Natural coprevalence of Strongwellsea castrans, Cystosporogenes deliaradicae, and Bacillus thuringiensis in the host, Delia radicum

Adult cabbage root flies (Delia radicum) from three Danish localities were diagnosed microscopically for the natural prevalence of Strongwellsea castrans, Cystosporogenes deliaradicae, and Bacillus thuringiensis. C. deliaradicae was significantly coprevalent with S. castrans. B. thuringiensis sporangia were diagnosed in the hemolymph in two D. radicum which were also infected with S. castrans and proved to belong to serovar aizawai and serovar balearica. The biological characterization of S. castrans proved that at 17.5 degrees C flies developed an abdominal hole 7.9 days (mean) after infection and that 5.7 days (mean) passed from the emergence of the hole to the death of the infected host. No mortality effect among D. radicum subjected to B. thuringiensis serovar aizawai, balearica, and kurstaki isolates was detected. RAPD with DNA proved that six B. thuringiensis serovar balearica isolates (all from the same fly) were indistinguisable. This indicates that proliferation of B. thuringiensis in the abdomen of an S. castrans-infected D. radicum may be due to just one genotype. The profiles of one isolated aizawai strain did not correspond to the profiles of other serovar aizawai strains used for comparison. The biological significance of the interaction between the involved pathogens is discussed.     

Entomophthora muscae resting spore formation in vivo in the host Delia radicum

The formation in vivo of Entomophthora muscae resting spores was investigated in the host, Delia radicum (cabbage root fly), by analysis of field data on the seasonal occurrence of E. muscae resting spores over 4 years. E. muscae resting spores in D. radicum were spherical with an average diameter of 39.4 microm, and the average numbers produced were estimated at 5.7 x 10(4) resting spores/female cadaver. Resting spores were found only after midsummer in D. radicum and almost exclusively in females. The proportion of infected females with resting spores was negatively correlated with average weekly day length after midsummer. We did not detect any significant year effect; thus, the results support the hypothesis that the photoperiod is the most important abiotic factor controlling E. muscae resting spore formation in D. radicum.     

The Linnaean Species of the Families Fanniidae, Anthomyiidae and Muscidae (Insecta: Diptera)

Linnaeus described eleven species in the genera Musca and Conops that are now placed in the Fanniidae, Anthomyiidae and Muscidae. A study is presented of the types and other material of these three families in his collection.     

Isolationin vitro ofStrongwellsea castrans [Fungi: Entomophthorales] a pathogen of adult cabbage root flies,Delia radicum [Dipt.: Anthomyiidae]

The entomogenous fungusStrongwellsea castrans was isolatedin vitro for the first time, by incubating conidia projected from infected cabbage root flies (Delia radicum) in a simple, semi-defined liquid medium comprising dextrose, yeast extract and lactalbumin hydrolysate buffered to pH 7. The fungus grew as long unitunicate hyphae. After transfer to a solid nutrient medium, multinucleate hyphal bodies were formed which developed a thick, laminated wall. Neither conidia nor resting spores developed in liquid or on solid media and the fungus survived successive sub-culturing only in liquid media. Using the API-ZYM system, tests on extracts on hyphae ofS. castrans were positive for 11 enzymes but there were no consistent differences in enzyme profiles betweenS. castrans and fungi of the related genusErynia.      

Application of nested-PCR technique to resting spores from the Entomophthora muscae species complex: implications for analyses of host-pathogen population interactions

We developed new Entomophthora-specific primers for nested-PCR of the ITS II region to be used on in vivo material and combined it with RFLP. Resting spores from Scathophaga stercoraria (3 specimens), Delia radicum (9 specimens), Botanophila fugax (1 specimen), and two syrphid host species, Platycheirus peltatus and Melanostoma mellinum (one specimen of each) were characterized genetically after analysis of RFLP-profiles of the PCR-products. The genetic characterization of the resting spore isolates was compared with twenty isolates of known primary conidial morphology (in vitro and in vivo) from the E. muscae species complex. The analysis allowed for the first time a separation of resting spore isolates into the species level, which is not possible only using morphological characters (diameter). Isolates originating from different specimens of the same host taxa appeared to be strongly clonal even they were sampled at different localities in different years. Isolates morphologically belonging to E. muscae s. str. (e.g., including E. scatophagae) could be separated genetically further into sub-groups entirely depending on the host taxa; each fungal genotype, either present at the conidial stage or at the resting spore stage, is correlated with one host species. Furthermore, E. muscae s. str. originating from D. radicum proved to be much more closely related to E. scatophagae than to E. muscae s. str. originating from M. domestica. None of the resting spore isolates could be assigned to E. schizophorae. The nested-PCR approach accompanied by RFLP proved its usefulness for identification of resting spores and for more detailed studies clarifying host-pathogen specificity and interactions. It seems that different members of the E. muscae species complex are able to complete their life cycle in only one host species and, further, that each pathogen-host system is independent.     

The Muscoidea (Diptera: Calyptratae) are paraphyletic: Evidence from four mitochondrial and four nuclear genes

Approximately 5% of the known species-level diversity of Diptera belongs to the Muscoidea with its approximately 7000 described species. Despite including some of the most abundant and well known flies, the phylogenetic relationships within this superfamily are poorly understood. Previous attempts at reconstructing the relationships based on morphology and relatively small molecular data sets were only moderately successful. Here, we use molecular data for 127 exemplar species of the Muscoidea, two species from the Hippoboscoidea, ten species representing the Oestroidea and seven outgroup species from four acalyptrate superfamilies. Four mitochondrial genes 12S, 16S, COI, and Cytb, and four nuclear genes 18S, 28S, Ef1a, and CAD are used to reconstruct the relationships within the Muscoidea. The length-variable genes were aligned using a guide tree that was based on the protein-encoding genes and the indel-free sections of the ribosomal genes. We found that, based on topological considerations, this guide tree was a significant improvement over the default guide trees generated by ClustalX. The data matrix was analyzed using maximum parsimony (MP) and maximum likelihood (ML) and yielded very similar tree topologies. The Calyptratae are monophyletic and the Hippoboscoidea are the sister group to the remaining calyptrates (MP). The Muscoidea are paraphyletic with a monophyletic Oestroidea nested within the Muscoidea as sister group to Anthomyiidae+Scathophagidae. The monophyly of three of the four recognized families in the Muscoidea is confirmed: the Fanniidae, Muscidae, and Scathophagidae. However, the Anthomyiidae are possibly paraphyletic. Within the Oestroidea, the Sarcophagidae and Tachinidae are sister groups and the Calliphoridae are paraphyletic.     

中国四川二郎山地区有瓣蝇类地理垂直分布

1980~2000年调查四川二郎山地区有瓣蝇类(Calyptratae)地理垂直分布。共获成蝇7科88属264种,本文优选其中代表性蝇类30种,以分析其地理垂直分布情况。结果发现因各蝇种特有生态习性的不同而各自在不同垂直地带表现不同的虫口数量分布。     

基于28S rRNA基因序列的常见有瓣蝇类的系统发育

用中国产双翅目有瓣蝇类6科15种和GenBank中登录的5科6种有瓣蝇类昆虫的28SrDNA序列片段组合成7科21种,进行同源性比较。应用Mega3.0软件,探讨了28S rRNA基因在有瓣蝇类的分子进化机制;以黑腹果蝇Drosophilia melanogaster为外群,NJ和MP法构建了上述类群的分子系统树。研究结果表明:在获得的698bp的序列中,有126个变异位点,101个简约信息位点;A T含量平均为68.8%,存在较强的A T含量偏向性。分子系统树中,所有内群聚为一支,支持有瓣蝇类为一单系。内群分别聚为2大支:丽蝇科和麻蝇科关系较近于寄蝇科,组成较进化的狂蝇总科;蝇科与花蝇科聚合的类群为蝇总科,上述结果与现代形态分类系统相同。但粪蝇科和厕蝇科脱离蝇总科,与狂蝇总科聚为一支,与现代形态分类系统不一致。     

中国四川省有瓣蝇类三新种(双翅目:厕蝇科,蝇科)

报道采自中国四川省西部山区有瓣蝇类Calyptraae3新种：厕蝇科Fanniiade厕蝇属Fannia2新种：五枝厕蝇Fannia quinquiramula sp.nov.,虞氏厕蝇Fannia yui sp.nov.;蝇科Muscidae棘蝇属Phaonia 1新种：太子棘蝇Phaonia taizipingga sp.nov.。新种虞氏侧蝇的命名,系对虞以新教授在中国蠓科Ceratopogoinidae等医学昆虫研究所作杰出贡献的敬意。厕蝇科模式标本存中国沈阳师范学院昆虫研究所;蝇科模式标本存北京军事医学科学院微生物流行病研究所医学昆虫标本馆。     

Intraspecific variation and host specificity of Entomophthora muscae sensu stricto isolates revealed by random amplified polymorphic DNA,universal primed PCR,PCR-restriction fragment length polymorphism,and conidial morphology

The intraspecific variations of Entomophthora muscae s. str. associated with particular host species, Musca domestica and Delia radicum, sampled from different localities and different years in Denmark and the variation of E. muscae s. str. originating from different host taxa were investigated. The isolates were compared both by primary spore morphology and by three molecular methods: random amplified polymorphic DNA, universal primed PCR, and PCR-restriction fragment length polymorphism. Analyses of the different molecular data showed the same overall picture and separated E. muscae s. str. into two main groups with all the M. domestica isolates in one group and isolates from D. radicum, Coenosia tigrina, and Pegoplata infirma in the second group. E. muscae s. str. isolates from M. domestica also differ significantly from the rest of the E. muscae s. str. isolates with regard to the morphology of the primary conidia, which were bigger and contained significantly more nuclei per conidium. Several different E. muscae s. str. genotypes were documented and each type was restricted to a single host species, indicating a very high degree of host specificity at or below the level of the subfamily.     

Revision of the aberrant New World genus Coenosopsia Diptera: Anthomyiidae, with a discussion of anthomyiid relationships

Abstract. Morphological evidence from the adults males, females corroborates the recent transfer of the problematic New World genus Coenosopsia from the Muscidae to the Anthomyiidae. It is argued that the calyptrate families Anthomyiidae and Muscidae are sister­groups, and that a Neotropical anthomyiid clade, Coenosopsia Malloch + Phaonantho Albuquerque, constitutes the sister-group of the remaining Anthomyiidae. At present, this clade is largely confined to tropical forests of South and Central America, i.e. an environment avoided by practically all other members of this pronouncedly cold-adapted, boreal family. The first, earliest Coenozoic, biotic exchange between North and South America and subsequent biotic isolation are proposed to lie behind the primary dichotomy of the Anthomyiidae. Five species of Coenosopsia , with apparently perfectly allopatric ranges, are recog nized: the Neotropical C.prima Malloch from Ecuador to SE Mexico, C.peruviana sp.n. from Peru, C.brasiliensis sp.n. from Brazil, and C.mexicana sp.n. from SW Mexico, and the Nearctic C.floridensis sp.n. from N Mexico and SE United States.     

Resting spore formation of aphid-pathogenic fungus Pandora nouryi depends on the concentration of infective inoculum

Resting spore formation of some aphid-pathogenic Entomophthorales is important for the seasonal pattern of their prevalence and survival but this process is poorly understood. To explore the possible mechanism involved in the process, Pandora nouryi (obligate aphid pathogen) interacted with green peach aphid Myzus persicae on cabbage leaves under favourable conditions. Host nymphs showered with primary conidia of an isolate (LC₅₀: 0.9–6.7 conidia mm⁻² 4–7 days post shower) from air captures in the low-latitude plateau of China produced resting spores (azygospores), primary conidia or both spore types. Surprisingly, the proportion of mycosed cadavers forming resting spores ( P _cfrs ) increased sharply within the concentrations ( C ) of 28–240 conidia mm⁻², retained high levels at 240–1760, but was zero or extremely low at 0.3–16. The P _cfrs – C relationship fit well the logistic equation P _cfrs  = 0.6774/[1 + exp(3.1229–0.0270 C )] ( r ² = 0.975). This clarified for the first time the dependence of in vivo resting spore formation of P. nouryi upon the concentration of infective inoculum. A hypothesis is thus proposed that some sort of biochemical signals may exist in the host–pathogen interaction so that the fungal pathogen perceives the signals for prompt response to forthcoming host-density changes by either producing conidia for infecting available hosts or forming resting spores for surviving host absence in situ .     

Entomophthora infecting wheat bulb fly at Rothamsted, Hertfordshire, 1967–71

Entomophthora dipterigena, E. hylemyiae and, most commonly, E. muscae infected wheat bulb flies at Harpenden, Hertfordshire, between 1967 and 1971. The mean annual percentages of infected flies caught were 19, 0, 1, 29 and 16 respectively. These showed an increase with increasing host density. In 1970, two-thirds of the female flies were killed by E. muscae before they laid any eggs.
Conidiophores developed in most flies infected with E. muscae during the 2 weeks after peak emergence of flies. Subsequently, resting spores developed in a progressively increasing proportion of infected flies. Resting spores developed in only six of 130 infected males compared with 103 of 244 infected females in 1970 and 1971. The physiological age of infected flies probably determined whether conidiophores or resting spores developed.     

Comparing the precision,accuracy, and efficiency of branch clipping and sweep netting for sampling arthropods in two Jamaican forest types

ABSTRACT Devising methods for sampling arthropods presents many challenges, including understanding possible differences in results obtained by different individuals (precision), investigating differences between estimates and the actual variable of interest (accuracy), and assessing the effort and cost of a given method (efficiency). We assessed the precision, accuracy, and efficiency of sweep netting and branch clipping, two common methods of sampling arthropods, in mangrove and second‐growth scrub forests in Jamaica, West Indies, in 2009. Three individuals used both methods sequentially to sample arthropods in the territories of American Redstarts (Setophaga ruticilla). We found that both branch clipping and sweep netting lacked precision because different individuals produced different estimates of either arthropod abundance (number of individuals per sample) or biomass. In both forests, more arthropods were sampled with sweep netting, in terms of biomass and abundance, and several orders of arthropods were collected that were missed by branch clipping. We also detected the absence of a predictable habitat‐based difference in arthropod biomass with sweep netting, but not with branch clipping. Sweep netting took longer overall (field and processing time combined) and was therefore less efficient. Despite problems with precision and efficiency, our results suggest that sweep netting may be a more accurate method than branch clipping for sampling foliage arthropods in some forest habitats. Our study also reveals the importance of recognizing and controlling for individual bias and of choosing arthropod sampling methods most appropriate to each study species and habitat type.     

Purification and infectivity ofEntomophaga grylli (Fresenius) Batko Pathotype 2 againstMelanoplus differentialis (Thomas) [Ort.: Locustidae]

The life stages ofEntomophaga grylli (Fresenius) Batko Pathotype 2 were purified and separated by centrifugation in Percoll^R density-gradient medium. The ranges of buoyant densities for germinated resting spores, germ conidia, and resting spores respectively were: 1.040–1.050, 1.055–1.085, and 1.080–1.120 g/ml. Cuticular invasion by germinated germ conidia was the means by whichMelanoplus grasshoppers became infected. Scanning electron micrographs revealed germination of germ conidia on the visible host integument at 100% RH, but not at 90% RH. Significantly higher mortality (P<0.05) was obtained after 3 weeks with grasshoppers incubated in constant light than in constant dark for 24 h following treatment. The disease was not transmitted by ingestion of any life stage. Contribution N^o 85-153-J, Department of Entomology. Agricultural Experiment Station, Kansas State University, Manhattan, KS 66506.     

Decomposition and dipteran succession in pig carrion in central Argentina: ecological aspects and their importance in forensic science

Data on the insect species associated with corpse decomposition are particularly important for estimation of the post-mortem interval (PMI) in forensic science because the PMI is based on the lifecycle and behaviour of necrophagous insects, among other measures. To determine the dipteran succession on pig carrion, four experiments, one in each season, were carried out during 2004 in a rural area of Córdoba, central Argentina. Two pigs ( Sus scrofa L.) were used in each of the four experiments. At each time-point one pig was placed in the shade and the other under direct sunlight. Insects were collected daily during the first 4 weeks and thereafter every 2 or 3 days. Five stages of decomposition were observed and a total of 24 710 adult specimens were collected, belonging to the following eight families of Diptera: Calliphoridae; Muscidae; Sarcophagidae; Phoridae; Piophilidae; Fanniidae; Sphaeroceridae, and Anthomyiidae. All Calliphoridae collected in this study were considered to be of potential forensic importance because of their necrophagous behaviour and because their immature stages use carrion as a food source. Other species, such as Musca domestica L. and Ophyra aenescens (Wiedemann), were also considered to represent potential forensic indicators.     

First record on epizootics of Entomophthora grylli on grasshopper in Indian subcontinent: pathogen city and bio control potential on Oxya velox

A naturally-occurring fungus called Entomophthora grylli was for the first time isolated from two species of grasshopper Oxya velox and Oxya vicinia in Jammu and Kashmir, India. The epizootic was confined along Indo–Pak border between 74 degrees 24′ and 75 degrees 18′, East longitude and 32 degrees 50′ and 33 degrees 30′ North latitude. The fungus proved to be highly pathogenic and the natural mortality was significantly influenced by the population density which increased from 26.00 to 73.60 over the period of epizootics. On the basis of the available literature this appears to be the first record from the Indian sub-continent. While many infected grasshoppers apparently produced neither conidia nor resting spores, the cadavers were found to be full of hyphal bodies and resting spores towards the end of epizootics. These resting spores or their germ tubes were not invasive as such but if provided a saturated environment for a week, they start germinating, resulting in germ conidia which were able to induce dermal pathogencity. Further, it was observed that the disease could not be transmitted to healthy individuals by ingestion. However, the intra-haemocoel infectivity of fresh resting spores, germinated resting spores, and germ conidia proved to be highly pathogenic as they resulted in 81.4% grasshopper mortality. Although E. grylli is fastidious, it is possible to multiply it on a large scale as protoplasts which are infective upon injection in their hosts. However, the lack of a cell wall renders them very fragile, and they are neither infective upon application to the insect's cuticle nor upon ingestion. In the present study, a method on delivery of pathogen through “sticky molasses pan trap” was developed for inducing infection in grasshoppers in a paddy nursery which would facilitate its use as a bioinsecticide, analogous to other entomopathogenic fungi.     

Laboratory evaluation of entomopathogenic fungi against larvae and adults of onion maggot (Diptera: Anthomyiidae)

Laboratory experiments were done to measure the susceptibility of larvae and adults of the onion maggot, Delia antiqua (Meigen) (Diptera: Muscidae: Anthomyiidae) to 27 isolates of entomopathogenic fungi from four genera [Beauveria Vuillemin, Lecanicillium (Petch) Zare & W. Gams, Metarhizium Sorokin, and Paecilomyces Bainier]. A novel bioassay was developed for D. antiqua larvae by using a diet based on mixed vegetable powder. When evaluated in a virulence screen, the fungal isolates caused less mortality of D. antiqua larvae than adults. Only three isolates caused > 50% mortality of larvae, whereas 12 isolates caused > 50% mortality of adults. Fungal species was a statistically significant factor affecting the mortality of larvae but not of adults. The fungal isolates causing the most mortality of larvae tended to belong to Metarhizium anisopliae (Metschnikoff) Sorokin. Two M. anisopliae isolates (389.93 and 392.93) were evaluated in dose-response bioassays. The median lethal concentrations of the isolates against larvae were 6.1 x 10(7) conidia ml(-1) for isolate 389.93 and 7.6 x 10(7) conidia ml(-1) for isolate 392.93. The emergence of adult flies from pupae was reduced at high concentrations of conidia (3.0 x 10(8) and 1.0 x 10(8) conidia ml(-1)). The median lethal concentrations of the isolates against adults were 1.7 x 10(7) and 4.0 x 10(7) conidia ml(-1), respectively. Some of the fungal isolates examined may have potential as biological control agents of larvae of D. antiqua and related species.     

Sweeping beauty: is grassland arthropod community composition effectively estimated by sweep netting?

Arthropods are critical ecosystem components due to their high diversity and sensitivity to perturbation. Furthermore, due to their ease of capture they are often the focus of environmental health surveys. There is much debate regarding the best sampling method to use in these surveys. Sweep netting and pan trapping are two sampling methods commonly used in agricultural arthropod surveys, but have not been contrasted in natural grassland systems at the community level. The purpose of this study was to determine whether sweep netting was effective at estimating arthropod diversity at the community level in grasslands or if supplemental pan trapping was needed. Arthropods were collected from grassland sites in Montana, USA, in the summer of 2011. The following three standardized evaluation criteria (consistency, reliability, and precision) were developed to assess the efficacy of sweep netting and pan trapping, based on analyses of variations in arthropod abundances, species richness, evenness, capture frequency, and community composition. Neither sampling method was sufficient in any criteria to be used alone for community‐level arthropod surveys. On a taxa‐specific basis, however, sweep netting was consistent, reliable, and precise for Thysanoptera, infrequently collected (i.e., rare) insects, and Arachnida, whereas pan trapping was consistent, reliable, and precise for Collembola and bees, which is especially significant given current threats to the latter's populations worldwide. Species‐level identifications increase the detected dissimilarity between sweep netting and pan trapping. We recommend that community‐level arthropod surveys use both sampling methods concurrently, at least in grasslands, but likely in most nonagricultural systems. Target surveys, such as monitoring bee communities in fragmented grassland habitat or where detailed information on behavior of the target arthropod groups is available can in some instances employ singular methods. As a general ecological principle, consistency, reliability, and precision are appropriate criteria to evaluate the applicability of a given sampling method for both community‐level and taxa‐specific arthropod surveys in any ecosystem.