The influence of host suitability on the range of grasshopper species utilized by Blaesoxipha atlanis (Diptera: Sarcophagidae) in the field

Blaesoxipha atlanis (Aldrich) is a common parasitic fly of agriculturally important grasshoppers in Canada. The suitability of Camnula pellucida (Scudder), Melanoplus bivittatus (Say), Melanoplus packardii Scudder, and Melanoplus sanguinipes (Fabricius) as hosts was studied in the laboratory. Grasshoppers were singly-parasitized or left unparasitized and reared for 9 days. Melanoplus bivittatus and M. packardii did not support parasite development, i.e. were non-permissive hosts. In both species, parasite larvae were melanized and encapsulated, but development proceeded further in M. packardii. Melanoplus sanguinipes and C. pellucida were permissive host species with, respectively, 70% and 35% of the implanted larvae emerging from their hosts of which 86% and 50% developed into adults. Parasite development time was longer in C. pellucida. Adult B. atlanis dry mass varied with host species and host mass at parasitism, but not with host sex. Parasites developing in M. sanguinipes were larger in terms of dry mass than counterparts developing in C. pellucida. In permissive species, unparasitized grasshoppers gained in body mass while parasitized insects lost mass during the 9-day observation period. In non-permissive species, all insects gained in body mass, but parasitized females gained less mass than unparasitized conspecifics. All unparasitized grasshoppers survived while 75-95% of permissive and 30-40% of non-permissive hosts died. Variation in the intensity of field parasitism among grasshopper species may be explained, at least in part, by qualitative differences in suitability between potential host species. Novel pest management strategies emphasize preservation of a small proportion of the pest population for natural enemies. Consideration of the outcome of specific host-parasite interactions should improve the understanding of grasshopper population dynamics and increase the predictive value of models that assess potential crop losses.     

A DNA investigation into the mysterious disappearance of the Rocky Mountain grasshopper, mega-pest of the 1800s

The mysterious extinction of the Rocky Mountain Grasshopper, Melanoplus spretus, a major pest species on the prairies and plains of the 1800s, is truly a remarkable event in the history of agriculture. Recently, we obtained specimens of M. spretus from museums and from 400-year-old glacial deposits in Wyoming. We report success in obtaining mitochondrial DNA sequences from both sources. This permitted us to examine two issues surrounding the species' disappearance. First, a long-standing view that M. spretus and the extant species Melanoplus sanguinipes are (if not phase transforms of one another) sister taxa, is disputed, but cannot be rejected with certainty. Interestingly, there is some evidence that suggests there may be a closer affinity with another member of the Mexicanus species-group, Melanoplus bruneri. Second, because M. spretus still possesses considerable nucleotide diversity (1.15+/-0.19%), a depletion of variation cannot be considered a factor contributing to its demise.     

Embryonic developmental rates of northern grasshoppers (Orthoptera: Acrididae): implications for climate change and habitat management

Accurate models of temperature-dependent embryonic developmental rates are important to assess the effects of a changing climate on insect life cycles and to suggest methods of population management by habitat manipulation. Embryonic development determines the life cycle of many species of grasshoppers, which, in cold climates, spend two winters in the egg stage. Increasing temperatures associated with climate change in the subarctic could potentiate a switch to a univoltine life cycle. However, egg hatch could be delayed by maintaining a closed vegetative canopy, which would lower soil temperatures by shading the soil surface. Prediapause and postdiapause embryonic developmental rates were measured in the laboratory over a wide range of temperatures for Melanoplus borealis Fieber and Melanoplus sanguinipes F. (Orthoptera: Acrididae) A model was fit to the data and used to predict dates of egg hatch in the spring and prediapause development in the fall under different temperature regimens. Actual soil temperatures were recorded at several locations over 5 yr. To simulate climate warming, 2, 3, or 4°C was added to each hourly recorded temperature. Results suggest that a 2, 3, or 4°C increase in soil temperatures will result in eggs hatching ≈ 3, 5, or 7 d earlier, respectively. An increase of 3°C would be required to advance prediapause development enough to allow for a portion of the population to be univoltine in warmer years. To simulate shading, 2 and 4°C were subtracted from observed temperatures. A 4°C decrease in temperatures could potentially delay hatch by 8 d.     

A new species of Mysidobdella (Hirudinida: Piscicolidae) from mysids along the California coast

Mysidobdella californiensis n. sp. is described from the mysid Holmesimysis sculpta from Bodega Bay on the central California coast and from Holmesimysis costata var. from San Pedro on the southern California coast. The internal anatomy of M. californiensis is similar to that of the only other species in the genus, Mysidobdella borealis from the north Atlantic Ocean, except that M. californiensis lacks the medial, unpaired seminal receptacle present in M. borealis. Externally, M. californiensis is slightly larger and more robust than M. borealis, with a much larger caudal sucker. The most striking difference between the species is the unusually large, trumpet-shaped, fluted oral sucker in M. californiensis. At Bodega Bay, the prevalence of M. californiensis on its host was 17% with an average intensity of 1.46 (range 1-3) leeches per host.     

Populations of the northern grasshopper, Melanoplus borealis (Orthoptera: Acrididae), in Alaska are rarely food limited

In some systems, grasshoppers appear to be food limited in most years, whereas in other systems top down forces, for example, predators, are more often implicated in population regulation. Sustainable strategies to manage grasshopper populations through habitat management require knowledge of the forces that regulate grasshopper populations. This experiment was undertaken to determine whether populations of Melanoplus borealis (Fieber), a common pest species in Alaska, are food-limited in Alaska. Cages were set up in a fallow field near Delta Junction, AK, in 3 yr (2007-2009). In 2007 and 2008, fertilizer was added to half the plots to increase primary production, and, in all years, cages within each plot were stocked with 0, 5, 9, or 13 fourth-instar M. borealis (equivalent to 0, 20, 36, or 52 grasshoppers/m(2)). Grasshoppers in each cage were counted weekly. Near the end of the growing season, surviving female grasshoppers (≈40% of the original number) were collected. Femur length was taken as a measure of adult size, and functional ovarioles were counted as a measure of current fecundity. If the grasshoppers were food limited, we expected to see significant effects of either density or fertilizer on grasshopper survival, size, or fecundity. The fertilizer treatment greatly increased primary production in both years. Neither fertilizer treatment nor grasshopper density had consistent effects on survival, size, or potential fecundity, leading us to conclude that food is seldom limiting to populations in the interior of Alaska at densities <50 m(-2).     

Evolution of the Alpha-Esterase Duplication within the Montana Subphylad of the Virilis Species Group of Drosophila

Previous studies on linkage disequilibrium involving four tightly linked genes that code for the alpha-esterases of Drosophila montana suggest that these loci arose from a primitive esterase gene by gene duplication, followed by tandem duplication (Roberts and Baker 1973). We have examined the esterase variants in the closely related species, lacicola, flavomontana and borealis. These studies reveal that borealis has only a single esterase locus, and flavomontana may have only two loci. Cytological studies, using aceto-orcein staining and Hoechst fluorescence of squashes of ganglion chromosomes, reveal acrocentric Y chromosomes for all six species of the montana phylad, with the exception of borealis, which has the primitive rod-shaped Y chromosome. These studies provide evidence against the hypothesis (Stone, Guest and Wilson 1960) that borealis and flavomontana are derived from montana, but support Throckmorton's (1978) conclusion of the early divergence of the former two species. This phylogenetic relationship supports our contention that the difference in the number of esterase genes with active alleles between borealis and montana is based on an increase in the number of genes coding for the alpha-esterases, rather than the retention in borealis of three genes with null alleles.     

Shifting distributions and speciation: species divergence during rapid climate change

Questions about how shifting distributions contribute to species diversification remain virtually without answer, even though rapid climate change during the Pleistocene clearly impacted genetic variation within many species. One factor that has prevented this question from being adequately addressed is the lack of precision associated with estimates of species divergence made from a single genetic locus and without incorporating processes that are biologically important as populations diverge. Analysis of DNA sequences from multiple variable loci in a coalescent framework that (i) corrects for gene divergence pre-dating speciation, and (ii) derives divergence-time estimates without making a priori assumptions about the processes underlying patterns of incomplete lineage sorting between species (i.e. allows for the possibility of gene flow during speciation), is critical to overcoming the inherent logistical and analytical difficulties of inferring the timing and mode of speciation during the dynamic Pleistocene. Estimates of species divergence that ignore these processes, use single locus data, or do both can dramatically overestimate species divergence. For example, using a coalescent approach with data from six loci, the divergence between two species of montane Melanoplus grasshoppers is estimated at between 200,000 and 300,000 years before present, far more recently than divergence estimates made using single-locus data or without the incorporation of population-level processes. Melanoplus grasshoppers radiated in the sky islands of the Rocky Mountains, and the analysis of divergence between these species suggests that the isolation of populations in multiple glacial refugia was an important factor in promoting speciation. Furthermore, the low estimates of gene flow between the species indicate that reproductive isolation must have evolved rapidly for the incipient species boundaries to be maintained through the subsequent glacial periods and shifts in species distributions.     

Cuticular lipids of insects. VI. Cuticular lipids of the grasshoppers Melanoplus sanguinipes and Melanoplus packardii

The cuticular lipids of the grasshoppers Melanoplus sanguinipes and Melanoplus packardii contain 60 and 68% alkanes and 28 and 18% secondary alcohol wax esters, respectively, with lesser amounts of normal and sterol wax esters, triglycerides, alcohols, sterols, and free fatty acids. All the hydrocarbons are saturated, and four types of alkanes are present: n-alkanes, 3-methylalkanes, internally branched monomethylalkanes, and internally branched dimethylalkanes. The principal n-alkanes in both insects are C(29) and C(27), with a range from C(21) to C(33). Trace amounts of 3-methylalkanes of 28, 30, and 32 total carbons are present. The principal internally branched monomethylalkanes are C(32) and C(34), whereas the main dimethylalkane contains 35 carbons. The n-alkanes do not correspond in chain length to the secondary alcohols. The primary alcohols range from C(22) to C(32) in both insects, with C(24) and C(26) predominating. The fatty acids in the triglyceride and free fatty acid fractions range from C(12) to C(24) in M. sanguinipes and from C(12) to C(18) in M. packardii.     

A New Record of Kaloula(Amphibia: Anura: Microhylidae) in Shanghai,China

We discovered a medium-sized species of narrow-mouthed frog of the genus Kaloula in June and September 2014 during municipal surveys of amphibians in Shanghai. Three narrow-mouthed frogs were collected in city drains of the Binjiang Forest Park, Shanghai. Based on subsequent examination and morphological characters, these specimens were identified as Kaloula borealis(Barbour, 1908). The species was mainly distributed in Northern China and Korea. It is a new amphibian record for Shanghai. We found the visible differences in male secondary sexual characteristics between our specimens and Beijing specimens. K. borealis was first described inhabiting urban greenlands which could benefit amphibian conservation in urban and urbanizing areas.     

Seasonal occurrence and vertical distribution of appendicularians in Toyama Bay, southern Japan Sea

To investigate seasonal variation in the community structureof appendicularians, vertical hauls (0–500 m) with a Norpacnet were made at an offshore station in Toyama Bay at intervalsof 2–4 weeks from February 1990 to January 1991. Additionalsamples were collected with MTD nets at 12–17 differentdepth layers between the surface and a depth of 600–700m at the same position in June, September and December 1986,and March 1992, to examine the vertical distribution of appendicularians.Twenty-one species (including two unidentified species) belongingto five genera were found, and the dominant species were dividedinto three groups by their occurrence period. Oikopleura longicauda,Fritillaria borealis f. typica and F. borealis f. sargassi occurredthroughout most of the year. Fritillaria pellucida, O. fusiformisand O. rufescens were found in summer and autumn. Oikopleuradioica was found in spring and winter. Oikopleura longicaudawas overwhelmingly the most abundant species throughout theyear. This species was always distributed in the upper 100 mdepth, with a peak at a depth of 0–50 m that correspondedto the peak of chlorophyll a concentration during the day andnight in all seasons. The day–night vertical distributionpatterns of F. borealis f. typica, F. pellucida, O. fusiformisand O. rufescens were similar to that of O. longicauda. Seasonalvariations in abundance of appendicularians are considered tobe the result of biological factors rather than physical factorssuch as temperature and salinity. In particular, O. dioica seemsto be affected by food availability.     

Immunological relationship between oocyte nuclear proteins of Xenopus laevis and X. borealis

Monoclonal antibodies (mABs) have been raised against oocyte nuclear proteins of Xenopus laevis and X. borealis and have been screened for species specificity. Although about 40% of all germinal vesicle polypeptides differ between the two species as judged by two-dimensional gel analysis, most mABs react with polypeptides of both species. Biochemical analysis of the antigens by immunoblotting revealed that a homologue of each antigen of one species could be detected in the other species, despite frequent differences in molecular structure. Nevertheless, five strictly species-specific mABs have been identified. All five are directed against the same acidic polypeptide B3 of X. borealis, which is a structurally altered homologue of the protein N1, previously described in X. laevis germinal vesicles. In oocyte nuclei of hybrids between X. laevis females and X. borealis males, polypeptide of both species appear to be accumulated equivalently. Exceptions to this rule are most easily explained by differences between individuals and by the loss of certain alleles resulting from the cross.     

Relationship between the successful infection by entomopathogenic nematodes and the host immune response

Reproduction of entomopathogenic nematodes requires that they escape recognition by a host's immune system or that they have mechanisms to escape encapsulation and melanization. We investigated the immune responses of larvae for the greater wax moth (Galleria mellonella), tobacco hornworm (Manduca sexta), Japanese beetle (Popillia japonica), northern masked chafer (Cyclocephala borealis), oriental beetle (Exomala orientalis) and adult house crickets (Acheta domesticus), challenged with infective juveniles from different species and strains of entomopathogenic nematodes. The in vivo immune responses of hosts were correlated with nematode specificity and survival found by infection assays. In P. japonica, 45% of injected infective juveniles from Steinernema glaseri NC strain survived; whereas the hemocytes from the beetle strongly encapsulated and melanized the Heterorhabditis bacteriophora HP88 strain, S. glaseri FL strain, Steinernema scarabaei and Steinernema feltiae. Overall, H. bacteriophora was intensively melanized in resistant insect species (E. orientalis, P. japonica and C. borealis) and had the least ability to escape the host immune response. Steinernema glaseri NC strain suppressed the immune responses in susceptible hosts (M. sexta, E. orientalis and P. japonica), whereas S. glaseri FL strain was less successful. Using an in vitro assay, we found that hemocytes from G. mellonella, P. japonica, M. sexta and A. domestica recognized both nematode species quickly. However, many S. glaseri in M. sexta and H. bacteriophora in G. mellonella escaped from hemocyte encapsulation by 24h. These data indicate that, while host recognition underlies some of the differences between resistant and susceptible host species, escape from encapsulation following recognition can also allow successful infection. Co-injected surface-coat proteins from S. glaseri did not protect H. bacteriophora in M. sexta but did protect H. bacteriophora in E. orientalis larva; therefore, surface coat proteins do not universally convey host susceptibility. Comparisons of surface coat proteins by native and SDS-PAGE demonstrated different protein compositions between H. bacteriophora and S. glaseri and between the two strains of S. glaseri.     

Bat rabies in South Carolina, 1970-90.

This retrospective study examines the geographic and temporal distribution of bat species submitted for rabies testing in South Carolina (USA) from 1970 to 1990. Histories of human or animal exposures to rabid and nonrabid bats submitted during this time period were compared. Two hundred and thirty-one bats were found to be rabid from the 2,657 bats submitted over this 20 yr period. The two species most frequently submitted for testing were Lasiurus borealis with 785 specimens (30% of the total) and Nycticeius humeralis with 607 specimens (22% of the total). Lasiurus borealis also had the highest prevalence of rabies (18%) while N. humeralis had the lowest prevalence (3%). Fifty-one percent (1,259) of the bats received for testing were submitted from June through August. The majority (54%) of rabid bats were received from August through October.     

基于线粒体12S和16S rRNA基因部分序列的角蟾亚科部分属种的系统发育关系

测定了角蟾亚科2属8种(亚种)和外群3种的线粒体12S和16S rRNA基因部分DNA序列,比对后序列长共949bp,其中变异位点数320,简约位点数206。邻接法和最大简约法分析的系统关系树一致表明内群为一单系群,其中腺角蟾首先与其他物种分开;沙坪角蟾与宽头短腿蟾聚为一支;余下的5种(亚种)角蟾组成一支,其中小角蟾短肢亚种的广西种群和香港种群聚为一亚支,另一亚支包括峨眉角蟾、小角蟾指名亚种、尾凸角蟾和重庆武隆的角蟾种,后两种角蟾进化关系最近。本结果支持短肢角蟾为有效种,同时提示腺角蟾、沙坪角蟾与宽头短腿蟾可能隶属3个不同的亚属或属。     

Predatory role of Neoseiulus fallacis (Acari: Phytoseiidae): spatial and temporal dynamics in Washington red raspberry fields

The seasonal abundance of spider mites and their predator Neoseiulus fallacis (Garman) (Acari: Phytoseiidae) was determined during three consecutive years in Washington State red raspberry fields. Tetranychus urticae Koch (Acari: Tetranychidae), Eotetranychus carpini borealis (Ewing) (Acari: Tetranychidae), and N. fallacis were commonly found in Skagit and Whatcom Counties. E. carpini borealis colonized the fruiting canes earlier in the season than T. urticae. The two phytophages overlapped in midseason, but T. urticae entered diapause earlier than E. carpini borealis and N. fallacis. Densities of N. fallacis increased with increase in spider mite densities. However, the numerical response of the predator was more evident for T. urticae than for E. carpini borealis. Nevertheless, the predator was spatially associated with the two prey species. The spatial and seasonal distribution of N. fallacis in relationship to host plant phenology and prey distribution may influence the effectiveness of this predator as a biological control agent against spider mites in red raspberry. Densities of the predator increased too late to prevent spider mite damage. The predatory role of N. fallacis could be enhanced by introducing or conserving predators that are more tolerant to climatic factors that prevail in and around the cane canopy in the beginning of the season.     

Mycobacterium kumamotonense Sp. Nov. recovered from clinical specimen and the first isolation report of Mycobacterium arupense in Japan: Novel slowly growing, nonchromogenic clinical isolates related to Mycobacterium terrae complex

Three mycobacterium strains isolated from clinical specimens in Japan were provisionally assigned to the genus Mycobacterium based on their phenotypical characteristics. These isolates were further investigated to determine their specific taxonomic statuses. Mycolic acid analysis and 16S rRNA gene, rpoB, and hsp65 sequence data for the isolates showed that they are most similar to M. terrae complex. DNA-DNA hybridization studies indicated that the three strains were of two species and were distinguishable from M. terrae, M. nonchromogenicum, and M. hiberniae. Therefore, these strains represent two novel species within the genus Mycobacterium. However, one potential new species should have been considered as M. arupense with the 16S rRNA gene and hsp65 sequences similarities of 99.8% and 100% respectively; it was isolated from human specimens in the United States and was proposed in June 2006 as a new species. This report describes the first isolation of M. arupense in Japan, suggesting that the organism is clinically relevant. In addition, we propose the novel species designation Mycobacterium kumamotonense sp. nov. The type strain is CST 7247(T) (=GTC 2729(T), =JCM 13453(T), =CCUG 51961(T)).     

Experimental analysis of lens-forming capacity in Xenopus borealis larvae

Previously, the only anuran amphibians known to have the capacity to regenerate a lens after lentectomy were Xenopus laevis and Xenopus tropicalis. This regeneration process occurs during the larval life through transdifferentiation of the outer cornea promoted by inductive factors produced by the retina and accumulated inside the vitreous chamber. However, the capacity of X. tropicalis to regenerate a lens is much lower than that of X. laevis. This study demonstrates that Xenopus borealis, a species more closely related to X. laevis than to X. tropicalis, is not able to regenerate a lens after lentectomy. Nevertheless, some morphological modifications corresponding to the first stages of lens regeneration in X. laevis were observed in the outer cornea of X. borealis. This suggested that in X borealis the regeneration process was blocked at early stages. Results from histological analysis of X. borealis and X. laevis lentectomized eyes and from implantation of outer cornea fragments into the vitreous and anterior chambers demonstrated that: (i) in X. borealis eye, the lens-forming competence in the outer cornea and inductive factors in the vitreous chamber are both present, (ii) no inhibiting factors are present in the anterior chamber, the environment where lens regeneration begins, (iii) the inability of X. borealis to regenerate a lens after lentectomy is due to an inhibiting action exerted by the inner cornea on the spreading of the retinal factor from the vitreous chamber towards the outer cornea. This mechanical inhibition is assured by two distinctive features of X. borealis eye in comparison with X. laevis eye: (i) a weaker and slower response to the retinal inducer by the outer cornea; (ii) a stronger and faster healing of the inner cornea. Unlike X. tropicalis and similar to X. laevis, in X. borealis the competence to respond to the retinal factor is not restricted to the corneal epithelium but also extends to the pericorneal epidermis.     

The fertility of thorny-headed worms in the genus Echinorhynchus (Acanthocephala: Echinorhynchidae) from Lake Baikal

The total number of eggs (absolute fecundity) and the number of eggs per 1 gr of body weight (relative fecundity) of Echinorhynchus borealis Linstow, 1901, E. salmonis salmonis Muller, 1784, E. s. baicalensis Bogolepova, 1957 and E. truttae Schrank, 1788 from the Baikal lake was examinide. The absolute fecundity decreases in the row or species: E. borealis (26,200 eggs), E. s. salmonis (110,113), E. truttae (8123), E. s. baicalensis (6087). The fecundity of acanthocephalans depends on the host species. The dependence of the whole number of larvae upon the body length of females (r = 0.804) is shown.     

Organellar Inheritance in Liverworts: An Example of <Emphasis Type="Italic">Pellia borealis</Emphasis>

Liverwort Pellia borealis is an allopolyploid species that originated after the hybridization and chromosome doubling of two cryptic species; Pellia epiphylla species N and Pellia epiphylla species S. A sequence comparison of chloroplast tRNAUCCGly, tRNAUUULys gene introns, the mitochondrial tRNAGCUSer gene intron, and the first intron of the coxIII gene in the case of three liverwort species studied revealed that the chloroplast and mitochondrial sequences are identical in P. borealis and P. epiphylla species N but different from homologous P. epiphylla species S sequences. Both mitochondria and chloroplasts of P. borealis were thus inherited from one parent- P. epiphylla species N. Studies on 14 different populations of P. borealis gave the same result. These are the first data on organellar transmission in liverworts, the earliest land plants. Moreover, we show that the intron sequences of some organellar genes, until now not used in any systematic studies, could be very good markers in studying taxonomic relationships in closely related species and reconstructing historical events.     

Genetic divergence and analysis of the relationships between species of Mosla (Labiatae)

Seven species were recognized in Mosla in China. M. pauciflora (C. Y. Wu) C. Y. Wu et H. W. Li is an allotetraploid (2n=36 ), while the other six species are diploids (2n=18). Cluster analysis based on allozyme data from 28 loci of 15 enzyme systems reveals that the six diploid species formed three species pairs. M. cavaleriei Lévl.is closely related to M. dianthera (Buch.-Ham. ex Roxb. ) Maxim., M. chinensis and M. hangchouensis Matsuda are sibling species, and M. scabra (Thunb.) C. Y. Wu et H. W. Li is allied to M. soochouensis. Although M. cavaleriei and M. dianthera are close relatives, considerable genetic divergence has been detected between them. One third of alleles are unique to either of them, and 28.6 % of their loci have different alleles fixed. The average genetic identity ( 1 ) between populations of these two species is 0.770, and the average genetic distance (D) is 0.261. M. scabra and M. soochouensis are the least divergent species pair (I =0.979, D＝0.025). No completely divergent locus was detected, and the percentages of unique alleles are 11.1% to M. scabra and 16.7 % to M. soochouensis. This finding indicates that a high level of genetic differentiation is unnecessarily a prerequisite of speciation. A moderate divergence is detected between M. chinensis and M. hangchouensis (I＝0.899, D=0.107, and 7.1% of completely diverged loci) yet the latter harbors four times as many unique alleles (45.1% ) as the former does(11.8 % ). Compared to the genetic divergence between M. scabra and M. soochouensis, M. dianthera and M. hangchouensis and may well been undergoing active speciation have the high genetic distance betweenpopulations (0.034 and 0.026 respectively).