos de los puparios de cuatro especies de Pseudacteon criados sobre Solenopsis invicta Buren y Solenopsis richteri Forel. La presencia de cuernos respiratorios estuvo asociada a la viabilidad de las pupas para las especies consideradas (p < 0,01), pero no el color de los opérculos (p > 0,09); excepto cuando Pseudacteon cultellatus Borgmeier se desarrolló sobre hormigas de la reserva y niñeras de S. invicta (p < 0,01). Los opérculos claros predominaron en P. cultellatus; mientras que en las demás especies, que atacan a hormigas más grandes, predominaron los opérculos castaños. Debido a que los opérculos presentaron un color similar al de la hormiga parasitada, esto representaría un mimetismo por parte del parasitoide para evitar ser detectado por el huésped. Dado que los cuernos respiratorios son necesarios para la supervivencia de la mayoría de las pupas, sugerimos que sean usados como indicadores de eficiencia en los protocolos de cría. Recomendamos usar solo forrajeras dado que las otras castas no parecen ser huéspedes apropiados.ABSTRACT. Pseudacteon Coquillett phorid flies oviposit on Solenopsis Westwood ants and pupate within the ant's head. We have evaluated the relationship between pupae's viability, presence of respiratory horns and the operculum color in four species of Pseudacteon reared on Solenopsis invicta Buren and Solenopsis richteri Forel ants. The presence of respiratory horns was significantly associated with pupae's viability for all species considered (p < 0,001) but operculum color was not (p > 0,09), except (p < 0,01) when Pseudacteon cultellatus Borgmeier had developed on S. invicta nanitic and reserve workers. Pupae with light-colored opercula were more frequent in P. cultellatus, whereas brown opercula were more frequent for the other species that attack bigger ants. Mimetism can be invoked to explain the similarity in opercula color with that of the head of the parasitized ant as a way to avoid recognition by members of the colony. We conclude that the presence of respiratory horns is necessary for pupae survival of most of the pupae and we suggest to use the presence of respiratory horns as an indicator of the efficiency of rearing protocols for this group of parasitoids. We also recommend using forager ants because other casts do not seem to be appropriate hosts.

Predaceous ant fauna present in natural sugarcane field plantations in the state of São Paulo, Brazil, was evaluated by using sardine baits sampling technique. Three-month-old sugarcane plants were used for ant fauna estimation in two sugarcane mills, São João and Barra Mill. Twelve 30m X 30 m (900 m²) plots were previously delimited in each sugarcane mill for ant sampling. Ants were sampled in each plot by placing nine sardine baits in 12 mm X 75 mm plastic tubes. In the São João Mill, the predominant ant species observed was Solenopsis saevissima, followed by Dorymyrmex sp. 1, Pheidole sp. 2, and Crematogaster sp. 1. Considering only ant genus, Solenopsis, Pheidole, Dorymyrmex, and Crematogaster, were predominant. In the Barra Mill, the predominant ant genus sampled was Solenopsis, followed by Pheidole, Crematogaster, and Dorymyrmex. As generalist predatory ants could be one of the reasons for the naturally low levels of D. saccharalis infestation on sugarcane in the state of São Paulo, this study could be helpful for the researchers to gain knowledge about the fauna of predaceous ants which acted as predators of eggs and early larval stages of D. saccharalis in Brazil.A fauna de formigas predadoras presentes em lavouras de cana-de-açúcar localizadas no Estado de São Paulo, Brasil, foi avaliada utilizando-se iscas de sardinha. Plantas de três meses de idade foram utilizadas para a estimativa da fauna de formigas predadoras em duas usinas de cana-de-açúcar, usina São João e usina da Barra. Doze áreas [30m X 30 m (900 m²) cada] foram previamente delimitadas em cada usina para a coleta das formigas. As formigas foram amostradas colocando-se nove iscas no solo por área, sendo cada isca composta por um tubo de ensaio plástico (12 mm X 75 mm), contendo sardinha em seu interior. Na usina São João, a espécie de formiga predominante observada foi Solenopsis saevissima, seguida por Dorymyrmex sp. 1, Pheidole sp. 2, and Crematogaster sp. 1. Considerando apenas o gênero, os mais abundantes foram Solenopsis, Pheidole, Dorymyrmex e Crematogaster. Na usina da Barra, o gênero predominante amostrado foi Solenopsis, seguido por Pheidole, Crematogaster e Dorymyrmex. Como a predação por formigas predadoras generalistas deve ser uma das razões para os baixos níveis populacionais das infestações de Diatraea saccharalis em lavouras de cana-de-açúcar no Estado de São Paulo, este estudo ajudará futuras pesquisas destinadas a se conhecer as formigas predadoras que de fato agem como predadoras de ovos e estágios larvais iniciais de D. saccharalis no Brasil.

Habitat selection is one of many aspects of red imported fire ants, Solenopsis invicta Buren, (RIFA) that has been intensively studied since their initial introduction in the United States. Concurrently, innumerable studies have attempted to identify effective chemical insecticides for RIFA control. More recently, several species of Pseudacteon spp. phorid flies (Diptera: Phoridae) have been intensively evaluated to determine their potential utility in biologica control of RIFA. These flies belong to a suite of natural enemies of RIFA in their native South American range, and have been selected for release in the United States as biological control agents against RIFA. It is hypothesized that phorid flies, through parasitism and suppression of RIFA foraging, will provide measureable RIFA population suppression as phorid ranges expand and fly densities increase. Relatively little scientific attention has been paid to habitat selection and partitioning by these flies in their introduced range(s) in the US. We assessed RIFA and phorid (Pseudacteon curvatus and Pseudacteon tricuspis) densities in four central Texas habitats. The habitat types selected represent a continuum of habitat diversity, micro-habitat availability, and plant heterogeneity. Within the habitat types studied, RIFA mound densitieswere significantly different, but foraging intensity was not significantly different in three of four habitat types. Population densities of P. curvatus were determined to be significantly higher in one habitat than all others. Alternatively, P. tricuspis densities followed a trend within the surveyed habitats that correlated with RIFA densities observed in this study. These data imply that the successful release, establishment, and range expansion of P. curvatus may require a greater degree of critical consideration regarding the ecologyof each system into which they are released, as opposed to P. tricuspis. These implications also suggest that the successful establishment of additional phorid species in the US should take into consideration the habitat matrix and habitat-based expansion corridors available to the flies.

Se revisa la información sobre biología de hormigas presentes en Chile publicada en revistas científicas nacionales y extranjeras durante el período 1900-1999. Se evalúan estos antecedentes en términos de: (i) la dinámica temporal de la producción de publicaciones, (ii) las principales temáticas de estudio, y (iii) los géneros de formícidos en los cuáles se ha concentrado la investigación. Los datos recolectados muestran que sólo a partir de la década del 60' se produce un marcado crecimiento del número de artículos sobre hormigas, lo cual alcanza su máxima expresión durante la década del 90'. Los principales tópicos de investigación han sido, en orden decreciente, aspectos sobre taxonomía, uso del hábitat, períodos de actividad, conductas tróficas y de reconocimiento entre individuos. Los géneros de formícidos en los que se han centrado estos estudios corresponden a Camponotus, Solenopsis, Pogonomyrmex, Brachymyrmex, Conomyrma y Linepithema. Estos resultados son discutidos a la luz de acontecimientos históricos que habrían determinado el curso de las investigaciones. Finalmente, se proponen líneas de investigación que en el futuro podrían desarrollar los estudios sobre hormigas en ChileInformation is reviewed on the biology of ants found in Chile published in national and foreign scientific journals during the period 1900-1999. The information is evaluated in terms of: (i) temporal dynamics of publication production, (ii) main themes of study, and (iii) formicid groups in which the investigation has been concentrated. The collected data show that in the decade the 60's, the number of articles on ants grew, reaching a peack during the 90's. The main topics of investigation have been, in decreasing order, aspects of taxonomy, habitat use, periods of activity, trofic behavior and inter-individuals recognition. The formicid groups in which these studies have been focused correspond to Camponotus, Solenopsis, Pogonomyrmex, Brachymyrmex, Conomyrma and Linepithema. These results are discussed in the light of historical events that may have determined the course of research. Finally, future lines of investigation for the studies of ants in Chile are proposed

Ants are social, and their metabolism should be measured on at least two levels: (i) the individual workers and brood of which the colony is composed and (ii) the colony in its entirety. Whole colony respiration, tempo (size-free running speed in body lengths per second) and whole colony activity were simultaneously measured for 15 species of ants in four subfamilies, and these data are related to average worker and whole-colony weight, activity, percentage brood and percentage fat. Across all 15 species, whole colony respiration rate (μL CO2 h−1) is linearly related to whole colony live weight (log-log slope = 1.0). Colonies composed of large workers respire less than colonies composed of an equal live weight of small workers, and colonies with high tempos respire more than lower tempo colonies of equal weight. The tempos and respiration rates of smaller ants tend to be higher, and a higher tempo exacts a cost in higher respiration independent of the effect of small body size. Individual worker respiration (μL CO2 h−1) scales to worker live weight with an exponent of 0.76. Whole colony specific respiration rate (μL CO2 g−1 h−1) is unrelated to colony live weight. The regressions of respiration rates against colony and worker dry weight, lean weight and metabolic weight have similar slopes to those of live weight but different intercepts. Respiration is not related to worker percentage fat, percentage brood or activity. Ant ecology, tempo, body size, polymorphism and colony size are discussed in relation to respiration. [ABSTRACT FROM AUTHOR]

The article discusses the consumption of bird feces by fire ant Solenopsis geminata in a garden at a residential area in Caracas, Venezuela. The author observed that the ant consumed feces from mistnetted Blue-gray tanager Thraupis episcopus that contained mostly papaya pulp. Other ant species that also consume bird feces are mentioned, including Cephalotes atratus and Camponotus sericeiventris.

1. The coffee berry borer Hypothenemus hampei ( Coleoptera, Curculionidae) (Ferrari) is the most important pest of coffee production worldwide. 2. The hypothesis that the tropical fire ant, Solenopsis geminata Westwood, indirectly protects the coffee berry borer by suppressing other ant species that are the coffee berry borer's primary predators was tested. 3. It was found that removing S. geminata from coffee plots significantly increased the disappearance of adult coffee berry borer beetles from coffee berries compared with control plots. An average of 6% of beetles disappeared from plots with S. geminata whereas 23% of beetles disappeared from plots from which S. geminata was removed. This pattern was observed on two shade coffee farms with marked differences in ant species composition, one in the rainforest in central Costa Rica and one in the cloudforest in northwest Costa Rica. 4. If the results of this small-scale study can be replicated on the farm level, then S. geminata suppression may represent a new management technique for the coffee berry borer throughout Central and South America. [ABSTRACT FROM AUTHOR]

Tradeoffs in functional traits facilitate species coexistence within communities and are important contributors to community assembly. Two aspects of a life-history tradeoff known to structure ant communities include foraging efficiency (i.e. resource discovery and retrieval) and competitive dominance (territoriality and survivorship following competition)., This work examined these aspects in workers of two fire ant species ( Solenopsis xyloni and Solenopsis geminata) and their F1 hybrids using laboratory experiments., Parental foraging strategies were consistent with a tradeoff between discovery efficiency and competitive territorial dominance. Desert-adapted S. xyloni was the most efficient forager but the least effective territory defender; mesic-adapted S. geminata was a less efficient forager, but fared best in competition trials. Hybrid workers were generally intermediate, leading to increased survival by hybrids in competitive encounters with S. geminata compared with the performance of S. xyloni., These findings suggest that traits associated with foraging and competitive ability in the parental species are subject to environmental filtering; across habitats, species with a similar dominance rank in their respective communities differ in their placement along the discovery-dominance axis., Interspecific hybridisation may play a role in extending eastern range limits of S. xyloni via shifting colony allocation towards the strategy of its competitor. In the overlap zone, S. xyloni with hybrid workers may be sufficiently competitive to persist with S. geminata, while colonies with S. xyloni workers cannot, providing a substantial selective advantage to hybridisation for S. xyloni queens that may explain the unusual hybridogenetic social structure of this population. [ABSTRACT FROM AUTHOR]

Several species of fire ants, well known for their painful stings, have spread from their native ranges and have become invasive pests, notably Solenopsis geminata, Solenopsis invicta, and Solenopsis richteri. Here, I report the first known exotic spread of another fire ant, Solenopsis nr. saevissima, a South American species now established on the French West Indian island of Guadeloupe. In 2008, I first found this shiny yellow fire ant at Plage de Viard beach on Guadeloupe. Genetic analyses indicated that this species was close to the yellow-brown variant of S. saevissima known only from Western Amazonia, but not an exact match. I returned to Guadeloupe in 2011 and found S. nr. saevissima at Plage de Viard plus five additional sites along a >20 km stretch on the east coast of Basse-Terre, from the Jarry commercial shipping port in the north to Plage Roseau in the south. It seems most likely that S. nr. saevissima arrived in Guadeloupe from South America in a commercial shipment unloaded at the port in Jarry. It is unclear whether this species will develop into a major new problem. Solenopsis nr. saevissima may simply replace another pernicious fire ant, S. geminata, which apparently arrived in Guadeloupe from South America several 100 years ago. [ABSTRACT FROM AUTHOR]

Contemporary adaptation of native prey species to invasive predators has been relatively well documented, but that of native predators to invasive prey has received less attention. Because the level of impact an invasive species will have on its predators versus its prey will determine changes in community trophic structure, it is important to understand how native predators respond to novel prey. Here we examine the response of native fence lizards to the invasion of red imported fire ants, a novel toxic prey. Examining invaded and uninvaded lizard populations, we tested whether or not aversion-learning occurs in juvenile fence lizards over successive feedings (within lifetime), how previous fire ant exposure may affect avoidance behavior (over generations), and whether population differences are consistent when prey choice exists. We also examine rates of phenotypic divergence in traits associated with the native species as both predator and prey. Aversion-learning did not occur in either population. Instead, the incidence of fire ant consumption increased over both successive feedings and generations. Lizards from the fire ant invaded population had a higher propensity to eat fire ants than fire ant-naïve lizards, even when given a choice between prey items. We found greater phenotypic divergence in traits associated with the native species as predator on, versus as prey to, fire ants. Although the strategy of eating these novel toxic prey can impose survival costs in the short term, over the longer-term, eating fire ants may cost little or even benefit survivors. [ABSTRACT FROM AUTHOR]

Responses to novel threats (e.g. invasive species) can involve genetic changes or plastic shifts in phenotype. There is controversy over the relative importance of these processes for species survival of such perturbations, but we are realizing they are not mutually exclusive. Native eastern fence lizards ( Sceloporus undulatus) have adapted to top-down predation pressure imposed by the invasive red imported fire ant ( Solenopsis invicta) via changes in adult (but not juvenile) lizard antipredator behaviour. Here, we examine the largely ignored, but potentially equally important, bottom-up effect of fire ants as toxic prey for lizards. We test how fire ant consumption (or avoidance) is affected by lifetime (via plasticity) and evolutionary (via natural selection) exposure to fire ants by comparing field-caught and laboratory-reared lizards, respectively, from fire ant-invaded and uninvaded populations. More naive juveniles from invaded populations ate fire ants than did adults, reflecting a natural ontogenetic dietary shift away from ants. Laboratory-reared lizards from the invaded site were less likely to eat fire ants than were those from the uninvaded site, suggesting a potential evolutionary shift in feeding behaviour. Lifetime and evolutionary exposure interacted across ontogeny, however, and field-caught lizards from the invaded site exhibited opposite ontogenetic trends; adults were more likely to eat fire ants than were juveniles. Our results suggest that plastic and evolutionary processes may both play important roles in permitting species survival of novel threats. We further reveal how complex interactions can shape adaptive responses to multimodal impacts imposed by invaders: in our system, fire ants impose stronger bottom-up selection than top-down selection, with each selection regime changing differently across lizard ontogeny. [ABSTRACT FROM AUTHOR]

We revise the four species of Kaszabister Mazur, 1972, one of which, Kaszabister barrigai sp. n., is described as new. The other species in the genus are K. rubellus (Erichson, 1834), K. ferrugineus (Kirsch, 1873) and K. carinatus (Lewis, 1888). The species are principally known from the subtropics of South America, with one in Central America. Lectotypes are designated for K. rubellus and K. ferrugineus, and a key is provided for all the species. Ants of the genus Solenopsis Westwood, mainly S. invicta Buren and S. saevissima (Smith), are documented as hosts of three of the four species. [ABSTRACT FROM AUTHOR]

Insecticides are widely used to manage turfgrass pest such as white grubs (Coleoptera: Scarabaeidae). Red imported fire ants, Solenopsis invicta (Buren) are important predators and pests in managed turfgrass. We tested the susceptibility of white grub life stages (adults, egg, and larvae) to predation by S. invicta and determined if insecticides applied for control of S. invicta would result in locally greater white grub populations. Field trials over 2 yr evaluated bifenthrin, fipronil, and hydramethylnon applied to large and small scale turfgrass plots for impacts on fire ant foraging and white grub populations. Coincident with these trials, adults, larvae, and eggs of common scarab species were evaluated for susceptibility to predation by S. invicta under field conditions. Field trials with insecticides failed to show a significant increase in white grub populations resulting from treatment of turfgrass for fire ants. This, in part, may be because of a lack of predation of S. invicta on adult and larval scarabs. Egg predation was greatest at 70% but <20% of adults and larvae were attacked in a 24 h test. Contrary to other studies, results presented here suggest that fire ants and fire ant control products applied to turfgrass have a minimal impact on white grub populations. [ABSTRACT FROM AUTHOR]

Invasive species eradication and control are considered vital components of the conservation, restoration, and management of many native ecosystems. Invasive ants, which are notoriously difficult to eradicate, can cause catastrophic changes in ecosystems and are aggressive colonists. Here we report the eradication and control of two widely distributed invasive ants and subsequent unanticipated effects on arthropod and avian communities. We used a paired experimental design that included 1 year of baseline data collection, to test the effects of the formicide hydramethylnon on abundances of two ant species on two pairs of offshore islets. Pheidole megacephala was eradicated from the treated islet in pair 1 and was not detected during 2003-2008. On pair 2 Solenopsis geminata numbers declined, but the species remained present. Target ant densities remained high on untreated islets. Application of hydramethylnon reduced numbers of alien cockroaches (Order: Blattaria), but we did not detect effects on other non-target arthropods. The eradication of P. megacephala was followed by dynamic compositional changes in the ant community, including the apparent colonization by three species ( S. geminata, Tetramorium bicarinatum and Anoplolepis gracilipes) previously undetected on the islet. One of these, A. gracilipes, underwent a rapid range expansion during 2006-2008 which corresponded with reduced seabird nesting success. We conclude that hydramethylnon can be used effectively to eradicate P. megacephala. However, ant eradications can have detrimental effects on ecosystems and the potential for subsequent colonization of sites by other ant species that may be more harmful and more difficult to eradicate needs to be considered. [ABSTRACT FROM AUTHOR]

Multiple species of Pseudacteon phorid flies (Diptera: Phoridae) are currently being released throughout the southern United States to aid biological control of red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae). It is anticipated that these flies will interfere with S. invicta foraging, allowing native ant assemblages to outcompete S. invicta for available resources. Numerous studies have shown a decrease in S. invicta foraging intensity when exposed to phorids. This study documents a behavioral change in phorid-exposed S. invicta colonies at a phorid release site in central Texas. Significant differences in forager size ratios were detected between phorid-exposed and phorid-absent colonies. A similar phenomenon was recently documented in the native range of these insects in South America as well. Experimental manipulation of ratios of S. invicta worker sizes has been shown to have important effects on colony success. This newly documented phorid-mediated S. invicta colony-level effect represents a significant shift in S. invicta foraging dynamics and may provide an additional mechanism by which phorids can influence S. invicta populations in their United States range. [ABSTRACT FROM AUTHOR]

Species delimitation has been invigorated as a discipline in systematics by an influx of new character sets, analytical methods, and conceptual advances. We use genetic data from 68 markers, combined with distributional, bioclimatic, and coloration information, to hypothesize boundaries of evolutionarily independent lineages (species) within the widespread and highly variable nominal fire ant species Solenopsis saevissima, a member of a species group containing invasive pests as well as species that are models for ecological and evolutionary research. Our integrated approach uses diverse methods of analysis to sequentially test whether populations meet specific operational criteria (contingent properties) for candidacy as morphologically cryptic species, including genetic clustering, monophyly, reproductive isolation, and occupation of distinctive niche space. We hypothesize that nominal S. saevissima comprises at least 4–6 previously unrecognized species, including several pairs whose parapatric distributions implicate the development of intrinsic premating or postmating barriers to gene flow. Our genetic data further suggest that regional genetic differentiation in S. saevissima has been influenced by hybridization with other nominal species occurring in sympatry or parapatry, including the quite distantly related Solenopsis geminata. The results of this study illustrate the importance of employing different classes of genetic data (coding and noncoding regions and nuclear and mitochondrial DNA [mtDNA] markers), different methods of genetic data analysis (tree-based and non–tree based methods), and different sources of data (genetic, morphological, and ecological data) to explicitly test various operational criteria for species boundaries in clades of recently diverged lineages, while warning against over reliance on any single data type (e.g., mtDNA sequence variation) when drawing inferences. [ABSTRACT FROM PUBLISHER]

Some phorid flies of the genus Pseudacteon Coquillett parasitize workers of Solenopsis geminata (F.) complex fire ants. The group is found to comprise at least 21 species of flies, of which 11 are new to science and described here: P. amuletum, P. andinus, P. annulus, P. catarinae, P. deltoides, P. hippeus, P. kungae, P. laticarinatus, P. palomita, P. quinni, and P. robustus. An identification key to the females is included. This expansion of known Pseudacteon species parasitizing the S. geminata complex makes it an interesting system for comparison with Pseudacteon flies that parasitize fire ants of the S. saevissima (Smith) complex. [ABSTRACT FROM AUTHOR]

Phorid flies are well known myrmecophilic organisms and are often parasitoids of ants. In some cases, phorids live commensally with ants, with the colony offering protection and/or feeding opportunities. In this study we examined the phorid Commoptera solenopsidis in association with a new host species, Pheidole dentata . An ethogram was performed describing the fly and its association with different P. dentata castes. The flies spent most of their time performing grooming behaviors, allogrooming ants, or self-grooming and most commonly were associated with the major workers. We discuss the significance of this association as well as the possible evolutionary driving force behind C. solenopsidis having multiple hosts. [ABSTRACT FROM AUTHOR]