A computer-based systematic survey reveals the predominance of small inverted-repeat elements in wild-type rice genes.

Several recent reports indicate that mobile elements are frequently found in and flanking many wild-type plant genes. To determine the extent of this association, we performed computer-based systematic searches to identify mobile elements in the genes of two "model" plants, Oryza sativa (domesticated rice) and Arabidopsis thaliana. Whereas 32 common sequences belonging to nine putative mobile element families were found in the noncoding regions of rice genes, none were found in Arabidopsis genes. Five of the nine families (Gaijin, Castaway, Ditto, Wanderer, and Explorer) are first described in this report, while the other four were described previously (Tourist, Stowaway, p-SINE1, and Amy/LTP). Sequence similarity, structural similarity, and documentation of past mobility strongly suggests that many of the rice common sequences are bona fide mobile elements. Members of four of the new rice mobile element families are similar in some respects to members of the previously identified inverted-repeat element families, Tourist and Stowaway. Together these elements are the most prevalent type of transposons found in the rice genes surveyed and form a unique collection of inverted-repeat transposons we refer to as miniature inverted-repeat transposable elements or MITEs. The sequence and structure of MITEs are clearly distinct from short or long interspersed nuclear elements (SINEs or LINEs), the most common transposable elements associated with mammalian nuclear genes. Mobile elements, therefore, are associated with both animal and plant genes, but the identity of these elements is strikingly different.

Forecasting Helicoverpa populations in Australia: A comparison of regression based models and a bio-climatic based modeling approach

Long-term forecasts of pest pressure are central to the effective management of many agricultural insect pests. In the eastern cropping regions of Australia, serious infestations of Helicoverpa punctigera (Wallengren) and H. armigera (Hübner)(Lepidoptera: Noctuidae) are experienced annually. Regression analyses of a long series of light-trap catches of adult moths were used to describe the seasonal dynamics of both species. The size of the spring generation in eastern cropping zones could be related to rainfall in putative source areas in inland Australia. Subsequent generations could be related to the abundance of various crops in agricultural areas, rainfall and the magnitude of the spring population peak. As rainfall figured prominently as a predictor variable, and can itself be predicted using the Southern Oscillation Index (SOI), trap catches were also related to this variable. The geographic distribution of each species was modelled in relation to climate and CLIMEX was used to predict temporal variation in abundance at given putative source sites in inland Australia using historical meteorological data. These predictions were then correlated with subsequent pest abundance data in a major cropping region. The regression-based and bioclimatic-based approaches to predicting pest abundance are compared and their utility in predicting and interpreting pest dynamics are discussed.

Effect of growing site, moisture stress and seed size on viability and dormancy of Sporobolus pyramidalis (giant rats tail grass) seed

Sporobolus pyramidalis P. Beauv (giant rats tail grass) is a serious agricultural and environmental weed in tropical and subtropical areas of Australia. Infestations of this unpalatable plant reduce the productivity of pastures and the profitability of industries dependent on grazing animals. This paper reports a series of studies undertaken to assist in the development of control strategies for this species. In particular, these studies measured the viability and dormancy status of fresh seed of S. pyramidalis and the decline of dormancy with time. Variability in these characteristics was determined in seeds collected from several sites within south-east Queensland. The effect of moisture availability during the inflorescence and seed production phases on seed viability and dormancy was also determined. The dormancy of freshly collected seed from several sites ranged from 15 to 95%, but decreased to negligible levels after 4-6 months. Seeds that matured under conditions of high moisture availability were initially more dormant than seeds matured where moisture was less readily available. The proportion of viable seeds was significantly lower in smaller than larger seeds even though viability for all seed sizes exceeded 90%. This study has shown that seed of S. pyramidalis generally has high viability with a large proportion of the seed germinable soon after maturity.

Prevalence, severity, and heritability of Stephanofilaria lesions on cattle in central and southern Queensland, Australia

Observations of cattle in central and southern Queensland are collated to de. ne the prevalence and area of Stephanofilaria lesions associated with infestations of the buffalo fly, Haematobia irritans exigua. The observations were made on herds that were being used for other purposes. In a survey of similar to 1500 animals at Belmont in central Queensland in 1982, 98% of cows and 70% of calves had lesions. Most lesions were on the neck and dewlap and 10% were raw and weeping at the time of sampling. The total area of lesions per animal was strongly related to cattle breed and age. Old Bos taurus animals had the greatest area of lesions, whereas young Bos indicus had the least. Heritability estimates were low, averaging 0.01 for calves and 0.18 for cows. A smaller survey of cows and steers at Craighoyle in central Queensland in 1986 showed a higher numbers of lesions and positive correlations between the total lesion area and animal size. The lesion area increased with tick survival, suggesting that tick-resistant animals are also resistant to Stephanofilaria infection. Steers had smaller areas of lesions than cows, as found previously with cattle ticks. Long-term monitoring observations in central and southern Queensland between 1981 and 1986 showed that the total area of lesions was seasonal with a peak in late summer, consistent with the seasonal incidence of buffalo fly. Animals segregated into Low and High lesion herds maintained their differences over time. The lesions penetrated the dermis of the cattle hides and rendered the affected area unusable, but few lesions occurred on valuable parts of the hide so such economic effects are likely to be insignificant. One animal nearly died of a haemorrhage from a lesion on the dewlap and had to be treated. The results can inform policy on buffalo fly control, and biosecurity preparations in relation to the potential establishment of the OldWorld screw-worm fly, Chrysomyia bezziana, in Australia, which will be facilitated by the lesions. The results emphasise the significant animal welfare and biosecurity risks posed by the lesions in northern Australia.

Spatial distribution of triatomines in domiciles of an urban area of the Brazilian Southeast Region

Reports of triatomine infestation in urban areas have increased. We analysed the spatial distribution of infestation by triatomines in the urban area of Diamantina, in the state of Minas Gerais, Brazil. Triatomines were obtained by community-based entomological surveillance. Spatial patterns of infestation were analysed by Ripley’s K function and Kernel density estimator. Normalised difference vegetation index (NDVI) and land cover derived from satellite imagery were compared between infested and uninfested areas. A total of 140 adults of four species were captured (100 Triatoma vitticeps, 25 Panstrongylus geniculatus, 8 Panstrongylus megistus, and 7 Triatoma arthurneivai specimens). In total, 87.9% were captured within domiciles. Infection by trypanosomes was observed in 19.6% of 107 examined insects. The spatial distributions of T. vitticeps, P. geniculatus, T. arthurneivai, and trypanosome-positive triatomines were clustered, occurring mainly in peripheral areas. NDVI values were statistically higher in areas infested by T. vitticeps and P. geniculatus. Buildings infested by these species were located closer to open fields, whereas infestations of P. megistus and T. arthurneivai were closer to bare soil. Human occupation and modification of natural areas may be involved in triatomine invasion, exposing the population to these vectors.

Flat grain beetle fumigation protocol

Flat grain beetle (FGB) is a major emergency plant pest (EPP) of stored grain in Australia. Populations of FGB have recently developed high level resistance to phosphine (the only viable fumigant available for non-quarantine use) resulting in control failures with current dosage regimes. As there is no practical alternative to phosphine, failure to control FGB with phosphine places at risk market access for Australian grain worth up to $7 billion in annual trade. Therefore there is an urgent need to develop appropriate phosphine fumigation protocols to eradicate outbreaks of strongly resistant FGB. Research outcomes: - Characterisation of high resistance to phosphine in flat grain beetles (FGB) for the first time internationally. - Establishment of fumigation protocols and an eradication strategy that will enable industry to eradicate infestations of phosphine-resistant flat grain beetle and prevent or delay further selection for resistance to phosphine. - Development of a rapid test to detect highly resistant FGB. -Facilitate continued market access of Australian grain.

Pond apple (Annona glabra L.) - Investigating novel mechanical control options

Pond apple usually occurs in swampy areas, but mechanical control may be a viable option in some locations during drier periods. Two machines, the Positrack™ and the Tracksaw™, have been trialled for initial kill rate, amount of follow-up control required, safety to field operators, cost-efficiency and selectivity (effect on native vegetation), compared to other control options. The Positrack™ is a tracked bobcat with a slasher-type attachment that cuts individual trees off near ground level and mulches them. It has no on-board herbicide application capability and requires an additional on-ground operator to apply herbicide by hand. The Tracksaw™ is a tracked mini-excavator with a chainsaw bar and spray applicator on the boom that cuts individual trees off near ground level and applies chemical immediately to the cut stump, requiring only a single operator. Initial trials were done in infestations of similar sizes and densities at the Daintree (Positrack™) and in Innisfail (Tracksaw™) in late 2009. Kill rates to date are 83% for Positrack™ mechanical, 95% for Positrack™ mechanical plus herbicide, and 78% for the Tracksaw™ combined treatment. If ongoing comparison proves either of these machines to be more cost effective, selective, and safer than traditional control methods, mechanical control methods may become more widely used.

Non-target Impacts to Eelgrass from Treatments to Control Spartina in Willapa Bay, Washington

Four methods to control the smooth cordgrass Spartina (Spartina alterniflora) and the footwear worn by treatment personnelat several sites in Willapa Bay, Washington were evaluatedto determine the non-target impacts to eelgrass (Zostera japonica). Clone-sized infestations of Spartina were treated bymowing or a single hand-spray application of Rodeo® formulatedat 480 g L-1acid equivalence (ae) of the isopropylaminesalt of glyphosate (Monsanto Agricultural Co., St. Louis, MO;currently Dow AgroSciences, Indianapolis, IN) with the nonionic surfactant LI 700® (2% v/v) or a combination of mowing and hand spraying. An aerial application of Rodeo® with X-77 Spreader® (0.13% v/v) to a 2-ha meadow was also investigated. Monitoring consisted of measuring eelgrass shoot densities and percent cover pre-treatment and 1-yr post-treatment. Impacts to eelgrass adjacent to treated clones were determined 1 m from the clones and compared to a control 5-m away. Impacts from footwear were assessed at 5 equidistant intervals along a 10-m transect on mudflat and an untreated control transect at each of the three clone treatment sites. Impacts from the aerial application were determined by comparing shoot densities and percent cover 1, 3 and 10 m from the edge of the treated Spartina meadow to that at comparable distances from an untreated meadow. Methods utilized to control Spartina clones did not impact surrounding eelgrass at two of three sites. Decreases in shoot densities observed at the third site were consistent across treatments. Most impacts to eelgrass from the footwear worn by treatment personnel were negligible and those that were significant were limited to soft mud substrate. The aerial application of the herbicide was associated with reductions in eelgrass (shoot density and percent cover) at two of the three sampling distances, but reductions on the control plot were greater. We conclude that the unchecked spread of Spartina is a far greater threat to the survival and health of eelgrass than that from any of the control measures we studied. The basis for evaluating control measures for Spartina should be efficacy and logistical constraints and not impacts to eelgrass. PDF is 7 pages.

The search for exudates from Eurasian watermilfoil and hydrilla

Secondary metabolites are produced by aquatic plants, and in some instances, exudation of these metabolites into the surrounding water has been detected. To determine whether infestations of Eurasian watermilfoil or hydrilla produce such exudates, plant tissues and water samples were collected from laboratory cultures and pond populations and were analyzed using solid phase extraction, HPLC, and various methods of mass spectrometry including electrospray ionization, GC/MS, electron impact and chemical ionization. Previously reported compounds such as tellimagrandin II (from Eurasian watermilfoil) and a caffeic acid ester (from hvdrilla), along with a newly discovered flavonoid, cyanidin 3 dimalonyl glucoside (from hydrilla), were readily detected in plant tissues used in this research but were not detected in any of the water samples. If compounds are being released, as suggested by researchers using axenic cultures, we hypothesize that they may be rapidly degraded by bacteria and therefore undetectable.

Forensic acarology: an introduction

Mites can be found in all imaginable terrestrial habitats, in freshwater, and in salt water. Mites can be found in our houses and furnishings, on our clothes, and even in the pores of our skin-almost every single person carries mites. Most of the time, we are unaware of them because they are small and easily overlooked, and-most of the time-they do not cause trouble. In fact, they may even proof useful, for instance in forensics. The first arthropod scavengers colonising a dead body will be flies with phoretic mites. The flies will complete their life cycle in and around the corpse, while the mites may feed on the immature stages of the flies. The mites will reproduce much faster than their carriers, offering themselves as valuable timeline markers. There are environments where insects are absent or rare or the environmental conditions impede their access to the corpse. Here, mites that are already present and mites that arrive walking, through air currents or material transfer become important. At the end of the ninetieth century, the work of Jean Pierre M,gnin became the starting point of forensic acarology. M,gnin documented his observations in 'La Faune des Cadavres' [The Fauna of Carcasses]. He was the first to list eight distinct waves of arthropods colonising human carcasses. The first wave included flies and mites, the sixth wave was composed of mites exclusively. The scope of forensic acarology goes further than mites as indicators of time of death. Mites are micro-habitat specific and might provide evidential data on movement or relocation of bodies, or locating a suspect at the scene of a crime. Because of their high diversity, wide occurrence, and abundance, mites may be of great value in the analysis of trace evidence.

Cardinium endosymbionts are widespread in synanthropic mite species(Acari: Astigmata)

‘Candidatus Cardinium’ is an intracellular endosymbiont or parasite frequently occurring in invertebrates including mites and ticks. In this work we report Cardinium bacteria in Astigmata mites and explore their incidence in synanthropic species. Amplification of a 776 bp bacterial 16S rRNA gene fragment, using specific primers, enabled identification of closely related Cardinium sequences in 13 laboratory-reared populations of mites. In addition, Cardinium sequences were identified in three wild mite populations. Large scale screening of these populations showed 100% prevalence of Cardinium, representing the highest incidence compared to other major Chelicerate groups.

Acarología forense [Forensic acarology]

Mites are a highly diversified group of chelicerates (arthropods) adapted to a broad spectrum of habitats and diets, presenting extreme specificity to habitats. They are considered to be important indicators of environmental conditions including those modified by human beings. Therefore, they can inform about the environment where a corpse has been exposed to, about the route of specific merchandises, as well as about other applied aspects of forensic entomology. It is not rare the presence of species adapted to cadaveric environments. Jean Pierre Mégnin, forensic veterinarian considered pioneer in the development of forensic entomology, conscious about the importance of mites as forensic indicators, was the first including mites in the decomposition process. For Mégnin, wave six was formed by mites only. Due to the increasing interest of forensic experts in including these organisms in their analysis of trace evidence, as mites are one of the most ubiquitous organisms, we have developed standards for the sampling, conservation and custody of mite evidence of forensic interest.

Resistência de genótipos de batata, Solanum spp., a afídeos (Homoptera: Aphididae) e influência sobre parasitóides

Avaliou-se a resistência de genótipos de batata aos afídeos Myzus persicae (Sulz.), Macrosiphum euphorbiae (Thomas) e Aphis gossypii (Glover), e a influência desses genótipos sobre parasitóides, em dois ensaios em plantios de inverno (1996 e 1997), em condições de campo, em Jaboticabal, SP. Os genótipos plantados no primeiro ano foram: Achat, Baronesa, Bintje, BR-2, Contenda, Monalisa, N 140-201 e NYL 235-4, distribuídos em quatro blocos ao acaso. Dois levantamentos foram efetuados, aos 70 e 85 dias após o plantio, avaliando-se o número de pulgões/folha e pulgões parasitados, nos terços superior, médio e inferior da planta. em 1997 plantaram-se os mesmos genótipos, excetuando-se o N 140-201, com levantamentos aos 72 e 80 dias. O genótipo NYL 235-4 mostrou-se suscetível a M. euphorbiae, sob infestações médias de 2,90 (1996) e 1,19 pulgões/folha (1997); dentre as cultivares comerciais, Baronesa foi a menos atacada por M. persicae (0,12 e 0,10 pulgões/folha em 1996 e 1997), enquanto BR-2 foi bem suscetível (1,10 e 0,66 pulgões/folha). Os afídeos ocorreram em maior população nas partes média e inferior das plantas; maior número de pulgões mumificados por Aphidius ervi Hal. e Diaretiella rapae (McIntosh), com parasitismo variando de 15 a 36%, foi observado em NYL 235-4, que foi o genótipo mais infestado pelos afídeos.

Eficiência de diferentes ramais de pulverização e volumes de calda no controle de Brevipalpus phoenicis na cultura do café

Efficiency of different spraying lances and spraying volumes on the control of Brevipalpus phoenicis in coffee crops. The mite Brevipalpus phoenicis is found on coffee plantations in Brazil since the 1950's. Responsible for indirect losses due to its role as vector of a virus disease, this mite species often requires control measures, the most common based on mitecide spraying. It was evaluated the mortality of B. phoenicis due the coverage of spraying liquid applied on coffee plants, with two types of lances used in air assisted sprayers and four spraying. volumes. Treatments were applied with mitecide abamectin (Vertimec 18 CE (R) at 0.4 L per hectare), in volumes of 250, 400, 550 and 700 L per hectare, with two types of lances for the nozzles. The control efficiency against B. phoenicis, deposition and coverage by spray liquid on coffee plants was evaluated. Experimental delineation was in randomized blocks, with eight treatments plus a check plot in four replications. The statistical analysis was carried in a factorial scheme 2x4+1. No significant differences in the number of mites were found between treatments. As regards spraying liquid deposition, it was observed an increment with increasing spraying volumes, with the plant tops showing the best deposition of spraying liquid. The duplication of the lances (nozzle branches) resulted in a significant increase in control efficiency for B. phoenicis compared with conventional branch and with check plot, without dependence of spraying volume.

Efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros

A adição de óleos à calda de pulverização, muitas vezes, é utilizada a campo sem o adequado conhecimento sobre a absorção do produto fitossanitário pelo alvo, retenção de calda e até mesmo sobre a praga e a cultura. O objetivo do trabalho foi avaliar o efeito da adição de óleos ao acaricida cyhexatin sobre o ácaro Brevipalpus phoenicis e na retenção de calda por folhas de citros. Avaliou-se a mortalidade de ácaros, utilizando-se de frutos de laranja com uma arena circundada com cola entomológica para confinar os ácaros. Adotou-se o delineamento inteiramente casualizado, em esquema fatorial, constituído pelos fatores: duas formulações de cyhexatin (WG e SC), dois tipos de óleo (mineral e vegetal) e duas concentrações dos óleos (0,5 e 1,0%), e mais dois tratamentos adicionais (acaricidas não adicionados de óleo) e uma testemunha sem aplicação. A aplicação dos produtos foi realizada sobre frutos de laranja até além do ponto de escorrimento. Logo após a aplicação, transferiram-se 10 ácaros B. phoenicis para cada fruto.A contagem dos ácaros vivos, mortos e retidos na barreira adesiva foi realizada um dia após a aplicação. Para a determinação da quantidade de calda retida, utilizaram-se folhas de laranjeira, que foram pulverizadas até além do ponto de escorrimento, adotando-se os mesmos tratamentos e o delineamento estatístico mencionados para a avaliação da mortalidade de ácaros, com exceção da testemunha sem aplicação. Determinou-se a massa de líquido retido após a aplicação dos produtos por folha, com auxílio de balança de precisão. Verificou-se que um dia após a aplicação dos produtos, todos os tratamentos apresentaram mortalidade de B. phoenicis acima de 99%. Dessa forma, a adição de óleo, seja mineral, seja vegetal, ao acaricida cyhexatin não afetou a eficácia biológica deste acaricida nas formulações SC e WG. A maior fuga de B. phoenicis para a barreira de cola foi verificada nos tratamentos com adição de óleos, em comparação ao cyhexatin aplicado isoladamente. A adição de óleo, seja mineral, seja vegetal, ao cyhexatin na calda de pulverização reduziu a quantidade máxima de líquido retido pelas folhas de citros, podendo contribuir para a redução da quantidade de calda necessária para uma boa cobertura da planta.