article{931223, abstract = {Aphids are important agricultural pests and also biological models for studies of insect-plant interactions, symbiosis, virus vectoring, and the developmental causes of extreme phenotypic plasticity. Here we present the 464 Mb draft genome assembly of the pea aphid Acyrthosiphon pisum. This first published whole genome sequence of a basal hemimetabolous insect provides an outgroup to the multiple published genomes of holometabolous insects. Pea aphids are host-plant specialists, they can reproduce both sexually and asexually, and they have coevolved with an obligate bacterial symbiont. Here we highlight findings from whole genome analysis that may be related to these unusual biological features. These findings include discovery of extensive gene duplication in more than 2000 gene families as well as loss of evolutionarily conserved genes. Gene family expansions relative to other published genomes include genes involved in chromatin modification, miRNA synthesis, and ...
Zucchiniyellow mosaic virus (ZYMV) is an important non- persistent virus causing high squashproduction losses in Egypt. Aphis gossypii Glover and Myzus persicaeSulazer insects have high efficiency of ZYMV transmission from infected squashplants to healthy ones in Egypt,in advance of their rapid spreading. ZYMV was isolated fromnaturally infected squash plants collected from two locations (Sennoris &Fayoum), at Fayoum governorate. Virus identification was done byserological tests (ELISA) using four different antiserums. Virus wastransmitted to healthy squash plants by mechanical transmission and by using thetwo aphid insects. Fecundity and life span of two aphids andforms (alate and apterous) were studied. ELISA test had relay that the viruswas ZYMV. Typical symptoms of virus were observed by mechanical and aphidinsects inoculation,yellowmosaic, necrosis, leaf curling, blisters stunting, deformation, reduction inleaf size and knobbed fruits (sever malformation).Fecundity and life span ofAphis gossypii
Damage from aphids to wheat plants is noticeable from a distance and can result in water stress, reduced plant growth and wilting. Different aphids are said to cause different colorations when damaging the plants. The comparison of aphid performance on a set of closely related species can help identify traits related to plant defense and aphid performance. Such studies can help inform future experiments that study specific mechanisms of plant resistance. Its important to know what causes aphids to damage some plants more than others so we can find ways to prevent it. I observed the effects that wheat, barley and sorghum have on the population growth rate of corn leaf aphids and green bugs. Also, the effect the aphids have on the plants and how much they damage each type. Will one aphid species have an exceptionally higher rate of reproduction on a specific plant? Is aphid population growth affected by competition between species? I found the green bug population grew faster than the corn leaf ...
Sampling. Day-degree models using a developmental threshold of 4°C can be used to predict various phenological events such as egg hatch and immigration of alate aphids. Yellow traps, particularly water pan traps, are commonly used for population monitoring. Sequential sampling plans for green peach aphid on potato were developed by Hollingsworth and Gatsonis (1990). Sampling of aphid natural enemies in this crop was studied by Mack and Smilowitz (1980). Insecticides. Despite the numerous options potentially available, many producers are dependent on insecticides for suppression of green peach aphid abundance. Systemic insecticide applications are especially popular at planting time, most of which provide long-lasting protection against aphid population buildup during the critical and susceptible early stages of plant growth (Powell 1980) and some of which provide protection for 3 months (Palumbo and Kerns 1994). Green peach aphid is often a pest of cold-weather crops such as spinach. Aphids are ...
Reared as a single genotype, green pea aphid populations decreased in response to elevated CO2 concentrations, but not in response to elevated CO2 + O3 concentrations. Pink pea aphid populations reared as a single genotype were unaffected by augmented CO2 or O3. Populations of mixed genotypes, however, were reduced under elevated CO2 concentrations, irrespective of O3 concentrations ...
The pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae), is a well-studied species in terms of its colour polymorphism, where it occurs as two distinct colour morphs, red and green. It is proposed that the occurrence and maintenance of this ...
The pea aphid, Acyrthosiphon pisum (Hemiptera: Aphididae), is a well-studied species in terms of its colour polymorphism, where it occurs as two distinct colour morphs, red and green. It is proposed that the occurrence and maintenance of this ...
The bacterial communities of aphids were investigated by terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis analysis of 16S rRNA gene fragments generated by PCR with general eubacterial primers. By both methods, the -proteobacterium Buchnera was detected in laboratory cultures of six parthenogenetic lines of the pea aphid Acyrthosiphon pisum and one line of the black bean aphid Aphis fabae, and one or more of four previously described bacterial taxa were also detected in all aphid lines except one of A. pisum. These latter bacteria, collectively known as secondary symbionts or accessory bacteria, comprised three taxa of -proteobacteria (R-type [PASS], T-type [PABS], and U-type [PAUS]) and a rickettsia (S-type [PAR]). Complementary analysis of aphids from natural populations of four aphid species (A. pisum [n 74], Amphorophora rubi [n 109], Aphis sarothamni [n 42], and Microlophium carnosum [n 101]) from a single geographical location revealed Buchnera ...
Background |p|In many insect taxa, wing polymorphism is known to be a consequence of tradeoffs between flight and other life-history traits. The pea aphid |i|Acyrthosiphon pisum|/i| exhibits various morphs with or without wings associated with their complex life cycle including wing polyphenism in viviparous females, genetic wing polymorphism in males, and a monomorphic wingless phenotype in oviparous females and fundatrices. While wing differentiation has been investigated in some detail in viviparous females and males, these processes have not yet been elucidated in monomorphic morphs. The ontological development of the flight apparatus, including wings and flight muscles, was therefore carefully examined in oviparous females and fundatrices and compared with other morphs.|/p| Results |p|The extensive histological examinations showed that flight-apparatus primordia were not at all produced throughout their postembryonic development in oviparous females and fundatrices, suggesting that during the
Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included. Onion thrips populations remain high in many onion fields due to the high temperatures. (view image) Numbers are decreased somewhat, but heavy rainfall, but can quickly rebound. Carzol appears to be working well to control thrips (See the July 19 issue of the Vegetable CAT Alert.). We have received reports of high populations of corn leaf aphids in sweet corn. Corn leaf aphids are about a sixteenth of an inch long, blue-green and have short black cornicles ("stovepipes"). Like other aphids, females give live birth to offspring (all of which are also females) without fertilization. Also, like other aphids, populations can build very rapidly, especially in hot weather. High corn leaf aphid populations can reduce yield in drought-stressed plants. Of more significance is the honeydew they produce while feeding. The honeydew accumulates on the plant and promotes the growth of sooty mold. Sweet corn ...
Soybean aphid (Aphis glycines Matsumura) is a native pest of soybean [Glycine max (L.) Merr.] in eastern Asia and was detected on soybeans in North America in 2000. In 2004, the soybean cultivar Dowling was described to be resistant to soybean aphids with the Rag1 gene for resistance. In 2006, a virulent biotype of soybean aphid in Ohio was reported to proliferate on soybeans with the Rag1 gene. The objective was to survey the occurrence of virulent aphid populations on soybean indicator lines across geographies and years. Nine soybean lines were identified on the basis of their degree of aphid resistance and their importance in breeding programs. Naturally occurring soybean aphid populations were collected in 10 states (Kansas, Illinois, Indiana, Iowa, Michigan, Minnesota, North Dakota, Ohio, South Dakota, and Wisconsin) and the Canadian province of Ontario. The reproductive capacity of field-collected soybean aphid populations was tested on soybean lines; growth rates were compared in ...
TY - CHAP. T1 - Site-specific management of green peach aphid, Myzus persicae (Sulzer), in seed potato. AU - Carroll, Matthew W. AU - Radcliffe, Edward. AU - Macrae, Ian. AU - Olson, Kent. AU - Ragsdale, David. PY - 2004. Y1 - 2004. M3 - Chapter. BT - Proc 7th Internat. Conf. on Precision Agric. & Precision Res. Mgmt. PB - Univ. of Minnesota Precision Ag. center. CY - Minneapolis, USA. ER - ...
On rape, in the autumn the generalist aphids like the green peach aphid (Myzus persicae) and the black bean aphid (Aphis fabae) can provoke yield losses due to virus transmission. The most widespread virus is the beet western yellow virus (BWYV), transmitted through the persistent mode. The cauliflower mosaic virus (CaMV) and the turnip mosaic virus (TuMV) are less frequent. In spring, the aphids can also cause direct damage if strong outbreaks occur: failure of flowers to develop and leaf scald owing to the cabbage aphid (Brevicoryne brassicae) and leaf deformation due to Myzus persicae and Aphis fabae. In autumn, large colonies of turnip aphids (Lipaphis erysimi) can also jeopardize the plants growth.. These kinds of damage can be shown by yield losses of 5-8 q (500-800kg)/ha. The presence of aphids on winter rape will signal the need for close surveillance right from early sprouting. The earliest attacks are the most harmful so rapid action is essential. Treatments using insecticides are ...
Anyone who has grown anything has at one time or another come in contact with some type of Aphid. There are over 4,400 species of Aphids worldwide, and are affectionately termed plant lice. Pea Aphids attack forage crops such as Peas, Alfalfa, and Clovers. They can take out a crop within a series of weeks due…
Transmission. The virus is believed to have spread worldwide through the exchange of infected seed. Seed transmission rates of up to 100% in field peas and up to 44% in lentils have been reported. In Victoria, the DEPI has detected PSbMV at low levels in commercial chickpea seedlots (0.4% of seed) and at higher levels in field pea and lentil seedlots (greater than 2% of seed).. In the USA, PSbMV infection has been reported in pea seedlots (3%) and in lentil seedlots (32-40%). Research at the International Centre for Agriculture in the Dry Areas (ICARDA) found PSbMV was transmitted through lentil seeds at rates of up to 44%. PSbMV is also transmitted in a non-persistent manner by more than 20 aphid species, and by mechanical means.. The most efficient vector of PSbMV worldwide is the pea aphid (Acyrthosiphon pisum). DEPI surveys of Victorian pulse crops have found cowpea aphid (Aphis craccivora), foxglove aphid (Aulacorthum solani), and green peach aphid (Myzus persicae) to be important vectors ...
Our results confirmed that there were significant differences between the two strains of apterous A. pisum in host relocation. Some biological differences were observed between the two aphid strains. These two A. pisum strains were identified by COI sequences (primers shows in Table S1) and confirmed as the same species. Our preliminary tests also showed that the two A. pisum strains could mate and produce normally. The LZ strain was superior at host seeking and leaf identification under starvation, but the movement ability of the YL strain was actually stronger than the LZ strain. Considering the relationship between energy reserves and movement ability of the two aphid strains, this phenomenon was probably caused by higher glycogen reserves that provide more energy for walking a longer distance and spreading out a wider range. We found that the key enzyme activities between the two strains were not significantly different, and the differences in glycogen reserves between the two strains might ...
Aphis gossypii Glover is a major pest of cotton and can severely affect cotton yield and lint quality. In this study, the efficacy of sulfoxaflor applied via drip irrigation and foliar spray on controlling cotton aphids was evaluated in 2016 and 2017 in Xinjiang, China. The distribution of sulfoxaflor in cotton roots, stems, leaves, and aphids, as well as its effects on two natural enemies of aphids, were also investigated. Results showed that sulfoxaflor applied through drip irrigation mainly concentrated in leaves and provided effective control of cotton aphids for 40 days, compared to 20 days when applied through foliar spray. Furthermore, drip application resulted in much lower sulfoxaflor concentrations in aphids than foliar spray. As a result, ladybird beetle and lacewing populations were higher in drip applied plants than in foliar sprayed plants. Additionally, the cost of drip irrigation was lower than foliar spray as cotton plants are commonly irrigated via drip irrigation in Xinjiang. Our
Endoparasitoid wasps are important natural enemies of the widely distributed aphid pests and are mainly used as biological control agents. However, despite the increased interest on aphid interaction networks, only sparse information is available on the factors used by parasitoids to modulate the aphid physiology. Our aim was here to identify the major protein components of the venom injected at oviposition by Aphidius ervi to ensure successful development in its aphid host, Acyrthosiphon pisum. A combined large-scale transcriptomic and proteomic approach allowed us to identify 16 putative venom proteins among which three γ-glutamyl transpeptidases (γ-GTs) were by far the most abundant. Two of the γ-GTs most likely correspond to alleles of the same gene, with one of these alleles previously described as involved in host castration. The third γ-GT was only distantly related to the others and may not be functional owing to the presence of mutations in the active site. Among the other abundant proteins
The City uses Lady Beetles to handle aphid infestations. Learn more about aphid infestations, and how the City is taking action without using pesticides.
The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) is a significant soybean pest in the north central United States. Insecticidal seed treatments and host plant resistance are two commercially available management tools. Here we investigate the efficacy of both management tools throughout the season. Soybean lines containing the soybean aphid resistance genes Rag1, Rag2, or both Rag1 + Rag2 were compared with a near-isogenic aphid-susceptible line. Each line was grown in field plots both with and without thiamethoxam applied to the seed. Individual plants from each plot were caged and infested with soybean aphids to measure the efficacy and potential interaction of aphid resistance and thiamethoxam. Aphid population growth rate was measured for each caged plant for 9‐12 d after infestation. New cages were established each week from 34 d after planting (dap) to 92 dap to track seasonal variations in efficacy. Thiamethoxam reduced population growth only at the 42 dap time point and only
In topical and systemic plant treatment, in three host-parasite systems, i.e. Vicia faba - Uromyces appendiculatus, Vicia faba - Aphis fabae and Triticum aestivum - Rhopalosiphum padi the culture filtrate and supernatant of Bacillus subtilis (FZB24, FZB37 and FZB38 from FZB Biotechnik Berlin) was shown to inhibit the development of urediospores produced by Uromyces appendiculatus. The performance of Aphis fabae and Rhopalosiphum padi was evaluated using life table tests where the aphids development time (tD), pre-reproduction time (td), relative growth rate (RGR) and intrinsic rate of natural increase (rm) were assessed. A wide range of antibiosis effects in Aphis fabae and Rhopalosiphum padi was observed when the supernatant of Bacillus subtilis was used as foliar topical treatment. The tested aphids presented longer development and pre-reproduction time; conversely a lower relative growth rate and intrinsic rate of natural increase was observed. The investigation of the free amino acids of ...
In topical and systemic plant treatment, in three host-parasite systems, i.e. Vicia faba - Uromyces appendiculatus, Vicia faba - Aphis fabae and Triticum aestivum - Rhopalosiphum padi the culture filtrate and supernatant of Bacillus subtilis (FZB24, FZB37 and FZB38 from FZB Biotechnik Berlin) was shown to inhibit the development of urediospores produced by Uromyces appendiculatus. The performance of Aphis fabae and Rhopalosiphum padi was evaluated using life table tests where the aphids development time (tD), pre-reproduction time (td), relative growth rate (RGR) and intrinsic rate of natural increase (rm) were assessed. A wide range of antibiosis effects in Aphis fabae and Rhopalosiphum padi was observed when the supernatant of Bacillus subtilis was used as foliar topical treatment. The tested aphids presented longer development and pre-reproduction time; conversely a lower relative growth rate and intrinsic rate of natural increase was observed. The investigation of the free amino acids of ...
Several species of aphids attack brassicas in East Africa:. The cabbage aphid (Brevicoryne brassicae). The false cabbage aphid (Lipaphis erysimi). The green peach aphid (Myzus persicae). In particular the cabbage aphid is a major pest in the region. Cool, dry weather is most favourable for aphid development. Large numbers of aphids may kill small plants. Their feeding can distort leaves of older plants and causes leaf curl.. Often, the most serious problem associated with aphids is virus transmission. The cabbage aphid and the false cabbage aphid are vectors of virus diseases such as cabbage black ring spot, cabbage ring necrosis, and mosaic diseases of cauliflower, radish and turnip. ...
Bird cherry-oat aphid (Rhopalosiphum padi L.) is an important pest on spring-sown cereals. The aphid reduces yield and can act as a vector of barley yellow dwarf virus. R. padi does not give visible symptoms, but heavy infestation can reduce the yield substantially. R. padi is one of the most important pests of barley, which has the fourth rank among the cereals in global production. In order to overcome this problem, the plants are treated with pesticides. However, some of the pesticides are no longer permitted to use due to their negative environmental effects. Another problem is that the aphids develop resistance against them. Therefore, a new approach is to identify genetic factors that could be used in breeding host plants for resistance. There are many examples of successful plant breeding for resistance to aphids, but in the case of R. padi and barley, no resistant cultivar is commercially available. The aim of this thesis was to identify and characterise aphid resistance and ...
A field experiment was conducted over two cropping seasons to investigate the effectiveness of cereal border crops in managing potato aphids and the associated viruses during seed potato production. Potato plots were surrounded with maize, sorghum or wheat borders. Aphid population was monitored on leaves and on yellow sticky traps. Other data collected included viral disease incidence and tuber yield. The border crops reduced aphid population on leaves compared to non-bordered potato plots. More alate aphids were caught on yellow sticky traps placed inside potato plots than on traps placed inside the border crops. In addition, viral disease incidence was reduced in all plots surrounded by the border crops. However, plots surrounded by border crops had reduced tuber yield, although the yield of seed grade was increased. Thus use of border crops is beneficial in management of viral diseases during seed potato production ...
The aim of this study was to analyze patterns of nucleotidic composition and codon usage in the pea aphid genome (Acyrthosiphon pisum). A collection of 60,000 expressed sequence tags (ESTs) in the pea aphid has been used to automatically reconstruct 5809 coding sequences (CDSs), based on similarity with known proteins and on coding style recognition. Reconstructions were manually checked for ribosomal proteins, leading to tentatively reconstruct the nea-complete set of this category. Pea aphid coding sequences showed a shift toward AT (especially at the third codon position) compared to drosophila homologues. Genes with a putative high level of expression (ribosomal and other genes with high EST support) remained more GC3-rich and had a distinct codon usage from bulk sequences: they exhibited a preference for C-ending codons and CGT (for arginine), which thus appeared optimal for translation. However, the discrimination was not as strong as in drosophila, suggesting a reduced degree of translational
In accordance with studies on pea aphids (Henter & Via 1995; Ferrari et al. 2001), we detected significant clonal variation for susceptibility to parasitoids in the peach potato aphid, M. persicae. In aphids, reduced susceptibility to parasitoids can be conferred by the endosymbiotic bacteria H. defensa and S. symbiotica (Oliver et al. 2003), yet neither of these secondary symbionts was detected in our collection of clones. Instead, we found that the one entirely resistant clone harboured R. insecticola. This secondary endosymbiont has so far not been implicated in defence against parasitoids, but it was shown to decrease susceptibility to a fungal pathogen and to affect host plant specialization in the pea aphid (Tsuchida et al. 2004; Scarborough et al. 2005). Our finding suggests that certain strains of R. insecticola may also provide protection against parasitoids, although the critical experiments of curing clone 5.15 from R. insecticola and/or transferring the symbiont to susceptible M. ...
Mitochondrial DNA (mtDNA) is an important genetic marker in population and evolutionary biology. To test the feasibility of two mitochondrial gene markers (COI and Cytb) for Rhopalosiphum padi, we collected 275 individuals of the insect species from 15 locations, which cover most of the species distribution range in China, and analyzed the diversity of the two genes. Seven COI haplotypes and 15 Cytb haplotypes were identified by 13 and 36 polymorphic sites, respectively. Across the entire samples, the average haplotype diversities (Hd) of COI and Cytb were 0.491 and 0.607, and the nucleotide diversities (π) of COI and Cytb were 0.147% and 0.160%, respectively. Relatively low levels of genetic diversity and genetic differentiation were observed among all R. padi populations based on the two genes. Moreover, parsimony networks of the COI and Cytb haplotypes of R. padi all supported a single clade. Although the nucleotide variation of mitochondrial genes has been used in other insect species, reviewing
Mitochondrial DNA (mtDNA) is an important genetic marker in population and evolutionary biology. To test the feasibility of two mitochondrial gene markers (COI and Cytb) for Rhopalosiphum padi, we collected 275 individuals of the insect species from 15 locations, which cover most of the species distribution range in China, and analyzed the diversity of the two genes. Seven COI haplotypes and 15 Cytb haplotypes were identified by 13 and 36 polymorphic sites, respectively. Across the entire samples, the average haplotype diversities (Hd) of COI and Cytb were 0.491 and 0.607, and the nucleotide diversities (π) of COI and Cytb were 0.147% and 0.160%, respectively. Relatively low levels of genetic diversity and genetic differentiation were observed among all R. padi populations based on the two genes. Moreover, parsimony networks of the COI and Cytb haplotypes of R. padi all supported a single clade. Although the nucleotide variation of mitochondrial genes has been used in other insect species, reviewing
The infestation of the cultivated grain crops by phloem feeding aphids has generated a great deal of interest over the years, due to the serious damage they cause to the crops and yield losses that result. The mechanism of the interaction between aphids and host plants remains largely unknown in spite of efforts to understand the basis of aphid feeding on grain crops. Greater efforts are required to explain the mechanism(s) of this interaction in order to achieve sustainable agriculture. This thesis focused on an investigation of the mechanism of feeding by the Russian wheat aphid, Diuraphis noxia Mordvilko (RWA) and the bird cherry-oat aphid, Rhopalosiphum padi L. (BCA) on barley and wheat cultivars. These two aphids co-occur naturally, but they inflict very different feeding effects on host plants. Structural and functional approaches were employed to investigate their feeding habits and these were then related to the observed differences in their host plants. Transmission electron microscopy ...
We determined the chlorophyll a and b levels (SPAD readings) in uninfested leaves and in leaves after 7 and 17 days of aphid infestation in four Fabaceae species (Pisum sativum L., Vicia faba L., Trifolium pretense L, Medicago sativa L.). Feeding by pea aphids Acyrthosiphon pisum Harris (Hemiptera: Aphididae) caused significant loss of chlorophyll a and b in the infested plants. Uninfested leaves ...
by Merry Youle | Because it prefers to dine on some of our valued crop plants, the pea aphid (Acyrthosiphon pisum) is considered a major pest - thus a Bad Guy from our perspective. Pea aphids are not without their enemies. Enemy number one is a parasitoid wasp, Aphidius ervi. As parasitoid wasps are used to do, females provide for their offspring by...
Acyrthosiphon pisum, commonly known as the pea aphid (and colloquially known as the green dolphin, pea louse, and clover louse ), is a sap-sucking insect in the Aphididae family. It feeds on several species of legumes (plant family Fabaceae) worldwide, including forage crops, such as pea, clover, alfalfa, and broad bean, and ranks among the aphid species of major agronomical importance. The pea aphid is a model organism for biological study whose genome has been sequenced and annotated. In the autumn, female pea aphids lay fertilized eggs overwinter that hatch the following spring. The nymphs that hatch from these eggs are all females, which undergo four moults before reaching sexual maturity. They will then begin to reproduce by viviparous parthenogenesis, like most aphids. Each adult female gives birth to four to 12 female nymphs per day, around a hundred in her lifetime. These develop into mature females in about seven to ten days. The life span of an adult is about 30 days. Population ...
The availability of genomic data in the last decade relating to different aphid species has allowed the analysis of the genomic variability occurring among such species, whereas intra-specific variability has hitherto very largely been neglected. In order to analyse the intra-genomic variability in the peach potato aphid, Myzus persicae, comparative analyses were performed revealing several clone-specific gene duplications, together with numerous deletions/rearrangements. Our comparative approach also allowed us to evaluate the synteny existing between the two M. persicae clones tested and between the peach potato aphid and the pea aphid, Acyrthosiphon pisum. Even if part of the observed rearrangements are related to a low quality of some assembled contigs and/or to the high number of contigs present in these aphid genomes, our evidence reveals that aphid clones are genetically more different than expected. These results suggest that the choice of performing genomes sequencing combining different
Phytophagous insects with wide host ranges often exhibit host-associated genetic structure. We used microsatellite analysis to assess the population structure of the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), a serious pest on many economically important crops worldwide. We sampled aphids from five host plant species in Iran and detected strong population subdivision, with an overall multilocus FST of 0.191. The matrix of pairwise FST values indicated that differentiation between populations collected from different hosts was significantly stronger than between populations from the same hosts. Host-associated differentiation was further supported by Bayesian clustering analyses, which grouped all samples from cotton together with aubergine, and all samples from cucumber together with pumpkin and hibiscus. This adds to the growing body of evidence that many seemingly generalist aphids are in fact an assemblage of host-specialized lineages. Although we detected a clear genetic ...
Since the most recent issue (No. 17, July 18, 2003) of the Bulletin was printed and mailed, there has been considerable telephone and e-mail traffic regarding soybean aphids in northern Illinois. We have received numerous reports regarding insecticide applications to control the aphids in soybean fields. Although some fields still do not have densities of aphids large enough to warrant control, the densities in a fairly large number of fields have exceeded economic thresholds. In addition, some people are finding very few natural enemies in some fields, so aphid population densities have increased rapidly.. Drs. David Voegtlin (Illinois Natural History Survey) and David Onstad (Department of Natural Resources and Environmental Sciences) recently visited several soybean fields in Kendall County. They have studying soybean aphid populations there since 2001. In fact, one of the first fields of soybeans Dave Voegtlin visited in 2000 was in Kendall County. They have provided an overview of the ...
Your basket is currently empty. i ,p>When browsing through different UniProt proteins, you can use the basket to save them, so that you can back to find or analyse them later.,p>,a href=/help/basket target=_top>More...,/a>,/p> ...
Soybean aphids in Nebraska usually reach the economic threshold and require treatment in late July through August, with a few fields requiring treatment earlier in July. Treatment during this period usually is enough to keep aphid populations from resurging because there is not enough time for populations to build-up before they would naturally leave the fields in late August and early September. The earlier a field is treated, the greater the chance that any surviving aphids can later reproduce or new aphids can repopulate the field. And remember, insecticide treatment also kills many natural enemies, so any aphids that do re-infest a field are not constrained by predators and other natural controls. Even insecticides with a relatively long residual cannot last when insecticide treatment is done in early or mid-July, particularly during a year when aphid populations are thriving. If one has to treat early, make sure to closely monitor the field until early September.. Another practice that can ...
OCHILO, Willis N. and NYAMASYO, Gideon H. Pest status of bean stem maggot (Ophiomyia spp.) and black bean aphid (Aphis fabae) in Taita District, Kenya. Trop. subtrop. agroecosyt [online]. 2011, vol.13, n.1, pp.91-97. ISSN 1870-0462.. On-station and on-farm studies were carried out in Taita district, Kenya, to assess the effect of various soil fertility regimens on bean stem maggot (BSM) (Ophiomyia spp.) and black bean aphid (BBA) (Aphis fabae) incidence. These studies aimed at gathering information useful in the development of an IPM programme for the project on conservation and sustainable management of below-ground biodiversity (CSM-BGBD). Field survey of bean stem maggot and black bean aphid was conducted in both the on-station and on-farm plots four weeks after bean emergence. From each plot forty bean plants were sampled. The parameter assessed included stems, leaves and flowers and the percent numbers of plants having bean stem maggot and black bean aphid were expressed as the percentage ...
The cucumber mosaic virus (CMV) 2b protein not only inhibits anti-viral RNA silencing but also quenches transcriptional responses of plant genes to jasmonic acid, a key signalling molecule in defence against insects. This suggested that it might affect interactions between infected plants and aphids, insects that transmit CMV. We found that infection of tobacco with a 2b gene deletion mutant (CMVD2b) induced strong resistance to aphids (Myzus persicae) while CMV infection fostered aphid survival. Using electrical penetration graph methodology we found that higher proportions of aphids showed sustained phloem ingestion on CMV-infected plants than on CMVD2b-infected or mock-inoculated plants although this did not increase the rate of growth of individual aphids. This indicates that while CMV infection or certain viral gene products might elicit aphid resistance, the 2b protein normally counteracts this during a wild-type CMV infection. Our findings suggest that the 2b protein could indirectly ...
Aphids and other herbivorous insects are able to travel between plants in their environment. While plants cannot directly choose their consumers, they may stop or mitigate the harmful effects of herbivory using secondary metabolites. A salicylic acid (SA) pathway facilitates defense from biotrophic fungi and some necrotrophic pathogens, while a jasmonic acid (JA) pathway is associated with defense from other necrotrophic pathogens and chewing insects. We investigated the effect of deficiency in SA or JA in Arabidopsis thaliana on plant growth and on herbivory by green peach aphids (Myzus persicae). Three ascensions of A. thaliana were placed in two blocks with three aphids on each individual. The genotypes consisted of a SA-deficient ascension (Sid2), a JA-deficient ascension (Lox2), and a wild type (Col). Wild-type A. thaliana showed significantly greater growth relative to the other ascensions, suggesting better performance, as well as dramatically higher aphid count. Aphid count showed a ...
Outbreaks of cucumber mosaic virus (CMV) disease, caused by an aphid- transmitted pathogen, greatly reduced yields of bell pepper in southern Illinois in the mid-1990s. To provide the basis for further studies of the roles of individual apbid species in virus transmission, we surveyed aphid flights in and around pepper fields in 1996 and 1997 by using suction traps, interception nets, landing traps, sweep nets, and hand-picking. We collected 78 species of aphids, 15 of which have been reported to transmit CMV to peppers. The most abundant species taken from suction traps and interception nets in combination were Lipaphis erysimi, Rhopalosiphum padi, Rhopalosiphum maidis, Schizaphis graminum, and Aphis craccivora. All of these species are known to transmit CMV to peppers, but the phenology of R. maidis in Illinois suggests it is not the vector that brings CMV to pepper fields to initiate disease outbreaks. Brachycaudus helichrysi was relatively abundant in 1996 in May and June when a CMV outbreak may
This study examines the effects of climatic conditions on interactions among pea and lentil yields, pea aphid Acyrthosiphon pisum (Harris) infestations, and outbreaks of PEMV (Pea enation mosaic) and BLRV (Bean leaf roll) viruses in the Palouse region of easternWashington. The study analytically and empirically evaluates the effects of aphid outbreaks on per acre yields, implicitly including the effects of adopted pest management activities and explicitly taking into account possible effects of climatic conditions on the severity of pea aphid outbreaks. The results show that aphid outbreaks have historically decreased pea and lentil yields by approximately 5% and 7% on average respectively. Elbakidze, Levan; Lu, Liang; Eigenbrode, Sanford
Agriculture and Agri-food Canada (AAFC) has, until now, never developed an app. Until now, that is, with the launch of a new app called CAM.. The Cereal Aphid Manager (CAM) is the first app ever developed by AAFC. Dale Leftwich, RealAgricultures Saskatchewan field editor, met with Tyler Wist, field crop entomology research scientist with AAFC, to talk about what CAM is and what it can do.. Wist explains, "What it does is help you scout for cereal aphids in your fields. Its meant for agronomists, its meant for producers. The real key to this app is that it takes the beneficial insects that control those cereal aphids and works them into an equation called the dynamic action threshold," he says. (Story continues below) ...
A survey of the aphids associated with Maltese shrubs, herbaceous plants and crops was carried out. Sixty six aphid species were recorded from more than 90 species of host plants. Forty eight aphids were recorded from the Maltese islands for the fi rst time bringing the total number of aphid species known from these islands to 99. New records include: Acyrthosiphon lactucae, A. pisum, Anoecia vagans, Aphis alienus, A. euphorbiae, A. hederae, A. lambersi, A. multifl orae, A. nasturtii, A. parietariae, A. picridicola, A. ruborum, A. sedi, Aulacorthum solani, Brachycaudus helichrysi, Capitophorus sp. nr. similis, Clypeoaphis suaedae, Cryptomyzus korschelti, Dysaphis apiifolia, D. foeniculus, D. pyri, D. tulipae, Hyadaphis coriandri, H. foeniculi, H. passerinii, Hyperomyzus lactucae, Idiopterus nephrelepidis, Macrosiphoniella absinthii, M. artemisiae, M. sanborni, Macrosiphum euphorbiae, Ma. rosae, Melanaphis donacis, Metopolophium dirhodum, Pterochloroides persicae, Rectinasus buxtoni, ...
Sap-sucking insects such as aphids cause substantial yield losses in agriculture by draining plant nutrients as well as vectoring viruses. The main method of control in agriculture is through the application of insecticides. However, aphids rapidly evolve mechanisms to detoxify these, so there is a need to develop durable plant resistance to these damaging insect pests. The focus of this review is on aphid interactions with legumes, but work on aphid interactions with other plants, particularly Arabidopsis and tomato is also discussed. This review covers advances on the plant side of the interaction, including the identification of major resistance genes and quantitative trait loci conferring aphid resistance in legumes, basal and resistance gene mediated defence signalling following aphid infestation and the role of specialised metabolites. On the aphid side of the interaction, this review covers what is known about aphid effector proteins and aphid detoxification enzymes. Recent advances in ...
Cauliflower mosaic virus (CaMV) is transmitted to crucifers in a noncirculative manner by several aphid species. CaMV is preferentially acquired from the phloem, although acquisition also occurs after brief intracellular stylet punctures of aphid vectors in nonvascular leaf tissues. In the present work, we used the electrical penetration graph technique to study the specific aphid stylet activities and behavioral events leading to the inoculation of CaMV to turnip plants by its two major vectors, Brevicoryne brassicae (L.) and Myzus persicae (Sulzer). Aphids subjected to an 8-h acquisition access time on infected plants were transferred to test plants and removed immediately after specific behavioral events were recorded. CaMV was readily inoculated after the first intracellular puncture in nonvascular tissues by both vector species. Inoculation rate of CaMV by B. brassicae was the highest after a 3-h inoculation access period, regardless of whether aphids had reached the phloem phase during ...
Principal Investigator:AKIMOTO Shin-ichi, Project Period (FY):1998 - 1999, Research Category:Grant-in-Aid for Scientific Research (C), Section:一般, Research Field:生態
The host acceptance behaviour in Aphidius ervi is investigated, assessing the role of both external and internal host-associated cues, offered to the experimental parasitoids with parafilm-made aphid dummies. The reaction to internal cues present in the host haemolymph is clearly evident, and its intensity is enhanced by external cues. Parasitoid females lay few eggs in aphid dummies filled with host haemolymph. A significant increase in the number of both oviposition reactions (host stinging) and egg laying is observed only when these dummies are coated with cornicle secretion. However, this enhancement is not observed when the aphid dummies contain distilled water. Thus, the host acceptance behaviour of A. ervi females appears to be controlled by the integration of both external and internal chemical cues. The physiological basis of this behavioural response is investigated with a detailed study on the anatomy and ultrastructure of A. ervi ovipositor. The detection of chemical cues present in ...
Here and in and a previous article (8), we have identified a protein, Protein C002, that appears to play an essential role (or roles) in the foraging and feeding of the pea aphid on fava beans, a typical host plant for this aphid species.. Protein C002 can, on the basis of our results, be considered a specialized, salivary gland protein, which does not exclude the possibility that it is synthesized in other organs in small amounts. Indeed, we have a preliminary indication that transcript c002 occurs in gut, but at ≈100-fold lower amounts than in salivary gland (10). The organ distribution of transcript c002 (and Protein C002) is one of the many aspects of this transcript and protein that will be under continued investigation in our laboratories.. Both Protein C002 and its transcript occur in the principal salivary glands in the pea aphid but apparently in only some of those cells (≈5 of the 21 cells within each lobe). This restriction of expression of the c002 gene to a subset of secretory ...