Comparative foraging behavior of Neotropical robber flies (Diptera: Asilidae)

Summary Robber fly species within a Panamanian rain forest comprised distinct shade-seeking (SS) and light-seeking (LS) groups. Thoracic temperatures of LS species averaged 9.2°C greater than ambient, whereas those of SS species averaged only 1.3°C above ambient. Among SS species, attack rate decreased with increasing body mass, whereas relocation rate and attack and relocation distances increased with increasing body mass. Attack and relocation distances of LS species were similar to those of SS species of similar size. Large (>100 mg) LS species, however, had much higher attack and relocation rates than large SS species. The potential costs and benefits of basking are briefly discussed.     

Body temperature regulation in desert robber flies (Diptera: Asilidae)

ABSTRACT.

• 1 We investigated effective thermal environments and behavioural and physiological mechanisms for thermoregulation in two sympatric desert robber flies, Promachus giganteus (Hine) and Efferia texana (Banks). Although similar in body shape and colour, P. giganteus are 4–8 times heavier than E. texana.
• 2 During midday, operative temperatures near the ground were substantially higher for P. giganteus (56–73°C) than for E. texana (54–63°C). Correspondingly, P. giganteus generally perched at greater heights above the ground than did E. texana.
• 3 Both species maintained thoracic temperatures between 40 and 45°C during most of the day. However, differences between thoracic and abdominal temperatures for individual flies were significantly lower in P. giganteus than in E. texana.
• 4 In the laboratory, P. giganteus regulated thoracic temperature by pumping haemolymph into the abdomen. This ability may have accounted for the smaller differences observed between thoracic and abdominal temperatures in P. giganteus and may have allowed this species to search for food and mates during midday when E. texana sought shade.

     

Notes on the morphology of the robber flies (Diptera, Asilidae)

The position of antennae in the ventral part of head in the species of the genus Eremodromus Zimin is considered. It is different in the three species: the antennae are situated close to the mystacal bristles (E. noctivagus), distant from them (E. gracilis), and near the border between dorsal and ventral parts of head (E. zimini). All three species have reduced pulvilli. It is shown that both species of Theurgus Richter have a single straight apical anteroventral spur on the middle tibia.     

Landscape and stational distribution of the robber flies (Diptera, Asilidae) in the Lower Volga area

The distribution of 108 species of robber flies over different landscapes and plant associations in the Lower Volga area was studied.     

Host-seeking behavior in larvae of the robber fly Mallophora ruficauda (Diptera: Asilidae)

The robber fly Mallophora ruficauda is the most important pest of apiculture in the Pampas region of Argentina. Adults prey on honeybees and other insects, while larvae parasitize larvae of scarab beetles, which live underground. Females of M. ruficauda do not search for hosts but instead lay eggs in tall pastures. Once hatched, larvae drop to the ground and burrow underground to search for their hosts. We tested in the laboratory whether larvae of M. ruficauda actively search for their hosts using host and/or host-related chemical cues. We report that M. ruficauda detects its host using chemical cues that originate in the posterior half of the host's body, most likely from an abdominal exocrine structure. This particular host-searching strategy is described for the first time in Asilidae.     

Ecological comparisons of robber fly species (Diptera: Asilidae) coexisting in a neotropical forest

Summary Data regarding seasonal abundance, microhabitat preference, and diet were collected over 3 field seasons for adults of 15 robber fly species on Barro Colorado Island, Panama. The species comprised 2 distinct thermal guilds; light-seeking (hereafter LS) species foraged in sunlit areas, while shade-seeking (SS) species foraged only in deep shade. All species were rare during the dry season. During the rainy months, most SS species had flight periods of 2–3 months, and no temporal segregation was apparent. In contrast, most LS species had flight periods of only 4–6 weeks, and a distinct sequence of occurrence was evident during 2 years of censusing. Most SS and LS species displayed a pronounced specificity for perches of a particular substrate type. However, the ranges of perching heights utilized varied considerably among species. Dietary comparisons revealed that mean and maximum prey sizes increased with increasing robber fly size, while minimum prey sizes were constant. Robber fly species <20 mg fed primarily upon nematocerous Diptera, whereas larger species generally fed upon a wide variety of prey types. For each thermal guild, the actual mean overlap for a particular niche dimension was compared to mean overlaps generated by randomly assigning species to thermal guilds. No significant differences from the random null hypothesis were found for the SS guild. However, niche complementarity between dietary and spatial overlaps and dietary overlap was apparent among the 5 large LS species.     

Male perch selection and the mating system of the robber fly,Promachus albifacies (Diptera: Asilidae)

We studied the activity and spatial distribution of the robber fly,Promachus albifacies, in a desert grassland habitat in central New Mexico. Late in the season males spent most of the daytime on or near cholla and yucca plants that had dead stems or dead flower stalks at least 1 m high. Of the three hypotheses (thermoregulation, foraging, mate encounter site) considered as explanations for this distribution, the mate-encounter-site hypothesis was best supported. Plants used by females as oviposition sites were the focus of male activity. Males perched within or near these plants and attempted copulations with females detected nearby. Most matings were initiated at these locations. Seasonal changes in male and female activity also supported the mate-encounter-site hypothesis. Early in the season, females spent little time ovipositing, and predictably, males spent little time on or near these plants. Such a mating system may be described as resource defense polygyny, since males acted aggressively toward one another at oviposition sites even when females were not present. However, the short tenure of males at these sites is suggestive of scramble competition polygyny. We discuss possible reasons why this particular mating system has evolved.     

Impact of predation by the robber fly Proctacanthus milbertii (Diptera: Asilidae) on grasshopper (Orthoptera: Acrididae) populations

The impact of predation by the robber fly Proctacanthus milbertii Macquart on populations of adult grasshoppers from grasslands of the Nebraska sandhills was estimated. Densities of P. milbertii were estimated at 437 individuals per hectare (2 se=122). Overall densities of 23 species of grasshoppers were estimated to be 64,000 individuals per hectare with the most abundant species (Ageneotettix deorum) having a population size of approximately 15,000 individuals per hectare. Based on three estimates of predation level (ranging from 0.5 to 2 prey per day per robber fly), P. milbertii may take from 0.5% to 2% of the adult grasshoppers per day. Species of grasshoppers were taken by P. milbertii in about the same proportion in which they occurred at the study site and no size-selective component of predation was detectable.     

Evolutionary history of Stratiomyidae (Insecta: Diptera): the molecular phylogeny of a diverse family of flies

Stratiomyidae is a cosmopolitan family of Brachycera (Diptera) that contains over 2800 species. This study focused on the relationships of members of the subfamily Clitellariinae, which has had a complicated taxonomic history. To investigate the monophyly of the Clitellariinae, the relationships of its genera, and the ages of Stratiomyidae lineages, representatives for all 12 subfamilies of Stratiomyidae, totaling 68 taxa, were included in a phylogenetic reconstruction. A Xylomyidae representative, Solva sp., was used as an outgroup. Sequences of EF-1alpha and 28S rRNA genes were analyzed under maximum parsimony with bootstrapping, and Bayesian methods to recover the best estimate of phylogeny. A chronogram with estimated dates for all nodes in the phylogeny was generated with the program, r8s, and divergence dates and confidence intervals were further explored with the program, multidivtime. All subfamilies of Stratiomyidae with more than one representative were found to be monophyletic, except for Stratiomyinae and Clitellariinae. Clitellariinae were distributed among five separate clades in the phylogeny, and Raphiocerinae were nested within Stratiomyinae. Dating analysis suggested an early Cretaceous origin for the common ancestor of extant Stratiomyidae, and a radiation of several major Stratiomyidae lineages in the Late Cretaceous.     

A molecular phylogeny for the Tribe Dacini (Diptera: Tephritidae): systematic and biogeographic implications

With well over 700 species, the Tribe Dacini is one of the most species-rich clades within the dipteran family Tephritidae, the true fruit flies. Nearly all Dacini belong to one of two very large genera, Dacus Fabricius and Bactrocera Macquart. The distribution of the genera overlap in or around the Indian subcontinent, but the greatest diversity of Dacus is in Africa and the greatest diversity of Bactrocera is in south-east Asia and the Pacific. The monophyly of these two genera has not been rigorously established, with previous phylogenies only including a small number of species and always heavily biased to one genus over the other. Moreover, the subgeneric taxonomy within both genera is complex and the monophyly of many subgenera has not been explicitly tested. Previous hypotheses about the biogeography of the Dacini based on morphological reviews and current distributions of taxa have invoked an out-of-India hypothesis; however this has not been tested in a phylogenetic framework. We attempted to resolve these issues with a dated, molecular phylogeny of 125 Dacini species generated using 16S, COI, COII and white eye genes. The phylogeny shows that Bactrocera is not monophyletic, but rather consists of two major clades: Bactrocera s.s. and the 'Zeugodacus group of subgenera' (a recognised, but informal taxonomic grouping of 15 Bactrocera subgenera). This 'Zeugodacus' clade is the sister group to Dacus, not Bactrocera and, based on current distributions, split from Dacus before that genus moved into Africa. We recommend that taxonomic consideration be given to raising Zeugodacus to genus level. Supportive of predictions following from the out-of-India hypothesis, the first common ancestor of the Dacini arose in the mid-Cretaceous approximately 80mya. Major divergence events occurred during the Indian rafting period and diversification of Bactrocera apparently did not begin until after India docked with Eurasia (50-35mya). In contrast, diversification in Dacus, at approximately 65mya, apparently began much earlier than predicted by the out-of-India hypothesis, suggesting that, if the Dacini arose on the Indian plate, then ancestral Dacus may have left the plate in the mid to late Cretaceous via the well documented India-Madagascar-Africa migration route. We conclude that the phylogeny does not disprove the predictions of an out-of-India hypothesis for the Dacini, although modification of the original hypothesis is required.     

Leinendera achaeta sp. n., a new species of robber fly from Brazil (Diptera,Asilidae, Asilinae)

The third species of the Neotropical genus Leinendera Carrera, 1945, Leinendera achaeta sp. n., is described from Rio Grande do Sul state, Brazil. The habitus, wing and male terminalia are described and illustrated, and a key to the three Brazilian species is provided.     

Molecular phylogeny of black flies (Diptera: Simuliidae) from Thailand, using ITS2 rDNA

The sequences of the second internal transcribed spacer (ITS2) of ribosomal DNA (rDNA) were determined for 40 black fly species from Thailand, belonging to 4 subgenera of the genus Simulium, namely Gomphostilbia (12 species), Nevermannia (5 species), Montisimulium (1 species), Simulium sensu stricto (21 species), and an unknown subgenus with one species (Simulium baimaii). The length of the ITS2 ranged from 247 to 308 bp. All black fly species had high AT content, ranging from 71 to 83.8%. Intraindividual variation (clonal variation) occurred in 13 species, ranging from 0.3 to 1.1%. Large intrapopulation and interpopulation heterogeneities exist in S. feuerboni from the same and different locations in Doi Inthanon National Park, northern Thailand. Phylogenetic relationships among 40 black fly species were examined using PAUP (version 4.0b10) and MrBAYS (version 3.0B4). The topology of the trees revealed two major monophyletic clades. The subgenus Simulium and Simulium baimaii were placed in the first monophyletic clade, whereas the subgenera Nevermannia + Montisimulium were placed as the sister group to the subgenus Gomphostilbia in the second monophyletic clade. Our results suggest that S. baimaii belongs to the malyschevi-group or variegatum-group in the subgenus Simulium. The molecular phylogeny generally agrees with existing morphology-based phylogenies.     

Towards a molecular phylogeny of the fungus gnat genus Boletina (Diptera: Mycetophilidae)

Martinsson, S., Kjærandsen, J. & Sundberg, P. (2011). Towards a molecular phylogeny of the fungus gnat genus Boletina (Diptera: Mycetophilidae). —Zoologica Scripta, 40, 272–281. Boletina is a species rich genus of fungus gnats (Diptera: Mycetophilidae) with a mainly Holarctic distribution. The systematics within the genus has gained little attention and this is a first attempt to shed some light over the systematics of Boletina and to test the segregation of the genera Saigusaia and Aglaomyia from Boletina. The nuclear marker 28S and mitochondrial 16S, COI and CytB were amplified and sequenced for 23 taxa that were analysed separately and together with a broad sample of outgroup taxa obtained from GenBank, where also 18S sequences were added. Phylogenies were estimated using maximum likelihood, Bayesian inference and parsimony. We strengthen the hypothesized sister‐group relationship between Docosia and Boletina, but the genus Boletina as currently delimited appears to be paraphyletic and nested in a clade together with Aglaomyia, Coelosia and Gnoriste. The genus Saigusaia, on the other hand, seems to be well separated from Boletina. The Boletina erythropyga species group is consistently found as a distinct basal clade within Boletina s.l. The results obtained are otherwise ambiguous both for the taxa in focus and in some analyses globally with a statistically supported total breakdown of the traditional higher classification into tribes, subfamilies and even families. Interestingly, this breakdown almost disappeared when additional 18S sequences were added.     

A molecular phylogeny of Anopheles annulipes (Diptera: Culicidae) sensu lato: the most species-rich anopheline complex

The Australasian Annulipes Complex is the most species-rich among Anopheles mosquitoes, with at least 15 sibling species suspected. Members of this complex are the most likely vectors of malaria in the past in southern Australia and are involved in the spread of myxomatosis among rabbits. In this, the first comprehensive molecular study of the Annulipes Complex, 23 ITS2 rDNA variants were detected from collections throughout Australia and Papua New Guinea, including diagnostic variants for the previously identified An. annulipes species A-G. Specimens of each ITS2 variant were sequenced for portions of the mitochondrial COI, COII and nuclear EF-1alpha genes. Partitioned Bayesian and Maximum Parsimony analyses confirmed the monophyly of the Annulipes Complex and revealed at least 17 clades that we designate species A-Q. These species belong to two major clades, one in the north and one mainly in the south, suggesting that climate was a driver of species radiation. We found that 65% (11) of the 17 sibling species recorded here had unique COI sequences, suggesting that DNA barcoding will be useful for diagnosing species within the Annulipes Complex. A comparison of the taxa revealed morphological characters that may be diagnostic for some species. Our results substantially increase the size of the subgenus Cellia in Australasia, and will assist species-level studies of the Annulipes Complex.     

Das Paarungsverhalten von Pycnopogon fasciculatus Loew (Diptera,Asilidae)

• 1 Bei der Raubfliege Pycnopogon fasciculatus vollführt das ♂ vor dem sitzenden ♀ eine Flugbalz, die hauptsächlich anhand von Filmaufnahmen analysiert wurde. Das ♂ schwebt bei der Flugbalz dicht vor dem ♀, schwenkt dann bis 10 cm nach hinten aus, um auf der gleichen Flugbahn stoßartig nach vorne vor das ♀ zu fliegen. Diesen Hin- und Herflug wiederholt das ♂ durchschnittlich 28mal. Zu Beginn der Flugbalz orientiert sich das ♂ durch Ertasten des weiblichen Vorderendes. Das ♂ hält die Beine an den beiden Umkehrpunkten der Flugbahn ganz verschieden (vgl. Abb. 2 c), zeigt aber keine Landehaltung. Flugtechnisch scheint die Veränderung der Beinstellung wenig Bedeutung zu haben. Ob die Beinhaltung vor dem ♀ aus einer ritualisierten Beuteübergabe hervorgegangen ist, bleibt offen. Das ♀ zeigt seine Abwehrbereitschaft bei der Flugbalz durch ritualisiertes Wackeln hochgehaltener Hinterbeine.
• 2 Das ♂ vollführt seine Flugbalz auch vor toten, artgleichen ♀ und ♂♂ und auch vor artfremden, z. T. größeren Fliegen. Die Flugbalz ist kürzer als vor lebenden ♀♀ (durchschnittlich nur 14 Anflüge) und führt wegen des Fehlens von Abwehrsignalen des ♂ doppelt so haufig zu einem unmittelbar anschließenden Kopulationsversuch.
• 3 Sitzende ♂♂ schlagen gegen anfliegende ♂♂ ihre Vorderbeine schnell abwechselnd in die Luft. Dieses Vorderbeinwirbeln tritt auch beim Schweben des ♂ vor dem ♀ während der Balz auf und wird als Abwehrhandlung gedeutet. Durch das Vorderbeinwirbeln gegen andere ♂♂ kommt es unter natürlichen Umständen nicht zur Flugbalz vor sitzenden ♂♂.
• 4 ♀♀ vertreiben arteigene ♀♀ und artfremde Fliegen häufig von ihrem Sitzast durch Anlaufen mit schräg angestellten, seitlich abgespreizten Flügeln.
• 5 Das ♂ versucht in 31 % der Fälle die Kopulation unmittelbar nach der Flugbalz (n = 96). Nicht Hochhalten der Hinterbeine des ♀ löst beim ♂ einen Kopulationsversuch aus. Die Kopulation dauert mindestens 15 min und vollzieht sich in der “end-to-end position”.
• 6 Das Paarungsverhalten von Pycnopogon fasciculatus läßt sich als Handlungskette darstellen (Tab. 2).
• 7 Das Paarungsverhalten der räuberischen, in einigen Fällen auch kannibalischen Asilidenfamilie ist sehr unterschiedlich. Außer Flugbalz ist Balz auf fester Unterlage und Überwältigung des ♀ durch das ♂ ohne vorausgehende Balzhandlungen bekannt.

     

Relationships of new world phlebotomine sand flies (Diptera: Psychodidae) based on fossil evidence

The fossil record and systematics of phlebotomid sand flies, vectors of leishmaniasis and arbovirus in several regions of the world, strongly support that living genera existed long before the Oligocene (38 million years, myr). A common Phlebotominae ancestor was present in the Triassic period before the separations of continents (248 myr).     

Neodiptera: New insights into the adult morphology and higher level phylogeny of Diptera (Insecta)

This paper outlines several aspects of the skeleto-muscular organization of the adult prothorax and cervix pertaining to the ground pattern of Diptera, which in turn leads to the characterization of Neodiptera, a higher level dipterous taxon which includes Brachycera and bibionomorph Nematocera ( sensu Hennig). The monophyly of Neodiptera is firmly supported by four skeleto-muscular modifications of the pronoto-cervical region. The bibionomorph Nematocera are shown to be paraphyletic in terms of Brachycera. On more preliminary evidence it is argued that the fundamental dichotomy of the extant Diptera lies between a 'polyneuran' clade which includes Trichoceridae, Tipuloidea, Tanyderidae, and Ptychopteridae and an 'oligoneuran' clade which includes all the remaining groups. Preliminary evidence for a sister group relationship between Blephariceroidea and Culicomorpha is also provided. The possible adaptational significance of the cervical specializations in Neodiptera is discussed.     

A molecular phylogeny of the cotingas (Aves: Cotingidae)

The phylogenetic relationships of members of Cotingidae were investigated using >2100 bp of sequence data from two nuclear introns (myoglobin intron 2 and G3PDH intron 11) and one protein-coding mitochondrial gene (cytochrome b). Strong support was found for a monophyletic clade including 23 traditional cotingid genera, corresponding to the Cotingidae sensu [Remsen, J.V. Jr., Jaramillo, A., Nores, M., Pacheco, J.F., Robbins, M.B., Schulenberg, T.S., Stiles, F.G., da Silva, J.M.C., Stotz, D.F., Zimmer, K.J., 2005. Version 2005-11-15. A classification of the bird species of South America. American Ornithologists' Union. ]. Neither Oxyruncus nor any of the genera in Tityrinae sensu [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] are members of Cotingidae. Within Cotingidae a polytomy of four well-supported clades was recovered: (1) the fruiteaters Pipreola and Ampelioides; (2) the Ampelion group, including Phytotoma; (3) Rupicola and Phoenicircus; and (4) the 'core cotingas' consisting of the remainder of the Cotingas (e.g. fruitcrows, Cotinga, Procnias, Lipaugus, and Carpodectes), with Snowornis in a basal position. The separation of Snowornis from Lipaugus [Prum, R.O, Lanyon, W.E., 1989. Monophyly and phylogeny of the Schiffornis group (Tyrannoidea). Condor 91, 444-461.] was strongly supported, as were the close relationships between Gymnoderus and Conioptilon, and between Tijuca and Lipaugus. However, basal relationships among 'core cotinga' clades were not resolved.     

A molecular phylogeny of the Chalcidoidea (Hymenoptera)

Chalcidoidea (Hymenoptera) are extremely diverse with more than 23,000 species described and over 500,000 species estimated to exist. This is the first comprehensive phylogenetic analysis of the superfamily based on a molecular analysis of 18S and 28S ribosomal gene regions for 19 families, 72 subfamilies, 343 genera and 649 species. The 56 outgroups are comprised of Ceraphronoidea and most proctotrupomorph families, including Mymarommatidae. Data alignment and the impact of ambiguous regions are explored using a secondary structure analysis and automated (MAFFT) alignments of the core and pairing regions and regions of ambiguous alignment. Both likelihood and parsimony approaches are used to analyze the data. Overall there is no impact of alignment method, and few but substantial differences between likelihood and parsimony approaches. Monophyly of Chalcidoidea and a sister group relationship between Mymaridae and the remaining Chalcidoidea is strongly supported in all analyses. Either Mymarommatoidea or Diaprioidea are the sister group of Chalcidoidea depending on the analysis. Likelihood analyses place Rotoitidae as the sister group of the remaining Chalcidoidea after Mymaridae, whereas parsimony nests them within Chalcidoidea. Some traditional family groups are supported as monophyletic (Agaonidae, Eucharitidae, Encyrtidae, Eulophidae, Leucospidae, Mymaridae, Ormyridae, Signiphoridae, Tanaostigmatidae and Trichogrammatidae). Several other families are paraphyletic (Perilampidae) or polyphyletic (Aphelinidae, Chalcididae, Eupelmidae, Eurytomidae, Pteromalidae, Tetracampidae and Torymidae). Evolutionary scenarios discussed for Chalcidoidea include the evolution of phytophagy, egg parasitism, sternorrhynchan parasitism, hypermetamorphic development and heteronomy.