Selective attractiveness of rodent-baited traps for female blowflies

Five species of Calliphoridae, mostly females, were collected using fly-traps baited with freshly killed rodent carcasses. Female blowflies were examined to determine the stages of ovarian development. The traps were selective for certain ovarian stages which varied according to the species. Phaenicia eximia (Wiedemann) was attracted to the traps mainly to oviposit, whereas females of Chrysomya albiceps (Wiedemann), C. putoria (Wiedemann) and C. megacephala (Fabricius) were captured in intermediate stages of oogenesis but seldom with eggs mature for oviposition. It is concluded that this kind of baited trap is unsuitable for the collection of male blowflies and that samples of female blowflies are specifically biased in favour of certain ovarian conditions.     

Ecdysone oxidase in insects

The occurrence of the enzyme ecdysone oxidase was demonstrated in several insect species. In blowflies it was detected mainly in eggs and pupae. The enzyme activity in blowflies varies during development parallel to the ecdysteroid content. This suggests a specific but presently unknown function of the enzyme. Ecdysone oxidase was located mainly in the fat body and gut of blowflies. It is a cytosolic enzyme.     

A chemically triggered transition from conflict to cooperation in burying beetles

Although interspecific competition has long been recognised as a major driver of trait divergence and adaptive evolution, relatively little effort has focused on how it influences the evolution of intraspecific cooperation. Here we identify the mechanism by which the perceived pressure of interspecific competition influences the transition from intraspecific conflict to cooperation in a facultative cooperatively breeding species, the Asian burying beetle Nicrophorus nepalensis. We not only found that beetles are more cooperative at carcasses when blowfly maggots have begun to digest the tissue, but that this social cooperation appears to be triggered by a single chemical cue – dimethyl disulfide (DMDS) – emitted from carcasses consumed by blowflies, but not from control carcasses lacking blowflies. Our results provide experimental evidence that interspecific competition promotes the transition from intraspecific conflict to cooperation in N. nepalensis via a surprisingly simple social chemical cue that is a reliable indicator of resource competition between species.     

The dynamics of intraguild predation in Chrysomya albiceps Wied. (Diptera: Calliphoridae): interactions between instars and species under different abundances of food

The pattern of larval interaction in blowflies confined with Chrysomya albiceps Wied. and C. rufifacies Maquart can be changed in response to the predatory behaviour of the two species to a contest-type process instead of the scramble competition that usually occurs in blowflies. Facultative predation is a frequent behaviour in C. albiceps and C. rufifacies that occurs as an alternative food source during the larval stage. In this study, we investigated the dynamics of intraguild predation by C. albiceps on other fly species in order to analyse interspecific and intraspecific survival in C. albiceps, C. megacephala and C. macellaria Fabricius. The experimental design of the study allowed us to evaluate how factors such as species, density and abundance of food influenced the survival of the calliphorid species. When C. albiceps was confined with C. megacephala or C. macellaria, only adults of C. albiceps survived at different larval densities and abundance of food. In addition, the survival of C. albiceps was higher in two-species experiments when compared to single species experiments. The implications of these results for the dynamics of C. albiceps were discussed.     

Behavioural response of Lucilia sericata to a decaying body infested by necrophagous insects

Numerous insect species are necrophagous, with Dipterans and Coleopterans being the most abundant on a corpse. Whether the presence of necrophageous species on a corpse affects the attraction of adult blowflies to the corpse is sparsely studied. We test the hypothesis that Lucilia sericata can discriminate the odour of a noncolonized cadaver from the odour of a cadaver on which conspecific and/or heterospecific necrophagous insects are feeding. The volatile organic compounds are collected from decomposing rats under four modalities: (i) in the absence of insects; (ii) in the presence of L. sericata adults; (iii) in the presence of Dermestes frischii adults; (iv) and in the presence of both D. frischii adults and L. sericata adults. During a multiple‐choice bioassay, blowflies are exposed to the four odour samples, and are shown to prefer the odour of a corpse where conspecific larvae are present. We also expect blowflies to avoid cadavers on which predators where present, although L. sericata are not repulsed by the odour of a cadaver colonized by hide beetles. We then compare the average quantities of all 61 volatile molecules identified, finding that the presence of necrophagous insects impacts some of them. However, none of the volatile organic compounds previously reported in the literature as being attractive for L. sericata adults are impacted by the presence of necrophagous insects. The results of the present study suggest that blowfly larvae modify the volatilome of a corpse, enabling adults to discriminate a colonized from a noncolonized corpse.     

Benefits of heterospecific aggregation on necromass: in fluence of temperature,group density,and compositi on on fitness-related traits

Necrophagous blowflies(Diptera:Calliphoridae)such as Calliphora vicina,a cold-tolerant species,and L ucilia serie ata,a warm-adapted species,are pioneer carrion?breeder.Although these two species have different temperature preferences,larvae aggregate actively and often feed simultaneously on carrion.The hypothesis to be tested was that L.sericata benefits from the association with C.vicina at lower temperatures(i.e.,15℃)and that C.vicina derives greater benefits from this association at higher temperatures(i.e.,28℃).Therefore,both species were raised at these two constant temperatures from first instars to adults under three different conditions:monospecific low-density,monospecific high-density,and heterospecific high-density.The time until larval migration,surface area of puparia,and survival rates were determined for each condition.Differences between these fitness-related traits were found between species,temperatures,group densities,and species compositions.At 28°C,C.vicina larvae bred in heterospecific groups migrated significantly earlier and in higher numbers than that under same density conspecific con?ditions,with a lower mortality rate.At 15°C,both species benefited from high-density heterospecific associations,expressed by faster development and larger puparia.In conclusion,necrophagous larvae benefited from heterospecific aggregations at suboptima 1 temperatures by adapting their migration time to that of the faster species.Since temperature changes throughout the day and over the year,the beneficiary of such a collective association also changes.The costs involved and deviations to the temperature-size rule highlight the complexity of the carrion ecosystem.     

两种入侵广州的丽蝇——宽额丽蝇与红头丽蝇

采自广州的两种丽蝇--宽额丽蝇Calliphora latifron_xs Hough,1899、红头丽蝇Clliphora uicina Robineau-Des-voidy,1830,宽额丽蝇为我国新记录种,分析认为这两种丽蝇为入侵种.     

Balearic lizards use chemical cues from a complex deceptive mimicry to capture attracted pollinators

Deceptive flowers from several plant species emit odors that mimic oviposition cues and attract female insects seeking for a laying site. Helicodiceros muscivorus is a species that emits an odor mimicking the foul smell of rotting meat and thereby attracts blowflies that usually oviposit on carcasses but are deceived into pollinating the plant. Thus, H. muscivorus is a striking case of pollination by brood‐site deception. The Balearic lizard, Podarcis lilfordi, exhibits remarkable interactions with dead horse arum. Balearic lizards, which sometimes forage on carcasses, are attracted to blooming dead horse arum. We showed experimentally that P. lilfordi can detect chemical cues from carcasses on cotton swabs and exhibits elevated tongue‐flick rates to carcass chemical cues compared to control stimuli. Lizards also detected and located hidden carcasses using only airborne chemical cues. The responses of lizards to chemical cues from the spadix of blooming dead horse arum were qualitatively and quantitatively similar to those to carcass odors. Therefore, the decay‐like odor that attracts blowflies for the plant's benefit also attracts lizards. This attraction may initially have been somewhat favorable for lizards that eat blowflies, but slightly unfavorable for plants because the lizards ate some pollinators. We suggest that lizards attracted by odor may have learned later to use the plant for thermoregulation and then consume its fruits, making the association more positive for lizards and benefitted arum by seed dispersal.     

THE CONTROL OF BLOWFLIES INFESTING SLAUGHTER-HOUSES I. FIELD OBSERVATIONS OF THE HABITS OF BLOWFLIES

The habits of blowflies infesting slaughter-houses have been studied to determine the conditions under which control measures are most likely to be effective. Flies found in such numbers as to be considered pests of economic importance were: Calliphora erythrocephala (Meig.) and C. vomitoria (L.); Lucilia caesar (L.), L. illustris (Meig.) and L. sericata (Meig.); and Phormia terrae-novae (R.-D.). All were found breeding profusely on slaughter-house refuse.
The reactions of adult blowflies to weather and the working conditions at the slaughter-house are recorded; the three genera react in differing degrees to relatively minor changes in weather conditions, and redistribution of populations caused by these changes is so rapid as to make difficult the accurate assessment of degree of infestation. It was found that blowflies normally do not settle on the internal fabric of slaughter-house buildings but tend rather to congregate on nearby vegetation. The preferences were studied of adult flies for certain types of meat, for particular parts of carcasses, and for meat exposed to sunlight.
Conditions favouring rapid development of larvae were determined and the rates of breeding recorded for the three genera when in natural competition and when breeding independently. The larvae of P. terrae-novae were found to be predacious on other species and each other. Lucilia sericata was found to oviposit and breed successfully in vegetable matter.
Blowflies overwinter as fully grown larvae which pupate only a short while before emerging in the spring.
Various methods are discussed whereby the findings of this investigation into the life history and habits of blowflies can be utilized in the control of these pests.     

Beyond barcoding: A mitochondrial genomics approach to molecular phylogenetics and diagnostics of blowflies (Diptera: Calliphoridae)

Members of the Calliphoridae (blowflies) are significant for medical and veterinary management, due to the ability of some species to consume living flesh as larvae, and for forensic investigations due to the ability of others to develop in corpses. Due to the difficulty of accurately identifying larval blowflies to species there is a need for DNA-based diagnostics for this family, however the widely used DNA-barcoding marker, cox1, has been shown to fail for several groups within this family. Additionally, many phylogenetic relationships within the Calliphoridae are still unresolved, particularly deeper level relationships. Sequencing whole mt genomes has been demonstrated both as an effective method for identifying the most informative diagnostic markers and for resolving phylogenetic relationships. Twenty-seven complete, or nearly so, mt genomes were sequenced representing 13 species, seven genera and four calliphorid subfamilies and a member of the related family Tachinidae. PCR and sequencing primers developed for sequencing one calliphorid species could be reused to sequence related species within the same superfamily with success rates ranging from 61% to 100%, demonstrating the speed and efficiency with which an mt genome dataset can be assembled. Comparison of molecular divergences for each of the 13 protein-coding genes and 2 ribosomal RNA genes, at a range of taxonomic scales identified novel targets for developing as diagnostic markers which were 117–200% more variable than the markers which have been used previously in calliphorids. Phylogenetic analysis of whole mt genome sequences resulted in much stronger support for family and subfamily-level relationships. The Calliphoridae are polyphyletic, with the Polleninae more closely related to the Tachinidae, and the Sarcophagidae are the sister group of the remaining calliphorids. Within the Calliphoridae, there was strong support for the monophyly of the Chrysomyinae and Luciliinae and for the sister-grouping of Luciliinae with Calliphorinae. Relationships within Chrysomya were not well resolved. Whole mt genome data, supported the previously demonstrated paraphyly of Lucilia cuprina with respect to L. sericata and allowed us to conclude that it is due to hybrid introgression prior to the last common ancestor of modern sericata populations, rather than due to recent hybridisation, nuclear pseudogenes or incomplete lineage sorting.     

Flies in the ointment: a morphological and molecular comparison of Lucilia cuprina and Lucilia sericata (Diptera: Calliphoridae) in South Africa

Abstract.  Complementary nuclear (28S rRNA) and mitochondrial (COI) genes were sequenced from blowflies that phenotypically resembled Lucilia cuprina (W.), Lucilia sericata (Meigen) or exhibited characters of both species. The aim was to test a long-held hypothesis that these species hybridize under natural conditions in South Africa ( Ullyett, 1945 ). Blowflies were obtained predominantly from the Cape Town metropolitan area, but reference samples were acquired for L. sericata from Pretoria. Several L. cuprina -like flies were shown to possess a conflicting combination of nuclear and mitochondrial genes that has also been seen in Hawaiian specimens. Homoplasy, sampling of pseudogenes, hybridization and incomplete lineage sorting are discussed as possible hypotheses for the pattern and the latter is concluded to represent the most likely explanation.     

Thermal ecophysiology of seven carrion-feeding blowflies in Southern Africa

A variety of temperature thresholds for larvae, pupae, and adults of seven African species of carrion‐feeding blowflies (Diptera: Calliphoridae) was measured and compared to understand their basic thermal biology and the influence of temperature on their behaviour. Calliphora croceipalpis (Jaennicke) had consistently lower temperature thresholds than all other species tested for all larval (42.9 °C), pupal (16.6 °C), and adult (45.6 °C) stages. Larvae (50.1 °C) and adults (53.4 °C) of Chrysomya marginalis (Robineau‐Desvoidy) had higher upper lethal temperature thresholds than all other species and weighed more than all other species. Pupae and adults of both Chrysomya albiceps (Wiedemann) and Lucilia sericata (Meigen) had similar temperature thresholds, whereas Chrysomya putoria (Wiedemann), Chrysomya chloropyga (Wiedemann), and Chrysomya megacephala (Fabricius) had inconsistent rank temperature thresholds between the larval, pupal, and adult stages. With a few minor exceptions, the nervous activity, muscle activity, and death thresholds in female adult flies responded at higher temperatures than conspecific male flies for all species tested. Similarly, female adult flies weighed consistently more than conspecific male flies for all species tested, except Ca. croceipalpis. These data suggest that there is a phylogenetic component to the thermal biology of blowflies, because Ca. croceipalpis belongs to a primarily Holarctic genus and shows adaptation to that climate even though it inhabits Africa. Comparisons between these temperature thresholds and the distributions of blowfly species present on three rhinoceros carcasses suggest that blowfly larvae with high upper lethal temperature thresholds (particularly C. marginalis) dominate in interspecific competition on the carcass by raising the temperature of the amassed maggots above the thresholds of other carrion‐feeding blowflies, through metabolically generated heat.     

Long‐term variation in environmental conditions influences host–parasite fitness

Long‐term data on host and parasite fitness are important for predicting how host–parasite interactions will be altered in an era of global change. Here, we use data collected from 1997 to 2013 to explore effects of changing environmental conditions on bird–blowfly interactions in northern New Mexico. The objectives of this study were to examine what climate variables influence blowfly prevalence and intensity and to determine whether blowflies and climate variables affect bird fledging success. We examined how temperature, precipitation, and drought affect two parasitic blowflies and their hosts, Western Bluebirds (Sialia mexicana) and Ash‐throated Flycatchers (Myiarchus cinerascens). We found that blowfly prevalence did not change over time. Blowfly intensity increased over time in bluebird nests, but not in flycatcher nests. More blowflies result in slightly higher fledging success in bluebirds, but not flycatchers. There was a significant interaction between blowflies and precipitation on bluebird fledging success. For flycatchers, there was a significant interaction between blowflies and temperature and between blowflies and drought severity on fledging success. Given that the southwest is projected to be hotter and have more frequent and prolonged droughts, we predict that flycatchers may be negatively impacted by blowflies if these trends continue. Future work should focus on investigating the role of both blowflies and climate on fledging success. Climate patterns may negatively impact host fitness through altered parasite pressure.     

The molecular systematics of blowflies and screwworm flies (Diptera: Calliphoridae) using 28S rRNA, COX1 and EF-1α: insights into the evolution of dipteran parasitism

The Calliphoridae include some of the most economically significant myiasis-causing flies in the world - blowflies and screwworm flies - with many being notorious for their parasitism of livestock. However, despite more than 50 years of research, key taxonomic relationships within the family remain unresolved. This study utilizes nucleotide sequence data from the protein-coding genes COX1 (mitochondrial) and EF1α (nuclear), and the 28S rRNA (nuclear) gene, from 57 blowfly taxa to improve resolution of key evolutionary relationships within the family Calliphoridae. Bayesian phylogenetic inference was carried out for each single-gene data set, demonstrating significant topological difference between the three gene trees. Nevertheless, all gene trees supported a Calliphorinae-Luciliinae subfamily sister-lineage, with respect to Chrysomyinae. In addition, this study also elucidates the taxonomic and evolutionary status of several less well-studied groups, including the genus Bengalia (either within Calliphoridae or as a separate sister-family), genus Onesia (as a sister-genera to, or sub-genera within, Calliphora), genus Dyscritomyia and Lucilia bufonivora, a specialised parasite of frogs and toads. The occurrence of cross-species hybridisation within Calliphoridae is also further explored, focusing on the two economically significant species Lucilia cuprina and Lucilia sericata. In summary, this study represents the most comprehensive molecular phylogenetic analysis of family Calliphoridae undertaken to date.     

Pollination activity by blowflies and honeybees on onions in breeders' cages

Honeybees (Apis mellifera) and three species of blowflies (Calliphora vomitoria, Lucilia caesar and L. sericata) were observed on mass-pollinated populations of onions (Allium cepa) in 4·4 × 3·6 m × 2-2·5 m cages in June-August 1977. Pollination activity at temperatures from 14° to 28°C was compared on the basis of mean time per flower touched on each umbel visit. Honeybees did not forage below 16°C. Above 16°C their mean time per flower was short (1·4 s) and varied little with temperature. For blowflies, it decreased markedly from 12·1 s at 14–15·5°C to 2·7 s at 26°C and above, largely because at low temperatures flies spent long periods quiescent or grooming rather than actively feeding. When flowering was not completely synchronous between cultivars, honeybees were more selective than blowflies, but where flowering was synchronous, both types of pollinator visited the two cultivars at random. For the size of cage used, neither type of insect had a distinct advantage as a pollinator of onions, despite their different behaviour patterns.     

Influence of trap surface on the numbers of insects caught in water traps in brassica crops

The contribution of the various surfaces of a water trap to the trap's overall effectiveness was studied in brassica crops by painting black different parts of fluorescent-yellow water-traps. Three pest species, Delia radicum (L.), D. platura (Meig.), and Meligethes aeneus (Fab.)/Meligethes viridescens (Fab.), together with blowflies and syrphids, were caught in large numbers. Each insect responded differently to the yellow/black traps. The numbers of insect caught indicated that the area of trap involved in capturing D. radicum was effectively twice the surface area of the water. Yellow traps for monitoring D. radicum populations could be made more selective by painting the inner wall black, as such traps caught similar numbers of D. radicum to all-yellow traps but 50% fewer D. platura, Meligethes sp. and blowflies, and 95% fewer syrphids.     

The calliphorid larvae parasitic on birds in Japan (Diptera: Calliphoridae)

The immature stages of Protocalliphora maruyamensis Kano et Shinonaga are newly described and the third instar larva of P. azurea (Fallén) is redescribed from specimens collected in Japan. The larval morphology of Protocalliphora is discussed. A key to the third instar larvae of Japanese bird-parasitic blowflies is given.     

The evolution of myiasis in blowflies (Calliphoridae)

Blowflies (Calliphoridae) are characterised by the ability of their larvae to develop in animal flesh. Where the host is a living vertebrate, such parasitism by dipterous larvae is known as myiasis. However, the evolutionary origins of the myiasis habit in the Calliphoridae, a family which includes the blowflies and screwworm flies, remain unclear. Species associated with an ectoparasitic lifestyle can be divided generally into three groups based on their larval feeding habits: saprophagy, facultative ectoparasitism, and obligate parasitism, and it has been proposed that this functional division may reflect the progressive evolution of parasitism in the Calliphoridae. In order to evaluate this hypothesis, phylogenetic analysis of 32 blowfly species displaying a range of forms of ectoparasitism from key subfamilies, i.e. Calliphorinae, Luciliinae, Chrysomyinae, Auchmeromyiinae and Polleniinae, was undertaken using likelihood and parsimony methods. Phylogenies were constructed from the nuclear 28S large subunit ribosomal RNA gene (28S rRNA), sequenced from each of the 32 calliphorid species, together with suitable outgroup taxa, and mitochondrial cytochrome oxidase subunit I and II (COI+II) sequences, derived primarily from published data. Phylogenies derived from each of the two markers (28S rRNA, COI+II) were largely (though not completely) congruent, as determined by incongruence-length difference and Kishino-Hasegawa tests. However, the phylogenetic relationships of blowfly subfamilies based on molecular data did not concur with the pattern of relationships defined by previous morphological analysis; significantly, molecular analysis supported the monophyly of blowflies (Calliphoridae), distinct from the bot and warble flies (Oestridae). Comparative analysis of the myiasis habit based primarily on the 28S rRNA phylogeny indicated that obligate parasitism, and the ability to initiate myiasis in higher vertebrates, has multiple independent origins across myiasis-causing flies (Calliphoridae and Oestridae) and in at least three subfamilies of blowfly (Calliphoridae). Finally, the general association of various blowfly genera and subfamily clades with particular continental and geographical regions suggests that these groups probably came into existence in the Late Cretaceous period, following the break-up of Gondwana.     

Seasonal prevalence of blowflies and flesh flies in Osaka City

Blowflies (Diptera: Calliphoridae) and flesh flies (Sarcophagidae) were collected using a bait trap in Osaka City between April 1998 and June 1999. Seven species from four Calliphoridae genera and three species from one Sarcophagidae genus were captured. Seasonal fluctuations of captured adults for most blowflies showed a bimodal pattern, having peaks in spring and autumn, whereas all flesh flies were captured between spring and autumn. The sex ratios of captured flies were mostly biased toward females.     

Ovarian development in the blowflies Chrysomyaputoria and C. megacephala on natural diets

Fresh human, chicken and cattle faeces were compared as diets for adult female blowflies Chrysomya megacephala (Fabricius) and C.putoria (Wiedemann) (Diptera: Calliphoridae). As controls, sugar and raw beef liver were used. For females of both species, fresh beef liver was the best of these diets: oogenesis was completed in 10-13 days. Human or chicken faeces facilitated slower oogenesis in 27-48 days. On a diet of cattle faeces, C.putoria females began vitellogenesis only 17 days after emergence, whereas females of C.megacephala remained previtellogenic until the end of the experiment (56 days).