不同植物浸液对白纹伊蚊的产卵引诱作用

应用孕卵蚊虫粘捕法现场测试不同植物浸液对白纹伊蚊Aedes albopictus(Skuse)的产卵引诱作用,发现樟树叶、黄杨叶、狗尾草、绊根草、玉兰叶和竹叶的浸液现场诱蚊效果与自来水对照没有显著的差异;竹叶、玉兰叶、狗尾草和绊根草室内发酵21、30和45d的现场诱蚊效果没有显著的差异,而应用诱卵器法显示:竹叶、玉兰、狗尾草、绊根草植物浸液和自来水对照的诱卵数却差异显著。现场试验发现自来水、室外积水和蚊虫饲养水对白纹伊蚊的引诱效果没有显著的差异。     

Species and cultivar influences on survival and parasitism of fall armyworm

Interactions between host plant resistance and biological control may benefit or hinder pest management efforts. Turfgrass cultivars have rarely been tested for extrinsic resistance characteristics such as occurrence and performance of beneficial arthropods on plant genotypes with resistance to known turf pests. Parasitism of fall armyworm, Spodoptera frugiperda (J.E. Smith), among six turfgrass genotypes was evaluated. The six grasses tested [Sea Isle-1 and 561-79 seashore paspalum, Paspalum vaginatum Swartz; TifSport and TifEagle hybrid Bermuda grass, Cynodon dactylon (L.) x C. transvaalensis (Burtt-Davy); and Cavalier and Palisades zoysiagrass, Zoysia japonica von Steudel and Z. matrella (L.) Merrill, respectively] represented a range in resistance to S. frugiperda. Differential recovery of larvae released as first instars reflected this gradient in resistance of Cavalier > or = Palisades > or = TifSport = TifEagle > or = 561- = Sea Isle-1 Larval recovery (percentage of initial number released) was greatest in May, less in July and August, and least in October, probably reflecting the increase in activity of on-site predators and disease pressure. Parasitism of the fall armyworm by the braconid Aleiodes laphygmae Viereck varied among turfgrass genotypes. Parasitism was greatest during July. In total, 20,400 first instars were placed in the field; 2,368 were recovered; 468 parasitoids were subsequently reared; 92.2% were A. laphygmae. In the field, the greatest percentage of reduction in S. frugiperda larvae by A. laphygmae occurred on the armyworm-susceptible seashore paspalums (51.9% on Sea Isle-1 in July). Cotesia marginiventris Cresson and Meteorus sp. also were reared from collected larvae. No parasitoids were reared from larvae collected from resistant Cavalier zoysiagrass. A. laphygmae and C. marginiventris were reared from larvae collected from the other five grass cultivars. No parasitoids of older larvae or pupae were observed.     

Incidence of turf-damaging white grubs (Coleoptera: Scarabaeidae) and associated pathogens and parasitoids on Kentucky golf courses

Root-feeding grubs (Coleoptera: Scarabaeidae) were sampled from damaged areas of 61 irrigated roughs on 32 Kentucky golf courses to determine species composition and natural enemy incidence, the first such survey in the United States' transitional turfgrass climatic zone. Masked chafers (Cyclocephala lurida Bland and C. borealis Arrow) and Japanese beetle (Popillia japonica Newman) accounted for ≈73 and 26% of grubs found in an autumn survey, with Cyclocephala spp. predominating at most sites, although mixed infestations were common. Only a few Phyllophaga spp., and no exotic species other than P. japonica were found. Cyclocephala spp. also predominated in seasonal and statewide surveys regardless of whether a course had cool- or warm-season grass fairways. Pathogenic bacteria, Paenibacillus and Serratia spp., and the autumn-active parasitoid Tiphia pygidialis Allen were the main enemies associated with Cyclocephala spp. Predominant enemies of P. japonica were Paenibacillus, Serratia, and Metarhizium spp. in autumn, and eugregarines, Stictospora sp. (probably S. villani Hays and Clopton) and Tiphia vernalis Rohwer in spring. Entomopathogenic nematodes and the microsporidian Ovavesicula popilliae Andreadis & Hanula were nearly absent in our samples. No predictive relationships were found between soil parameters and proportionate abundance of Cyclocephala or P. japonica, or with natural enemy incidence at particular sites. Although incidence of individual enemies was generally low (<20%; often <5%) in these point-in-time surveys, collectively and over their hosts' prolonged development they may take a significant toll on grub populations.     

Turfgrass, crop, and weed hosts of Blissus occiduus (Hemiptera: Lygaeidae)

Blissus occiduus Barber is an important pest of buffalograss, Buchlo? dactyloides (Nuttall) Engelmann, turf. No-choice studies documented the susceptibility of selected turfgrasses, crops, and weeds to B. occiduus feeding. Highly to moderately susceptible grasses included buffalograss; yellow Setaria glauca (L.) and green foxtail Setaria viridis (L.); Kentucky bluegrass, Poa pratensis L.; perennial ryegrass, Lolium perenne L.; brome, Bromus spp. Leyss.; zoysiagrass, Zoysia japonica Steudel; Bermuda grass, Cynodon dactylon (L.) Pers.; sorghum, Sorghum bicolor (L.) Moench; tall fescue, Festuca arundinacea Schreb.; and barley Hordeum vulgare (L.). Slightly to nonsusceptible grasses included fine fescue, Festuca ovina hirtula L.; rye, Secale cereale L.; crabgrass Digitaria sanguinalis (L.); bentgrass, Agrostis palustris Huds.; wheat, Tritium aestivun L.; corn, Zea mays L.; fall panicum Panicum dichotomiflorum Michx.; and St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze. The reproductive potential of B. occiduus was also investigated on these same grasses. B. occiduus produced offspring on 15 of the 18 turfgrass, crop, and weed species evaluated. No reproduction occurred on either Bermuda grass or St. Augustinegrass, and buffalograss plants were killed by B. occiduus feeding before offspring could be produced.     

Comparison of scarab grub populations and associated pathogens and parasitoids in warm- or cool-season grasses used on transitional zone golf courses

Seven different turfgrass species or mixes used on golf courses in the United States' transitional climatic zone were maintained as randomized and replicated plots in separate stands mowed at fairway (1.6 cm) or rough (6.4 cm) cutting heights and sampled in autumn to assess the density and species composition of scarab grubs; incidence of disease and parasitism thereof; and extent of turf damage from foraging insectivorous skunks, Mephitis mephitis. Influence of grass species on parasitism by spring or autumn-active tiphiid wasps was further assessed on implanted grubs in open enclosures. Masked chafers (Cyclocephala spp.) were three-fold more abundant than Japanese beetle, Popillia japonica Newman, grubs in plots of Zoysia and Cynodon sp. mowed at fairway height, and P. japonica were five-fold more abundant than masked chafer grubs in cool-season turf plots mowed at rough height. Phyllophaga spp. accounted for <1% of grubs in the samples. Milky disease bacteria (Paenibacillus sp.) were the predominant pathogens of Cyclocephala spp., followed by Serratia sp. bacteria and gregarines (Stictospora cf. villani). Cyclocephala grub densities, milky disease incidence (25%), and parasitism by the native tiphiid Tiphia pygidialis Alien (10-12%) were especially high in zoysiagrass. Japanese beetle grubs were infected by Paenibacillus, Serratia, Stictospora, and microsporidia (Ovavesicula sp.), but incidence of individual pathogens was relatively low (<6%) and similar among grasses within each stand. Few nematode-infected grubs were found. Skunk damage was mainly in the cool-season fairway-height grasses, probably reflecting difficulty in foraging in the much tougher stolons and rhizomes of the warm season turfgrasses. The degree of natural suppression of scarab grubs provided by endemic pathogens or parasitoids is unlikely to be compromised by the grass species used on a particular site.     

Optimization of a valine:isoleucine methyl ester pheromone blend and comparison of Robbins and Trécé traps for capture of Phyllophaga anxia (Coleoptera: Scarabaeidae) in Rhode Island

Eight ratios of L-valine:L-isoleucine methyl esters were tested in Robbins traps for capture of Phyllophaga anxia (LeConte) adult males. The 90:10, 80:20, and 60:40 ratios of valine:isoleucine were the most effective blends for capture of beetles in Rhode Island. Females were captured in small numbers in some traps but not consistently to any particular blend. Other male Phyllophaga species captured included Phyllophaga fusca (Fr?lich), Phyllophaga forsteri (Burmeister), P. hirsuta (Knoch), and P. marginalis (LeConte). The number of these species collected was low, and it was not possible to determine whether they were attracted to any particular pheromone blend. Peak captures of P. anxia males occurred 31 May in 1999 and 2002 in Kingston, RI. The standard Japanese beetle trap manufactured by Trécé (Adair, OK) captured significantly more beetles than the Robbins trap. Because the Trécé trap is already marketed for Japanese beetles, a lure and trapping system can be adopted for P. anxia.     

Parasitism of Ascogregarina taiwanensis and Ascogregarina culicis (Apicomplexa: Lecudinidae) in larvae of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) from Manaus, Amazon region, Brazil

The aim of the study was to determine the existence of Ascogregarina spp. in larvae of Aedes albopictus and Aedes aegypti collected in urban and suburban areas of Manaus, Amazon region, Brazil. Between May 2004 and July 2005, the mid-gut of 3rd and 4th instar larvae, collected in tire traps in six neighborhoods of Manaus, was examined for the presence of trophozoites of Ascogregarina. Coexistence of Ae. albopictus larvae infected by A. taiwanensis, and Ae. aegypti larvae by A. culicis, was detected in traps in the field. The percentage of Ae. albopictus larvae infected by A. taiwanensis ranged from 21% to 93.5% and of Ae. aegypti larvae infected by A. culicis from 22% to 95%. The mean infection intensity was similar in both species of Aedes. In traps located in Mauazinho, the replacement of Ae. aegypti by Ae. albopictus larvae was observed. In Manaus, Ae. albopictus larvae were parasitized by A. taiwanensis, and Ae. aegypti larvae by A. culicis. Infection rates were high when the species of Aedes were found separately.     

Phytoremediation Effect and Growth Responses of Cynodon spp. and Agropyron desertorum in a Petroleum-Contaminated Soil

In order to compare the petroleum tolerance and phytoremediation ability of a native grass, Agropyron desertorum (desert Wheatgrass) with Cynodon spp. (Bermuda grass) in a petroleum hydrocarbon-contaminated soil, a 7-month greenhouse experiment was performed. There were 4 soil treatments with 0% (uncontaminated soil), 2%, 4%, and 12% (w_oil/w_soil) petroleum concentration. Parameters including shoot and root fresh weight and dry weight, root penetration depth and root density depth, soil respiration, and total petroleum hydrocarbons (TPH) degradation were measured during and after experiments. The results showed an increase in shoot fresh weight of A. desertorum in soil polluted with 2% petroleum sludge compared to the uncontaminated soil, whereas the growth of Bermuda grass significantly decreased in corresponding treatment. Root growth of A. desertorum was decreased in 2% and 4% petroleum sludge, whereas it was increased in Bermuda grass species. Overall, root fresh weight of Bermuda grass was higher than that of A. desertorum in all treatments. Significant increase in microorganisms' activity was observed in the presence of petroleum sludge and plants in soil compared with uncontaminated soil without plants, and the highest soil respiration (37.6 mg C-CO₂/kg soil day) has been observed in the rhizosphere of Bermuda grass in treatment with 12% petroleum sludge. Plants had a significant role in the degradation of soil contaminants as TPH degradation in planted soils was significantly higher than that in unplanted soil (TPH degradation (%) was 30.4 and 38.9 in A. desertorum and Bermuda grass, respectively, whereas it was just 13.3 in unplanted soil). The rhizosphere of Bermuda grass had significantly less residual TPHs compared to A. desertorum. The results indicated that both Cynodon spp. and A. desertorum had a peculiar tolerance to petroleum pollution. Therefore, as Bermuda grass has already been suggested to be a typical and efficient species for phytoremediating petroleum-contaminated sites, A. desertorum may also prove to be a suitable native alternative.     

Molecular identification of dipteran pests (Diptera: Sciaroidea) from shiitake mushroom

On shiitake farms, mycophagous maggots can cause serious damage by preventing formation of the fruiting body. Recently, these pests have significantly reduced shiitake production in Korea. However, larvae and female adults cannot be identified due to their lack of morphological characteristics. Therefore, farmers and applied entomologists are unable to determine which species is the primary cause of the shiitake damage. In this study, mycophagous flies (colonized larvae) were collected from damaged shiitake farms and subsequently identified by matching identified males with the cytochrome c oxidase subunit I (COI) sequences from the larvae. Divergences of the COI sequences among the species discriminated the clusters clearly, and the mycophagous pests were identified as Camptomyia corticalis and C. heterobia. Interestingly, these two species coexisted under the bark of shiitake oak bed logs.     

Do sexual pheromone traps provide biased information of the local gene pool in the pine processionary moth?

Abstract 1 Sexual pheromone traps are commonly used to monitor populations of the pine processionary moth, Thaumetopoea pityocampa, assuming that trapped males are representative of the breeding population. 2 For seven Italian populations, mitochondrial haplotypes (COI and COII) of adult males caught in traps were compared with those of larvae obtained from egg batches laid in the same year, to test whether the males trapped were representative of the local populations. 3 The distribution of haplotype frequencies revealed substantial homogeneity between adult males and larvae samples from the same population, except for Aosta Ruines Verrès, a population recently expanding in the south‐western Alps. In this case, the results suggested that trapped males were recruited over a wider area than local moths because haplotype diversity was higher than that of larvae. 4 A further analysis of this population using nuclear markers (AFLP) confirmed that adults, collected in pheromone traps, were genetically different from the larvae emerging in the same stand. 5 In conclusion, the assumption that trapped males are representative of breeding populations was confirmed for core populations, but has not been verified for the recently established population of Aosta Ruines Verrès. This should encourage discussion with respect to the reliability of pheromone traps in monitoring programmes of the pest, especially at the range's edge.     

A DNA barcode library for Korean Chironomidae (Insecta: Diptera) and indexes for defining barcode gap

Non-biting midges (Diptera: Chironomidae) are a diverse population that commonly causes respiratory allergies in humans. Chironomid larvae can be used to indicate freshwater pollution, but accurate identification on the basis of morphological characteristics is difficult. In this study, we constructed a mitochondrial cytochrome c oxidase subunit I (COI)-based DNA barcode library for Korean chironomids. This library consists of 211 specimens from 49 species, including adults and unidentified larvae. The interspecies and intraspecies COI sequence variations were analyzed. Sophisticated indexes were developed in order to properly evaluate indistinct barcode gaps that are created by insufficient sampling on both the interspecies and intraspecies levels and by variable mutation rates across taxa. In a variety of insect datasets, these indexes were useful for re-evaluating large barcode datasets and for defining COI barcode gaps. The COI-based DNA barcode library will provide a rapid and reliable tool for the molecular identification of Korean chironomid species. Furthermore, this reverse-taxonomic approach will be improved by the continuous addition of other speceis’ sequences to the library.     

Lack of interactions between fire ant control products and white grubs (Coleoptera: Scarabaeidae) in turfgrass

Insecticides are widely used to manage turfgrass pest such as white grubs (Coleoptera: Scarabaeidae). Red imported fire ants, Solenopsis invicta (Buren) are important predators and pests in managed turfgrass. We tested the susceptibility of white grub life stages (adults, egg, and larvae) to predation by S. invicta and determined if insecticides applied for control of S. invicta would result in locally greater white grub populations. Field trials over 2 yr evaluated bifenthrin, fipronil, and hydramethylnon applied to large and small scale turfgrass plots for impacts on fire ant foraging and white grub populations. Coincident with these trials, adults, larvae, and eggs of common scarab species were evaluated for susceptibility to predation by S. invicta under field conditions. Field trials with insecticides failed to show a significant increase in white grub populations resulting from treatment of turfgrass for fire ants. This, in part, may be because of a lack of predation of S. invicta on adult and larval scarabs. Egg predation was greatest at 70% but < 20% of adults and larvae were attacked in a 24 h test. Contrary to other studies, results presented here suggest that fire ants and fire ant control products applied to turfgrass have a minimal impact on white grub populations.     

The lipopolysaccharide biosynthesis core of the Mexican pathogenic strain Serratia entomophila is associated with toxicity to larvae of Phyllophaga blanchardi

The Mexican bacteria Serratia entomophila strain Mor4.1 (Enterobacteriaceae) is pathogenic to coleopteran species of the Phyllophaga genus, which are considered important soil-dwelling pests. Mor4.1 causes anti-feeding activity and mortality to larvae after oral and injection bio-assay either, by bacteria or by cell free culture broth inoculation. The pathogenic determinants of Mor4.1 have not been elucidated. We hypothesize that Mor4.1 produces several toxins and other virulence factors, some acting at the level of the insect gut and others at the hemocoel. To identify and characterize virulence factors, a fosmid library of S. entomophila Mor4.1 was made in Escherichia coli. Five different insecticidal clones were isolated by injecting individual clones into Phyllophaga blanchardi larvae. The complete 40 kb DNA sequence and gene organization of clone G8 was determined. By comparative genomics, 21 genes were associated with virulence. By transposon (Tn5) insertion mutagenesis of G8 and further bio-assays we show that a dUTPase, a flavoprotein and a heptosyltransferase III, are key factors for G8 toxic activity. The heptosyltransferase III, is part of the lipopolysaccharide (LPS) biosynthesis core. We demonstrated that purified LPS from G8 and Mor4.1 are toxic to P. blanchardi larvae by injection bio-assay.     

GRAY WHALE (ESCHRICHTIUS ROBUSTUS) HABITAT UTILIZATION AND PREY SPECIES OFF VANCOUVER ISLAND, B. C.

Habitat utilization and prey species of Vancouver Island gray whales were investigated by (1) summarizing 26 yr of distribution and feeding data and (2) conducting intensive observations in Clayoquot Sound, Vancouver Island, from 1989 to 1996. Whale distribution and movements were monitored from March to November through systematic boat surveys and whale-watch sighting programs. Prey species were collected by suction hose and plankton net or determined through analysis of fecal samples. Gray whales utilized virtually all of the southern west coast of Vancouver Island over the 26-yr observation period. Distribution, prey species, and feeding behavior showed marked variability during any one season and between years. Some feeding areas were used on an annual basis, others with >10-yr intervals between use. Feeding occurred in shallow sand or mud bays, eel grass beds, kelp beds, in the open water column, and at the surface. Young whales appeared to utilize habitat and prey species differently than adults. Main prey species included herring eggs/larvae ( Clupea harengus pallasi ), crab larvae ( Cancer magister megalops, Pachycbeles spp. zoea), mysids ( Holmesimysis sculpta, Neomysis rayii, Acanthomysis spp.), amphipods ( Ampelisca spp., Atylus borealis ), and ghost shrimp ( Callianassa californiensis ). The definition and relative importance of specific feeding grounds and the study of human impacts on this population are complicated by its broad and variable use of habitat and prey species.     

Response of phlebotomine sand flies to light-emitting diode-modified light traps in southern Egypt.

Centers For Disease Control and Prevention (CDC) light traps were modified for use with light-emitting diodes (LED) and compared against a control trap (incandescent light) to determine the effectiveness of blue, green, and red lights against standard incandescent light routinely used for sand fly surveillance. Light traps were baited with dry ice and rotated through a 4 x 4 Latin square design during May, June, and July, 2006. Trapping over 12 trap nights yielded a total of 2,298 sand flies in the village of Bahrif, 6 km north of Aswan on the east bank of the Nile River in southern Egypt. Phlebotomus papatasi comprised 94.4% of trap collections with five other species collected in small numbers. Over half (55.13%) of all sand flies were collected from red light traps and significantly more sand flies (P < 0.05) were collected from red light traps than from blue, green, or incandescent light traps. Red light traps collected more than twice as many sand flies as control (incandescent) traps and > 4 x more than blue and green light traps. Results indicate that LED red light is a more effective substitute for standard incandescent light when surveying in areas where P. papatasi is the predominant sand fly species. Each LED uses approximately 15% of the energy that a standard CDC lamp consumes, extending battery life and effective operating time of traps. Our prototype LED-modified traps performed well in this hot, arid environment with no trap failures.     

狗牙根白化病植原体16S rDNA序列

[目的]狗牙根(草坪草的一种)白化病是狗牙根的一种重要病害,在全世界均有分布.为了确定中国大陆狗牙根白化病病原,进一步与世界其他地区的病原相比有无特异性.[方法]采用植原体16S rDNA PCR扩增、序列分析、Southern分子杂交等技术对狗牙根健康植株及白化病患病植株进行研究.[结果]仅白化病植株扩增获得1.3 kb的特异片段,序列分析表明特异片段与CandidatusPhytoplasm Cynodontis有99%同源性.Southern杂交有特异条带,大小在预期范围之内.证实了在中国大陆发生的狗牙根健株型白化病病原含有植原体.[结论]大陆狗牙根白化病病原中含有植原体,为该病病原的进一步鉴定与防治奠定了基础.     

Analysis of sequence variation in Gnathostoma spinigerum mitochondrial DNA by single-strand conformation polymorphism analysis and DNA sequence

Morphological variations were observed in the advance third stage larvae of Gnathostoma spinigerum collected from swamp eel (Fluta alba), the second intermediate host. Larvae with typical and three atypical types were chosen for partial cytochrome c oxidase subunit I (COI) gene sequence analysis. A 450 bp polymerase chain reaction product of the COI gene was amplified from mitochondrial DNA. The variations were analyzed by single-strand conformation polymorphism and DNA sequencing. The nucleotide variations of the COI gene in the four types of larvae indicated the presence of an intra-specific variation of mitochondrial DNA in the G. spinigerum population.     

Spatial and Temporal Ecology of Native and Introduced Fish Larvae in Lower Putah Creek,California

For two years we studied the distribution and abundance of native and introduced fish larvae in Putah Creek (Yolo County, CA), a low elevation regulated stream. We used light traps and conical drift nets to sample the fish larvae at two spatially separated sites from March through July 1997 and at four sites from February through August 1998. Native larvae occurred both earlier in the year and in higher abundance than those of introduced species. Both native larvae and overall numbers of larvae were more abundant at upstream sites in both years. Sampling of larvae appeared to be sensitive to the detection of rare species. Drift nets and light traps collected similar numbers of larvae, but each method tended to select for different taxa. There were significant trends in diel patterns of abundance, with more fish larvae being found during the hours of darkness. We suggest that differences between the sites were due to habitat changes resulting from an upstream dam that has created a refuge of diverse habitat and cool flowing water for native taxa.     

Breeding places of Phlebotomus ariasi in the cevennes focus of leishmaniasis in the south of France

In a search for sandfly breeding sites in the Cévennes, France, six larvae of Phlebotomus ariasi were found in rotted manure in a cellar housing goats, and six adult flies of the same species were collected from emergence traps, one in the same cellar and five on a disused refuse dump. No sandflies were found emerging from holes of long-tailed field mice (Apodemus spp.) and no sandfly larvae were extracted from 77 kg (dry weight) and 130 kg (undried weight) of samples of soil or litter from different places. Total catches and the proportions of male flies in CDC miniature light traps were much higher in peridomestic than silvatic stations. About 15% of males caught in 3 peridomestic stations had unrotated genitalia. It is concluded that the larval breeding sites of P. ariasi are probably peridomestic and have a high content of organic matter. Observations on colonized P. ariasi show that, although immature stages of this fly need moisture, their requirements are comparatively low. It is suggested that female P. ariasi choose oviposition sites by sensing the presence of immature stages already in an optimal place.