Search

In urban and peri-urban areas in West Africa, the cabbage Brassica oleracea L. (Brassicaceae) is protected using repeated high doses of synthetic insecticides. After a brief description of available IPM components, this paper presents a literature review focused on the botanical extracts that have been experimented with at the laboratory or in the field in West Africa against major cabbage pests. The literature reviewed mentions 19 plant species from 12 families used for cabbage protection in the subregion. The species most used are Azadirachta indica, Capsicum frutescens, Ocimum gratissimum and Ricinus communis. An overview of the world literature showed that a total of 13 plant species belonging to 8 families used to control cabbage pests are reported from the rest of Africa, and 140 plant species belonging to 43 families from the rest of the world. The most commonly used and tested plant species against insect pests in the three geographical areas considered is A. indica.

Dentre as pragas que infestam a cultura da canola destacam-se os afídeos, Brevicoryne brassicae, Lipaphis pseudobrassicae, Macrosiphum euphorbiae e Myzus persicae, que ao se alimentarem da seiva das plantas provocam deformações e enrolamento das folhas, e em infestações severas podem ocasionar a morte das plantas. Estudos que abordem a dinâmica de afídeos na canola são escassos no Brasil. Portanto, este trabalho teve por objetivo realizar a flutuação populacional de afídeos nessa cultura no estado do Rio Grande do Sul, o maior produtor de canola do país. O estudo foi conduzido numa área experimental da Embrapa Trigo, Passo Fundo/RS, onde foi semeada uma área de 800 m2 com canola, híbrido Hyola 433, em maio de 2015. Nessa área, foi definida uma área de 125 m2 , da qual, semanalmente, de maio a setembro de 2015, 25 plantas de canola eram coletadas e transportadas em sacos plásticos para o laboratório de Entomologia. Nesse laboratório, os afídeos foram coletados das plantas, quantificados e identificados em nível de espécie. Variáveis climatológicas foram obtidas a partir de Estação Meteorológica localizada na Embrapa Trigo. No total, foram coletados 2024 espécimes, M. persicae (58%), L. pseudobrassicae (41%) e M. euphorbiae (1%). Os picos populacionais foram: M. persicae em junho (296 espécimes), L. pseudobrassicae em setembro (238) e M. euphorbiae em maio (26). As populações de afídeos foram baixas durante todo o período avaliado. A ocorrência de temperaturas amenas e de precipitações bem distribuídas durante o estudo contribuíram para que as populações das espécies de afídeos não fossem elevadas. ABSTRACT- Among the pests that infest the culture of canola, aphid species Brevicoryne brassicae, Lipaphis pseudobrassicae, Macrosiphum euphorbiae and Myzus persicae stand out, which when feeding on the sap cause deformation and curling of the leaves, and in severe infestations they can cause death of the plants. Studies that address the dynamics of aphids in canola are scarce in Brazil. Therefore, this work aimed to carry out the population fluctuation of aphids in this crop in the state of Rio Grande do Sul, the largest producer of canola in the country. The study was conducted in an experimental area of Embrapa Trigo, in Passo Fundo/RS, where an area of the 800 m2 with canola, Hyola 433 hybrid, was planted in May 2015. In this area, an area of the 125 m2 was defined, of which weekly, from May to September 2015, 25 canola plants were collected and transported in plastic bags to the Entomology laboratory. In this laboratory, aphids were collected from plants, quantified and identified at the species level. Climatological variables were obtained from the Meteorological Station located at Embrapa Trigo. In total, 2024 specimens were collected, M. persicae (58%), L. pseudobrassicae (41%) and M. euphorbiae (1%). The population peaks were: M. persicae in June (296 specimens), L. pseudobrassicae in September (238) and M. euphorbiae in May (26). Aphid populations were low throughout the evaluated period. The occurrence of mild temperatures and well-distributed rainfall during the study contributed so that the populations of aphid species were not high. Made available in DSpace on 2021-10-08T19:00:37Z (GMT). No. of bitstreams: 1 MarsaroJunior-2021.pdf: 387817 bytes, checksum: 6fed1b52f989624f37509ab6fe43ae13 (MD5) Previous issue date: 2021

International audience; Thirty-three species of aphids are now established in New Caledonia. All species appear to have been introduced accidentally by human activity in the last century. Here, 17 aphid species are recorded for the first time: Aphis eugeniae, Aphis glycines, Aphis odinae, Aulacorthum solani, Brachycaudus helichrysi, Cerataphis orchidearum, Greenidea psidii, Hyperomyzus carduellinus, Hysteroneura setariae, Lipaphis pseudobrassicae, Micromyzus katoi, Myzus ornatus, Pentalonia caladii, Rhopalosiphum nymphaeae, Rhopalosiphum rufiabdominale, Schizaphis rotundiventris, and Tetraneura fusiformis. Thirteen more species are also more or less regularly intercepted at the borders through biosecurity surveys, without further establishment. This demonstrates that aphids represent a major biosecurity threat, including a threat as potential plant virus vectors. The reinforcement of biosecurity is a priority for such biodiversity hotspots, from the perspectives of both agriculture and the native environment. Prioritisation and promotion of local development of vegetable and fruit production, rather than their risky importation from abroad, is desirable. Such an approach also should be promoted and extended to other Pacific islands, which all share the lack of native aphid fauna and their associated plant disease vector risks.; Trente trois (33) espèces de pucerons sont aujourd’hui recensées de Nouvelle-Calédonie. Toutes ces espèces sont exotiques et ont été introduites accidentellement par les activités humaines. Dix-sept (17) espèces y sont ainsi recensées pour la première fois : Aphis eugeniae, Aphis glycines, Aphis odinae, Aulacorthum solani, Brachycaudus helichrysi, Cerataphis orchidearum, Greenidea psidii, Hyperomyzus carduellinus, Hysteroneura setariae, Lipaphis pseudobrassicae, Micromyzus katoi, Myzus ornatus, Pentalonia caladii, Rhopalosiphum nymphaeae, Rhopalosiphum rufiabdominale, Schizaphis rotundiventris et Tetraneura fusiformis. Par ailleurs, au moins 13 autres espèces sont régulièrement interceptées par la biosécurité sans établissement actuel de populations. Les pucerons apparaissent donc comme une menace croissante pour la biosécurité de l’archipel. Aussi, le renforcement des mesures de biosécurité aux frontières apparaît prioritaire en association à une promotion du développement local de productions maraîchères et fruitières. Ainsi, la limitation de ces importations à risque, devrait contribuer à une meilleure protection des productions agricoles et de la biodiversité. Une telle approche devrait également être promue dans les pays insulaires du Pacifique, qui se caractérisent par la même disharmonie de peuplements, l’absence de communautés natives de pucerons et du risque associé de vectorisation de maladies phytopathogènes.

Biological features of Diaeretiella rapae (McIntosh), an aphid parasitoid, are conditioned by temperature and host. However, studies of host quality changes due to temperature adaptability have not been performed previously. Therefore, this study evaluated the adaptability of Lipaphis pseudobrassicae (Davis) and Myzus persicae (Sulzer) to high temperature, high temperature effect on their quality as hosts for D. rapae, and on parasitoid's thermal threshold. Aphid development, survivorship, fecundity, and longevity were compared at 19 °C and 28 °C. Host quality in different temperatures was determined through evaluation of parasitoid biology. Thermal threshold of D. rapae was determined using development time data. At 28 °C, development time, rate of immature survival, and total fecundity rates were greater in L. pseudobrassicae than in M. persicae. Development time of D. rapae in L. pseudobrassicae was shorter than that in M. persicae at 28 °C and 31 °C for females and at 31 °C for males. The thermal threshold of D. rapae was 6.38 °C and 3.33 °C for females and 4.45 °C and 3.63 °C for males developed on L. pseudobrassicae and M. persicae, respectively. Diaeretiella rapae size gain was greater in L. pseudobrassicae than that in M. persicae at 25 °C and 28 °C. Lipaphis pseudobrassicae showed better adaptation than M. persicae to elevated temperatures, which resulted in a better quality host for D. rapae at temperatures of 28 °C and 31 °C and a higher lower thermal threshold when the parasitoid developed within L. pseudobrassicae. The host's adaptation to high temperatures is a determinant of host quality for the parasitoid at that same climatic condition.

The effects of high voltage electromagnetic fields (EMF) on populations of aphpids, leaf miners and snails associated with rapeseed under subtropical conditions were studied. A field study was conducted during the spring season of 2015, at Wuhan, China (30.59°N, 114.30°E; 23.3 m asl). Plots with four different emission rates (0 kV, 5.2 kV, 26 kV and 39 kV) were established, each containing an EMF emission device located 2.6 m above the soil, Lipaphis erysimi aphid and Liriomyza brassicae leaf miner population densities were recorded at 10 d intervals throughout the cropping season. Aphids, leaf miners and snails infested all plots, but significantly higher population densities of all pests were observed in control plots. The plots with the highest emission rate (39 kV) had lower population densities of pests throughout the entire experiment. High voltage EMF may have the ability to suppress pests of rapeseed. However, much remains to be learned about the suitability and reliability of EMF for in...

Aphids are regarded as important pest problems of vegetable crops worldwide. Most vegetable growers in sub-Saharan Africa heavily rely on synthetic chemical insecticides for aphids’ control. Fungus-based biopesticides are being considered as alternatives to chemical insecticides. This study evaluates virulence of five isolates of Metarhizium anisopliae and three of Beauveria bassiana against Brevicoryne brassicae, Lipaphis pseudobrassicae, and Aphis gossypii, and their thermotolerance and conidial yield as a prerequisite for strain selection. The study also evaluates performance of the best isolate in screenhouse experiment against target aphid species. Three isolates of M. anisopliae ICIPE30, ICIPE62, and ICIPE69 outperformed the others, causing mortality of 85–98 %, 83–97 %, and 73–77 %, in B. brassicae, L. pseudobrassicae, and A. gossypii, respectively, 7 days post-inoculation. Isolate ICIPE62 had the shortest LT50 values of 3.4, 2.5, and 2.6 days at 1 × 108 conidia ml−1, and the lowest LC50 values of 7.3 × 105, 9.3 × 104, and 3.0 × 104 conidia ml−1 on day 7 against A. gossypii, B. brassicae, and L. pseudobrassicae, respectively. Furthermore, ICIPE62 produced more conidia on the surface of aphid cadavers than ICIPE30 and ICIPE69 and showed wider thermotolerance with optimum ranges between 25 and 30 °C. Application of conidia of ICIPE62 formulated in aqueous and emulsifiable formulations negatively affected aphid population growth rate on kale and okra plants compared to controls in screenhouse experiments. These results have demonstrated the potential of M. anisopliae isolate ICIPE62 in suppression of A. gossypii, B. brassicae, and L. pseudobrassicae populations and could therefore be considered as biopesticide candidate for the control of these target aphids.

We assessed the host stage preference and performance of the aphid parasitoidDiaeretiella rapae(McIntosh) on two aphid species,Brevicoryne brassicae(L.) andLipaphis pseudobrassicae(Davis). Although the parasitoid parasitized all nymphal instars of both aphid species, it showed a higher oviposition preference for 2nd (48.2 ± 7.74%) and 3rd (41.0 ± 7.82%) instars ofL. pseudobrassicae, and for the 3rd (40.0 ± 4.59%) instar ofB. brassicae. Across the host species, there was no significant difference in parasitoid preference between the 3rd and 4th instars, while 1st and 2nd instars ofL. pseudobrassicaewere significantly more preferred than their counterparts (B. brassicae). Days to mummification among different instars of the same host was not significantly different when the parasitoid was reared onB. brassicae, whereas this was highest on the 2nd, 3rd and 4th instars ofL. pseudobrassicae. Number of mummies was also significantly different among the nymphal instars of both host species and between the two host species for the 1st and 2nd instars. In terms of body size, femaleD. rapaereared onL. pseudobrassicaewere significantly larger than those reared onB. brassicae. We discuss the findings in the context of laboratory mass rearing ofD. rapaeand its potential as a biological control agent for both aphid pest species.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-11-27T12:27:14Z No. of bitstreams: 1 Mauricea Fidelis de Santana.pdf: 1886645 bytes, checksum: 60f72f35c4eba792fa6dba0119735ae1 (MD5) Made available in DSpace on 2018-11-27T12:27:14Z (GMT). No. of bitstreams: 1 Mauricea Fidelis de Santana.pdf: 1886645 bytes, checksum: 60f72f35c4eba792fa6dba0119735ae1 (MD5) Previous issue date: 2018-02-23 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES The research aimed to determine the acaricidal potential of essential oils on Tetranychus urticae Koch and Neoseiulus californicus Koppert; to investigate the effect on T. urticae eggs; to evaluate the toxicity of oils on Lipaphis pseudobrassicae and Aphidius sp; evaluate the repellent effect and the instantaneous rate of growth. Tested oils: Citrus aurantifolia L., Citrus limon (L.) Burm. f., Citrus sinensis (L.) Osbeck., Lippia sidoides Cham., , Croton rhamnifolioides Pax & Hoffm. , Piper divaricatum G. Mayer, Croton grewioides Baill., positive control (Azamax) and control (water + 0.5% DMSO). All oils were toxic to T. urticae, with L. sidoides, P. divaricatum, C. sinensis, and C. limon the ones that presented better LC50. L. sidoides (5.26 μL/mL) and P. divaricatum (6.66 μL/mL) showed higher toxicity to T. urticae eggs. C. grewioides (163.30 μl/mL) and C. sinensis (143.54 μL/mL) provided lower mortality for N. californicus. For L. pseudobrassicae, C. grewioides (2.78 μL/20 mL) and C. rhamnifolioides (3.70 μL/20 mL) were more toxic (LC50). The oils were repellent at the highest concentrations in 24 and 48 hours, exeto C. sinensis. All oils reduced the instantaneous rate of growth, with P. divaricatum (150 μl/20 ml), C. limon (120 μL/20 ml) and Azamax (500 μL/20 ml) the smallest. P. divaricatum, C. limon and C. rhamnifolioides were the ones that reduced the number of nymphs, with 96.7%, 96.5% and 96.2%, respectively. For Aphidus sp in the development stage (mummy), the highest LC50s were 147.67 mL/20mL (L. sidoides); 51.34 mL/20mL (C. aurantifolia); 49.43 mL/20mL (C. rhamnifolioides); 41.66 mL/20 mL (C. sinensis) and 41.41 mL/20 mL (P. divaricatum). In the adult phase of Aphidus sp the LC50 were higher when compared to L. pseudobrassicae, ranging from 0.28 mL/mL (Croton grewioides) to 2.37 mL/mL (C. sinensis), with C. grewioides being 8.37 times more toxic to the parasitoid. A pesquisa objetivou: determinar o potencial acaricida de óleos essenciais sobre Tetranychus urticae Koch e Neoseiulus californicus Koppert; investigar o efeito sobre ovos do T. urticae; avaliar a toxicidade dos óleos sobre Lipaphis pseudobrassicae e Aphidius sp; avaliar efeito repelente e a taxa instantânea de crescimento. Óleos testados: Citrus aurantifolia L., Citrus limon (L.) Burm. f., Citrus sinensis (L.) Osbeck., Lippia sidoides Cham., Croton rhamnifolioides Pax & Hoffm., Piper divaricatum G. Mayer, Croton grewioides Baill., controle positivo (Azamax) e testemunha (água + DMSO 0,5%). Todos os óleos foram tóxicos para T. urticae, sendo L. sidoides, P. divaricatum, C. sinensis e C. limon os que apresentaram melhores CL50. L. sidoides (5,26 μl/mL) e P. divaricatum (6,66 μl/mL) apresentaram maior toxicidade para ovos de T. urticae. C. grewioides (163,30 μl/mL) e C. sinensis (143,54 μl/mL) proporcionaram menor mortalidade para N. californicus. Para L. pseudobrassicae, C. grewioides (2,78 μl/20 mL) e C. rhamnifolioides (3,70 μl/20 mL) foram mais tóxicos (CL50). Os óleos foram repelentes nas maiores concentrações em 24 e 48 horas, exeto C. sinensis. Todos os óleos reduziram a taxa instantânea de crescimento, sendo P. divaricatum (150 μl/20 mL), C. limon (120 μl/20 mL) e Azamax (500 μl/20 mL) os que mais reduziram. P. divaricatum, C. limon e C. rhamnifolioides foram os que mais reduziram o número de ninfas, com 96,7%, 96,5% e 96,2%, respectivamente. Para Aphidus sp na fase de desenvolvimento (múmia), as CL50 mais altas foram de 147,67 mL/20 mL (L. sidoides); 51,34 mL/20mL (C. aurantifolia); 49,43 mL/20 mL (C. rhamnifolioides); 41,66 mL/20mL (C. sinensis) e 41,41 mL/20 mL (P. divaricatum). Na fase adulta de Aphidus sp as CL50 foram mais altas quando comparadas às de L. pseudobrassicae, variando de 0,28 mL/mL (Croton grewioides) a 2,37 mL/mL (C. sinensis), sendo C. grewioides foi 8,37 vezes mais tóxico para o parasitoide.

In Senegal, vegetable production is an important area within the agricultural sector and contributes to improve the local diet. Damage caused by aphids in particular puts heavy pressure on vegetables production. Crop associations play an important role in controlling insect pests in some countries. The aims of this study include investigations into the diversity of aphid and parasitoid populations, and an evaluation of the effects of crop associations between cabbage and pak choi. The experimental design used is a randomized block with four treatments and two controls, that is cabbage and pak choi , and two crop associations, that is pak choin between cabbage rows, and pak choi around cabbage beds. Two aphid species, Myzus persicae, and Lipaphis pseudobrassicae are identified. The Braconidae Diaeretiella rapae (Mac Intosh) (Hymenoptera: Braconidae) is the only parasitoid met during the study. Myzus persicae (Sulzer) is more abundant than Lipaphis pseudobrassicae (Davis). Myzus persicae and L. pseudobrassicae were not controlled by the cabbage / pak choi associations. Aphids populations decreased during the heading phase of the cabbage. This preliminary study contributes to a better understanding of the potential use of crop associations to manage cabbage aphid populations in Senegal. Keywords : Crop associations, Myzus persicae, Lipaphis pseudobrassicae, Diaeretiella rapae, Brassicaceae, Senegal.

Three aphid species (Hemiptera: Aphididae) typically infest winter canola, Brassica napus L. (Brassicales: Brassicaceae), fields in central Oklahoma. They are the turnip aphid, Lipaphis pseudobrassicae (Davis), the cabbage aphid, Brevicoryne brassicae L., and the green peach aphid, Myzus persicae (Sulzer). The expansion of canola acreage in Oklahoma and the ubiquitous nature of aphid infestations in the crop indicate the need to understand the role of natural enemies in controlling aphid infestations. This study determined the parasitoid species attacking aphids in canola during the flowering through pod development growth stages, when aphid populations often build to the point requiring insecticide treatment. Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae) was the dominant parasitoid species. Individuals of all three aphid species were parasitized by D. rapae. Percent parasitism ranged from 0 to 45% depending on aphid species, field, and sample date. An Aphelinus sp. (Hymenoptera: Apheli...

Cosmopolitan pests such asBrevicoryne brassicae, Lipaphis pseudobrassicae, andMyzus persicae(Aphididae) cause significant damage to Brassicaceae crops. Assessment of the important biotic and abiotic factors that regulate these pests is an essential step in the development of effective Integrated Pest Management programs for these aphids. This study evaluated the influence of leaf position, precipitation, temperature, and parasitism on populations ofL. pseudobrassicae, M. persicae, andB. brassicaein collard greens fields in the Triângulo Mineiro region (Minas Gerais state), Brazil. Similar numbers ofB. brassicaewere found on all parts of the collard green plants, whereasM. persicaeandL. pseudobrassicaewere found in greatest numbers on the middle and lower parts of the plant. While temperature and precipitation were positively related to aphid population size, their effects were not accumulative, as indicated by a negative interaction term. AlthoughDiaeretiella rapaewas the main parasitoid of these aphids, hyperparasitism was dominant; the main hyperparasitoid species recovered from plant samples wasAlloxysta fuscicornis. Parasitoids seem to have similar distributions on plants as their hosts. These results may help predict aphid outbreaks and gives clues for specific intra-plant locations when searching for and monitoring aphid populations.

While the aphid Lipaphis pseudobrassicae (Davis) (Hemip.: Aphididae: Macrosiphini) is considered one of the preferred hosts of Diaeretiella rapae (McIntosh) (Hym.: Braconidae: Aphidiinae) in several parts of the world, field surveys in Uberlandia (Brazil) found parasitism of this aphid to not exceed 10%. This study sought to determine the cause of this low parasitism, as well as the effects of parasitism on the intrinsic growth rate of the aphid population. We evaluated parasitism, percentage emergence, developmental time, longevity, number of attacks and number of parasitoid larvae in L. pseudobrassicae and compared these to the same characteristics in Brevicoryne brassicae (L.) and Myzus persicae (Sulzer). The lowest percentage of parasitism was found in L. pseudobrassicae, followed by M. persicae and B. brassicae. The ratio between the number of parasitoid larvae and the number of ovipositions in L. pseudobrassicae ranged from 0.02 to 0.03, while, in B. brassicae, it was between 0.41 and 0.44 ...

Genetic and morphological differentiation of insect populations in relation to the use of different host plants is an important phenomenon that leads to ecological specialization. In this study, we describe variations in morphology, and in ecological and biological parameters of Lipaphis pseudobrassicae (Kaltenbach) clones associated with three host species of Cruciferae, Brassica juncea (L.) var. rai sarson Czern and Cross (brown mustard), Brassica campestris L. var. sarson Prain (yellow mustard), and Rorippa indica (L.) Hiern (wild herb). This study was aimed at obtaining evidence regarding phenotypic differentiation induced by, or associated with, the use of distinct host species. Ten morphological characters, 4 growth parameters and 8 biological functions were investigated in wingless aphids collected from plants of the three host species. Aphids from B. campestris and B. juncea clones were bigger in size, heavier in weight and showed higher growth rates and fecundity than the clones from R. indica . Between the two crop plants, clones from B. juncea showed significantly higher growth rates than the clones from B. campestris . Transfer of L. pseudobrassicae populations from B. campestris to B. juncea and R. indica and vice versa resulted in poor performance. Results indicate that the average phenotype of L. pseudobrassicae individuals inhabiting different host plant species differs as a consequence of the contrasting feeding environments the host species provide.

This study describes the fauna of predator insects, parasitoids and ants associated with aphids on kale (Brassica oleracea L. var. acephala D.C.) in organic system. The aphid was identified as Lipaphis pseudobrassicae Davis, and this is the first record of the species attacking kale in Brazil. Primary parasitism by Diaeretiella sp. and Aphidius sp. and hyperparasitism by Aphydencyrtus sp., Alloxysta sp., Pachyneuron sp. and Syrphophagus sp. were observed. Twenty species of Coccinellidae were collected, and eight of them were observed in adult and larval stages attacking the aphid: Hyperaspis (Hyperaspis) festiva Mulsant, which was the most abundant (72.5% of all predator insects obtained), Cycloneda sanguinea (L.), Eriopis connexa Germar, Coleomegilla maculata DeGeer, Hippodamia convergens Guerin, Heterodiomus sp., Scymnus (Pullus) sp.1 and Scymnus (Pullus) sp.2. Aphidophagous Syrphidae larvae collected on leaves ofkale infested by L. pseudobrassicae belong to the species Allograpta exotica (Wiedemann) and Ocyptamus gastrostactus (Wiedemann). Larvae and pupae of Syrphidae were parasitized by Pachyneuron sp., Syrphophagus sp. and Diplazon laetatorius Fabricius. Larvae of Chrysopodes sp. were observed feeding on L. pseudobrassicae. Species of ants associated with the colony of this aphid were Ectatomma quadridens Fabricius and Pheidole sp.

Seasonal dispersal and diversity of aphid species were monitored on pepper farms in St. Catherine, Jamaica throughout 1998 and 1999 to identify the most likely vectors of tobacco etch virus (TEV) in pepper fields. Flight activity was monitored weekly on five farms using water pan traps. More than 30 aphid species were identified, 12 of which are new records for Jamaica. Ninety-two percent of the aphids captured from October 1998 through July 1999 belonged to only seven of the >30 species identified. Of these seven species, Aphis gossypii Glover and those in the Uroleucon ambrosiae (Thomas) complex comprised more than two-thirds of the total. Five known vectors of TEV were captured: A. gossypii, Aphis craccivora Koch, Aphis spiraecola Patch, Myzus persicae (Sulzer), and Lipaphis pseudobrassicae Davis. Generally, more aphids were collected from mid-September through mid-May than from mid-May through mid-September. The influence that rainfall and temperature had on periods of aphid flight activity a...

In southern Korea, the two aphid species, Myzus pessicae (Sulzer) and Lipaphis pseudobrassicae (Davis), had been known to have sexual phase to produce hibernating eggs on their alternate hosts. However, we have frequently found that they were still alive in the parthenogenetic form even in below freezing conditions in winter. This study had been focused on verifying the possibility of overwintering of the two important aphid species in the parthenogenetic morph, by comparing the population density changes within greenhouse and open field condition. In greenhouse condition, though not heated, both species successfully continued reproducing in a parthenogenetic form. In open field, L. pseudobrassicae successfully survived and reproduced on chinese cabbage and spinach even below freezing temperatures. M. persicae were also able to survive in the winter but not as much capability of reproduction as L. pseudobrassicae. This study provided the evidence that the aphid infestations in greenhouse can be mostly from overwintering populations in the parthenogenetic morph in southern greenhouse area of Korea.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais Survival, development time, fertility, behavior, longevity, and other biological features of Diaeretiella rapae (McIntosh) are conditioned by temperature and host. However, studies of host quality changes due to its temperature adaptability have not been performed yet. Therefore, this study evaluated the adaptability of Lipaphis pseudobrassicae (Davis) and Myzus persicae (Sulzer) to high temperature and its effect on the quality of these aphids as hosts and on the thermal threshold of D. rapae. The biology of the aphids was compared at 19 and 28°C, using 60 replicates per temperature, to determine the adaptability of the host to temperature. Changes in host quality as a function of different temperatures were determined by maintaining a female of D. rapae for one hour in a Petri dish containing thirty 2nd instar nymphs of one host species for oviposition. The plates containing the parasitized aphids were transferred to 16, 19, 22, 25, 28 or 31°C to evaluate the biological features of the parasitoid and the hind tibia length of the mummy and females of D. rapae, using 10 replicates per host and temperature. Thermal threshold of D. rapae was determined using the development time data. No differences in the biological features of L. pseudobrassicae and M. persicae were observed at 19°C. Reproductive period and longevity of aphids also did not differ at 28°C; however, development time, rate of immature survival and total fecundity rates were greater in L. pseudobrassicae than in M. persicae. Also, the percentage of emergence and total viability rate of D. rapae were greater in L. pseudobrassicae. The development time of D. rapae in L. pseudobrassicae was shorter than in M. persicae at 28 and 31°C for females and at 31 °C for males. The thermal threshold of D. rapae was 6.38 and 3.33°C for females and 4.45 and 3.63ºC for males developed on L. pseudobrassicae and M. persicae, respectively. The hind tibia length of mummified M. persicae was greater than in L. pseudobrassicae at all temperatures. The hind tibia length of the parasitoid was greater at 25 and 28°C when reared on L. pseudobrassicae than on M. persicae. The host L. pseudobrassicae showed better adaptation than M. persicae to elevated temperatures, which resulted in better quality as host for D. rapae at temperatures of 28 and 31°C and higher base temperature when the parasitoid developed in the L. pseudobrassicae than in M. persicae. The adaptation of the host to high temperatures is determinant for the host quality for the parasitoid in that same climatic condition. Sabe-se que a sobrevivência, desenvolvimento, fertilidade, comportamento, longevidade, entre outros aspectos de Diaeretiella rapae (Mc Intosh) são condicionados pela temperatura e pelo hospedeiro. Entretanto, estudos de mudanças na qualidade do hospedeiro, em função de sua adaptabilidade a temperatura, ainda não foram realizados. Assim, o objetivo desse trabalho foi avaliar a adaptabilidade de Lipaphis pseudobrassicae (Davis) e Myzus persicae (Sulzer) à temperatura elevada, e determinar as alterações, tanto na qualidade desses hospedeiros, quanto na temperatura base de D. rapae, em função da adaptabilidade do hospedeiro à temperatura. Para a determinação da adaptabilidade à temperatura dos hospedeiros, a biologia dos pulgões foi comparada nas temperaturas de 19 e 28ºC, utilizandose 60 repetições por temperatura. Para verificar a mudança na qualidade do hospedeiro, em função da temperatura, uma fêmea de D. rapae foi mantida para ovipositar por uma hora em placa de Petri, contendo 30 ninfas de 2º instar de uma das espécies do pulgão hospedeiro. As placas, contendo os pulgões parasitados, foram mantidas nas temperaturas de 16, 19, 22, 25, 28 e 31°C, para avaliar a biologia do parasitoide e o tamanho da tíbia posterior da múmia e das fêmeas de D. rapae. Foram utilizadas 10 repetições por temperatura para cada hospedeiro. Com os dados do período de desenvolvimento, calculou-se a temperatura base de D. rapae. Na temperatura de 19°C não houve diferença entre as características analisadas de L. pseudobrassicae e M. persicae. A 28ºC, o período reprodutivo e a longevidade dos pulgões também não apresentaram diferença, já o período de desenvolvimento, a sobrevivência de imaturos e a fecundidade total foram maiores em L. pseudobrassicae do que em M. persicae. A porcentagem de emergência e a viabilidade total de D. rapae foram maiores em L. pseudobrassicae. O período de desenvolvimento de D. rapae foi menor em L. pseudobrassicae do que em M. persicae a 28 e 31°C para fêmeas, e a 31°C para os machos do parasitoide. A temperatura base de D. rapae foi 6,38 e 3,33°C para as fêmeas, e de 4,45 e 3,63ºC para machos desenvolvidos em L. pseudobrassicae e em M. persicae, respectivamente. O tamanho de M. persicae mumificados foi maior do que L. pseudobrassicae em todas as temperaturas. O tamanho da tíbia do parasitoide nas temperaturas de 25 e 28°C foi maior, quando desenvolvido em L. pseudobrassicae, do que em M. persicae. O hospedeiro L. pseudobrassicae apresentou maior adaptação que M. persicae à temperaturas elevadas, o que acarretou em maior qualidade como hospedeiro de D. rapae nas temperaturas de 28 e 31ºC e na maior temperatura base do parasitoide, quando desenvolvido em L. pseudobrassicae do que em M. persicae. A adaptação do hospedeiro às temperaturas elevadas é um fator determinante de sua qualidade para o parasitoide nessas condições climáticas. Mestre em Agronomia

Fundação de Amparo a Pesquisa do Estado de São Paulo The aphids Brevicoryne brassicae (Linné), Lipaphis pseudobrassicae (Davis) and Myzus persicae (Sulzer) are cosmopolitan pests that cause significant damage in the Brassicaceae family plants. The determination of which biotic and abiotic factors are most important in regulating pests is very important in Integrated Pest Management programs. Thus, this study evaluated the influence of leaf position, rainfall, temperature, parasitism and hyperparasitism in populations of L. pseudobrassicae, M. persicae and B. brassicae in kale, and analyzed which species is the most abundant. The experiment was conducted in field conditions, in Uberlândia MG, from August 2005 to March 2006 and October 2006 to January 2008. The quantification of aphids was done weekly, removing three leaves of each plant part (top, middle and bottom), totaling 101 samples. The leaves were taken to the laboratory for counting live and mummified aphids. Mummified aphids were kept in eppendorf tubes for 30 days and the identification of emerged parasitoids and hyperparasitoids was done. Data analysis was performed by three linear models relating the abundance of aphids and environmental factors. The most abundant species that could be considered the main aphid pests of kale in this region are B. brassicae and L. pseudobrassicae. Furthermore, similar number of B. brassicae was found in the apical portion of kale and it the other portions, differently from the two other species, which were found in greater number in the middle and bottom portions. The combined effect of increased temperature and rainfall had a negative effect on B. brassicae population. As B. brassicae was the only species to exploit intensively the apical plant part, it is concluded that its population was reduced by the mechanical effects of rainfall. Diaeretiella rapae (M Intosh) was the only emerged species of parasitoid on the family Braconidae and Alloxysta fuscicornis (Hartig) was the main hyperparasitoid species. The population of the three aphid species was influenced by the number of emerged hyperparasitoids, showing that this is the key factor regulating the aphids populations. Parasitism was affected only by the population of B. brassicae. This fact can be explained by its greater abundance, small population of M. persicae and low parasitism in L. pseudobrassicae. The relationship of parasitism in the three species with temperature and rainfall was similar to that found in the population of B. brassicae and climatic factors. This indicates that parasitism in the three species appears to have been affected by the most parasitized host, in this case, B. brassicae. Parasitism was low in L. pseudobrassicae (0.8% on average), intermediate in M. persicae (8.5% on average) and high in B. brassicae (16% on average). The low parasitism in L. pseudobrassicae could be a key factor for its pest status of crucifers in the survey region Em plantas da família Brassicaceae, os afídeos Brevicoryne brassicae (Linné), Lipaphis pseudobrassicae (Davis) e Myzus persicae (Sulzer) são pragas cosmopolitas que causam danos significativos. Determinar quais são os fatores bióticos e abióticos mais importantes na regulação de pragas é de grande importância em programas de Manejo Integrado. Desta forma, neste trabalho foi avaliada a influência da posição da folha, precipitação, temperatura, parasitismo e hiperparasitismo na população de L. pseudobrassicae, M. persicae e B. brassicae em couve, além de avaliar qual é a espécie mais abundante. Os experimentos foram instalados em campo, na cidade de Uberlândia MG, no período de agosto de 2005 a março de 2006 e outubro de 2006 a janeiro de 2008. A quantificação dos pulgões foi realizada semanalmente, retirando-se três folhas, uma de cada parte da planta (apical, mediana e inferior), totalizando 101 coletas. As folhas foram levadas ao laboratório para a contagem de pulgões vivos (sadios) e mumificados (parasitados). As múmias foram mantidas em tubos tipo eppendorf por até 30 dias e foram feitas as identificações dos parasitóides e hiperparasitóides emergidos. A análise dos dados foi feita por três modelos lineares, relacionando a abundância dos pulgões e os fatores ambientais analisados. As espécies mais abundantes e que podem ser consideradas os principais pulgões pragas da couve na região foram B. brassicae e L. pseudobrassicae. Além disso, foi encontrado número semelhante de B. brassicae na porção apical da planta quando comparado com as outras porções, diferentemente das outras duas espécies, as quais foram encontradas em maior número nas folhas medianas e inferiores. O efeito conjunto do aumento da temperatura e da precipitação foi negativo para a população de B. brassicae. Como B. brassicae foi a única espécie a explorar intensamente a região apical da planta, conclui-se que sofreu maior efeito mecânico da chuva, o que reduziu sua população. Diaeretiella rapae (M Intosh) foi a única espécie de parasitóide da família Braconidae emergida e Alloxysta fuscicornis (Hartig) a principal espécie de hiperparasitóide. A população das três espécies de pulgões foi influenciada pelo número de hiperparasitóides emergidos, mostrando ser este um fator chave na regulação da população dos pulgões. Já o parasitismo foi influenciado apenas pela população de B. brassicae. Este fato pode ser explicado pela maior ocorrência de B. brassicae, população reduzida de M. persicae e baixo parasitismo em L. pseudobrassicae. A relação do parasitismo nas três espécies com a temperatura e a precipitação foi semelhante àquela encontrada para a população de B. brassicae e os fatores climáticos. Isto indica que o parasitismo nas três espécies parece ter recebido influência do hospedeiro mais utilizado pelo parasitóide, no caso, B. brassicae. O parasitismo foi baixo em L. pseudobrassicae (0,8% em média), intermediário em M. persicae (média de 8,5%) e alto em B. brassicae (16% em média). O baixo parasitismo em L. pseudobrassicae pode ser um fator chave para o seu status de praga das brássicas na região de estudo. Mestre em Agronomia

High volume uses of conventional pesticides end up contaminating ground water and soil with highly toxic pesticide residues. Nano‐pesticides and nano‐encapsulated pesticides are expected to reduce the volume of application and slow down the fast release kinetics. Nature inspired Diatomaceous Earth (DE) were used to design and fabricate a variety of 15–50 nm size range hydrophilic, hydrophobic and lipophilic SiO2, ZnO, TiO2 (anatase and rutile) and Al2O3 (α and γ) nanoparticles (Nanocides). Mustard aphid (Lipaphis pseudobrassicae) causes devastations on oil producing mustard crops every year in Asia. Due to several distinct adaptations present in insects, tools of Genetics, Plant breeding, Biochemistry and Transgenic technology have not been so far effective. Nano Al2O3 and amorphous nano SiO2 were found to be highly effective and nano TiO2 was moderately effective against L. pseudobrassicae. But nano Al2O3 has deleterious effects on plant growth, whereas non crystalline nano SiO2 has no such adverse effect on plants. Here we present the first report showing that nanocides, especially nano SiO2 can be effectively used to control insect pests.

Brevicoryne brassicae (Linnaeus), Lipaphis pseudobrassicae (Davis), Acyrthosiphon kondoi (Shinji), Aphis craccivora (Koch) and Rhopalosiphum padi (Linnaeus) are among the most important aphid pests in Australian broadacre systems. In this study a leaf-dip method was used to assay pirimicarb, dimethoate, α-cypermethrin and imidacloprid against field populations collected from Victoria, New South Wales, South Australia, Western Australia and Queensland. This research established toxicity baseline data that will be important for future monitoring of insecticide responses in broadacre crops. It also provided an opportunity to identify any chemical tolerance that may be evolving in these pests. Acyrthosiphon craccivora populations showed differences in their responses to dimethoate, pirimicarb and imidacloprid (but not to α-cypermethrin), indicating possible shifts in field sensitivity to these three chemicals. Rhopalosiphum padi had the lowest sensitivity to all insecticides tested, with two populations (collected from South Australia and Queensland) showing less than 100% mortality when tested at the field rate of α-cypermethrin. There were few differences in insecticide responses between populations of the other three species. Continued screening of A. craccivora and R. padi populations is needed to fully assess the current status of tolerance among field populations and to strengthen resistance management tactics.

WOS: 000232676200013, PubMed ID: 16075408, Essential oils from 23 species of plants comprising 14 genera and 4 plant families were obtained by Clevenger-type water distillation. The major compounds in these essential oils were identified with GC-MS and their insecticidal activity against adult turnip aphids, Lipaphis pseudobrassicae (Davis), tested with dosage-mortality bioassays. We examined mortality only for viviparous adults because sizeable aphid populations on crucifer (Brassicaceae) hosts are largely produced by these wingless, parthenogenic females. Twenty-two of the oils were directly applied to aphid females in randomized blocks at concentrations of 0.0, 1.0, 2.5, 5.0 and 10.0 mg ml(-1). Essential oils mixed with a non-toxic emulsifying agent, dimethyl sulfoxide (DMSO), more easily penetrated the waxy insect cuticle. Probit analysis and LC50 at three different exposures showed aphids were quickly incapacitated and killed by aliphatic aldehydes, phenols and monocyclic terpenes contained in Bifora and Satureja oils and at applied concentrations as low as 0.3 to 1.0 mg ml(-1). Only enough Pimpinella isaurica oil and its three phenylpropanoid fractions were available for testing at a single concentration of 10 mg ml(-1). We could not spare any additional P. isaurica oil for testing at other concentrations. Phenylpropanoids isolated from P. isaurica oil when recombined or left naturally blended in the oil were highly bioactive against L. pseudobrassicae at 10 mg ml(-1)

The aphids Lipaphis pseudobrassicae (Davis) and Myzus persicae (Sulzer) (Hemiptera: Aphididae) are important Brassicaceae pests, occurring worldwide and causing significant damage to crops. Interspecific variations in the resistance to natural enemies can potentially impact the interaction among aphid populations. Here we evaluated the hypothesis of associational resistance by determining if the presence of resistant aphids (L. pseudobrassicae) reduces the rate of parasitism by Diaeretiella rapae (McIntosh) on non-resistant aphids (M. persicae). The experiment was conducted using collard green plants infested with M. persicae and L. pseudobrassicae either resistant or susceptible to D. rapae. The percentage of parasitism by D. rapae was greater on L. pseudobrassicae in the susceptible than in the resistant treatment, but parasitism rates on M. persicae did not differ between the treatments. There was no difference in average growth rate between M. persicae and susceptible L. pseudobrassicae populations, but resistant L. pseudobrassicae had greater growth rate than M. persicae. These results suggest that over a short period of time the presence of resistant L. pseudobrassicae does not affect the rate of parasitism by D. rapae on M. persicae. Keywords: Aphid, Aphididae, Aphidiinae, Competition mediated by parasitoid, Indirect resistance

SummarySeven aphids were tested for their ability to transmit 3 viruses of papaya. Mild mosaic virus (MMV) was transmitted by Aphis craccivora, A. gossypii and Myzus persicae. Distortion ringspot virus (DRV) was transmitted by A. nerii, Lipaphis pseudobrassicae and M. persicae. Ringspot virus (RSV) was transmitted only by M. persicae. Specificity of transmission by the aphid vectors of MMV and DRV was demonstrated. A. craccivora, A. nerii and L. pseudobrassicae are reported as new vectors of these viruses.