Rhopalosiphum Insertum Research Articles

Rhopalosiphum insertum (apple-grass aphid)

This datasheet on Rhopalosiphum insertum covers Identity, Overview, Distribution, Hosts/Species Affected, Diagnosis, Biology & Ecology, Natural Enemies, Impacts, Prevention/Control, Further Information.

Biljne vaši (Hemiptera: Aphididae) - štetočine jabuke

Aphids are often present in apple orchards in Serbia. They represent a significant group of pests for which insecticides are regularly used. The most important species are: Aphis pomi, Aphis spiraecola, Dysaphis devecta, Dysaphis plantaginea, Dysaphis spp., Rhopalosiphum insertum and Eriosoma lanigerum. The paper provides basic data on the development of aphids and the most important data on their morphology, biology, distribution and harmfulness on apple plants. A species identification key is attached.

OCCURRENCE AND POPULATION DENSITY OF APHIDS IN APPLE ORCHARDS OF SOUTH BULGARIA

Abstract In a 2006-2008 study, seven aphid species (Hemiptera: Aphididae) were detected on apple trees in South Bulgaria: Rhopalosiphum insertum Walk. (apple-grass aphid), Dysaphis plantaginea Pass (rosy apple aphid), Dysaphis devecta Walker (rosy leaf-curling aphid), Macrosiphum euphorbiae Thomas (potato aphid), Aphis pomi De Geer (green apple aphid), Aphis spiraecola Patch. (spiraea aphid/green citrus aphid) and Eriosoma lanigerum Nausm. (wooly apple aphid). The dominant species were D. plantaginea, found in 97.8% of the surveyed orchards. Two green aphid species from the genus Aphis were both found in 96.4% of the orchards. The rosy apple aphid was a more important pest of bearing orchards, where infestation in spring always exceeded the economic injury level (1-2% of infested shoots). The green aphids were more important in young orchards and nurseries, where they developed during the entire vegetation period and infestation sometimes exceed 50-80% of shoots. A. pomi was still more widespread, but A. spiraecola was found throughout all of South Bulgaria. As pests of apple, the other species were less common, causing lower infestations and minor economic importance.

Aphids (Homoptera, Aphidodea) inhabiting the trees Crataegus x media Bechst. in the urban green area. Part I. The population dynamics

The studies were conducted in the years 1999-2001 in the green areas of Lublin, on the trees of <i>Crataegus</i> x <i>media</i> Bechst. The purpose of the studies was to establish the species composition and the population dynamics of aphids inhabiting hawthorn in the street and park sites. The studies found out the presence of four aphid species on the examined trees, namely <i>Aphis pomi</i> De Geer, aphids from the genus <i>Dysaphis</i> Börn., <i>Ovatus crataegarius</i> (Walk.) and <i>Rhopalosiphum insertum</i> (Walk.). More aphid species and bigger populations were found in the street site (A) as compa red with the park site (B).The weather conditions (air temperatures of over 30°C and stormy rainfalls) limited the population of all aphid species. On the other hand, a mild winter and a warm spring with the rainfalls within the norm caused that the number of aphids decreased considerably.

Molecular and Morphometric Data Indicate a New Species of the Aphid GenusRhopalosiphum(Hemiptera: Aphididae)

AbstractHere, we provide evidence for a new aphid species from the genus Rhopalosiphum Koch, based upon an Australian survey of variation in the mitochondrial cytochrome oxidase I gene, and subsequently validated by cytochrome b, nuclear microsatellites, nuclear sequence characterized amplified region locus, and karyotypic analyses. Despite the new species being morphologically very similar to Rhopalosiphum padi (L.), there was significant genetic differentiation, with the new species being closer to the Rhopalosiphum insertum (Walker) group. Karyotypic analyses indicated a putative hybrid origin for the new species, but mitochondrial and nuclear DNA sequence data showed that the available Australian and overseas populations of Rhopalosiphum spp. did not serve as parental lineages. Diagnostic methods were developed that enabled the identification of the new species based on morphometric data and a polymerase chain reaction-restriction fragment length polymorphism based molecular technique.

Diversity in agricultural and forest entomology

2006 was an important year for Agricultural and Forest Entomology. Since being listed in the ISI Web of Knowledge for four years, we obtained our first Impact Factor, which, at 1.533, put Agricultural and Forest Entomology in the top 10 entomological journals. In the last four years we have published 150 papers, written by 449 authors, covering a wide variety of topics on agricultural and forest entomology. Papers have discussed important pests such as the Colorado potato beetle Leptinotarsa decemlineata and the large pine weevil Hylobius abietis, natural enemies such as the predatory mites of the apple-grass aphid Rhopalosiphum insertum and the entomopathogenic nematodes of the cabbage root fly Delia radicum, options for managing pests, including trap cropping and floral understoreys, the implications of climate change, organic farming and many other topics. For the last five years, the Royal Entomological Society journals have been awarding prizes for the best papers published over a two-year period. The paper awarded the Agricultural and Forest Entomology prize for 2002–3 was by Dirk Babendreier et al. (2003) who considered the risk posed by the inundative release of Trichogramma brassicae to nontarget insects in meadows, flower strips and hedgerows. The paper awarded the prize for 2005–6 was by Zhang & Schlyter (2004) who studied the effect of nonhost volatiles on conifer-inhabiting bark beetles. The authors proposed a semiochemical-diversity hypothesis, based on the inhibitory effect of nonhost volatiles on host location by bark beetles. They suggested that this could contribute to the lower frequency of outbreaks of forest insects in mixed forests. In providing support for the more general ‘stability-diversity hypothesis’, this paper has much wider relevance. Agricultural and Forest Entomology will continue to publish a wide on a wide range of entomological topics, including, in this issue, papers on the impact of dead wood on saproxylic insects, bacteria associated with grape phylloxera, methods for studying root-feeding insects, the effect of forest design on sawflies, gypsy moth mating disruption, and the effect of farm diversity on leaf-cutting ants. Agricultural and Forest Entomology was established because of the view that agricultural entomology and forest entomology have much in common. This issue provides good examples of this perspective. The effects of diversity on the pests and other insects found in farms and forests are closely related topics. Root-feeding insects pose problems for both agriculture and forestry and looking back over previous issues we can see, for example, that research reported in this issue on the disruption of gypsy moth mating is related to work on scarabids (Wenninger & Averill, 2006), pine sawflies (Lyytikainen-Saarenmaa et al., 2006), codling moth (Yang et al., 2005) and grape berry moth (Trimble et al., 2003). We look forward to many more years of diversity in agricultural and forest entomology.

Environmental monitoring of economically important invertebrate pests in Bramley apple orchards in Northern Ireland

Apple orchards are host to many species of both pest and beneficial invertebrates. Many of the pest species can cause severe economic damage if populations are left unchecked. Within Northern Irish Bramley apple orchards only four species are deemed to be of economic importance; Panonychus ulmi, Aculus schlechtendali,Rhopalosiphum insertum and Archips podana. Little information exists on the current population status and economic damage potential of these four pests. The population levels of these species and their potential to cause economic damage on the Bramley fruit is therefore discussed in regard to current economic spray thresholds.

Updated check-list of iberian-balearic Aphidini (Hemiptera, Aphididae)

The check-list of species in the Tribe Aphidini (Hemiptera, Aphididae: Aphidinae) recorded to date from the Iberian Peninsula and Balearic Isles is presented, 139 species are listed. A list of the countries (Andorra, Spain and Portugal) and provinces (Spanish) or districts (Portuguese) where each species and subspecies is known is also included. Five species are mentioned for the first time in Iberian-Balearic territory: Aphis callunae Theobald, A. comosa (Borner), A. lantanae Koch (with the subspecies A. lantanae coriaria Borner), A. erigerontis Holman and Schizaphis longicaudata Hille Ris Lambers. Nine species have been removed from the check-list: Aphis euphorbiae Kaltenbach, A. genistae Scopoli, A. pilosellae (Borner), A. salsolae (Borner), A. striata Hille Ris Lambers, Brachyunguis zygophylli (Nevsky), B. suaedus (Paik), Protaphis centaurea (Gomez-Menor) and Schizaphis pilipes (Ossiannilsson). Aphis ruborum Borner & Schilder, 1931 is recognized as the valid name for Aphis ruborum Borner, 1932 syn. nov. and Rhopalosiphum oxyacanthae (Schrank) for Rhopalosiphum insertum (Walker). Two new combinations are established: Xerobion blascoi comb. nov. for Aphis blascoi Garcia Prieto & Sanchis Segovia and Xerobion brutii comb. nov. for Absinthaphis brutii Barbagallo. Five binomens have been re-established: A. althaeae (Nevsky), A. ballotae Passerini, A. longirostris (Borner), A. ononidis (Schouteden) and A. picridis (Borner) to replace A. davletshinae Hille Ris Lambers, A. balloticola Szelegiewicz, A. longirostrata Hille Ris Lambers, A. kaltenbachi Hille Ris Lambers and A. stroyani Szelegiewicz, respectively. The life cycle of Aphis stachydis Mordvilko is given and its males and oviparous females are described. Taxonomic, faunistics and nomenclatural data of other taxa are also given.

Aphid galls accumulate high concentrations of amino acids: a support for the nutrition hypothesis for gall formation

AbstractThe nutrition hypothesis for the adaptive significance of insect gall formation postulates that galls accumulate higher concentrations of nutritive compounds than uninfested plant tissue, resulting in a high performance of the gall former. This hypothesis has been supported by some taxa of gall insects, but not by taxa such as cynipid wasps. Aphid galls are expected to require higher levels of nitrogen than other insects’ galls with a single inhabitant, because aphid galls are required to sustain a number of aphids reproducing parthenogenetically over two generations. The present study tested this hypothesis by evaluating aphid performance and amino acid concentration in phloem sap, using the aphidRhopalosiphum insertum(Walker) (Homoptera: Aphididae), which establishes colonies on leaves ofSorbus commixtaHedlund or in galls of the aphidSorbaphis chaetosiphonShaposhnikov (Homoptera: Aphididae). We prepared the gall and non‐gall treatments on trees ofS. commixta, in whichR. insertumfundatrices were reared and allowed to reproduce. InS. chaetosiphongalls,R. insertumcolonies propagated more rapidly, and the second generation grew larger and more fecund than on ungalled leaves. The amount of amino acids exuding from cut galled leaves was fivefold that in ungalled leaves; however, there was no significant difference in the amino acid composition between galled and ungalled leaves. In the intact leaves, total amino acid concentration in the phloem sap declined rapidly from late April to late May; however, the galls retained this high amino acid concentration in developing leaves for 1 month. These results indicate that the improved performance inR. insertumis ascribed to the increased concentration of amino acids in galled leaves. We suggest thatS. chaetosiphongalls function to promote the breakdown of leaf protein, leading to an increased performance of gall‐inhabiting aphids.

Detection of Rhopalosiphum insertum (apple‐grass aphid) predation by the predatory mite Anystis baccarum using molecular gut analysis

Abstract 1 A simple, yet sensitive polymerase chain reaction based technique was developed for the detection of the apple‐grass aphid Rhopalosiphum insertum in the gut of Anystis baccarum, a predatory mite.2 A range of conserved polymerase chain reaction primers for insect mitochondrial and ribosomal DNA were tested in order to amplify R. insertum DNA. The mitochondrial DNA primers LrRNAR2 + N1F1, amplified a region between the ND1 and large subunit RNA genes.3 DNA sequencing of the R. insertum ND1‐LRNA polymerase chain reaction product allowed aphid‐specific polymerase chain reaction primers to be designed. These amplified a 283‐bp product from individual aphids. No polymerase chain reaction product was amplified from individual A. baccarum.4 Using the aphid‐specific primers against A. baccarum fed on R. insertum, the diagnostic 283‐bp product was amplified.5 Two restriction enzymes (RsaI and AluI) produced patterns that allowed unambiguous identification of R. insertum DNA from that of Macrosiphum euphorbiae and Myzus persicae.

Vector specificity of barley yellow dwarf virus serotypes and variants in southwestern Idaho

SummaryPlants with symptoms of barley yellow dwarf virus (BYDV) obtained in infection feeding assays of aphids collected in the field in Idaho between 1986 and 1988 were tested for virus transmissibility by possible aphid vectors. Isolates obtained during 1987–1988 were also tested with a range of polyclonal antisera which distinguished PAV, MAV, SGV, RPV and RMV serotypes. In 1989 some Idaho (ID) BYDV isolates, maintained as standards for comparison, were serotyped and tested for aphid transmissibility, using 11 species of aphids.There was not always the expected correspondence between serotype and vector specificity for ID isolates. For isolates obtained from field‐collected Rhopalosiphum padi, vector transmissibility and serotype corresponded with previous reports; however, 44% of isolates which were serotyped as RMV were also transmissible by species other than Rhopalosiphum maidis. Similarly, the transmissibility of the ID laboratory standards did not always conform to the reported vector specificity of serotypes. The laboratory ID‐MAV culture was transmitted by Metopolophium dirhodum and Myzus persicae as well as by Sitobion avenae. The laboratory ID‐SGV culture was transmitted by R. padi and 5. avenae as well as by Schizaphis graminum. The ID‐RPV culture was transmitted by S. graminum and Rhopalosiphum insertum as well as R. padi. Both of two laboratory ID‐RMV cultures were transmissible by R. insertum and R. padi transmitted one of them. The results indicate that, for isolates collected in Idaho, vector specificity cannot be assumed from their serotypes.

Transmission of barley yellow dwarf virus by field collected aphids (Homoptera: Aphididae) and their relative importance in barley yellow dwarf epidemiology in southwestern Idaho

SummaryPopulations of cereal aphids were sampled from 1985–1988 and assayed for transmission of barley yellow dwarf virus (BYDV), Rhopalosiphum padi, Rho‐palosiphum maidis, Sitobion avenae, Metopolophium dirhodum, Schizaphis graminum and Macrosiphum euphorbiae collected from host plants transmitted BYDV in bioassays. Of the 1028 Diuraphis noxia collected from plants, one may have transmitted BYDV. The isolate involved resembled SGV in serological and biological characteristics, but since it was not recoverable by any of more than 800 D. noxia subsequently tested, we suspect it may have been a contaminant.Among those aphids collected during the autumn from a suction trap adapted for live collection, R. padi transmitted BYDV most frequently. Other trapped species which transmitted BYDV included: R. maidis, Rhopalosiphum insertum, Macrosiphum euphorbiae, Metopolophium dirhodum and Ceruraphis eriophori. An adapted Infectivity Index indicated that R. padi is by far the most important vector of BYDV during the autumn sowing season in southwestern Idaho. Male R. padi consistently transmitted BYDV more frequently than did females collected during the same period.

Flight activity and cereal host relationships ofRhopalosiphumspp. (Homoptera: Aphididae) in Canterbury

Abstract Flight activity of Rhopalosiphum spp. was recorded in a suction trap between 1981 and 1987. Field studies on cereals in Canterbury during the period 1984–1987 showed that Rhopalosiphum padi L., the most frequent species, was usually present at low densities and only occasionally reached maxima greater than 10 aphids per tiller on wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.). Greater numbers of R. padi were found on rye (Secale cereale L.) than on wheat, barley, oats (Avena sativa L.), or ryegrass cv Tama (Lolium perenne × multiflorum). Rhopalosiphum maidis (Fitch) was frequent on barley in 1985 and 1986 but was rare in other years. Rhopalosiphum insertum (Walker) and R. rufiabdominalis (Sasaki) were recorded on cereals in autumn 1987. Comparison of suction trap catches and numbers of winged aphids landing on cereals showed that R. padi concentrated on barley crops to a lesser extent than did R. maidis or Metopolophium dirhodum (Walker).

RHOPALOSIPHUM INSERTUM (WALKER) (HOMOPTERA: APHIDIDAE) NEWLY RECORDED FROM AUSTRALIA

Abstract Rhopalosiphum insertum (Walker), the apple‐grass aphid, has been recorded for the first time from Australia.

Hosts and Habitats of Parasitoids (Hymenoptera: Aphidiidae) Implicated in Biological Control of Apple Aphid (Homoptera: Aphididae)

No parasitoids able to complete development on apple aphid, Aphis pomi De Geer, were found in north-central Washington. However, several aphidiid species oviposited in A. pomi and developed to last instars before dying. Of these, Praon unicum Smith and Lysiphlebus testaceipes (Cresson) were found attacking A. pomi in apple orchards. P. unicum was most active in spring and parasitized a high percentage of apple aphids in some orchards. L. testaceipes was more prevalent during summer and apparently contributed little to apple aphid control. Hosts and habitats of these and two other species, Praon occidentale (Baker) and Diaretiella rapae (M'Intosh), were investigated. Winter and spring generations of P. unicum were found on apple, peach, and hawthorne. The summer generation was found mainly on hawthorne, weeds, and grasses. Aphid hosts of P. unicum on apple included Dysaphis plantaginea (Passerini), Rhopalosiphum insertum (Walker), and Nearctaphis bakeri (Cowen). Myzus persicae (Sulzer) was the major host on peaches in winter and spring and on weeds during summer.

Cold‐hardiness and development of eggs of Rhopalosiphum insertum

Abstract. 1. The eggs of Rhopalosiphum insertum (Walker) showed a seasonal increase in cold‐hardiness under field conditions. Their supercooling point fell from ‐35°C in November to below ‐40°C in January, then rose to‐35°C or above by March.2. Laboratory experiments demonstrated that both temperature and date affected cold‐hardiness of the eggs. The supercooling points of eggs kept at 16 h photoperiod or in darkness did not, however, differ significantly.3. Eggs brought from the field into warm, long‐day conditions would not hatch until after mid‐January. After this date, per cent hatch was significantly greater in 16 h photoperiod than in darkness; it did not differ between eggs kept at 5 or 0°C, but was reduced at ‐5°C.4. It is concluded that eggs of Rinserturn are in diapause until mid‐January, and that hatching rate and cold‐hardiness are determined by separate environmental factors.

Some observations in west Wales on the relationships between numbers of alate aphids and weather

SUMMARYSome preliminary associations are reported between monthly totals of cereal aphids (Metopolophium dirhodum, Rhopalosiphum insertum, R. padi and Sitobion avenae) caught in suction traps and weather data. Catches at 1.2 and 12.2 m during the summer and autumn flight peaks from 1969 to 1979 were compared with combinations of prior monthly totals of rainfall and accumulated day‐degree temperatures. The best models fitting these results are reported and proposed for testing against future data. The possible relevance of these models, for forecasting whether measures for the control of barley yellow dwarf virus in autumn‐sown cereals are necessary in any year, are discussed.

Surveys of apple‐grass aphid on apple in southern England, 1965–76

SUMMARYSurveys of oviparae of the apple‐grass aphid, Rhopalosiphum insertum(Wlk.), were made in southern England in each autumn from 1965 to 1976 inclusive. Resuhs varied considerably between years; greatest numbers were recorded in 1966 and 1969 and smallest numbers in 1972. The numbers of oviparae were compared with the numbers of gynoparae caught from mid‐September to the end of October in the traps operated by the Rothamsted Insect Survey. The correlation was sufficiently good for the latter to be used to forecast the hkely abundance of these aphids on fruit trusses in the following spring. The autumn surveys of oviparae were, therefore, discontinued. In Kent the numbers of oviparae were positively correlated with rainfall in the previous July and August.

The Median Latent Periods for Three Isolates of Barley Yellow Dwarf Virus in Aphid Vectors

The Median Latent Periods for Three Isolates of Barley Yellow Dwarf Virus in Aphid Vectors

The effect of crowding on alate production and weight of apterous exules of the apple‐grass aphid, Rhopalosiphum insertum

SUMMARYOffspring of Rhopalosiphum insertum are most sensitive to crowding immediately before and after birth. Crowding throughout the nymphal and adult life of the mothers irreversibly determines most offspring as alatae whether the offspring are crowded or not. Offspring of mothers having less exposure to crowding require additional stimuli after birth. The possible evolutionary advantages of such a system are discussed. Hormonal control of alary polymorphism is implicated.The weight of apterae declined with increased crowding. This is correlated with an increase in alate production, and may thus serve to limit the population increase to a level tolerable by the plant without killing it.