The Experts below are selected from a list of 378 Experts worldwide ranked by ideXlab platform

Kamil Karut - One of the best experts on this subject based on the ideXlab platform.

  • effect of cold storage on performance of Eretmocerus Mundus larval parasitoid of bemisia tabaci in a conventional tomato growing greenhouse
    Crop Protection, 2020
    Co-Authors: Cengiz Kazak, İsmail Döker, Mete M Karaca, Kamil Karut
    Abstract:

    Abstract Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest that causes economic losses in agricultural production systems, including greenhouses. Chemical control is the main control method against B. tabaci; biological control practices, however, have also been applied against this pest, especially in greenhouse production systems. Due to its parasitism potential and adaptation to environmental conditions of the Mediterranean region, Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) is considered one of the most successful biological control agents of B. tabaci. In mass production, having adequate numbers of natural enemies is critical for the augmentative biological control programs. Therefore, this study was conducted with the aim of evaluating the efficacy of stored indigenous Er. Mundus on B. tabaci under greenhouse conditions. In storage experiments, red-eyed Er. Mundus pupae were stored separately for 4, 8 and 12 days at 5 and 10 °C with 45 ± 5% RH conditions. The most suitable storage duration and temperature were determined as 8 days and 10 °C for the greenhouse release experiments. In the greenhouse experiments, the treatments consisted of B. tabaci release (control), stored and unstored Er. Mundus releases in the Spring of 2015 and 2016 growth seasons. For the evaluation of population development of whitefly and the parasitoid, leaf samples were taken at five-day intervals. In both years, similar parasitism fluctuations were detected in stored and unstored parasitoid-released treatments, wherein initially-lower parasitism rates showed a dramatic increase at later sampling dates. In general, statistical parasitism rates of stored and unstored Er. Mundus populations were found in the same group for 2015 and 2016. The results showed that storage of the parasitoid did not have a negative effect on its parasitism ability, and eight-day-stored native strain of Er. Mundus could be used successfully in the biological control of B. tabaci in greenhouse-grown tomato plants.

  • potential of single and combined releases of Eretmocerus Mundus and macrolophus melanotoma to suppress bemisia tabaci in protected eggplant
    Biological Control, 2018
    Co-Authors: Kamil Karut, Cengiz Kazak, İsmail Döker
    Abstract:

    Abstract The parasitoid Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) and the predator Macrolophus melanotoma (Costa) (Hemiptera: Miridae) are two important natural enemies of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) which are distributed throughout the Mediterranean region. Both natural enemies are used in the biological control of B. tabaci. In this study, the success of single and combined release of Er. Mundus and M. melanotoma against B. tabaci on eggplant was determined in 3 × 3 × 2.5 m net cages established in a greenhouse during the period of 2009 and 2010. Four different experiments were conducted; Er. Mundus single release, M. melanotoma single release, Er. Mundus + M. melanotoma combined release, and B. tabaci single release (control). For the evaluation of population development of whitefly and the parasitoid, leaf samples were taken at five day intervals. In addition, numbers of the predatory insects were calculated by using visual control method on whole parts of 15 plants in different treatments. Results of this study showed that the number of whiteflies was the highest in the control treatment, followed by the M. melanotoma (single), Er. Mundus (single) and Er. Mundus + M. melanotoma (combined) treatments, in both years. Low B. tabaci populations were observed in combined release treatments and the weekly mean density of immature whiteflies never exceeded 3.99 per cm2 leaf area. M. melanotoma was not successful against B. tabaci when released alone. However, it does contribute to the success of biological control of B. tabaci when released with Er. Mundus. In light of these results, we suggest the combined release of Er. Mundus and M. melanotoma for effective control of whitefly in greenhouse grown eggplants.

  • bemisia tabaci genn hemiptera aleyrodidae nin farkli kultur bitkilerinde Eretmocerus Mundus mercet mercet hymenoptera aphelinidae tarafindan parazitlenmesi
    Türkiye Biyolojik Mücadele Dergisi, 2016
    Co-Authors: Amir Abdullahi Yousif Malık, Kamil Karut
    Abstract:

    Bu calismada Cukurovada yetistirilen bazi kultur bitkilerinde (hiyar, pamuk, patlican ve soya) Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae)nin Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) tarafindan parazitlenme durumunun kafes denemeleri ile belirlenmesi amaclanmistir. Denemeler, Cukurova Universitesi, Ziraat Fakultesi, Bitki Koruma Bolumu Arastirma ve Uygulama arazisinde bulunan yari kontrollu cam seralarda 2009 ve 2010 yillarinda yurutulmustur. Denemeler tercihli ve tercihsiz olacak sekilde, 4 tekrarli olarak tesaduf bloklari deneme deseninde kurulmustur. Tercihli testte, kafes icerisine hiyar, pamuk, patlican ve soya bitkilerinin her birinden birer adet yerlestirilmistir. Tercihsiz testte ise kafes icerisine ayni bitkiden 4 adet yerlestirilmistir. Bitkilerin 3. yapragina, klips kafesler yardimiyla 40 adet ergin beyazsinek salinmistir. Beyazsinek larvalari 2. ve 3. doneme geldiklerinde her kafese 12 adet ergin disi parazitoid salinmistir. Parazitoid salimindan 10–12 gun sonra yapilan sayimlarla parazitli ve parazitli olmayan B. tabaci larvalari kaydedilmistir. Tercihli testte en yuksek parazitlenme orani % 53.4 ile hiyar bitkisinde elde edilmis, bunu % 38.9 ve % 30.3 ile sirasiyla soya ve patlican bitkilerinde elde edilen oranlar izlemistir. Tercihli testte en dusuk parazitlenme orani % 6.9 ile pamuk bitkisinden elde edilmistir. Tercihsiz testte ise en yuksek parazitlenme orani % 26.6 ile pamuk bitkisinde elde edilmis, bunu % 21.9 ve % 18.5 ile hiyar ve soya bitkilerinde elde edilen degerler izlemistir. Tercihsiz testte en dusuk parazitlenme orani % 9.5 ile patlican bitkisinde elde edilmistir.

  • efficacy of Eretmocerus Mundus hymenoptera aphelinidae and macrolophus melanotoma aganist bemisia tabaci hemiptera miridae aleyrodidae in protected tomato
    Turkish journal of entomology, 2016
    Co-Authors: Kamil Karut, Cengiz Kazak, İsmail Döker, Amir Abdullahi Yousif Malık
    Abstract:

    Bu calismada, Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) ve Macrolophus melanotoma (Costa) (Hemiptera: Miridae)’nin Bemisia tabaci (Gennadius) (Hemiptera: (Aleyrodidae) ’ ye karsi ayri ayri ve bir arada etkinlikleri cam sera icerisine yerlestirilmis tul kafesler icerisinde yetistirilen domates bitkileri uzerinde belirlenmistir. Calisma 2009 ve 2010 yillarinda bahar uretim sezonunda gerceklestirilmistir. Denemeler, tek B. tabaci (kontrol), tek M . melanotoma , tek E . Mundus ve M . melanotoma + E . Mundus bir arada olmak uzere 4 farkli uygulama ve 3 tekrarli (kafes) olarak kurulmustur. B . tabaci , E . Mundus ve M . melanotoma , her iki yilda da bitki basina sirasiyla 20, 6 ve 0.5 adet olacak sekilde salinmistir. Deneme suresince B . tabaci ve E . Mundus populasyon gelisimlerini belirlemek amaciyla haftalik araliklarla yaprak ornekleri alinmistir. Ayrica, her kafeste rastgele secilen 15 bitkinin tamaminda gozle kontrol yontemi kullanilarak M . melanotoma ’nin nimf ve ergin donemleri sayilmistir. Calismada tek parazitiot salimi yapilan kafeslerde ergin oncesi B . tabaci yogunluklari 2009 ve 2010 yillarinda sirasiyla 0.56 adet/cm 2 ve 2.82 adet/cm 2 ’nin uzerine cikamamis ve kontrol ile tek avci salimi yapilan kafeslerden dusuk bulunmustur. En yuksek B . tabaci ergin oncesi yogunlugu ise ayni yillarda 51.10 ve 31.12 adet/cm 2 ile kontrol uygulamalarindan elde edilmistir. Tek basina M . melanotoma uygulamasi, kontrolle karsilastirildiginda beyazsinek yogunlugunda istatistiksel olarak onemli dususe sebep olsa da E . Mundus kadar basarili olamamistir. Bu calismada elde edilen sonuclar, Turkiye’de domates seralarinda E . Mundus ve M . melanotom a’nin birlikte kullanildigi biyolojik mucadele yonteminin B . tabaci populasyonunu hic insektisit uygulamaya gerek kalmadan basariyla baski altina alabildigini gostermistir.

  • Efficacy of Eretmocerus Mundus (Hymenoptera: Aphelinidae) and Macrolophus melanotoma aganist Bemisia tabaci (Hemiptera: Miridae, Aleyrodidae) in protected tomato
    2016
    Co-Authors: Kamil Karut, Cengiz Kazak, İsmail Döker, Amir Abdullahi Yousif Malık
    Abstract:

    Bu çalışmada, Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) ve Macrolophus melanotoma (Costa) (Hemiptera: Miridae)'nın Bemisia tabaci (Gennadius) (Hemiptera: (Aleyrodidae)'ye karşı ayrı ayrı ve bir arada etkinlikleri cam sera içerisine yerleştirilmiş tül kafesler içerisinde yetiştirilen domates bitkileri üzerinde belirlenmiştir. Çalışma 2009 ve 2010 yıllarında bahar üretim sezonunda gerçekleştirilmiştir. Denemeler, tek B. tabaci (kontrol), tek M. melanotoma, tek E. Mundus ve M. melanotoma+E. Mundus bir arada olmak üzere 4 farklı uygulama ve 3 tekrarlı (kafes) olarak kurulmuştur. B. tabaci, E. Mundus ve M. melanotoma, her iki yılda da bitki başına sırasıyla 20, 6 ve 0.5 adet olacak şekilde salınmıştır. Deneme süresince B. tabaci ve E. Mundus popülasyon gelişimlerini belirlemek amacıyla haftalık aralıklarla yaprak örnekleri alınmıştır. Ayrıca, her kafeste rastgele seçilen 15 bitkinin tamamında gözle kontrol yöntemi kullanılarak M. melanotoma'nın nimf ve ergin dönemleri sayılmıştır. Çalışmada tek parazitiot salımı yapılan kafeslerde ergin öncesi B. tabaci yoğunlukları 2009 ve 2010 yıllarında sırasıyla 0.56 adet/cm2 ve 2.82 adet/cm2'nin üzerine çıkamamış ve kontrol ile tek avcı salımı yapılan kafeslerden düşük bulunmuştur. En yüksek B. tabaci ergin öncesi yoğunluğu ise aynı yıllarda 51.10 ve 31.12 adet/cm2 ile kontrol uygulamalarından elde edilmiştir. Tek başına M. melanotoma uygulaması, kontrolle karşılaştırıldığında beyazsinek yoğunluğunda istatistiksel olarak önemli düşüşe sebep olsa da E. Mundus kadar başarılı olamamıştır. Bu çalışmada elde edilen sonuçlar, Türkiye'de domates seralarında E. Mundus ve M. melanotoma'nın birlikte kullanıldığı biyolojik mücadele yönteminin B. tabaci popülasyonunu hiç insektisit uygulamaya gerek kalmadan başarıyla baskı altına alabildiğini göstermiştirIn this study, the success of single and combined releases of Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae) and Macrolophus melanotoma (Costa) (Hemiptera: Miridae) aganist Bemisia tabaci (Gennadius) (Hemiptera: (Aleyrodidae) were determined on greenhouse grown tomato plants that planted in net cages. The studies were conducted in spring growing seasons of the years 2009 and 2010. Experiments were established with four different treatments namely B. tabaci single (control), M. melanotoma single, E. Mundus single, M. melanotoma+E. Mundus combined releases with 3 replications (cage). In both years the B. tabaci, E. Mundus and M. melanotoma were released 20, 6 and 0.5/plants, respectively. In order to determine population development of B. tabaci and E. Mundus, leaf samples were taken at weekly intervals. In addition, numbers of immature and adult stages of M. melanotoma were counted by using visual control method on whole parts of 15 plants in each predator released cages. In the parasitoids released cages, the mean numbers of immature B. tabaci were not reached higher than 0.56 and 2.82 individuals/cm2 in 2009 and 2010, respectively. These numbers were found to be lower than control and M. melanotoma single releases. The highest immature B. tabaci numbers were determined in control treatments as 51.10 and 31.12 per cm2 in both years. Although M. melanotoma single release treatment reduced the whitefly numbers statistically compared to control treatment, it was not succeed as much as E. Mundus. The results of this study showed that B. tabaci populations could be control without any insecticide treatments in greenhouse by using biological control programs that will be consisted with E. Mundus and M. melantoma in Turke

Elisa Viñuela - One of the best experts on this subject based on the ideXlab platform.

  • Efficacy of a Long Lasting bifenthrin‐treated net against horticultural pests and its compatibility with the predatory mite Amblyseius swirskii and the parasitic wasp Eretmocerus Mundus.
    Pest management science, 2017
    Co-Authors: M Fernandez, Pilar Medina, Alberto Fereres, Ignacio Colomer, Pedro Del Estal, Elisa Viñuela
    Abstract:

    BACKGROUND The insecticide-treated nets (ITNs) are being investigated lately for their use in agriculture. Depending on the insecticide, the hole size and the way they are produced, these nets can target different pests and therefore they could be interesting options to be used in Integrated Pest Management (IPM). As the information on their compatibility with beneficial fauna is practically negligible, in this work we have tested the compatibility of an experimental bifenthrin long lasting insecticide-treated net (LLITN) with Amblyseius swirskii and Eretmocerus Mundus, important natural enemies of whiteflies and thrips, under laboratory, semi-field and commercial greenhouses. RESULTS In the laboratory, the treated-net was very deleterious to adults of both natural enemies, after 72-h exposure. However, in choice tests with Y-tubes, both natural enemies were neither attracted nor repelled by the treated-net and no short-term mortality was detected in individuals that had crossed it. No deleterious effects on the E. Mundus beneficial capacity were detected in semi-field trails. In field trials, the LLITN proved to be compatible with A. swirskii while decreasing pest densities. CONCLUSIONS Bifenthrin LLITN studied could be a valuable method for reducing pest population infestations in IPM programs while being compatible with biocontrol agents.

  • efficacy of a long lasting bifenthrin treated net against horticultural pests and its compatibility with the predatory mite amblyseius swirskii and the parasitic wasp Eretmocerus Mundus
    Pest Management Science, 2017
    Co-Authors: M Fernandez, Pilar Medina, Alberto Fereres, Elisa Viñuela, Ignacio Colomer, Pedro Del Estal
    Abstract:

    BACKGROUND The insecticide-treated nets (ITNs) are being investigated lately for their use in agriculture. Depending on the insecticide, the hole size and the way they are produced, these nets can target different pests and therefore they could be interesting options to be used in Integrated Pest Management (IPM). As the information on their compatibility with beneficial fauna is practically negligible, in this work we have tested the compatibility of an experimental bifenthrin long lasting insecticide-treated net (LLITN) with Amblyseius swirskii and Eretmocerus Mundus, important natural enemies of whiteflies and thrips, under laboratory, semi-field and commercial greenhouses. RESULTS In the laboratory, the treated-net was very deleterious to adults of both natural enemies, after 72-h exposure. However, in choice tests with Y-tubes, both natural enemies were neither attracted nor repelled by the treated-net and no short-term mortality was detected in individuals that had crossed it. No deleterious effects on the E. Mundus beneficial capacity were detected in semi-field trails. In field trials, the LLITN proved to be compatible with A. swirskii while decreasing pest densities. CONCLUSIONS Bifenthrin LLITN studied could be a valuable method for reducing pest population infestations in IPM programs while being compatible with biocontrol agents.

  • are mummies and adults of Eretmocerus Mundus hymenoptera aphelinidae compatible with modern insecticides
    Journal of Economic Entomology, 2015
    Co-Authors: M Fernandez, Pilar Medina, Alberto Fereres, Guy Smagghe, Elisa Viñuela
    Abstract:

    The parasitic wasp Eretmocerus Mundus (Mercet) is an important natural enemy of the widespread key pest Bemisia tabaci (Gennadius). The toxicity of 11 modern insecticides applied at their maximum field recommended rate in Spain was tested in two life stages of E. Mundus: adults and mummies. Laboratory and persistence tests were conducted and effects assessed not only in terms of mortality but on reproductive performance as well. Some insecticides caused the same effect to both life stages: flubendiamide, methoxyfenozide, spiromesifen, and flonicamid were harmless, while spinosad and sulfoxaflor were harmful. The last two insecticides cannot be used jointly with E. Mundus under any condition because they were highly persistent. The rest of tested insecticides (spirotetramat, metaflumizone, deltamethrin, abamectin, and emamectin) caused some direct mortality to one or both life stages and/or affected reproduction of the parasitic wasp and their harmful effect in the field ranged from short lived (metaflumizone and spirotetramat) to slightly persistent (emamectin) and to moderately persistent (abamectin and deltamethrin). Therefore, they could be recommended for use in integrated pest management programs together with the natural enemy if appropriate safety intervals after insecticide application are observed.

  • The effect of emamectin benzoate on two parasitoids, Aphidius colemani Viereck (Hymenoptera: Braconidae) and Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae), used in pepper greenhouses
    Spanish Journal of Agricultural Research, 2012
    Co-Authors: Paloma Bengochea, Pilar Medina, Fermín Amor, M. Cánovas, Pedro Vega, Rui Correia, F. García, M. Gómez, Flor Budia, Elisa Viñuela
    Abstract:

    Aphidius colemani Viereck and Eretmocerus Mundus Mercet are two of the most representative parasitoids used as biological control agents (BCAs) primarily against aphids and whiteflies, respectively. The macrocyclic lactone emamec tin benzoate (4”-deoxy-4”-methylamino-4”-epiavermectin B1 benzoate), an insecticide derived from the avermectin family of natural products, is being developed for controlling lepidopteran pests on a range of vegetable and other crops in Europe. The objective of this study was to determine the level of compatibility of the insecticide emamectin benzoate with A. colemani and Er. Mundus, which are used in greenhouse vegetable production in southeastern Spain. Trials were conducted under commercial greenhouses to assess the effect of 1-, 3- and 7-day-old residues of emamectin benzoate at the highest recommended concentration (14.25 mg L –1 ) on the population dynamics of the parasitoids. A. colemani, although released at higher rates than those commercially used, only reached low densities (less than 1 adult per plant), without significant differences among control plots and those treated with the compound. On the contrary, a natural infestation by native Er. Mundus occurred and this trial can be considered as a direct-spray trial. Neither adult population nor parasitism on emamectin benzoate treated plots differed significantly from the control. Therefore, emamectin benzoate residues did not diminish A. colemani population densities if applied 1 day before the

Marcela Ines Schneider - One of the best experts on this subject based on the ideXlab platform.

  • selectivity assessment of two biorational insecticides azadirachtin and pyriproxyfen in comparison to a neonicotinoid acetamiprid on pupae and adults of a neotropical strain Eretmocerus Mundus mercet
    Chemosphere, 2018
    Co-Authors: Natalia Francesena, Marcela Ines Schneider
    Abstract:

    Abstract Assessment of the susceptibility of natural enemies of pests to selective pesticides is relevant for a sustainable agriculture with low impact on the environment. The aim of this study was to assess the toxicity of two biorational insecticides, azadirachtin and pyriproxyfen in comparison to a neonicotinoid insecticide, acetamiprid, on pupae and adults of a Neotropical strain of Eretmocerus Mundus. Adult emergence and survival were evaluated as lethal effects whereas the sublethal effects were assessed through the reproductive capacity, sex ratio, and longevity of the surviving first progeny. Adult emergence from treated pupae was reduced by all three insecticides, but azadirachtin at its maximum field recommended concentration (MFRC) proved the most toxic insecticide. The survival probability of emerged adults was reduced by the three insecticides below than 50% from 2 to 5 days after the adult emergence. Malformations in nonemerged adults from treated pupal hosts were observed at the MFRC of all three insecticides. Sublethal effects on survivors from pupal treatment could be evaluated at only the lowest azadirachtin concentration. At that concentration, though azadirachtin did not affect the reproductive capacity of females, the sex ratio and the longevity of the first progeny were disrupted. The survival of parasitoid adults after adult exposure was reduced by all three insecticides, pyriproxyfen at the MFRC being the most toxic. All insecticides at their half of MFRCs induced sublethal effects in the survivors’ adults, with pyriproxyfen being the most harmful to the reproductive capacity of females. In conclusion, both biorational insecticides were toxic to E. Mundus.

  • Side effects of spirotetramat on pupae and adults of a Neotropical strain of Eretmocerus Mundus (Hymenoptera: Aphelinidae): Effects on the life parameters and demography
    Environmental Science and Pollution Research, 2017
    Co-Authors: Natalia Francesena, Nicolas Desneux, Mateus Ribeiro De Campos, Marcela Ines Schneider
    Abstract:

    The negative impact of conventional pesticides on the environment is already extensively discussed worldwide. Although the use of chemical agents for controlling agricultural pests remains as first-line strategy for pest control, novel biorational active insecticides, such as spirotetramat, have appeared in the pesticide market during recent years in Argentina. The aim of this study was to assess the toxicity of spirotetramat on two developmental stages of a Neotropical strain of Eretmocerus Mundus, with the conventional insecticide cypermethrin as a positive control, and to determine spirotetramat's side effects on parasitoid demographic parameters. Lethal effects of both insecticides on pupae and adults were evaluated by adult emergency and survival, respectively; whereas sublethal effects on both development stages were assessed by adult longevity, reproduction capacity, sex ratio, and longevity of the first progeny. Spirotetramat proved less harmful than cypermethrin at both developmental stages studied, corroborating once more the high toxicity of this pyrethroid to natural enemies. Although spirotetramat did not affect the emergence and reproductive capacity of adults surviving pupal exposure, the longevity of the first progeny was reduced as was adult survival and longevity after exposure to residues. Spirotetramat also reduced all demographic parameters in the population evaluation. This work is the first report of spirotetramat toxicity at the population level and demonstrates the need to assess the total effect of pesticides on natural enemies.

  • preliminary studies of effectiveness and selectivity of movento on bemisia tabaci and its parasitoid Eretmocerus Mundus
    Communications in agricultural and applied biological sciences, 2012
    Co-Authors: Natalia Francesena, Guy Smagghe, Marina Haramboure, T Stadler, Marcela Ines Schneider
    Abstract:

    The Bemisia tabaci Gennadius (Homoptera:Aleyrodidae) biotype complex is a key pest of several worldwide crops. The management and control of this pest has become difficult mainly due to its high reproductive rate and capacity to develop resistance to broad spectrum insecticides. In Argentina B. tabaci whitefly, causes economic losses in most areas of agricultural production. Eretmocerus Mundus Mercet (Hymenoptera:Aphelinidae) is the most important parasitoid of B. tabaci and is commercialized as a biocontrol agent, mainly in Europe. Conservation of this biological control agent in Argentinean orchards requires the adoption of sustainable pest management practices due the negative impact of traditional pesticides on non-target organisms. Spirotetramat (Movento) belongs to a new class of pesticides that acts as a lipid biosynthesis inhibitor and claims to be selective towards natural enemies. The objectives of this work were 1) to evaluate the effectiveness of spirotetramat on eggs and nymphs of B. tabaci and 2) to determine the selectivity of spirotetramat towards E. Mundus. Whitefly's eggs and nymphs (first nymphal settled instar) were exposed to the insecticide by foliar immersion whereas parasitoid adults (6 days old) were exposed to the insecticide by residual method for one hour, to simulate exposure of the parasitoid to the insecticide in the field. Lethal and sublethal effects of the insecticide were recorded daily. These preliminary studies have shown a high effectiveness of spirotetramat on the first nymphal instar of B. tabaci as well as a high selectivity for the pest in comparison to the parasitoid adults showing a low acute toxicity to them. These results suggest Movento could be included in Integrated Pest Management programs although more studies are required to complete its ecotoxicological profile.

Walker A. Jones - One of the best experts on this subject based on the ideXlab platform.

  • bemisia tabaci homoptera aleyrodidae instar effects on rate of parasitism by Eretmocerus Mundus and encarsia pergandiella hymenoptera aphelinidae
    Entomological Science, 2008
    Co-Authors: S M Greenberg, Walker A. Jones, Tongxian Liu
    Abstract:

    Studies were conducted to compare preference among Bemisia tabaci Gennadius, biotype B instars for parasitization by Eretmocerus Mundus Mercet and Encarsia pergandiella Howard when provided one instar only, two different instars, and four different instars simultaneously. In the single-instar no choice treatment, Er. Mundus was more successful in parasitizing the younger host instars, while En. pergandiella parasitized a greater proportion of the older instars. Similar results were observed when parasitoids were provided a choice of two instars in six different pair combinations. When all four instars were provided simultaneously, the numbers of first, second, and third instars parasitized by Er. Mundus were not significantly different from each other (range 10.3-16.4%), but all were significantly higher than parasitism of fourth instar nymphs (2.1%). The highest percentage parasitization by En. pergandiella was in third instar (17.2%), and the lowest in first instar (2.8%).

  • Transfer of methyl-branched hydrocarbons from the parasitoid, Eretmocerus Mundus, to silverleaf whitefly nymphs during oviposition
    Comparative biochemistry and physiology. Part A Molecular & integrative physiology, 2005
    Co-Authors: James S. Buckner, Walker A. Jones
    Abstract:

    The parasitic wasp Eretmocerus Mundus (Hymenoptera: Aphelinidae), a natural enemy of the silverleaf whitefly Bemisia argentifolii (Homoptera: Aleyrodidae), deposits eggs beneath nymphs and not within them. Experiments were designed to establish whether ovipositing E. Mundus females leave marking chemicals on nymphs to enable searching females to discriminate parasitized from unparasitized hosts. Cuticular lipids from three experimental treatment groups were characterized: parasitoid-exposed nymphs that had a parasitoid egg between the nymph and leaf; control nymphs not exposed to E. Mundus; and a third treatment condition of parasitized nymphs, held for 10 days after wasp exposure. Lipids were solvent-extracted from the nymphal cuticles of the various treatment groups and the lipid components were characterized and quantified by gas chromatography and mass spectrometry. Results indicated the presence of quantities of C31 and C33 dimethylalkanes only from parasitoid-exposed groups of nymphs and not in the extracts from control nymphs or the parasitized nymphs after 10-day exposure. Furthermore, the C31 and C33 dimethylalkanes were shown to be major lipid components of the hexane extracts from E. Mundus females. Since the lipids were removed from parasitoid-exposed nymphs before interaction with hatched parasitoid larvae, the findings indicated that the dimethylalkanes were transferred onto nymphal cuticles by ovipositing E. Mundus females.

  • ARTIFICIALLY-REARED WHITEFLIES, BEMISIA ARGENTIFOLII, (HOMOPTERA:ALEYRODIDAE) AS HOSTS FOR PARASITIC WASPS
    Florida Entomologist, 2002
    Co-Authors: Elizabeth W. Davidson, Faye E. Farmer, Walker A. Jones
    Abstract:

    Abstract Bemisia argentifolii (Powell & Bellows) (Homoptera: Aleyrodidae) (= B. tabaci Gennadius B biotype) nymphs reared on an artificial feeding system were successfully parasitized by three species of wasps, Encarsia formosa Gahan, Eretmocerus eremicus Rose and Zolnerwich, and Eretmocerus Mundus Mercet (Hymenoptera: Aphelinidae). Encarsia formosa and Eretmocerus spp. preferred to parasitize third and fourth instar nymphs including the late fourth instar “red eye” stage. Oviposition rate and developmental time compared favorably to some reports on plants, but successful production of adult wasps was low. This system can be used to elucidate host-parasite interactions without confounding interactions with plants.

  • Comparison of Functional Response and Mutual Interference Between Two Aphelinid Parasitoids of Bemisia argentifolii (Homoptera: Aleyrodidae)
    Journal of Entomological Science, 2001
    Co-Authors: S M Greenberg, Benjamin C. Legaspi, Walker A. Jones
    Abstract:

    Functional responses and mutual interference were compared in an indigenous parasitoid, Encarsia pergandiella Howard (Hymenoptera: Aphelinidae), with that of an exotic parasitoid, Eretmocerus Mundus Mercet (Aphelinidae) from Spain, attacking the silverleaf whitefly, Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae). Type II functional response curves were fitted to the data and were used to calculate handling time. Eretmocerus Mundus attacked more whitefly nymphs than E. pergandiella. Handling times estimated from the functional responses were 72 min for E. pergandiella and 12 min for E. Mundus, suggesting that lower attack rates for the former parasitoid may be attributed to longer handling times. The statistically estimated handling time for E. Mundus was compared with an estimate derived from empirical observations of parasitoid behavior. Actual observations of handling time, defined as oviposition, host feeding and associated preening, yielded a mean handling time of

  • The effect of varying Bemisia argentifolii and Eretmocerus Mundus ratios on parasitism
    BioControl, 1999
    Co-Authors: Walker A. Jones, S. M. Greenberg, B. Legaspi
    Abstract:

    We investigated the effects of different host: parasitoid ratios on the efficacy of the parasitoid Eretmocerus Mundus attacking the silverleaf whitefly, Bemisia argentifolii. When host density was held constant (100 second instars) and parasitoid density was decreased from 15 to 1 females, the percentage of total host mortality was significantly lower at low parasitoid densities. The number of host nymphs killed, and the number of female parasitoid progeny per female, increased 3.6 and 20.4 times, respectively. The emergence rate, sex ratio, longevity, and body lengths of progeny were significantly larger at the lowest parasitoid density while developmental time was significantly shorter. When the number of hosts was increased from 5 to 250 and parasitoid density was held constant (5 females), the percentage of nymphal mortality decreased 1.6 times. The percentage of desiccated nymphs was significantly highest (65.7%) at the lowest host density, while percentage parasitism (34.3%) was significantly lowest at the lowest host density. The data could be described using a Type I functional response curve. We propose a generalized index of efficacy (GIE) to summarize and compare the total effects of parasitoid--host ratios. This index showed that the most efficient ratio was one parasitoid female per ten second instar host nymphs.

Dan Gerling - One of the best experts on this subject based on the ideXlab platform.

  • immature development of Eretmocerus Mundus hymenoptera aphelinidae
    Arthropod Structure & Development, 2013
    Co-Authors: Dan Gerling, Michael B Blackburn
    Abstract:

    Abstract The development from egg to pupation is followed for the wasp Eretmocerus Mundus , parasitizing the whitefly Bemisia tabaci . We elucidate and describe structural details, histological developments and changes that the different parasitoid and host tissues have undergone during parasitism. These include the presence and apparent function of very large salivary glands, which probably produce substances that help to regulate the host's decomposition and parasitoid nutrition. Moreover, the gut of all instars is devoid of both peritrophic membrane and microvilli and, in the early instars, it has squamous rather than columnar epithelial cells. Differing from many other parasitoids, the E. Mundus larva usually does not come into contact with the host tissues and does not devour the entire host during its development. The possible reasons for the developmental mechanisms, as well as the functions of the host capsule that envelopes the parasitoid, are discussed.

  • Contagious sterility in the parasitoid wasp Eretmocerus Mundus (Hymenoptera: Aphelinidae)
    Biocontrol Science and Technology, 2012
    Co-Authors: Elad Chiel, Dan Gerling, Shimon Steinberg, Johannette Klapwijk, K. J. F. Bolckmans, Einat Zchori-fein
    Abstract:

    Abstract The parasitoid wasp Eretmocerus Mundus (Hymenoptera: Aphelinidae) is used commercially to control the sweet potato whitefly Bemisia tabaci (Homoptera: Aleyrodidae). Recently, a rapid deterioration of E. Mundus populations has been documented under mass-rearing conditions. We found that deteriorating cultures consist of increasing proportions of sterile individuals, up to 90% within 6 months. Microscopic examination revealed that the gonads of wasps from both sexes are severely underdeveloped. Preliminary screening for potential pathogen candidates by means of polymerase chain reaction and denaturating-gradient gel electrophoresis did not provide any indication of possible causative agents.

  • Parasitism of Bemisia tabaci (Homoptera: Aleyrodidae) by Eretmocerus Mundus (Hymenoptera: Aphelinidae) on cassava
    International Journal of Tropical Insect Science, 2008
    Co-Authors: M. Otim, G. Kyalo, Samuel Kyamanywa, P. Asiimwe, James P. Legg, Moshe Guershon, Dan Gerling
    Abstract:

    Parasitism rates of Bemisia tabaci (Gennadius) and searching and oviposition behaviours of its parasitoid Eretmocerus Mundus Mercet were compared on two cassava varieties: a glabrous variety, Nase 4 and a hirsute variety, MM97/0245 with c. 88 leaf hairs/cm 2 . Parasitism was assessed after potted plants of both varieties were exposed in open fields to natural infestation by B. tabaci and its natural enemy. For the behavioural studies, naive, less than 24-h-old females were individually observed on infested cassava leaflets under a microscope for a maximum of 1 h each. The different foraging behaviours were recorded using the computer software 'The Observer 5.0' (Noldus Ltd, Wageningen, The Netherlands). Total per cent parasitism and parasitism by E. Mundus did not differ significantly between varieties. Upon encounter with leaf hairs, the parasitoids stopped and groomed before resuming the host search. The frequency of repeat probing, host feeding and antennation after probing and host feeding were higher on the glabrous than on the hirsute variety, while the converse was observed when feeding on liquids on the leaf. The duration of host assessment, initial probing, grooming and resting on the leaf was higher on the glabrous than on the hirsute variety. Leaf hairiness at the density investigated caused some changes in the behaviour of the parasitoids, but did not have an overall effect on field parasitism. Since cassava is generally considered to have glabrous leaves and the variety MM97/0245 is one of the most hirsute varieties, we discount leaf hairiness as a factor in determining levels of parasitoid activity.

  • parasitization by the wasp Eretmocerus Mundus induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly bemisia tabaci
    BMC Genomics, 2008
    Co-Authors: Assaf Mahadav, Dan Gerling, Yuval Gottlieb, Henryk Czosnek, Murad Ghanim
    Abstract:

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), and the viruses it transmits, are a major constraint to growing vegetable crops worldwide. Although the whitefly is often controlled using chemical pesticides, biological control agents constitute an important component in integrated pest management programs, especially in protected agriculture. One of these agents is the wasp Eretmocerus Mundus (Mercet) (Hymenoptera: Aphelinidae). E. Mundus lays its egg on the leaf underneath the second-third instar nymph of B. tabaci. First instars of the wasp hatch and penetrate the whitefly nymphs. Initiation of parasitization induces the host to form a capsule composed of epidermal cells around the parasitoid. The physiological and molecular processes underlying B. tabaci-E. Mundus interactions have never been investigated. We used a cDNA microarray containing 6,000 expressed sequence tags (ESTs) from the whitefly genome to study the parasitoid-whitefly interaction. We compared RNA samples collected at two time points of the parasitization process: when the parasitoid first instar starts the penetration process and once it has fully penetrated the host. The results clearly indicated that genes known to be part of the defense pathways described in other insects are also involved in the response of B. tabaci to parasitization by E. Mundus. Some of these responses included repression of a serine protease inhibitor (serpin) and induction of a melanization cascade. A second set of genes that responded strongly to parasitization were bacterial, encoded by whitefly symbionts. Quantitative real-time PCR and FISH analyses showed that proliferation of Rickettsia, a facultative secondary symbiont, is strongly induced upon initiation of the parasitization process, a result that supported previous reports suggesting that endosymbionts might be involved in the insect host's resistance to various environmental stresses. This is the first study to examine the transcriptional response of a hemipteran insect to attack by a biological control agent (hymenopterous parasitoid), using a new genomic approach developed for this insect pest. The defense response in B. tabaci involves genes related to the immune response as described in model organisms such as Drosophila melanogaster. Moreover, endosymbionts of B. tabaci appear to play a role in the response to parasitization, as supported by previously published results from aphids.

  • BioMed Central
    2008
    Co-Authors: Bmc Genomics, Dan Gerling, Assaf Mahadav, Yuval Gottlieb, Henryk Czosnek, Murad Ghanim
    Abstract:

    Research article Parasitization by the wasp Eretmocerus Mundus induces transcription of genes related to immune response and symbiotic bacteria proliferation in the whitefly Bemisia tabac