Phoridae Research Articles

Phorid Flies Parasitizing Leaf-Cutting Ants: Their Occurrence, Parasitism Rates, Biology and the First Account of Multiparasitism

The leaf-cutting ants Atta sexdens (Linnaeus) and Atta laevigata (Smith) were parasitized by the following phorid flies: Apocephalus attophilus Borgmeier, Apocephalus vicosae Disney, Myrmosicarius grandicornis Borgmeier and species of Eibesfeldtphora Disney. It is also related here that the area of occurrence of phorids parasitizing A. sexdens was extended to include Central Brazil. The rate of parasitism on A. sexdens was three times lower than the rate found on A. laevigata; most common flies were, respectively, M. grandicornis in A. sexdens and A. attophilus in A. laevigata. This last phorid showed the shortest life span but the higher percentage of emergence. Multiparasitism on workers of A. sexdens and of A. laevigata involving three combinations of four phorid species was rare and is here related for the first time for leaf-cutting ants.

Big data from tiny flies: patterns revealed from over 42,000 phorid flies (Insecta: Diptera: Phoridae) collected over one year in Los Angeles, California, USA

The first ever large-scale inventory of an urban phorid fly fauna is described. Collections from 30 Malaise traps from urban Los Angeles over one year from the BioSCAN Project document the presence of 99 species from 42,480 specimens identified. Species accumulation curves predict 102–106 species actually occurring in this area. Collections are overwhelmingly dominated by the North American fungus feeding species Megaselia agarici, which accounts for about one quarter of all specimens identified. Percentage of M. agarici per site ranges from approximately 4% to 75%. Diversity varied significantly among sites, with species richness per site ranging from 23 to 82. Implications of patterns of abundance, diversity, and size are discussed.

Reproductive ecology of phorid parasitoids in relation to the head size of leaf-cutting ants Atta sexdens Forel.

The leaf-cutting ant Atta sexdens Forel (Hymenoptera: Formicidae) is one of the most damaging agricultural pests in the Neotropics. Management strategies predominantly rely on the use of general insecticides. What is needed are more species-specific and environmentally friendly options. Parasitioids such as phorid flies (Diptera: Phoridae) may be one such option, but a greater understanding of the ecology of the flies and their ant hosts is essential to devise biological control strategies. Here we report parasitism rates, ant host size, parasitoid abundance per host and resultant sex ratios of two phorid species Apocephalus attophilus Borgmeier and Eibesfeldtphora tonhascai Brown parasitizing A.sexdens. The two species achieved parasitism rates of 1.48 and 1.46%, respectively and the pupal period was 14.7 ± 1.1 days and 22.1 ± 2.8 days, respectively. There was no significant difference between the head capsule width of ants parasitized by either A. attophilus or E. tonhascai. Likewise, there was no significant effect between the head capsule width of parasitized and unparasitized ants for both species. A significant positive correlation was found between the head capsule width of the parasitized ants and the number of adult parasitoids A. attophilus emerged. Ants parasitized by E. tonhascai survived significantly longer than those parasitized by A. attophilus. There was no significant effect of ant head width on the sex ratio of the offspring of either parasitoid species and no significant difference in the sex ratio (male: female) of their offspring. In summary, these data addressed here are important steps when considering natural enemies for biological control. Studying survival of the parasitized ants, parasitoid offspring sex ratio and host size preference allows for a better understanding of ant natural biological control in the field and can help in rearing of A. attophilus and E. tonhascai in laboratory.

Research Progress of Carrion-breeding Phorid Flies for Post-mortem Interval Estimation in Forensic Medicine

It is a difficult problem of forensic medicine to accurately estimate the post-mortem interval. Entomological approach has been regarded as an effective way to estimate the post-mortem interval. The developmental biology of carrion-breeding flies has an important position at the post-mortem interval estimation. Phorid flies are tiny and occur as the main or even the only insect evidence in relatively enclosed environments. This paper reviews the research progress of carrion-breeding phorid flies for estimating post-mortem interval in forensic medicine which includes their roles, species identification and age determination of immatures.

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.

Dead ant walking: a myrmecophilous beetle predator uses parasitoid host location cues to selectively prey on parasitized ants.

Myrmecophiles (i.e. organisms that associate with ants) use a variety of ecological niches and employ different strategies to survive encounters with ants. Because ants are typically excellent defenders, myrmecophiles may choose moments of weakness to take advantage of their ant associates. This hypothesis was studied in the rove beetle, Myrmedonota xipe, which associates with Azteca sericeasur ants in the presence of parasitoid flies. A combination of laboratory and field experiments show that M. xipe beetles selectively locate and prey upon parasitized ants. These parasitized ants are less aggressive towards beetles than healthy ants, allowing beetles to eat the parasitized ants alive without interruption. Moreover, behavioural assays and chemical analysis reveal that M. xipe are attracted to the ant's alarm pheromone, the same secretion used by the phorid fly parasitoids in host location. This strategy allows beetles access to an abundant but otherwise inaccessible resource, as A. sericeasur ants are typically highly aggressive. These results are the first, to our knowledge, to demonstrate a predator sharing cues with a parasitoid to gain access to an otherwise unavailable prey item. Furthermore, this work highlights the importance of studying ant-myrmecophile interactions beyond just their pairwise context.

Cob Flies, Megaselia spp. (Diptera: Phoridae), in Sweet Corn

Phorid flies (Diptera), also known as humpback flies or scuttle flies for their appearance and behavior, are an extremely diverse group of flies that are saprophagous (feed on decaying organic matter), parasitic, or phytophagous (feed on plants). Within the Phoridae family, the genus Megaselia is also extremely diverse, with more than 1400 described species, many very similar in appearance. The name “cob fly” was given to a Megaselia spp. that attacked corn in Texas. This 5-page fact sheet describes the distribution of this pest, ways to distinguish it from other similar corn ear pests, its life cycle, the damage it causes, and some strategies for management. Written by David Owens, Gregg S. Nuessly, Robert Beiriger, and Nicholas Larsen, and published by the Department of Entomology and Nematology, August 2016. ENY-754/IN1144: Cob Flies, Megaselia spp. (Diptera: Phoridae), in Sweet Corn (ufl.edu)

Phorids associated with nests of Atta cephalotes (Hymenoptera: Formicidae) in a forest and a plantation

The external portion of Atta cephalotes nests is composed of three areas: openings, trails, and cutting; where cutting and transporting leaves, sharing information, and defending the nest take place. The richness of the fauna of these areas is not only dependent on the interactions among ants, but also the accumulation of plant material and nest waste, which are exploited by flies of the family Phoridae. Traps with two different kinds of bait were used both during the day and at night to exploit common aspects of phorid fly biology and behavior, such as their attraction to live ants and refuse dumps, their use of visual and olfactory signals, and their perching behavior. Nests in both a citrus monoculture and a forest remnant were studied to evaluate whether environmental characteristics of the sites influence the presence of phorids. One parasitoid, Eibesfeldtphora attae, and 13 additional, mostly saprophagous, genera of phorids associated with A. cephalotes were collected in the nests. Specimens from 12 genera were identified in the forest remnant, most frequently Megaselia, Coniceromyia, and Synclinusa. Nine genera were identified in the citrus plantation, mostfrequently Dohrniphora and Megaselia. Using Analysis of Similarities (Anosim), significant differences (P = 0.002) in faunal composition were found between the forest remnant and the plantation, but no significant effect was detected infaunal composition between areas of the nest (P = 0.206), between baits (P = 0.956), or between periods (P = 0.603).

Bambus mexicanus Cresson, un hospedante de Melaloncha , moscas parásitas de la abeja de miel en el nuevo mundo

A worker of Bambus mexicanus was found parasitized by a phorid fly of the genus Melaloncha , a common parasite of Apis mellifera in the New World tropics. Probably additional species of Bambus are also natural hosts of Melaloncha .

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.

Fossil evidence of social insect commensalism in the Phoridae (Insecta: Diptera)

Fossil phorid flies display various levels of morphological change that are correlated with myrmecophily (association with ants) and termitophily (association with termites) in the modern fauna. Three discrete episodes in the evolution of limuloidy, a defensive body form, are documented from Eocene Baltic amber. Extinct fossil stem-group taxa of the modern myrmecophilous genus Aenigmatias Meinert are described, with three new species – A. longicornis sp. nov., A. primitivus sp. nov. and A. nigeroticus sp. nov. – recognized and illustrated. Protoplatyphora Brues is synonymized with Aenigmatias, with its single previously described species, A. tertiarius (Brues), considered a new combination. Chaetopleurophora bisetosa Brown, 2007 is transferred to Aenigmatias as A. bisetosus (comb. nov.). An unrelated Aenigmatias-like fossil is described as Pseudaenigmatias ctenitibia gen. et sp. nov., and belongs to a modern termitophilous clade. Limulomyia tyche Brown, 1999 is interpreted as a separate, already highly limuloid lineage not related to either of the other two limuloid groups. A key to fossil Aenigmatias is given, along with a phylogenetic analysis of fossil taxa. Fossil specimens have profound implications for our knowledge of the evolution of the limuloid body form found in modern species of Aenigmatias.http://zoobank.org/urn:lsid:zoobank.org:pub:DE779D49-7636-4B1D-9F7D-CF3FF6D3CE97

Cuticular Hydrocarbon Cues Are Used for Host Acceptance by Pseudacteon spp. Phorid Flies that Attack Azteca sericeasur Ants.

Parasitoids often use complex cues to identify suitable hosts in their environment. Phorid fly parasitoids that develop on one or a few host species often use multiple cues, ranging from general to highly specific, to home in on an appropriate host. Here, we describe the hierarchy of cues that Pseudacteon phorid flies use to identify Azteca ant hosts. We show, through behavioral observations in the field, that phorid flies are attracted to two cryptic Azteca species, but only attack Azteca sericeasur (Hymenoptera: Formicidae: Dolichoderinae). To test whether the phorid flies use cuticular hydrocarbons (CHCs) to distinguish between the two Azteca taxa, we first documented and compared cuticular hydrocarbons of the two Azteca taxa using gas chromatography/mass spectrometry. Then, using cuticular hydrocarbon-transfer experiments with live ants, we characterized the cuticular hydrocarbons of A. sericeasur as a short-range, host location cue used by P. lasciniosus (Diptera: Phoridae) to locate the ants.

Two new bee-killing flies from Brazil (Insecta: Diptera: Phoridae: Melaloncha).

BackgroundThe genus Melaloncha is a large group of species of parasitoid phorid flies that attack Hymenoptera, mostly stingless bees (Meliponinae, Apidae) in the Neotropical Region.New informationTwo new Brazilian species, Melaloncha (Melaloncha) peacockorum sp. n. and Melaloncha (Udamochiras) nielsi sp. n., are described and their identification clarified.

New records and new species of Metopina Macquart (Diptera: Phoridae) from Tasmania

Metopina glandula sp. n., M. lacrimula sp. n., M. microquartus sp. n., and two species of males not yet linked to their females are described from Tasmania.

Induced Effects on Red Imported Fire Ant (Hymenoptera: Formicidae) Forager Size Ratios by Pseudacteon spp. (Diptera: Phoridae): Implications on Bait Size Selection.

Red imported fire ants, Solenopsis invicta Buren, are adversely affected by phorid flies in the genus Pseudacteon by instigating defensive behaviors in their hosts, and in turn reducing the efficiency of S. invicta foraging. Multiple Pseudacteon species have been released in Texas, and research has been focused on the establishment and spread of these introduced biological control agents. Field experiments were conducted to determine bait particle size selection of S. invicta when exposed to phorid populations. Four different particle sizes of two candidate baits were offered to foragers (one provided by a pesticide manufacturer, and a laboratory-created bait). Foragers selectively were attracted to, and removed more 1-1.4-mm particles than any other bait size. The industry-provided bait is primarily made of particles in the 1.4-2.0 mm size, larger than what was selected by the ants in this study. While there was a preference for foragers to be attracted to and rest on the industry-provided blank bait, S. invicta removed more of the laboratory-created bait from the test vials. There was an abundance of workers with head widths ranging from 0.5-0.75 mm collected from baits. This was dissimilar from a previous study wherein phorid flies were not active and in which large workers were collected in higher abundance at the site. This implies that phorid fly activity caused a shift for red imported fire ant colonies to have fewer large foragers.

Foundress queen mortality and early colony growth of the leafcutter ant, Atta texana (Formicidae, Hymenoptera)

Nest-founding queens of social insects typically experience high mortality rates. Mortality is particularly severe in leafcutter ants of the fungus-growing ant genus Atta that face the challenge of cultivating a delicate fungus garden in addition to raising brood. We quantified foundress queen survivorship of Atta texana that were collected in northwest Texas and maintained in single-queen laboratory nests, and we tracked the rate of colony growth during the first precarious months of the colony lifecycle. Ninety days post-mating flight, only 16.3 % of 141 of the original queens had survived, and colony growth rates varied markedly across the surviving colonies. Worker production was weakly correlated with fungus garden growth over the course of early colony development. Dead queens became overgrown by the parasitic fungi Fusarium oxysporum (26 % of dead queens) and Aspergillus flavus (34 %), and these fungi are therefore possible causes of queen mortality. The phorid fly Megaselia scalaris emerged from one dead queen, but was unlikely the cause of death. Under natural conditions, intense competition between conspecific colonies can amplify small differences in initial growth rates to generate drastic differences in colony fitness. The observed variation in colony growth rate therefore suggests that colony growth is likely an important target for selection to optimize fitness in Atta texana.

Metatranscriptomic analyses of honey bee colonies.

Honey bees face numerous biotic threats from viruses to bacteria, fungi, protists, and mites. Here we describe a thorough analysis of microbes harbored by worker honey bees collected from field colonies in geographically distinct regions of Turkey. Turkey is one of the World's most important centers of apiculture, harboring five subspecies of Apis mellifera L., approximately 20% of the honey bee subspecies in the world. We use deep ILLUMINA-based RNA sequencing to capture RNA species for the honey bee and a sampling of all non-endogenous species carried by bees. After trimming and mapping these reads to the honey bee genome, approximately 10% of the sequences (9–10 million reads per library) remained. These were then mapped to a curated set of public sequences containing ca. Sixty megabase-pairs of sequence representing known microbial species associated with honey bees. Levels of key honey bee pathogens were confirmed using quantitative PCR screens. We contrast microbial matches across different sites in Turkey, showing new country recordings of Lake Sinai virus, two Spiroplasma bacterium species, symbionts Candidatus Schmidhempelia bombi, Frischella perrara, Snodgrassella alvi, Gilliamella apicola, Lactobacillus spp.), neogregarines, and a trypanosome species. By using metagenomic analysis, this study also reveals deep molecular evidence for the presence of bacterial pathogens (Melissococcus plutonius, Paenibacillus larvae), Varroa destructor-1 virus, Sacbrood virus, and fungi. Despite this effort we did not detect KBV, SBPV, Tobacco ringspot virus, VdMLV (Varroa Macula like virus), Acarapis spp., Tropilaeleps spp. and Apocephalus (phorid fly). We discuss possible impacts of management practices and honey bee subspecies on microbial retinues. The described workflow and curated microbial database will be generally useful for microbial surveys of healthy and declining honey bees.

Longevity, trophallaxis, and allogrooming inMacrotermes gilvussoldiers infected by the parasitoid flyMisotermes mindeni

In this study, we documented the behavioral changes of major soldiers of the subterranean termite Macrotermes gilvus (Hagen) (Blattodea: Termitidae) infected with larvae of the phorid fly Misotermes mindeniDisney & Neoh (Diptera: Phoridae). During periods of starvation, the longevity of parasitized individuals was significantly greater than that of unparasitized individuals. Parasitized individuals received significantly more frequent trophallaxis from the workers than unparasitized individuals. The frequency of allogrooming of parasitized individuals by workers was also significantly greater than that of unparasitized individuals. The extent to which workers provided trophallaxis and allogrooming for parasitized individuals did not differ significantly between colonies with and without unparasitized individuals. Likewise, no significant difference in the frequency of trophallaxis between workers and unparasitized individuals was detected in the groups with and without parasitized individuals. However, distinct differences in allogrooming frequency between groups with and without parasitized individuals were detected. Workers/unparasitized individuals exhibited significantly more allogrooming behavior when parasitized individuals were present. Parasitized major soldiers and unparasitized, food-deprived major soldiers received significantly more often trophallaxis from the workers than unparasitized major soldiers. Presence of a parasitoid fly in major soldiers may promote the frequent feeding of parasitized individuals by workers. Based on these data, the behavioral adjustments appear to be beneficial to the parasitoids, as the changes clearly increase their chances of survival and their chances of completion of their larval development before the host dies.

A new type of ant-decapitation in the Phoridae (Insecta: Diptera).

The genus Dohrniphora is a hyperdiverse group of phorid flies, a family whose species are commonly characterized as generalized scavengers. The lifestyle of most species of Dohrniphora is unknown, although one cosmopolitan, synanthropic species, D. cornuta (Bigot) fits the general scavenger mold. Here we show that flies of the D. longirostrata species group exhibit highly specific “headhunting” behavior in which injured Odontomachus ants are decapitated, the heads dragged away, and females either feed on their contents or lay an egg nearby. Since most females studied lacked eggs in their ovaries, we conclude that this bizarrely specialized feeding is necessary to provide nutrients for reproduction in these flies. Our study provides further evidence that injured ants are a common, stable resource in tropical ecosystems that support a wide array of phorid flies. Such narrowly constrained lifestyles, as exemplified by exclusively feeding on and breeding in the head contents of certain ponerine worker ants, could allow the co-existence of a huge community of saprophagous flies.

Waste Management in the Stingless Bee Melipona beecheii Bennett (Hymenoptera: Apidae)

Waste management is important in insect societies because waste can be hazardous to adults, brood and food stores. The general organization of waste management and the influence of task partitioning, division of labor and age polyethism on waste processing were studied in three colonies of the tropical American stingless bee Melipona beecheii Bennett in Yucatan, Mexico. Waste generated in the colony (feces, old brood cells, cocoons, dead adults and brood) was collected by workers throughout the nest and taken to specific waste dumps within the nest. During the day, workers based at the waste dumps formed waste pellets, which they directly transferred in 93% of cases, to other workers who subsequently removed them from the nest. This is an example of task partitioning and is hypothesized to improve nest hygiene as has been found in leafcutting ants, Atta. To investigate division of labor and age polyethism we marked a cohort of 144 emerging workers. Workers forming waste pellets were on average 31.2±6.5 days old (±SD, N= 40, range of 18-45 days). The life span of M. beecheii workers was 49.0±14.0 days (N= 144). There was no difference in the life span of workers who formed (52.2±11.6 days, N= 40) or did not form (49.9±11.5 days, N= 97) waste pellets, suggesting that waste work did not increase mortality. Although waste was probably not hazardous to adults and brood, because the dumps are located outside the brood chamber, its presence inside the nests can attract phorid flies and predators, which can harm the colony.