Species Of Phorid Flies Research Articles

Megaselia kaarinaensis – a new species of Megaselia Rondani (Diptera: Phoridae) from Finland

A new species of phorid fly in the genus Megaselia, collected by Malaise trap in southwestern Finland, is described.

Sixteen in One: White-Belted Megaselia Rondani (Diptera: Phoridae) From the New World Challenge Species Concepts

Abstract We review the species of Megaselia similar to Megaselia sulphurizona Borgmeier. A close examination of M. sulphurizona indicates that its current concept includes at least 16 species, 15 of which— Megaselia albizona, Megaselia borealizona, Megaselia colombizona, Megaselia cryptizona, Megaselia danizona, Megaselia guanizona, Megaselia marizona, Megaselia nivizona, Megaselia oklizona, Megaselia paulizona, Megaselia reductizona, Megaselia solizona, Megaselia tropizona, Megaselia wendizona, and Megaselia winnizona are described as new, based primarily on molecular data. The identity of the holotype of the species M. sulphurizona is clarified through wing vein morphometrics. Two of the new species, M. albizona and M. cryptizona, are the 47th and 48th new species of phorid fly described from the BioSCAN project, an urban biodiversity study in Los Angeles, California, U.S.

Differential parasitism by four species of phorid flies when attacking three worker castes of the leaf-cutting ant Atta laevigata (Smith, 1858).

Certain species of parasitic flies belonging to the Phoridae are known to attack Atta spp. workers foraging along trails, near nest openings used by the ants to supply the colony with plant material, and in the areas where the ants are actively cutting plant material. However, there have been no previous studies of phorid parasitism of non-foraging worker ants, for example excavators and soldiers. Excavators can be found on the surface around specialized nest openings, carrying and dumping soil on characteristic mounds. Soldiers can be found on the trails protecting foragers or guarding the different types of nest openings. The current study was performed to investigate the differential parasitism rates of Atta laevigata (Smith, 1858) worker castes by four species of phorids. Ants of all castes on trails and at nest entrances were collect from 18 mature colonies in the field. A total of 21,254 ants were collected from trails and 14,649 collected from the mounds of loose soil near nest openings. The captured workers were maintained under controlled laboratory conditions to evaluate the rate of parasitism. Of the ants collected from trails, 1,112 (5.23%) were found to have been parasitized, of which 1,102 were foragers and only 10 were soldiers. Of the ants collected from the soil mounds near the nest openings, only 27 (0.18%) were found to have been parasitized, of those 25 were excavators and 2 were soldiers. When evaluating parasitism of ants on the trails, 46.2% were attacked by Apocephalus attophilus Borgmeier, 1928, 22.6% by Myrmosicarius grandicornis Borgmeier, 1928, 16.6% by Eibesfeldtphora erthali (Brown, 2001) and 14.6% by Apocephalus vicosae Disney, 2000. Only two species of phorid, M. grandicornis and E. erthali, were observed parasitizing excavators, whilst only E. erthali parasitized soldiers. This is the first time that Atta spp. excavators and soldiers have been shown to be parasitized by phorids. The low rates of parasitism and specificity of certain phorid species for excavators and soldiers is discussed in relation to the behavioral interactions of hosts and their parasitoids, as well as the relationship between host and parasitoid size.

Remarkable sexually dimorphic features ofConiceromyia(Diptera: Phoridae): evolution in the light of phylogeny and comparative evidence about their function

AbstractConiceromyia is a genus of 100 species of phorid flies mostly distributed in the Neotropical region. The genus is distinguishable based on several male-exclusive features in different parts of the body, many of which are unique among the Phoridae. In addition, many species of Coniceromyia have nearly identical morphology of their male copulatory apparatus (i.e. hypopygium). The co-occurrence of these unusual characteristics suggests an evolutionary correlation between them. To investigate this possible correlation and to understand other aspects of the evolution of these puzzling male-exclusive characters, we performed the first phylogenetic analysis of Coniceromyia, based on morphological and molecular data. Ancestral state reconstructions and comparative analyses then allowed us to infer the evolution of these characters and search for general evolutionary patterns and correlated histories. We demonstrate that these male-exclusive features varied from highly homoplastic to uniquely derived on the phylogenetic history of Coniceromyia. For some characters, we found evidence of a biased evolution favouring gains over losses of the feature, but no male characteristics were significantly correlated with hypopygium morphology. The evolutionary patterns of the male-exclusive features and comparative evidence with other better known groups suggest possible functions for these features related to sexual selection.

A Species delimitation approach to uncover cryptic species in the South American fire ant decapitating flies (Diptera: Phoridae: Pseudacteon).

South American fire ant decapitating flies in the genus Pseudacteon (Diptera: Phoridae) are potential biocontrol agents of the invasive fire ants Solenopsis invicta and S. richteri in the United States and other regions of the world due to their high host specificity and the direct and indirect damage to their host ants. Despite their importance and the fact that several flies have already been released in the US, little is known about the genetic variability and phylogenetic relationships of Pseudacteon flies parasitizing South American fire ants in the Solenopsis saevissima species-group. A species delimitation analysis was conducted using a distance-based method (ABGD) and two tree-based methods (GMYC and mPTP) using COI sequences of 103 specimens belonging to 20 of the 22 Pseudacteon species known from southern South America. Additionally, phylogenetic relationships between the already described and new candidate species were inferred using mitochondrial (COI) and nuclear (wingless) sequences. The species delimitation analysis suggests that species richness in these flies has been previously underestimated, due to the existence of putative cryptic species within nominal Pseudacteon obtusus, P. pradei, P. tricuspis, P. cultellatus, and P. nudicornis. Geographic distribution and host fire ant species seem to support cryptic lineages, though additional morphological data are needed to corroborate these results. All phylogenetic analyses reveal that South American fire ant decapitating flies are grouped into two main clades, with Pseudacteon convexicauda sister and well differentiated relative to these clades. Neither host nor geographic association appeared to be related to the differentiation of these two main clades within South American fire ant decapitating flies. This work provides information that will allow testing whether the putative cryptic phorid fly species show differences in their effectiveness as biocontrol agents against the highly invasive imported fire ants.

New records and new host-parasitoid interactions of phorids (Diptera: Phoridae) parasitizing leafcutter ants (Hymenoptera: Formicidae) in Argentina

Leafcutter ants are one of the most important crop pests in the Neotropics. In the present study, several specimens were collected from four provinces in Argentina in order to determine the species of phorid flies parasitizing them. We report our findings on seven phorid species, Apocephalus neivai Borgmeier, Ap. noetingerorum Disney, Neodohrniphora unichaeta Disney, Myrmosicarius catharinensis Borgmeier, M. cristobalensis Disney, M. crudelis Borgmeier and M. gracilipes Borgmeier, over the leafcutter ants Acromyrmex ambiguus Emery, Ac. crassispinus Forel, Ac. heyeri Forel, Ac. lobicornis Emery and Ac. lundii Guérin. All the known hosts and geographic ranges for these seven phorids in Argentina are provided. The seven phorid species represent new records for all the provinces studied, expanding their geographical ranges; furthermore, we establish a total of eleven new host-parasitoid interactions. Our data expand the knowledge of this little studied system and provide important considerations for the potential use of these parasitoids as biological control candidates of the leafcutter ants

A second species, and first Central American record, of the phorid fly genus Lenkoa Borgmeier (Diptera: Phoridae).

A second species, and first Central American record, of the phorid fly genus Lenkoa Borgmeier (Diptera: Phoridae). Many species of phorid flies have wingless or brachypterous females. Mostly, they belong to a group classified within the subfamily Metopininae corresponding to the Metopina group of genera of Brown (1992a) or the tribe Metopinini of Disney (2003, not 1987). The males of this group are much more typical in appearance, with well-developed wings, larger eyes, and fully developed abdominal tergites. These males carry females during a mating flight, often dispersing them to new breeding sites (Miller 1984). Generally, the sexual dimorphism is so great that the sexes cannot be confidently associated unless they are collected in copula. This has led to a profusion of species being described as males and females in separate genera. Some of these brachypterous females, both within the Metopinini and elsewhere in other Phoridae, have been correctly associated with their males when they are found together (e.g., Brown 1986, 1992b, 1994), but many remain unassociated.

Comparing longevity of Pseudacteon species of different sizes: effect of sugar feeding

AbstractSugar feeding is known to enhance lifespan in many parasitoid species. Several species of phorid flies in the genus Pseudacteon (Diptera: Phoridae) have been introduced in the Southern U.S.A. for the biological control of imported fire ants of Solenopsis species (Hymenoptera: Formicidae). Pseudacteon species are short‐lived flies and little is known about their nutritional ecology. Results from previous studies in our laboratory show that one of the introduced species, Pseudacteon tricuspis Borgmeier, is capable of feeding on sugar sources with a significant increase in lifespan. However, in Pseudacteon phorid flies, the degree to which sugar feeding can enhance the lifespan of other species is not clear, nor is it known whether there is a relationship between body size and longevity. In the present study, the effect of sugar feeding on the survival of three phorid fly species of different body sizes, Pseudacteon cultellatus Borgmeier, Pseudacteon curvatus Borgmeier and Pseudacteon obtusus Borgmeier, is investigated. For all three species, flies continuously provided with 40% or 20% sucrose solution live longer than individuals provided water only or 40% sucrose solution only on the first day of adult life. However, the degree to which sugar feeding enhanced longevity varies by species and is highest for P. obtusus. The data also indicate that longevity in Pseudacteon phorid flies is related to body size: the largest species (P. obtusus) lives significantly longer than the smaller species (P. cultellatus and P. curvatus). These results suggest that adults of all three Pseudacteon species are capable of feeding on sucrose solution and that sugar feeding can enhance their longevity. The significance of these results is discussed in relation to the field performance of Pseudacteon phorid flies as biological control agents of imported fire ants.

Comparative responses of four Pseudacteon phorid fly species to host fire ant alarm pheromone and analogs

Several species of Pseudacteon phorid flies, including Pseudacteon cultellatus, P. curvatus, P. obtusus, and P. tricuspis, have been introduced in the southern United States for biological control of imported fire ants, Solenopsis spp. Previous studies showed that Pseudacteon flies use the alarm pheromone and venom alkaloids of fire ants to locate host ant workers. A recent study by our group demonstrated attraction of one of the species, P. tricuspis, to certain alkylpyrazine analogs of fire ant alarm pheromone. If effective, alkylpyrazine analogs of fire ant alarm pheromone may provide cost-efficient alternatives as phorid fly attractants. To test the hypothesis that other phorid fly species are attracted to alkylpyrazine analogs of fire ant alarm pheromone, we compared electroantennogram (EAG) and behavioral responses of four Pseudacteon species, P. cultellatus, P. curvatus, P. obtusus, and P. tricuspis, to the commercially available alarm pheromone isomer (2-ethyl-3,6(or 5)-dimethyl pyrazine) and six structurally related alkylpyrazine analogs at physiologically relevant doses (ranging from picogram to 10 µg). The alarm pheromone isomer and two analogs, 2,3-diethyl-5-methyl pyrazine and 2 ethyl-3,5 + 6 methyl pyrazine, elicited the strongest EAG activity in all four species at all tested doses. Results from four-choice olfactometer bioassays testing the above three EAG-active compounds showed that all four species were strongly attracted to the alarm pheromone isomer at doses ranging from 0.001 to 1 µg. The flies also showed significant attraction to the two analogs (2,3-diethyl-5-methyl pyrazine and 2 ethyl-3,5 + 6 methyl pyrazine) compared to the solvent control but not as strong as the attraction elicited by the alarm pheromone isomer. These results confirm that multiple species of phorid flies use fire ant alarm pheromone as a host location cue. However, the flies are not strongly attracted to the tested alkylpyrazine analogs of the alarm pheromone.

Distribution of Pseudacteon spp. (Diptera: Phoridae), biological control agents of Solenopsis spp. (Hymenoptera: Formicidae), in Louisiana and associated prevalence of Kneallhazia solenopsae (Microsporidia: Thelohaniidae)

Phorid flies, Pseudacteon spp. (Diptera: Phoridae), have been released in the United States since 1996 as biological control agents for imported fire ants, Solenopsis invicta Buren, Solenopsis richteri Forel, and their hybrid (Hymenoptera: Formicidae). A statewide survey was conducted in Louisiana during 2009 and 2010 to determine the distribution of Pseudacteon tricuspis Borgmeier and Pseudacteon curvatus Borgmeier, and to quantify the potential spatial association between the two species. Additionally, collected phorid flies were tested for the microsporidium Kneallhazia (=Thelohania) solenopsae (Knell, Allen, and Hazard), another natural enemy of fire ants, to establish an account of the pathogen’s distribution and prevalence in phorid fly populations. P. tricuspis and P. curvatus have expanded their range from four and three separate release sites, respectively, in Louisiana. By 2010, P. tricuspis and P. curvatus occupied approximately 86,600 and 111,900km2, respectively. Overall, P. curvatus was more abundant than P. tricuspis, with 41.9±7.3 (SE) and 9.8±1.5 (SE) females, respectively, collected on average per sampling site in 2009. Spatial Analysis by Distance IndicEs (SADIE) suggested aggregation for the two phorid fly species. P. tricuspis collections were positively associated with P. curvatus collections, indicating that gaps and clusters of both species generally overlapped. K. solenopsae was detected in 22 of 64 parishes, and among 124 collection sites tested, 19% yielded positive responses for K. solenopsae. P. tricuspis males and females and P. curvatus females were found to harbor K. solenopsae. This study is the first to detect K. solenopsae in P. tricuspis.

The first known ant-parasitising phorid fly (Diptera: Phoridae) from New Zealand is an invasive species

A new species of phorid fly, Epacteon latifrons, is described from Raglan, New Zealand. It was observed attacking workers of the ant species Technomyrmex jocosus Forel (Hymenoptera: Formicidae).http://zoobank.org/urn:lsid:zoobank.org:pub:758AE47F-A486-4D5F-90AA-20C6CBE2F364

Effectiveness Comparison of Multiple Sticky-Trap Configurations for SamplingPseudacteonspp. Phorid Flies (Diptera: Phoridae)

A variety of traps have been developed for monitoring introduced populations of Pseudacteon spp. phorid flies (Diptera: Phoridae) across their established range in the United States. Such traps typically exploit common aspects of phorid fly biology and behavior, such as their attraction to live or dead red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), as well as the perching behavior of these parasitoids. However, populations of multiple species of phorid flies have been established in the United States to serve as biological control agents against S. invicta, and it is unclear if all trap designs are equally effective in sampling this variety of phorid species. This study investigated the effectiveness of six trap designs simultaneously during three sampling events in south-central Texas. Interactions between two species of phorid flies (Pseudacteon tricuspis Borgmeier and P. curvatus B.) and their hosts have been intensively studied at this location for over eight years. When analyzed independently, there were no significant differences in the mean number of P. curvatus or P. tricuspis phorids collected by any of the trap designs during any of the sampling events. However, when the total number of phorids collected were combined, significant trap performance differentials were observed during the October 2010 sampling event. Furthermore, there were significant differences among male flies during the September 2012 observation. Additionally, a trap component cost comparison is provided. The consistent and relatively equivalent performance of the phorid traps investigated in these trials suggests that all are appropriate for phorid surveillance, and cost and ease-of-use considerations may be the most important criteria when selecting a trap design.

Comparing electroantennogram and behavioral responses of two Pseudacteon phorid fly species to body extracts of Black, Red and Hybrid imported fire ants, Solenopsis spp.

Several phorid fly species were introduced to the southern United States for biological control of the invasive imported fire ants, Solenopsis richteri (Black), Solenopsis invicta (Red), and their Hybrid S. richteri×S. invicta (Hybrid). It has been previously reported that the Jaguariuna biotype of Pseudacteon tricuspis and the Formosan biotype of Pseudacteon curvatus could distinguish among the three fire ant species with greater preference for Hybrid and Red fire ants. We hypothesized that phorid flies might use host derived chemical cues to differentiate ant species. To determine possible differential olfactory sensitivity of phorid fly species to different fire ant species, we compared electroantennogram (EAG) and behavioral responses of both sexes of P. tricuspis and P. curvatus to body extracts of Black, Red and Hybrid fire ants. As worker sizes of Black and Hybrid fire ants used in this study were much larger than that of Red fire ant (the average weight for Black, Red and Hybrid workers was 1.707, 0.863, 1.223mg per ants, respectively), at doses of 0.01, 0.1, 1 worker equivalent, body extracts of Black and Hybrid fire ant elicited significantly greater EAG response in both sexes of P. tricuspis than that of Red fire ant. Similarly, the EAG response in female P. curvatus to body extract of Black fire ant was significantly greater than to body extract of Red fire ant. To eliminate worker size influence on EAG response in phorid flies, we conducted a second EAG study using a dose of 1mg ant equivalent (body extract from 1mg of worker). No difference in EAG responses was recorded to body extract obtained from the same amount of workers among the three fire ant species (we consider viable Hybrid fire ant as a species in this paper), suggesting that worker size differences contributed to difference in EAG response in the first EAG study. In both EAG studies, male P. tricuspis showed significantly greater EAG responses than male P. curvatus to all three fire ant species. In four-way olfactometer bioassay, worker body extracts of all three fire ant species were equally attractive to P. tricuspis and P. curvatus (i.e. both phorid fly species did not show any preferences among the three fire ant species). Together, the results of the EAG and behavior studies suggest that parasitic phorid flies utilize host derived non-polar compounds from worker ants extracted out by hexane for host location but not for host preference, since both fly species are not able to distinguish among the body extracts of the three fire ant species. Future study will investigate possible involvement of polar compounds and/or non-chemical cues in mediating host preference by phorid flies.

Morphology of immature stages of Dohrniphora cornuta (Bigot) (Diptera: Phoridae)

Morphology of all larval instars and puparium of Dohrniphora cornuta (Bigot), a most common phorid fly species indoors in China, is presented using scanning electron microscopy. The first instar larva was composed of 12 segments, each of segments 3-11 with six slender tubercles situated dorsally, dorsolaterally, and laterally in transverse row. These tubercles divided into two segments, of which the basal one was smooth, and the brush-shaped distal one was comprised of a cluster of fine spines. Antennae and maxillary palp complex were visible. Two slits could be seen at the posterior spiracle. Besides the presence of anterior spiracle, the tubercles of second instar became stouter than those of first instar and were covered by numerous long bristles from the base to top. The posterior spiracle contained four slits. Third larval instar was similar to second instar. The bubble membrane comprised of ≈120 globules with a pointed tip on their top presented at the segment 5 of third instar larvae. Puparia showed a retracted cephalic region and a pair of distinct pupal respiratory horns on the dorsum. The respiratory horns were long and bore numerous branches from base to apex. The apex of branch with two longitudinal slits was relatively broad and curled dorsally.

Small Size No Protection for Acrobat Ants: World's Smallest Fly is a Parasitic Phorid (Diptera: Phoridae)

Abstract A new species of phorid fly, Euryplatea nanaknihali (Diptera: Phoridae), is described from Thailand. This is the first Oriental Region record for this genus; it is otherwise known only from the type species from Africa, where it parasitizes ants of the genus Crematogaster Lund. The new species is probably capable of parasitizing the smallest host Crematogaster (Formicidae) ants in its range. At 0.40 mm in body length, it is the smallest known fly in the world.

A study on morphology of immature stages of Diplonevra peregrina (Wiedemann) (Diptera: Phoridae)

Morphology of all larval instars and puparium of Diplonevra peregrina, a most common phorid fly species indoors in China, is presented using scanning electron microscopy. The first instar larva was composed of 12 segments, each of segments 3-11 with six spicate tubercles situated dorsally, dorsolaterally, and laterally in transverse row. The dorsal tubercles were much longer than the laterals and dorsolaterals. Antennae and maxillary palp complex were visible. The caudal segment was margined by six long, stout tubercles covered by numerous long bristles at the base through the apex. Two slits could be seen at the posterior spiracle. Besides the presence of anterior spiracle, the tubercles of second instar became more stout than those of first instar and were covered by numerous long bristles from the base to top. The posterior spiracle contained four slits. Third larval instar was similar to second instar. The bubble membrane comprised of clusters of small spines presented at the segment 5 of third instar larvae. Puparia showed a retracted cephalic region and a pair of pupal respiratory horns on the dorsum.

Current Understanding and Future Prospects of Host Selection, Acceptance, Discrimination, and Regulation of Phorid Fly Parasitoids That Attack Ants

Phorid fly parasitoids (Diptera: Phoridae) have evolved a diverse array of cues used to successfully parasitize their ant hosts. Successful parasitism often involves (a) host habitat location, (b) host location, (c) host acceptance, (d) host discrimination, and (e) host regulation. In this paper we discuss our current understanding of how phorid flies use each of these steps to successfully parasitize ant hosts. We examine the wide variety of strategies and cues used by a multiple species of phorid flies within three separate genera that most commonly parasitize ants (Apocephalus,Pseudacteon,and Neodohrniphora) and discuss future directions within this field of study.

Distribution ofPseudacteon curvatusandPseudacteon tricuspis(Diptera: Phoridae) in Arkansas

From 1995 to 2009, four Pseudacteon species were released in the U.S. with 3 species, P. curvatus, P. tricuspis, and P. obtusus released in Arkansas. To determine Pseudacteon establishment and expansion, sticky traps were used to monitor phorid fly species at and near 10 release sites, in counties bordering neighboring states, and along regional transects. Pseudacteon flies were captured in 16 Arkansas counties: Ashley, Chicot, Clark, Desha, Drew, Hempstead, Howard, Little River, Montgomery, Nevada, Perry, Phillips, Pike, Polk, Sevier, and Union. Pseudacteon curvatus was found in areas far from release sites, suggesting dispersal from neighboring states. The range of P. tricuspis evidently also expanded from its initial release sites in southern Arkansas.

Parasite Lost: Chemical and Visual Cues Used by Pseudacteon in Search of Azteca instabilis.

An undescribed species of phorid fly (genus: Pseudacteon) parasitizes the ant Azteca instabilis F Smith, by first locating these ants through the use of both chemical and visual cues. Experiments were performed in Chiapas, Mexico to examine a) the anatomical source of phorid attractants, b) the specific chemicals produced that attract phorids, and c) the nature of the visual cues used by phorids to locate the ants. We determined that phorid-attracting chemicals were present within the dorsal section of the abdomen, the location of the pygidial gland. Further experiments indicate that a pygidial gland compound, 1-acetyl-2-methylcyclopentane, is at least partially responsible for attracting phorid flies to their host. Finally, although visual cues such as movement were important for host location, size and color of objects did not influence the frequency with which phorids attacked moving targets.

Introduction of the fire ant decapitating fly Pseudacteon obtusus in the United States: factors influencing establishment in Texas

The introduction and establishment of Pseudacteon obtusus Borgmeier (Diptera: Phoridae) into the United States is an important milestone in the effort to introduce a suite of parasitoids and pathogens as prospective biocontrol agents of the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae).P. obtusus is the fourth species of phorid fly to be established in the US and is now present in at least 11 sites in Texas. This species has a greater propensity for attacking foraging worker ants, and to a lesser degree it will attend mound disturbance events. The effectiveness of alternate field release strategies was evaluated across 28 sites in Texas, with establishment success 35 times more likely when no other phorid species were present at the outset of the releases. This result implies that competition between phorid species may interfere with establishment. Therefore release strategies should be directed to locations lacking other naturalized species or to times when abundances of other species are low.