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Increasing the biodiversity of agroecosystems can increase populations of natural enemies that are useful for pest control. Orchards often have a low diversity of plant species, which is not conducive to maintaining ecosystem functions and services. However, additional flowering plants could provide natural enemies with beneficial resources. To assess the ability of flowering plants to attract predators and increase the biological control of Aphis spiraecola Patch, we established individual plots of three different flowering plant species with sequential bloom periods between the rows of apple orchard. These plants attracted predators such as Coccinellidae, Syrphidae, and Chrysopidae when flowering. The density of predators on trees in the three flowering plant plots was significantly higher than that in the control, whereas the density of aphids on trees in Orychophragmus violaceus (L.) O. E. Schulz (Rhoeadales: Brassicaceae) and Cnidium monnieri (Linn.) Cuss. (Apiales: Apiaceae) plots were significantly lower than that in control. The density of aphids on trees in Calendula officinalis L. (Asterales: Asteraceae) plots was significantly lower than in other plots at second peak period. There was a significant negative correlation between the population of aphids and predators on trees at peak of aphids. Cage exclusion tests showed that the biocontrol services index (BSI) of O. violaceus was highest (32.7%) on 24 May, and the BSI of C. monnieri was highest (47.6%) on 7 June. Our results suggest that the temporal combination of different flowering plants could provide useful effective biocontrol to management pest in orchard. [ABSTRACT FROM AUTHOR]

Citrus plants (Citrus spp.) are among the most important fruit crops in Montenegro. The citrus producing area is located along a coastal plain with a length of 300 km. The satsuma mandarin (C. unshiu) is predominantly grown. Here we present a comprehensive review of the arthropod pests associated with the citrus crops in Montenegro. The study was based on previous research and experience, as well as on field surveys that were carried out along the coastal area from 2002 to 2019. The surveys included commercial citrus orchards, nurseries and individual trees in backyards and gardens, which were inspected once per month from April to November every year. Our results revealed 20 pest species recorded on citrus plants at the Montenegro seacoast. They included five species of mites (Acari) and 15 species of insects (Hemiptera, Lepidoptera and Diptera). The three species recorded throughout the whole growing season, most widespread and with the highest abundance were Aphis spiraecola, Phyllocnistis citrella and Panonychus citri. Of them, the spirea aphid A. spiraecola was the most common and with the highest population abundance in summer and autumn. Among the recorded species, Ceratitis capitata was considered the most important pest for the fruit production, followed recently by A. spiniferus. The most damaging for the nursery production was P. citrella, followed by P. citri and Dialeurodes citri. [ABSTRACT FROM AUTHOR]

Citrus tristeza virus (CTV) is one of the most serious diseases affecting citrus trees worldwide. CTV is dispersed in the field by various aphid species at different transmission efficiencies. As a result, any information about aphid species composition in citrus orchards is essential for epidemic prognosis and disease management. CTV was firstly detected in Greece in 2000 but, extended information on the prevalence of the aphid species in CTV-infected citrus orchards is currently missing. Here, we report data from an 8-year survey carried out over the last decade on the aphid species frequencies infesting citrus orchards in the only CTV transmission hot-spot (Chania region) of the island of Crete. In 9,500 wingless adult females collected mainly in spring-early summer, five aphid species were recorded, including the second most efficient CTV vector Aphis gossypii Glover, and the less efficient vectors Aphis spiraecola Patch, Aphis aurantii (Boyer de Fonsicolombe), Myzus persicae (Sulzer) and Aphis craccivora Koch. Aphis citricidus (Kirkaldy), the most efficient vector of CTV, was not detected. In all years, the most prevalent species was A. spiraecola (mean frequency 82.5%) followed by A. gossypii (mean frequency 13.5%), which was recorded in six of the eight years of the survey. Both species may play a significant role to the CTV spread in Chania region. As the determination of aphid transmission efficiencies for the prominent CTV isolate (GR-1825) is pending, the current study brings forward a panel of five CTV-aphid vector species in this area. The presence of the relatively efficient vector A. gossypii at low-moderate frequencies, in a CTV hotspot is a matter of concern and while monitoring and eradication of CTV infected trees continues, a first detection of A. citricidus or any increase of the A. gossypii prevalence would have a negative impact on containment measures. [ABSTRACT FROM AUTHOR]

Aphid species Aphis pomi (de Geer, 1773) is oligophagous on pomoideous host plants, whilst Aphis spiraecola Patch, 1914 is a polyphagous species alternating between Spiraea spp., its primary host, and a wide variety of secondary hosts, also including pomoideous species. Despite the biological distinction, these species are difficult to separate using their morphological characters. Partial sequences of mitochondrial COI and nuclear EF-1α genes were analyzed for samples from Central and Eastern Europe, Germany, Bulgaria, Italy, Turkey, China together with available data from GenBank. Interspecific pairwise sample divergences of the COI fragment ranged from 3.1 to 4.3%. One COI haplotype of A. pomi was predominant (n = 24), with a pan European distribution. The most abundant COI haplotype of A. spiraecola (n = 16) occurred in Lithuania, Latvia, Poland, Italy, Turkey and China. Interspecific pairwise sample divergences of the EF-1α fragment ranged from 0.6 to 1.2%. Analyzed partial sequences of EF-1α were identical in A. pomi. The most abundant EF-1α haplotype of A. spiraecola (n = 14) occurred in Lithuania, Poland, Italy, Turkey and China. The length of ultimate rostral segment appeared to be the most reliable morphological character for discrimination between apple and spirea aphid species. It allowed a 100% correct identification of A. pomi (n = 143) and 91.5% of A. spiraecola (n = 94) specimens in the European samples used for the molecular analysis. The existence of A. spiraecola in the Eastern Baltic region of Europe is documented for the first time.

Harmonia axyridis (Pallas) and Propylea japonica (Thunberg) (both Coleoptera: Coccinellidae) are two common aphidophagous predators that overlap in their natural niche; therefore, interactions between these two predator species could affect their overall prey consumption. The consequences of intraguild interactions on the foraging efficiency of the two coccinellid species were investigated by evaluating the functional responses of single beetles and intra‐ and interspecific combinations to densities of the spirea aphid, Aphis citricola van der Goot (Hemiptera: Aphididae), on apple seedlings, during 2 and 12 h under laboratory conditions. A type II functional response was observed in all the bioassays. Solitary H. axyridis consumed significantly more aphids than single P. japonica in both exposure periods. However, at intermediate prey densities the prey consumption of P. japonica was slightly greater than that of H. axyridis. The 95% confidence intervals of the functional response curves of conspecific and heterospecific pairs overlapped at 2 h. In contrast, conspecific pairs of H. axyridis showed a higher functional response curve at 12 h compared to a combination of H. axyridis and P. japonica. Prey's predation risk reduction was only detected for paired H. axyridis and mixed predators compared to their estimated functional responses at the 2‐h foraging period. By comparing functional responses between intraguild predatory lady beetle combinations, we could further predict the potential ecosystem service provided by these natural enemies. Comparison of functional responses between various combinations of predators is a valuable approach to predict and assess multiple predator impact on their shared prey populations. Functional responses of single and intra‐ and interspecific combinations of Harmonia axyridis and Propylea japonica (Coleoptera: Coccinellidae) to densities of Aphis citricola (Hemiptera: Aphididae) on apple seedlings were evaluated at two exposure times under laboratory conditions. Our results indicated that interactions between the predatory beetles can alter their functional responses, and thus their overall prey consumption. [ABSTRACT FROM AUTHOR]

Highlights • Ten amaryllidaceous alkaloids were isolated from L. radiata. • A significant aphicidal activity of L. radiata extract and alkaloids was reported for the first time. • AChE has a great possibility to be the target site for the aphicidal action of amaryllidaceous alkaloids. Abstract Aphids are one of the most destructive and economically important pests of plants on earth, causing severe financial losses worldwide. The extensive and unscientific use of insecticides has resulted in a universal zooming insecticide resistance among aphids across regions and substantial detrimental influences on the environment. This study investigates the insecticidal activity of alkaloids from L. radiata against A. citricola. The crude extract of Lycoris radiate showed a remarkable aphicidal activity against A. citricola. Ten known amaryllidaceous alkaloids were obtained according to the bioassay-guided isolation. The structures of these known alkaloids were identified as amabiline (1), deoxydihydrotazettine (2), deoxytazettine (3), 3-epimacronine (4), galanthamine (5), 11-hydroxygalanthamine (6), N -allylnorgalanthamine (7), 11 β -hydroxygalanthamine (8), lycorine (9) and colchicine (10). The results of aphicidal bioassay against A. citricola showed that compounds 1 - 9 exhibited considerable aphicidal activity with LD 50 values of 67.44, 76.33, 78.30, 96.70, 17.47, 32.60, 4.92, 20.33, 70.41 ng/aphid. N -Allylnorgalanthamine (7) possessed the highest aphicial activity, which was comparable with the commercial pesticide methomyl (2.91 ng/aphid). The results of in vivo AChE assay revealed that N -allylnorgalanthamine showed an obvious inhibitory effect on AChE in A. citricola in a time- and dose-dependent manner. The in vitro inhibition of AChE activity by N -allylnorgalanthamine was remarkable with an IC 50 value of 2.1 × 10−8 M, which was 104 times stronger than the positive control methomyl with an IC 50 value of 4.2 × 10–4 M. Meanwhile, N -allylnorgalanthamine can lead to an increase of the activities of SOD and CAT. The present work comprises the first report on insecticidal action of Amaryllidaceae alkaloids. N -Allylnorgalanthamine displayed a significant inhibition on AChE in Aphis citricola both in vivo and vitro. The insecticidal L. radiata extracts can be possibly used for controlling pests and isolated compounds, designing for new pesticides, can be the promising temples. [ABSTRACT FROM AUTHOR]

Citrus fruit detection is one of the most important and challenging steps in citrus yield mapping. The distinct color differences between the ripe fruit and leaves allowed previously-described imaging-based methods to achieve good results. However, immature green citrus fruit detection, which aims to provide valuable information for citrus yield mapping at earlier stages is much more difficult because the fruit and leaf colors are very similar. This study combines color and thermal images for immature green fruit detections. Experiments identified optimal conditions for thermal imaging. A multimodal imaging platform was built to integrate color and thermal cameras. A novel image registration method was developed for combining color and thermal images and matching fruit in both images which achieved pixel-level accuracy. A new Color-Thermal Combined Probability (CTCP) algorithm was created to effectively fuse information from the color and thermal images to classify potential image regions into fruit and non-fruit classes. Algorithms were also developed to integrate image registration, information fusion and fruit classification and detection into a single step for real-time processing. An increase in recall rate from 78.1% when using only color images to 90.4% after fusing the color and thermal images was obtained at similar precision rates, and an increase in precision rate from 86.6% to 95.5% was obtained at similar recall rates. The fusion of the color and thermal images effectively improved immature green citrus fruit detection. [ABSTRACT FROM AUTHOR]

Essential oils are a mixture of various compounds that can have acted against insect pests through complex mechanisms. Their constituents were shown to be a potent source of biological pesticides. The aims of the present study are to characterize the chemical composition and evaluate the aphidicidal activities of Tunisian Melaleuca styphelioides leaves essential oil. Fumigant and contact toxicities were determined against three major aphid infecting citrus trees: Aphis gossypi , Aphis spiraecola and Myzus persicae . The chemical composition of this oil was characterized by GC–MS. The major common compounds were caryophyllene oxide (23.42%), spathulenol (20.5%), isoaromadendrene epoxide (7.45%), ledol (5.98%), and α-pinene (3.82%).The results showed that M. styphelioides essential oil has a good fumigant and contact toxicity against the three citrus aphids tested. The highest activity was registered on A. spiraecola nymphs (LC 50  = 44.72 μL/L air for the fumigant activity and 115.93 μL/L for the contact toxicity). The adults of A. gossypii seem to be more resistant to essential oil in the contact bioassay with an LC 50  = 3660.99 μL/L. Overall, our work proposes the use of the M. styphelioides essential oil as contact and fumigant bio-insecticides against resistant citrus aphids. [ABSTRACT FROM AUTHOR]

Plant volatiles can act as chemical signals that influence the behavior and distribution of insects. Although considerable information has been acquired on the effects of plant volatiles emitted from plants on herbivorous insects and their natural enemies, practical implementation of this knowledge is still lacking. We investigated 3 aromatic plant species, French marigold, Tagetes patula L. (Asteraceae), ageratum, Ageratum houstonianum Mill. (Asteraceae), and catnip, Nepeta cataria L. (Lamiaceae), to test their effectiveness in repelling or attracting spirea aphid, Aphis citricola van der Goot (Hemiptera: Aphididae), and its natural enemy, the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae), in the field and the laboratory. We found that intercropping apple trees Malus spp. (Rosaceae) with aromatic plants in an orchard significantly reduced the number of A. citricola aphids present, but had the opposite effect on H. axyridis. In addition, the association between H. axyridis and A. citricola numbers was strengthened when the intercropping included French marigold. Using an H-tube olfactometer, we found that A. citricola was repelled by French marigold and catnip, whereas H. axyridis was attracted most by French marigold. Volatile analysis revealed that the sesquiterpenes Dlimonene and terpinolene and the alcohol 2-ethyl-1-hexanol were the most abundant volatile compounds released by French marigold and catnip. Harmonia axyridis was significantly attracted by 12.5 µL/L D-limonene, 50 µL/L terpinolene, and 25 µL/L of a 1:1 mixture of the 2 compounds, but was repelled by higher concentrations of D-limonene. The results suggest that aromatic plants increase the resistance of apple trees to A. citricola both directly, by reducing the population of A. citricola through chemical repulsion, and indirectly, by increasing the H. axyridis population through chemical attraction. [ABSTRACT FROM AUTHOR]

Conducting on-farm evaluations of pest control and economic feasibility is a necessary procedure to ensure successful adoption of new spray technologies by commercial horticulture enterprises. A newly developed laser-guided variable-rate air-assisted sprayer was tested for control of spirea aphids (Aphis spiraecola), pod gall midges (Dasineura gleditchiae), and pear sawflies (Caliroa cerasi) on crabapple (Malus species), 'Sunburst' honey locust (Gleditsia triacanthos inermis), and 'Mazzard' cherry (Prunus avium) trees, respectively, in three commercial nurseries in Ohio and Oregon. The efficacy of the laser-guided sprayer for pest control treatment was compared with the efficacy of two types of conventional constant-rate air-assisted sprayers. During the tests, the variable rate from the laser-guided sprayer was achieved automatically based on plant presence, canopy structure, and foliage density. The application rates for the conventional sprayers were determined to comply with best pest management practices. Compared to the conventional constant-rate sprayers with comparable and effective insect control, the laser-guided sprayer reduced the spray volume rate to control aphids by 60% and 36% in nurseries 1 and 2, respectively. Similarly, in nursery 3, the laser-guided sprayer used 77.6% and 29.7% less spray volume and chemicals to control pod gall midges and sawflies, respectively. Thus, the new variable-rate spray system reduced pesticide use, increased pesticide spray application efficiency, and improved profitability, thereby offering an economically and environmentally responsible approach to controlling insect pests. [ABSTRACT FROM AUTHOR]

First report of Citrus tristeza virus (CTV, Closterovirus) in Morocco datesback to 1961 in collections of citrus varieties. An exhaustive survey of citrus in the north of the country in 2009 revealed that CTV was spread all over the citrus production area. We attempted to evaluate the relative contribution of different aphid species in the spread of CTV disease in a Citrus reticulata orchard at the Loukkous region during 2 years (2012 and 2013). The overall CTV incidence estimated in the experimental site increased from 17.8% in 2012 to 31.15% in 2013. The most abundant aphid species colonising clementine trees was Aphis spiraecola and A. gossypii. Both aphid species reached their maximum peaks during the spring season. The rate of viruliferous aphids, estimated by real-time RT-PCR of single aphid, revealed that 35.4% of winged A. gossypii and 28.8% of winged A. spiraecola were viruliferous, confirming a high inoculum pressure in the area surrounding the experimental site. The aphid species Toxoptera citricida, which is able to transmit the aggressive isolates of CTV, was not found in the Loukkous region. The study of the spatial distribution of the CTV showed that in general, the disease was randomly distributed in the field. Overall, the results seem to indicate that A. spiraecola may be considered as the major aphid species contributing to CTV spread in our experimental conditions. The prevalence of mild strains in the region and the high level of aphid flight activity could explain the rapid evolution of CTV incidence in the experimental area. [ABSTRACT FROM AUTHOR]

Aphids cause significant damage tp crops, particularly citrus. To combat these pests, farmers typically use synthetic pesticides, yet these pesticides leave negative impacts on the environment. In an effort to find new efficient forms of control against aphids, especially Aphis citricola, without causing damage to the environment, we evaluated the toxicity of essential oil from the leafy twigs of Tetraclinis articulata and Juniperus phoenicea. Essential oil extraction was performed by steam distillation, and chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS). Thirty-six components were identified in the essential oil from T. articulata. Isobornyl acetate (58.32 %), α-pinene (9.31 %), and camphor (9.23 %) are the main components of this oil. For J. phoenicea, forty-seven compounds were identified; α-pinene was the major compound at 48.18 %, followed by δ-cadinene (6.61 %). Each of the essential oils we tested showed some degree of toxicity against A. citricola. This toxicity is amplified with concentration and time, and varies between plant species. Ultimately, the essential oil extracted from J. phoenicea's leafy twigs was the most toxic (54.03 μL/L after 24 h) against A. citricola; its compounds may therefore be considered as new biodegradable agents to control aphids and viable for use in an integrated pest management program. [ABSTRACT FROM AUTHOR]

Aphis spiraecola Patch. (Hemiptera: Aphididae) is a key pest of citrus clementines. This aphid colonizes tender clementine shoots in the spring and causes important economic losses. A complex of predators preys on A. spiraecola colonies but does not result in satisfactory control. To disentangle the reasons for this failure, we investigated the effect of predators on A. spiraecola colonies and damage over a 3-year period. A. spiraecola colonies were tracked every 48-72 h from the period of aphid colonization until the colony declined or disappeared. The number of aphids, their stage and the presence of predators were recorded in each colony. Different life parameters of A. spiraecola colonies (maximum number of aphids, longevity and colony phenology) varied among the orchards over 3 years. Predators attacked one-third of the colonies, and this did not significantly differ among orchards for the years studied. The maximum number of aphids and longevity of A. spiraecola colonies were not related to the ratio of colonies attacked by predators but were negatively correlated with the time of their first attack. More importantly, the percentage of shoots occupied by A. spiraecola remained below or close to the intervention threshold when colonies were attacked prior to ~200 degree days from the beginning of the aphid colonization. These results suggest that (1) the presence of predators at the beginning of the season should be considered to develop new intervention thresholds and (2) biological control programs should promote the early presence of predators in clementine orchards. [ABSTRACT FROM AUTHOR]

Utilization of timed virus acquisition access probes in studies of plum pox virus (PPV) transmission by aphids demonstrated that endemic species transmitted the virus readily from plum, Prunus domestica (L.) Batsch; peach, P. persica (L.); or dwarf flowering almond, P. glandulosa Thunberg., to peach seedlings. The green peach aphid, Myzus persicae (Sulzer), was shown to be the most efficient vector. Acquisition of virus by green peach aphids from infected peach leaves resulted in 18–28% infected peach seedlings, while aphids previously fed on infected leaves of plum transferred virus to 36% of peach seedlings. Although the spirea aphid, Aphis spiraecola (Patch), was a less efficient vector than M. persicae it is perhaps more important for the spread of PPV due to its greater abundance and occurrence earlier in the season when peach trees are thought to be more susceptible to infection. Virus transmission rates varied depending on the virus source and healthy test plant species. In contrast to many previous studies, aphid inoculation of the experimental host Nicotiana benthamiana Domin occurred at a low rate, never exceeding 4%. Acquisition of PPV by M. persicae from infected peach fruit was greatly reduced compared with acquisition from leaves. The results of this research indicate that the Ontario isolate of PPV-D is readily transmissible by aphids to peach and natural spread of the virus needs to be considered in future management or eradication programs. [ABSTRACT FROM AUTHOR]

Aphid species Aphis pomi (de Geer, 1773) is oligophagous on pomoideous host plants, whilst Aphis spiraecola Patch, 1914 is a polyphagous species alternating between Spiraea spp., its primary host, and a wide variety of secondary hosts, also including pomoideous species. Despite the biological distinction, these species are difficult to separate using their morphological characters. Partial sequences of mitochondrial COI and nuclear EF-1α genes were analyzed for samples from Central and Eastern Europe, Germany, Bulgaria, Italy, Turkey, China together with available data from GenBank. Interspecific pairwise sample divergences of the COI fragment ranged from 3.1 to 4.3%. One COI haplotype of A. pomi was predominant (n = 24), with a pan European distribution. The most abundant COI haplotype of A. spiraecola (n = 16) occurred in Lithuania, Latvia, Poland, Italy, Turkey and China. Interspecific pairwise sample divergences of the EF-1α fragment ranged from 0.6 to 1.2%. Analyzed partial sequences of EF-1α were identical in A. pomi. The most abundant EF-1α haplotype of A. spiraecola (n = 14) occurred in Lithuania, Poland, Italy, Turkey and China. The length of ultimate rostral segment appeared to be the most reliable morphological character for discrimination between apple and spirea aphid species. It allowed a 100% correct identification of A. pomi (n = 143) and 91.5% of A. spiraecola (n = 94) specimens in the European samples used for the molecular analysis. The existence of A. spiraecola in the Eastern Baltic region of Europe is documented for the first time. [ABSTRACT FROM AUTHOR]

Aphids host-plant preference was assessed in six cultivars of payaya (Tainung 01, Baixinho de Santa Amalia, BH-65, Red Lady, Golden, Sunrise) at the UCTB papaya collection in Jagüey Grande, Matanzas. Two leaves per plant were taken as samples during eight months and the number of aphids and natural enemies species on both sides of the leaves were counted. The identified aphids were Toxoptera citricida (Kirkaldy), T. aurantii (Boyer) y A. spiraecola (Pacth). The Chrysopa sp. y Adalia decempunctata L. eggs were observed. BH-65, Golden, Tainung 01, y Red Lady were the most prefered cultivars by aphides. Baixinho de Santa Amalia y Sunrise Solo de Brasil were the less prefered cultivars. [ABSTRACT FROM AUTHOR]

Abstract: Aphis spiraecola and Aphis gossypii cause harmful damages on clementine tree orchards. Weekly surveys measured the abundance of aphids (larvae, winged and wingless adults) as well as of auxiliary insects and parameters of energy metabolism. Correlatively, soluble carbohydrates, total free amino acids, free proline and condensed tannins were quantified in control and infested leaves. Both aphid species showed parallel temporal variations, but A. spiraecola was consistently more abundant regardless of the stage. Amino acids had a positive effect on both aphid species abundance, but neither condensed tannins nor auxiliary insects seemed to modulate aphid populations. Interestingly, the leaf carbohydrate content was positively correlated with the abundance of A. spiraecola, but not with that of A. gossypii. Moreover, A. gossypii's abundance was significantly down-regulated by high proline concentrations. Thus, the higher abundance of A. spiraecola could be explained by a better tolerance to high proline contents and a better conversion of foliar energy metabolites. [Copyright &y& Elsevier]

Enhancing biological control of pests through habitat management in agricultural systems has gained increasing attention. Three different aromatic plants, ageratum (Agerarum houstonianum Mill.), French marigold (Tagetes patula L.) and basil (Ocimum basilicum L.), were chosen as intercrops for apple orchards to evaluate the effects of intercropping on Aphis citricola Van der Goot and its local natural enemies in China. We found that compared with natural vegetation, A. citricola abundance was significantly decreased by 29.26%, 35.80% and 38.28% in plots intercropped with ageratum, French marigold and basil, respectively. The number of natural enemies of A. citricola in plots intercropped with T. patula and O. basilicum were significantly higher than in plots of natural vegetation. Equally important, intercropping affected the composition of natural enemies and the population dynamics of A. citricola and its natural enemies. Annual cumulative numbers of natural enemies were significantly negatively correlated with A. citricola annual cumulative individual numbers except for O. tantillus. Our results demonstrate that intercropping with aromatic plants could be an effective method for biological control of A. citricola in apple orchards. [ABSTRACT FROM AUTHOR]

Non-chemical methods for control of the most important aphids on apple in Bulgaria, rosy apple aphid (Dysaphis plantaginea Pass.) and spiraea aphid (Aphis spiraecola Patch.), were evaluated under field conditions in the region of Plovdiv (Central-South Bulgaria). Two treatments with the kaolin containing product, SurroundâWP, applied in October, significantly reduced the number of winter eggs of D. plantaginea. Its effectiveness was comparable to that of the defoliation of apple trees. The botanical insecticides Neem Azal T/S (azadirachtin) and Pyretrum FS EC (pyrethrum) showed an excellent effectiveness against rosy apple aphid but were ineffective against spiraea aphid. The microbial insecticides Naturalisâ (Beauveria bassiana) and Preferal WG (Paecilomyces fumosoroseus) had a delayed initial effect. However, on five to seven days after treatment, these pesticides showed a very good effectiveness against A. spiraecola and excellent effectiveness against D. plantaginea. [ABSTRACT FROM AUTHOR]

The yellowish aphid pigment furanaphin, isolated from Aphis spiraecola and possessing cytotoxicity against HL-60 (human promyelocytic leukemia-60) cells, was synthesized by utilizing the Fries rearrangement assisted with a BF3·2AcOH complex as a key step. It was confirmed that the complex effectively mediated the reaction even though the compounds had an electron-withdrawing substituent. [ABSTRACT FROM AUTHOR]

The spiraea aphid (Aphis spiraecola Patch) is a primary pest of fruit trees, particularly pear trees in China. Despite the economic importance of this pest, little is known about its genetic structure or its patterns of dispersal at local and regional scales; however, knowledge of these characteristics is important for establishing effective control strategies for this pest. The genetic variability of 431 individuals from 21 populations on pear trees in China was investigated using eight polymorphic microsatellite loci. The high polymorphism of these markers was evident from the expected heterozygosity value (He = 0.824) and the Polymorphism Information Content (PIC = 0.805), indicating that the spiraea aphid maintains a high level of genetic diversity. The analysis of molecular variance revealed a middle level of population differentiation (FST = 0.1478) among A. spiraecola populations. This result is consistent with the results of the STRUCTURE analysis (K = 3), the unweighted pair-group method with arithmetic average tree and the Mantel test (r = 0.6392; P < 0.05). Our results indicate high levels of genetic exchange in the spiraea aphid, possibly facilitated by geography and climate. Our findings emphasize the importance of considering regional differences in studies of population structure, even when strong isolation-by-distance influences the genetic population structure of species. [ABSTRACT FROM AUTHOR]

This article documents the addition of 299 microsatellite marker loci and nine pairs of single-nucleotide polymorphism (SNP) EPIC primers to the Molecular Ecology Resources (MER) Database. Loci were developed for the following species: Alosa pseudoharengus, Alosa aestivalis, Aphis spiraecola, Argopecten purpuratus, Coreoleuciscus splendidus, Garra gotyla, Hippodamia convergens, Linnaea borealis, Menippe mercenaria, Menippe adina, Parus major, Pinus densiflora, Portunus trituberculatus, Procontarinia mangiferae, Rhynchophorus ferrugineus, Schizothorax richardsonii, Scophthalmus rhombus, Tetraponera aethiops, Thaumetopoea pityocampa, Tuta absoluta and Ugni molinae. These loci were cross-tested on the following species: Barilius bendelisis, Chiromantes haematocheir, Eriocheir sinensis, Eucalyptus camaldulensis, Eucalyptus cladocalix, Eucalyptus globulus, Garra litaninsis vishwanath, Garra para lissorhynchus, Guindilla trinervis, Hemigrapsus sanguineus, Luma chequen. Guayaba, Myrceugenia colchagüensis, Myrceugenia correifolia, Myrceugenia exsucca, Parasesarma plicatum, Parus major, Portunus pelagicus, Psidium guayaba, Schizothorax richardsonii, Scophthalmus maximus, Tetraponera latifrons, Thaumetopoea bonjeani, Thaumetopoea ispartensis, Thaumetopoea libanotica, Thaumetopoea pinivora, Thaumetopoea pityocampa ena clade, Thaumetopoea solitaria, Thaumetopoea wilkinsoni and Tor putitora. This article also documents the addition of nine EPIC primer pairs for Euphaea decorata, Euphaea formosa, Euphaea ornata and Euphaea yayeyamana. [ABSTRACT FROM AUTHOR]

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Enhancing biological control in orchards is an efficient way to control insect pests. This study investigates the possibility of increasing biological control of spirea aphid by providing alternate food resources, in the form of peach extrafloral nectar, to adult Harmonia axyridis, its primary predator. Two pairs of apple orchards, each having one interplanted with 50% trees bearing extrafloral nectar and one a monoculture, were studied for aphid and predator populations from 1999 to 2005. There were no differences in spirea aphid or predator populations between interplanted and monoculture orchards. However, H. axyridis adults arrived earlier in the interplanted than in the monoculture orchards. In another apple orchard, the effect of peach extrafloral nectar on sentinel spirea aphid colonies surrounding a cluster of potted peach trees, or a cluster of apple trees as a control, was tested in 2007. Only the closest spirea colonies to the potted peach trees, trees within 3 m, showed an increase in biological control. Although there was some indication of enhancement of predation by adult H. axyridis on spirea aphids, adding alternative food resources in the form of peach trees bearing extrafloral nectar resulted in no detectable increase in biological control. [ABSTRACT FROM AUTHOR]

In the citric company of Jagüey Grande in orange plantations cultivar Valencia Citrus sinensis (L.) Osb. in development phase, was intercropping with papaya Carica papaya (L.) variety Red Maradol. The main affectation of this crop is the papayo ringspot. A sample of 400 plants was selected of each one of these crops distributed in 20 furrow by 20 plants each one, it was evaluated bimonthly the presence of symptoms of papayo ringspot during nine months. 20 plants were selected of citric and 20 of papaya in cross form, and four plants for quadrant of both crops. They were carried out samplings to determine the present of vectorial insects of virus, and the existent relationship between the dissemination of the diseases and the populations of insects. The species determinated were: Aphis gossypii Glover, Aphis spiraecola Patch and Toxoptera sp. The biggest increments were observed in the months of November and February for A. spiraecola and October and November for Toxoptera sp. The percentage of infection of the diseases was increased along the cycle of the crop. The first symptoms were observed at three month; the increment rate was of 0,018%, to the seven months of 0.195%, and starting from nine months of 0.645%. The dissemination of the diseases was closely related to the evolution of the populational levels of the vectorial species. [ABSTRACT FROM AUTHOR]

PPV was first detected in Spain in 1984 in Japanese plum ( Prunus salicina Lindl) cv. Red Beaut and spread very quickly to other Japanese and European plums and apricot cultivars but left peach cultivars unaffected. In the years following the detection of PPV, the predominant aphid species visiting Prunus orchards in Mediterranean areas were Aphis gossypii followed by Aphis spiraecola, the latter being the main aphid species found at present. Both species are considered to be the main vectors of PPV in Spanish early Prunus growing areas. Spatial analysis of the spread of PPV-D in Japanese plum and apricot trees confirmed the lack of significant association between immediately adjacent trees. The observed spatial pattern of sharka suggests a lack of movement of PPV-viruliferous aphid vectors to immediately adjacent trees and indicates their preferential movement to trees several tree spaces away. PPV-D is the only type currently present in Spain, with the exception of a PPV-M outbreak that was detected in and successfully eradicated from Aragón in 2002. The short-distance spread of PPV-M infection occurred as far as 12 m along the rows of peach trees. However, PPV-D has not been observed to spread through peach cultivars, despite being grown in the vicinity of heavily infected plots of apricot or Japanese plum trees. [ABSTRACT FROM AUTHOR]

Laboratory bioassays using leaf disks of apple dipped in test solutions of insecticides demonstrated that the apple aphid, Aphis pomi De Geer, and the spirea aphid, Aphis spiraecola Patch, differed significantly in susceptibility to a number of insecticides registered for control of aphids on apple (Malus spp.). Compared with A. pomi, A. spiraecola was approximately four- and three-fold less susceptible to pirimicarb and lambda-cyhalothrin, respectively, whereas there was little difference in response to dimethoate. Pymetrozine is thought to act on aphids primarily as a feeding inhibitor. Exposure of aphids to this material generated data that fit the probit model for only half the tested clones. However, the LC50 value for one clone of A. spiraecola was nearly 1,000 times higher than the value for one clone of A. pomi. Although the results from these trials did not indicate that either species had developed significant levels of resistance to the test materials, differences in LC50 levels of >10-fold suggest insecticide tolerances and the possibility of control failures in the future. The demonstrated differences in susceptibility to insecticides between these two morphologically similar species also should be considered during the evaluation of new products for use on apple. [ABSTRACT FROM AUTHOR]

The production of clementine fruit was affected by varying densities of Aphis spiraecola Patch (Hemiptera: Aphididae) maintained on four groups of clementine, Citrus clementina Hort. ex Tan., trees individually isolated in mesh cages. A formula relating the number of aphids per square meter of canopy per group of trees to yield loss in that group of trees was obtained, permitting us to calculate the economic injury levels (EILs) and economic thresholds (ETs) for treatment against A. spiraecola, i.e., EIL, ET, environmental economic injury level (EEIL), and environmental economic threshold (EET). In an example case with current values, EIL = 370, ET = 322, EEIL = 614, and EET = 533 aphids per m² of canopy. Formulae designed for easier use in the field were obtained to express each of these thresholds. The formulae are compared with those obtained for Aphis gossypii Glover in a previous study; the intervention thresholds for A. spiraecola are slightly higher than those found for A. gossypii. [ABSTRACT FROM AUTHOR]

The effect of prohexadione-calcium, a plant growth regulator that inhibits gibberellin metabolism, on Cacopsylla pyricoloa (Foerster) in pear trees, and Choristoneura rosaceana (Harris) and Aphis spireacola Patch, in apple trees was studied. C. pyricoloa and A. spireacola populations were significantly reduced in prohexadione-calcium-treated pear and apple, respectively. Insecticide control of both pests with imidacloprid was synergized in treatments with prohexadione-calcium. In apples treated with prohexadione-calcium, there was a significant reduction in the number of C. rosaceana shelters per tree and amount of fruit injury at harvest attributable to the C. rosaceana. There was an additive effect when tebufenozide was used to control C. rosaceana in trees treated with prohexadione-calcium. Prohexadione-calcium significantly reduced vegetative growth in both pears and apples. Synergistic and additive treatment effects of prohexadione-calcium and pesticides used in this study may be due to better penetration and coverage of pesticides due to reduced foliar growth or to changes in the nutritional quality of the host plants. [ABSTRACT FROM AUTHOR]

Predation by the aphidophagous syrphid fly Heringia calcarata (Loew) on woolly apple aphid, Eriosoma lanigerum (Hausmann), was studied in the laboratory and in Virginia apple orchards. Feeding studies compared the prey suitability of three temporally sympatric aphid pests of apple: spirea aphid, Aphis spiraecola Patch; rosy apple aphid, Dysaphis plantaginea (Passerini); and woolly apple aphid. Significantly more H. calcarata larvae survived and completed development on a pure diet of woolly apple aphid than on rosy apple aphid, and none survived on spirea aphid. Final larval weights were significantly greater, and the larval developmental period was significantly shorter on woolly apple aphid than on rosy apple aphid, but neither the duration of pupal development nor adult weight differed between diets. H. calcarata larvae consumed an average of 105 woolly apple aphids during their development. Naive, neonate larvae given access to all possible pair combinations of woolly apple aphid, rosy apple aphid, and spirea aphid consumed significantly more woolly apple aphids in all pairings that included woolly apple aphid. When given a choice of rosy apple aphid and spirea aphid, significantly more rosy apple aphids were consumed. Weekly counts of syrphid eggs found in woolly apple aphid, rosy apple aphid, and spirea aphid colonies collected from apple trees showed that two generalist hover fly predators, Eupeodes americanus (Wiedemann) and Syrphus rectus Osten Sacken, were present in colonies of all three aphid species and that E. americanus was the most abundant syrphid predator in A. spiraecola and D. plantaginea colonies. H. calcarata eggs were found only in woolly apple aphid colonies and were more abundant there than E. americanus and S. rectus. These data suggest that H. calcarata is a specialized predator of woolly apple aphid in the apple ecosystem in Virginia. [ABSTRACT FROM AUTHOR]

The development, survivorship, longevity, reproduction, and life table parameters of the spirea aphid, Aphis spiraecola Patch, were evaluated at 25°C on seven commonly grown plants (Polyscias crispata (Bull) Merrill cultivar chicken-gizzard aralia, P. scutellaria (Burman) Fosberg, Vibernum suspensum Lindley, grapefruit (Citrus paradisi Macfadyen), rough lemon (C. jambhiri Lushington), pineapple orange [C. sinensis (L.) Osbeck variety pineapple orange], orange jessamine [Murraya paniculata (L.) Jack]) in the laboratory. Spirea aphid failed to survive on orange jessamine. The developmental times for the immature stages ranged from 7.9 d on P. scutellaria to 9.9 d on grapefruit or pineapple orange. The immature survival varied from 92.7% on P. scutellaria to 78.8% on pineapple orange. The average number of nymphs reproduced per female were 42.7, 35.7, 28.7, 22.3, 18.0, and 11.7 on P. crispata, P. scutellaria, V. suspensum, grapefruit, rough lemon, and pineapple orange, respectively. Female adults lived an average of 14.1, 15.3, 12.2, 11.0, 12.0, and 9.3 d on these same hosts. The intrinsic rate of increase (r m) for spirea aphid on P. crispata was highest. Jackknife estimates of r m varied from 0.308 on P. crispata to 0.177 on pineapple orange. The mean population generation time on these hosts ranged from 11.6 to 13.2 d. It was concluded that the ability of spirea aphid to feed and develop on a wide range of host plants increases its chance to infest citrus and thereby spreading the citrus tristeza virus. [ABSTRACT FROM PUBLISHER]

Two generations of the spirea aphid were reared successfully on a diet previously used for the green peach aphid, when the sucrose concentration was increased to 24%. Better survival, larviposition and weight gain were obtained when the concentration of five amino acids was also increased. The pea aphid diet was also tested and found unsuitable for this aphid. Synthetic-diet-reared aphids reached a final body weight four times less than that of aphids reared on orange leaves, while their fecundity was about one-third of that recorded for the plant-fed aphids. The possible use of this diet for toxicological and physiological studies is discussed. [ABSTRACT FROM AUTHOR]

Aphis citricola was first recorded in Israel in 1970. The distinguishing characteristics of this species are discussed and a list of its host plants in Israel is presented. A quantitative sampling method for estimating its population is described, consisting of a 5- grade logarithmic scale of tree infestation (based on most infested leaf), from which the grove infestation index is calculated. Infestation trends observed in an orange grove in Israel in 1982-1984 are described. The main population rise was in spring, originating from a large number of colonies founded by immigrating alates, possibly also by alates produced on other host plants within the grove. The production of alates on citrus itself started later in spring. Of meteorological factors, only hot dry desert winds (khamsin) were found to cause sudden, massive death of the aphids. Zusammenfassung Populationsentwicklung von Aphis citricola van der Goot in einer Zitrus-Plantage in Israel Aphis citricola wurde in Israel 1970 erstmals entdeckt. Es werden die Erkennungsmerkmale dieser Art und eine Auflistung der Wirtspflanzen in Israel angegeben. Zur Bestimmung der Populationsdichte wurde eine quantitative Sammelmethode auf der Basis einer 5stufigen logarithmischen Skala der Befallsintensität (Grundlage sind die am stärksten befallenen Blätter) entwickelt, woraus sich der Befallsindex der Plantage berechnen läßt. Es wird die Befallsentwicklung in einer israelischen Orangenplantage von 1982 bis 1984 beschrieben. Der stärkste Populationsanstieg war im Frühjahr zu beobachten und ist auf die große Anzahl Kolonien, die von der Exil-Alata-Generation gegründet wurden, zurückzuführen und möglicherweise auch von Alata-Generationen, die von anderen Wirtspflanzen in der Plantage stammten. Auf der Zitruspflanze selbst setzte die Entwicklung der Alatae erst im späteren Frühjahr ein. Von den Witterungsfaktoren bewirkten lediglich die heißen und trockenen Wüstenwinde (khamsin) eine plötzliche und hohe Mortalität der Läuse. [ABSTRACT FROM AUTHOR]

• The insectary plant Cnidium monnieri attracted and sustained insect predators in an orchard. • Higher densities of predators were observed on trees interplanted with insectary plants. • Spirea aphid populations were suppressed in areas where insectary plants were present. • Rubidium marking verified the movement of predators from insectary plants to trees. Habitat management, such as adding insectary plants to agroecosystems, is a useful technique for biological control. It can improve pest control through natural enemy augmentation and conservation. We evaluated use of the insectary plant Cnidium monnieri (L.) Cuss. to increase the diversity and population density of natural enemies, promote the movement of natural enemies, and improve suppression of the spirea aphid (Aphis spiraecola Patch). An apple orchard experiment included C. monnieri as the treatment and the absence of C. monnieri as the control. The results suggested that C. monnieri can foster predatory natural enemies, such as Propylaea japonica , Harmonia axyridis , Hippodamia variegata , Chrysoperla sinica , and Episyrphus balteata. Density of the predators on the apple trees in the treatment was significantly higher than in the control. Density of spirea aphids on the apple trees in the treatment was significantly lower than in the control. Rubidium (Rb) was used as a tracking marker transferred along the food chain of C. monnieri (4.08 μg/ml) – celery aphid (Semiaphis heraclei) (0.46 μg/ml) – lady beetle (0.51 μg/ml) in a laboratory experiment. The highest Rb content in a lady beetle (0.62 μg/ml) was found 3 days after marking. Combined with field sampling and Rb marking, the results showed that 24.2% and 42.7% of H. axyridis on the apple trees moved from the insectary plant C. monnieri in 2018 and 2019, and that 53.2% and 48.4% of C. sinica on the apple trees transferred from C. monnieri in 2018 and 2019. The insectary plant C. monnieri attracts and fosters predatory natural enemies, which then move to the apple trees and suppress spirea aphids. These findings illustrate an effective method for enhancing biological control of aphids in apple orchards. [ABSTRACT FROM AUTHOR]

The green apple aphid ( Aphis pomi) and the spirea aphid ( Aphis spiraecola) are pests of apples in North America. Although management regimes exist to effectively control these pests, they differ significantly because of varying susceptibility of each species to common pesticides and differences in their life cycles. Therefore, accurate identification of the species present is essential for pest control. However, the identification process is complicated because of the morphological similarity between these two species. As a result, confusion between A. pomi and A. spiraecola often occurs. DNA barcoding has been proven to accurately identify species of Aphididae. A further study demonstrated that DNA barcodes could be used to accurately differentiate A. pomi and A. spiraecola. DNA barcoding represents an important step towards rapid identification of these pests as distinctions can be easily made between morphologically similar species as well as from eggs and immature individuals in addition to adults. However, samples must still be sent to specially equipped facilities for sequence analysis, which can take between several hours and days. Real-time PCR is emerging as a useful tool for more rapid pest identification. The purpose of this study was to develop a real-time PCR assay for differentiation of A.pomi from A. spiraecola based on DNA barcode sequences from the Barcode of Life Data System. This assay was designed on the portable SmartCycler II platform and can be used in field settings to differentiate these species quickly and accurately. It has the potential to be a valuable tool to improve pest management of A. pomi and A. spiraecola. [ABSTRACT FROM AUTHOR]