Chemically Mediated Interactions between Grapevine, Aphid, Ladybird, and Ant in the Context of Insect Chemical Ecology

This study simplifies the complex relationship among grapevine plants,aphids,ladybirds,and ants,which is essential for effective pest management and ecological balance.This study investigated the impact of aphid attacks and the presence of ants and ladybirds on the volatile compounds profile released into the chemosphere of the community consisting of the common vine Vitis vinifera,the aphid Aphis illinoisensis,the ladybird Cocci-nella undecimpunctata-and the ant Tapinoma magnum.This study aims to analyze the volatile compounds emitted by the grapevine and surrounding insects in response to these intricate interactions.The extraction of volatile organic compounds(VOCs)was carried out using closed-loop stripping(CLS)and then analyzed via gas chromatography-mass spectrometry(GC-MS)and principles coordinated analysis(PCA)was performed.The grapevine was exposed to different types and order of treatments,including non-infested,aphid-infested,aphid-infested with ant,aphid-infested with ladybird,and various combinations of ant and ladybird.After the aphid attack,the outcomes uncovered massive alterations in the volatile compound profiles.Infested grapevine displayed distinct emissions of germacrene D,an alcohol,and an alkene compared to non-infested plants.The characteristic VOC profile was the share of infested grapes in the presence of ants,with benzene derivatives and sesquiterpenes dominating the components.The coexistence of ladybirds with ants and aphids resulted in a dif-ferent volatile profile characterized by elevated levels of aldehydes,ketones,α-farnesene,and its hydroxy deriva-tive.It was concluded that the emission of VOCs into the chemosphere of the grapevine communities varied qualitatively and quantitatively depending on the level of the relationship complexity within each community in response to the infestation of grapevines by aphids,the presence of ladybirds as natural predators,and the presence of ant as protector.The grapevine’s status-dependent compounds can serve as indicators of infestation status and contribute to non-destructive early-stage diagnosis of the aphid.

Reactions of Maruca Resistant Transgenic Cowpea to Cowpea Aphid-Borne Mosaic Virus

Cowpea (Vigna unguiculata L. [Walp.]) in one of the main grain legumes contributing to food security and poverty alleviation in Sub-Saharan Africa. To control the highly damaging legume pod borer Maruca vitrata F., transgenic cowpea lines expressing the insecticidal Cry1Ab Bt protein were developed. In this study, we evaluated the impact of Cry1Ab transgene expression on the susceptibility of four cowpea lines (named IT97K-T, IT98K-T, Gourgou-T and Nafi-T) and their respective non-transgenic near isogenic lines (IT97K, IT98K, Gourgou and Nafi) to Cowpea aphid-borne mosaic virus (CABMV) in greenhouse conditions. In a preliminary quality control test by enzyme-linked immunosorbent assay, the presence of Cry1Ab protein in transgenic seed lots ranged from 59% to 72%, with no significant differences among the lines (χ2 = 3.26;p = 0.35). Upon virus inoculation, all cowpea lines exhibited mosaic symptoms with similar severity between 7- and 11-day post-inoculation. No significant differences were observed in symptom severity. Significant differences were found between cowpea lines for time of symptom onset, virus accumulation in plants and days to 50% flowering. However, while comparing pairs of transgenic lines and corresponding non-transgenic lines, virus accumulation showed not significant differences whatever the pair. Time of symptom onset and days to 50% flowering did not also differ significantly between pairs of cowpea lines except Nafi/Nafi-T in which transgenic Nafi-T showed earlier symptoms (7.4 ± 0.7 vs. 8.9 ± 0.8 days post-inoculation) and shorter flowering time (37.3 ± 0.6 vs. 42 ± 1.7 days after sowing). Overall, these findings improve our understanding of the effects of Cry1Ab gene mediated genetic modification on cowpea infection by Cowpea aphid-borne mosaic virus, with potential implications for environmental safety assessment.

Regional selection of insecticides and fungal biopesticides to control aphids and thrips and improve the forage quality of alfalfa crops

The efficacies of biological and conventional chemical insecticides against two major insect pests of alfalfa(aphids and thrips)were compared in three sites across China’s alfalfa belt.In addition,the persistence of the residues of chemical insecticides in alfalfa and their influence on the quality of alfalfa hay were examined.Efficacy varied among the different biological and chemical insecticides.The chemical insecticides were significantly more effective than biopesticides in a short time-frame.The efficacy period of biopesticides was significantly longer than that of chemical insecticides,and the corrected mortality rate of aphids in all regions was above 50%at 14 days after application.The analysis of pesticide residues showed that the residual doses of all the pesticides were within the allowed ranges after the safe period.The acid detergent fiber and neutral detergent fiber contents in alfalfa hay were higher and the protein content was lower in chemical insecticide treatments than in biopesticide treatments in Hebei.The relative feeding value of alfalfa hay treated with Metarhizium anisopliae IPP330189 was the highest among the treatments.Compared with chemical insecticides,the yield of alfalfa hay was higher in the biopesticides treatments.Biopesticides show a stronger control effect on insect populations and also a better improvement in the quality of alfalfa hay than chemical insecticides.This study provides a basis for exploring and developing a comprehensive control regime for alfalfa insect pests in the different alfalfa-growing regions in China,and for reducing chemical insecticide usage and improving forage quality.

Model fitting of the seasonal population dynamics of the soybean aphid, Aphis glycines Matsumura, in the field

The soybean aphid, Aphis glycines Matsumura(Hemiptera: Aphididae), is one of the greatest threats to soybean production, and both trend analysis and periodic analysis of its population dynamics are important for integrated pest management(IPM). Based on systematically investigating soybean aphid populations in the field from 2018 to 2020, this study adopted the inverse logistic model for the first time, and combined it with the classical logistic model to describe the changes in seasonal population abundance from colonization to extinction in the field. Then, the increasing and decreasing phases of the population fluctuation were divided by calculating the inflection points of the models, which exhibited distinct seasonal trends of the soybean aphid populations in each year. In addition, multifactor logistic models were then established for the first time, in which the abundance of soybean aphids in the field changed with time and relevant environmental conditions. This model enabled the prediction of instantaneous aphid abundance at a given time based on relevant meteorological data. Taken as a whole, the successful approaches implemented in this study could be used to build a theoretical framework for practical IPM strategies for controlling soybean aphids.

Identification of candidate genes for aphid resistance in upland cotton by QTL mapping and expression analysis

Lignin is one of the main components of cell walls and is essential for resistance to insect pests in plants.Cotton plants are damaged by aphid(Aphis gossypii) worldwide but resistant breeding is undeveloped due to scarce knowledge on resistance genes and the mechanism. This study reported a lignin biosynthesisrelated gene identified in the F_(2) population derived from the cross between cotton cultivars Xinluzao 61(resistant to aphid) and Xinluzao 50(susceptible to aphid). A quantitative trait locus was mapped on chromosome D04 with a logarithm of odds(LOD) score of 5.99 and phenotypic effect of 27%. RNA-seq analysis of candidate intervals showed that the expression level of GH_D04G1418 was higher in the resistant cultivar than in the susceptible cultivar. This locus is close to AtLAC4 in the phylogenetic tree and contains a conserved laccase domain. Hence, it was designated GhLAC4-3. Silencing of GhLAC4-3 in Xinluzao 61 via virus-induced gene silencing(VIGS) resulted in decreased lignin content and increased susceptibility to aphids. These results suggest that GhLAC4-3 might enhance aphid resistance by regulating lignin biosynthesis in cotton.

Identification of Early Peach Aphid Infestation Based on Hyperspectral Imaging Technology

Peach aphid is a common pest and hard to detect.This study employs hyperspectral imaging technology to identify early damage in green cabbage caused by peach aphid.Through principal component transformation and multiple linear regression analysis,the correlation relation between spectral characteristics and infestation stage is analyzed.Then,four characteristic wavelength selection methods are compared and optimal characteristic wavelengths subset is determined to be input for modelling.One linear algorithm and two nonlinear modelling algorithms are compared.Finally,support vector machine(SVM)model based on the characteristic wavelengths selected by multi-cluster feature selection(MCFS)acquires the highest identification accuracy,which is 98.97%.These results indicate that hyperspectral imaging technology have the ability to identify early peach aphid infestation stages on green cabbages.

Research on the Prevention and Control Technology of Rape Aphids

[Objective] The aim was to screen economic and environment-friendly pesticides adaptive to aphid-resistant varieties in main rape growing regions of Yunnan Province.[Method] The effects of 6 pesticides against aphids on 22 Brassica campestris materials of the main breeds in Yunnan Province,the new improved varieties in China and the core breeding materials were tested.[Result] Yunyoushuang 1,Huayou 4,Yunhuayou Early-maturing Variety No.1 and A35 showed better aphid-resistance.An optimum pesticide application strategy was to use Diyaling in sowing time,and interchangeably apply nitenpyram and imidacloprid during flowering and pod formation stages.[Conclusion] The present study had provided an important technical support for sustainable development of rape industry.

Isolation and Identification of Pandora neoaphidis and Its Pathogenicity against Turnip Aphid(Lipaphis erysimi)

[Objective] The study was to isolate and identify the pathogen of Pandora neoaphidis and to determine its pathogenicity against turnip aphid （Lipaphis erysimi）.[Method] Based on the morphological characteristics,the species of pathogenic fungus was identified.Spore shower method was used to carry out bioassay on the pathogen against turnip aphid.[Result] Primary conidia were ovoid,bitunicate and uninucleate,（24.7±1.4）μm×（10.7±0.9）μm,L/D=2.3±0.2.Secondary conidia had the similar shape with the primary ones,（18.6±2.1）μm×（13.3±1.3）μm,L/D=1.4±0.2.Hyphal body was like mycelium with the diameter of （10.6±0.8）μm.Conidiophores had palmate branch with the diameter of （10.0±0.9）μm.Pseudocystidia was not branched,which had rough base with the diameter of （19.2±1.7）μm,and gradually became more angular towards the apex with the diameter of （8.0±0.9）μm at tips.Rhizoid was like monohyphal shape with the diameter of （21.0±3.0）μm at base,the terminal apex had regular discoid holdfast.No resting spores were observed.The lethal dose of the pathogen against turnip aphid was 18.2/mm2.[Conclusion] The entomopathogenic fungus against turnip aphid was identified to be Pandora neoaphidis,and the pathogen was confirmed to have strong pathogenicity against turnip aphid.

Resistance in Barley (<i>Hordeum vulgare</i>L.) to New Invasive Aphid, Hedgehog Grain Aphid (<i>Sipha maydis</i>, Passerini) (Hemiptera: Aphididae)

Sipha maydis Passerini (Hemiptera: Aphididae) is a pest of cereals in many regions of the world and was identified as an invasive pest of the US in 2007. Regional surveys from 2015-2017 revealed this pest was broadly distributed throughout many of the western Great Plains states where it is a potential threat to cereal production. The common name hedgehog grain aphid, HGA, has been associated with Sipha maydis in the US. Cross-resistance where a plant is resistant to one aphid species and is also resistant to another species that is known to occur. Six barleys were evaluated for cross-resistance to HGA: Russian wheat aphid, RWA, resistant germplasms STARS 9301B and STARS 9577B and cultivar “Mesa”;greenbug, GB, resistant germplasm STARS 1501B and cultivar “Post 90”;and RWA and GB resistant experimental line 00BX 11-115. Cultivars “Morex” and “Schuyler” were susceptible controls. Antixenosis was measured 5 days after infestation by HGA. Seedling damage ratings and reductions in seedling growth were recorded after 17 days of infestation. Intrinsic rate of increase, rm, of HGA was determined by following the development of newborn aphids to adulthood and reproduction. 00BX 11-115 and Post 90 had significantly greater antixenosis (fewer aphids/seedling), significantly lower plant damage ratings, and significantly lower intrinsic rates of increase than other entries. Differences in seedling growth were not significant. 00BX 11-115 and Post 90 were the only entries with the Rsg1 greenbug resistance gene. Rsg1 greenbug resistance confers cross-resistance to HGA in the seedling stage.

Research on the Control Effects of Several Insecticides on Wheat Aphids

[Objective] The aim was to determine control effects of the 6 insecticides and recommended the optimal doses. [Method] In 2014, the control effects of sophocarpidine, pymetrozine, beta-cypermethrin, acetamiprid, imidacloprid, and chlor- pyrifos on wheat aphids were tested, and every pesticide was designed with three doses in Shou County, Anhui Province, to explore the significance of differences on control effects. [Result] The results showed that the control effects of the 6 insecti- cides were satisfied, and the insecticides were safe on wheat. [Conclusion] During initial diseasing stage of aphid, it is recommended to use sophocarpidine soluble concentrate （1.5%）, pymetrozine water dispersible granule （50%）, imidacloprid wet- table powder （25%）, and acetamiprid wettable powder （5%）, and chlorpyrifos missi- ble oil （40%）, cypermethrin missible oil （4.5%） and imidacloprid wettable powder （25%） can be applied in peak-diseasing stage.

Effect of Neoseiulus cucumeiris Carrying Paecilomyces fumosoroseus on the Prevention of Aphids and Spider Mites in Eggplant

Using predatory mites Neoseiulus cucumeris Oudermans dusted with en- tomopathgen Paecilomyces fumosoroseus （Wize） Brown ＆ Smith to control aphids and spider mites is a new idea of biological control. Some studies were conducted to confirm the feasibility of this idea. The germination condition of P. fumosoroseus conidia was determined by the method of different saturated salt solutions applying different humidity in small containers, and the pathogenicity test and the pot experi- ment were also conducted, under a suitable condition. There were 6 treatments for pot experiment as following： （1） CK; （2） releasing 50 N. cucumeds, （3） spraying 20 ml of 10^7 spores/ml conidial suspension; （4） releasing 50 N. cucumeris after spraying 20 ml of 10^7 spores/ml conidial suspension; （5） releasing 20 N. cucumeris dusted conidia of P. fumosoroseus; and （6） releasing 50 N. cucumeris dusted with conidia of P. fumosoroseus. The result showed that the germination condition of P. fu- mosoroseus conidia was 25-30 ℃ and 95%-100% RH, and under this condition, the 10s spores/ml conidia suspension caused a mortality of 86.52% in aphids and 41.78% in predatory mites after ten days. From the pot experiment, the numbers of aphids of treatment （3）, （4）, （6） were close to 0 at the 8th day. This study proved that the predatory mites N. cucumeris dusted with the entomogenous P. fu- mosoroseus could provide satisfactory control on both aphids and spider mites in potted eggplants under suitable temperature and humidity. The predatory mite vec- toring entomopathogen system could provide an economic and labor saving way for aphid control.

Spatial Distribution Pattern and Sampling Technique of Spring Wheat Aphid

[ Objective] The aim was to study the spatial distribution pattern and field sampling method of aphid population in spring wheat. [ Method] The aphid quantity in tested wheat field was calculated, the field distribution pattern of wheat aphid was calculated by using aggregated index method, the aggregated reason was analyzed and the field theoretical sampling number was ascertained. [ Result] The wheat aphid population showed aggregation distribution and negative binomial distribution, and such aggregation distribution was induced by interaction of its behavior and environmental factors. The field theoretical sampling number of wheat aphid was related to sample variance and permissible error; the less the sam- ple variance [ S^2 ） was, the less the permissible error [ d＇） was, the bigger the theoretical sampling number without replacement was; when the initial population numbers were different, the theoretical sampling numbers were also different; after the permissible error being set, the bigger the sample variance （ S^2 ） was, the bigger the theoretical sampling number was. [ Conclusion] This study supplied scientific basis for prediction and field control of wheat aphid.

VALIDATION AND ANALYSES OF THE SIMPLE METHOD FOR DETERMINING rm OF APHIDS AND MITES

This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. The value of rm can be estimated by the simple equation: rm=0.74ln (Md)/d, where d is the time from birth to first reproduction; Md is the number of female offspring produced per original female in 2d. This method was developed by Wyatt and White. We reached the following conclusions from our study: When the parameter, Md is less than 1, this equation is not appropriate for estimating rm of populations; When the parameter, Md is larger than 1 and about 70% or more of the reproductive contribution to the rm is achieved in 2d, the equation is appropriate for calculatng the rm of aphids and mites.As Md decreases, the required reproductive contribution to the rm in 2d corresponding to the constant 0.74 will increase. However, whether 70% or more of reproductive contribution to rm is achieved in 2d still is a problem for whole taxa of aphids and mites. Therefore, further siudy on reproductive distribution will be required for practical application of this method.

Toxicity and Antifeedant Activity of Extracts from Walnut Green Husk against Wheat Aphid

[Objective] The research aimed to study the toxicity and antifeedant activity of walnut green husk extract on wheat aphid. [Method] Using ultrasonic extraction, 5 kinds of different polarity solvents were used to prepare the extracts from walnut green husk. The toxicity and antifeedant activity on wheat aphid were determined, [ Result ] Walnut green husk extracts in the solvent of ethanol, acetone, ethyl acetate had higher toxicity and antifeedant activity on wheat aphid. When the concentration was 100 mg/ml, after 24 h, the toxicity and antifeedant activity of three kinds extracts on wheat aphid were greater than 84.35% and 66.98%, respectively. After 48 h, the toxicity and antifeedant activity were greater than 85.91% and 79.34%, respectively. Among 5 kinds extracts,ethanol extracts had the highest toxicity and antifeedant activity on wheat aphid. After 24 h, the corrected mortality rate was 93.64% and the antifeedant rate was 83.61%. After 48 h,the corrected mortality rate was 94.95% and antifeedant rate was 92.21%. Petroleum ether extract had the smallest toxicity and antifeedant activity on wheat aphid. After 24 h,the corrected mortality rate and antifeedant rate were 19.54% and 34.65%, respectively. After 48 h,the corrected mortality rate and antifeedant rate were 20.13% and 39. 03%, respectively. [ Conclsion] The extracts from walnut green husk with larger polarity solvent had better toxicity and higher antifeedant activity on wheat aphid.

Control Effect of Methanol Extract of Blumea megacephala Chang et Tseng against Turnip Aphid (Lipaphis erysimi Kaltenbach)

[ Objective ] The paper was to explore the application of botanical pesticides on controlling turnip aphid （ Lipaphis erysimi Kaltenbach）. [ Method ] Through potting efficacy experiment of Chinese cabbage, the control effects of two preparations（20% EC and 10% EW）of methanol extract of Blumea megacephala Chang et Tseng against turnip aphid, as well as leaf-protection effect on Chinese cabbage were determined. [ Result] 20% EC of B. megacephala had the highest efficacy in 10-fold dilution, and its control effects against turnip aphid were 57.78%, 77.19% and 84.79% after pesticide spraying for 24, 48 and 72 h; 10% EW of B. megacephala had the highest efficacy in 5-fold dilution, and its control effects against turnip aphid were 74.44%, 84.79% and 89.14% after pesticide spra- ying for 24, 48 and 72 h. The leaf-protection rates of 20% EC orB. megacephala in 10-fold dilution were 89.31% and 94.80% after pesticide spraying for 3 and 5 d; the leaf-protection rates of 10% EW of B. megacephala in 5-fold dilution were 93.50% and 97.83% after pesticide spraying for 3 and 5 d. [ Condusion] The methanol extract of B. megacephala had good control effect against turnip aphid and good protection rate on crops.

A Preliminary Study on Control Efficiency of New Nicotine Biopesticides against Pomegranate Aphids

In this study, toxicity and control efficiency of three nicotine biopesticides against pomegranate aphids were determined via indoor toxicity test and field effica- cy test, aiming at screening the appropriate reagent for prevention and control of pomegranate aphids. The results of indoor toxicity test showed that LC^o of reagent 1, reagent 2 and reagent 3 reached 10 270, 12 810 and 13 040 mg/L, respectively. The results of field efficacy test showed that control efficacy of reagent 1, reagent 2 and reagent 3 reached 60.52%, 34.60% and 46.99%, respectively. Overall, reagent 1 （91% ultrafine powder of tobacco leaves, 3% silicone oil, 2% sasangua cake, 2% emulsifier, 2% ascorbic acid） exhibited the highest control efficiency against pomegranate aphids, which can be further popularized and utilized.

The biotypes and host shifts of cotton-melon aphids Aphis gossypii in northern China

Aphis gossypfi is a globally distributed species and therefore has a highly variable life cycle. Populations of A. gossypii in northern China exhibit greater genotypic diversity and a broader host range, yet the details of life cycles of different biotypes is still unclear. In this study, the Cytb and 16S gene regions of A. gossypfi collected from 5 common summer hosts and 4 primary hosts were analyzed. A total of 57 haplotypes were obtained from 1 046 individual A. gossyp# sequences. The sequence included 44 variable sites, 27 of which were parsimony informative sites and 17 of which were singleton variable sites. The most frequent 3 haplotypes were found in 896 individuals, representing a total of 85.7% of all individuals and 36 haplotypes were found in 1 individual. A neighbor-joining tree was constructed using 21 haplotypes that were found in more than 2 individuals. Considering the individual host plant, 5 biotypes were identified. Type 1 corresponded exactly to the cucurbit host-race and the other 4 biotypes were found as cotton host-races. Type 3 was the most abundant biotype in cotton fields in northern China.

Aphids and their transmitted potato viruses: A continuous challenges in potato crops

Aphid is one of the most destructive insect pests on cultivated plants in temperate regions.Their piercing-sucking mouthparts and phloem feeding behavior directly damage crops and deplete plant nutrients.Potato(Solanum tuberosum L.)is one of the most important food sources on the planet,and several aphid species,e.g.,Myzus persicae(Sulzer)(green peach aphid)and Macrosiphum euphorbiae(Thomas)(potato aphid)(Hemiptera:Aphididae)colonize potato and transmit several economically important viruses.Aphid-transmitted potato viruses have been emerging all over the world as a very serious problem in potato production,inducing a wide variety of foliar and tuber symptoms,leading to severe yield reduction and loss of tuber quality.In this review,recent advances in understanding the interactions of potato viruses with their hosts,aphid vectors and the environment are described.

Identification of Soybean Resources of Resistance to Aphids

Four soybean [Glycine max （L.） Merr.] cultivars with soybean aphid resistance （Aphis glycines Matsmura）, p189, P203, P574, and P746, were identified in field test, choice test, and non-choice test, The grade of resistance to aphids and the damage index of P189, P203, and P746 were significantly different from the susceptible cultivars （P=0.05）. P574 and P746 showed antibiosis resistance, preventing aphids from reproducing on the plants. P203 showed antixenosis resistance, preventing aphids from reproducing in field test and choice test, but susceptible in non-choice test. Population development on plants was significantly different in field test, choice test, and non-choice test, which was caused by different selective pressures.

Identification of Molecular Markers for a Aphid Resistance Gene in Sorghum and Selective Efficiency Using These Markers

In this study, an F2 segregated population obtained by hybridization between the aphid-sensitive sorghum strain Qiansan and aphid-resistant cultivar Henong 16 was used to establish an aphid-resistant pool and an aphid-sensitive pool. 192 pairs of AFLP （amplified fragment length polymorphism） marker primers were screened in these pools using BSA （bulked segregant analysis）. Three pairs of EcoR I-CTG/Mse I-CCT, EcoR I-CTG/Mse I-CAT, and EcoR I-AGT/Mse I-CCC showed linkage with aphis resistance. EcoR I-CTG/Mse I-CCT-475, EcoR I-CTG/Mse I-CAT-390, and EcoR I-AGT/Mse I-CCC- 350 （E42/M52-350） were mapped within 6, 10, and 13 cM distances with the aphid-resistant gene by using Mapmaker 3.0 software. The bands amplified by EcoR I-CTG/Mse I-CCT-475 and EcoR I-CTG/Mse I-CAT-390 were extracted, cloned, and sequenced. Specific primers of SCAR （sequence characterized amplified regions） were then designed from these bands. A specific band of 300 bp was amplified by a pair of SCAR primers designed based on the sequence obtained from the EcoR I-CTG/Mse I-CAT-390 marker. The SCAR marker was named SCAS0. The marker was used to detect the F2, BC1, and F2：3 populations. The selective efficiency was 86.8, 91.1, and 86.3% in the BC1, F2, and F2：3 populations, respectively. The average selective efficiency was 88.2%.