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Oscar Alomar - One of the best experts on this subject based on the ideXlab platform.
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elliptic fourier analysis in the study of the male genitalia to discriminate three Macrolophus species hemiptera miridae
Insects, 2017Co-Authors: A M Jauset, Cristina Castane, Nuria Agusti, E Edotena, Pere M Parescasanova, Oscar AlomarAbstract:Within the genus Macrolophus (Heteroptera: Miridae), the species M. costalis (Fieber), M. melanotoma (Costa) and M. pygmaeus (Rambur) are present in the Mediterranean region on a wide variety of plant species. While M. costalis can easily be separated from the other two by the black tip at the scutellum, M. pygmaeus and M. melanotoma are cryptic species, extremely similar to one another in external traits, which has resulted in misidentifications. M. pygmaeus is an efficient biological control agent, both in greenhouse and field crops. The misidentification of these cryptic species could limit the effectiveness of biological control programs. Although the morphology of the left paramere of the male genitalia has been used as a character for identification of these two cryptic species, there is controversy surrounding the reliability of this character as a taxonomic tool for these species. Using geometric morphometric techniques, which are a powerful approach in detecting slight shape variations, the left parameres from these three Macrolophus species were compared. The paramere of M. costalis was larger and had a different shape to that of M. melanotoma and M. pygmaeus; however, no differences in size or shape were found between the left paramere of M. melanotoma and that of M. pygmaeus. Therefore, our results confirm that this character is too similar and it cannot be used to discriminate between these two cryptic species.
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comparative cytogenetic study of three Macrolophus species heteroptera miridae
Comparative Cytogenetics, 2015Co-Authors: Ana Maria Jauset, Eva Edotena, Cristina Castane, Nuria Agusti, Oscar Alomar, Snejana GrozevaAbstract:Macrolophus pygmaeus (Rambur, 1839) (Insecta, Heteroptera, Miridae) is a predator of key vegetable crop pests applied as a biocontrol agent in the Mediterranean region. Macrolophus pygmaeus and Macrolophus melanotoma (A. Costa, 1853) are cryptic species with great morphological similarity which results in their misidentification and negative consequences for the conservation of their populations on greenhouse and outdoor crops. In order to find out specific markers for their separation we studied the karyotype, male meiosis and heterochromatin composition of these species and additionally of a third species (as a reference one), Macrolophus costalis Fieber, 1858. We demonstrate here that all the three species share achiasmate male meiosis and sex chromosome pre-reduction. On the other hand, the species differ in karyotype, with 2n=28 (26+XY) in Macrolophus pygmaeus, 2n=27 (24+X1X2Y) in Macrolophus costalis, and 2n=34 (32+XY) in Macrolophus melanotoma, and heterochromatin distribution and composition. In addition, the species differ in sperm morphology: sperm cells of Macrolophus costalis are significantly longer with longer head and tail than those of Macrolophus melanotoma and Macrolophus pygmaeus, whereas sperm cells of Macrolophus melanotoma have a longer tail than those of Macrolophus pygmaeus. All these characters can be used as markers to identify the species, in particular the cryptic species Macrolophus melanotoma and Macrolophus pygmaeus.
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substrate borne vibrational signals in mating communication of Macrolophus bugs
Journal of Insect Behavior, 2015Co-Authors: Cesar Gemeno, Oscar Alomar, Giordana Baldo, Rachele Nieri, Joan Valls, Valerio MazzoniAbstract:The mirid bugs Macrolophus pygmaeus and M. costalis use substrate-borne vibrational signals during pair formation and in male-male interactions as determined by laser vibrometry. The vibrational communication of Macrolophus is more complex than in other mirids, with a signal repertoire composed of two elements, only produced by males, while the females are mute. The “yelp” signal consists of one or several consecutive brief pulses with harmonic structure and is commonly produced by stationary males before mating, as a key-element of courtship. “Yelping” is also associated with contacts between males. The “roar” signal differs from “yelps” in that it has a broadband frequency pattern, a longer and more variable duration than “yelping”, and is produced by males in association with walking on the leaf. Playback experiments did not affect male vibration emission, but when “roaring” was used as stimulus, it elicited a significant increase in the time spent walking. We detected significant differences between M. costalis and M. pygmaeus in some spectral parameters of the “roar” and “yelp” signals, so these signals could contain species-specific information. We conclude that “roaring” and “yelping” vibrational signals are used by Macrolophus in social communication, in particular in the context of mating behavior.
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taxonomic identification of Macrolophus pygmaeus and Macrolophus melanotoma based on morphometry and molecular markers
Bulletin of Entomological Research, 2013Co-Authors: Cristina Castane, Nuria Agusti, Judit Arno, Rosa Gabarra, Jordi Riudavets, J Comas, Oscar AlomarAbstract:Two Macrolophus species, M. melanotoma ( =M. caliginosus ) and M. pygmaeus , have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants ( Dittrichia viscosa and tomato) through crossing experiments. Then, using multivariate morphometric analysis, we proposed a linear discriminant function that combines head measurements separating males from the two species without error. Finally, we designed specific primers for a mitochondrial DNA region that were able to distinguish field-collected Macrolophus individuals through conventional PCR. In conclusion, the tools developed in the present study will allow reliable identification of the Macrolophus species present in crops and in the native flora that are the source of populations that colonise them. They will also allow correct identification of mass reared Macrolophus to be introduced in greenhouse crops in inoculative releases.
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cuticular hydrocarbons discriminate cryptic Macrolophus species hemiptera miridae
Bulletin of Entomological Research, 2012Co-Authors: Cesar Gemeno, Cristina Castane, Joan Valls, N Laserna, Magi Riba, Oscar AlomarAbstract:: Macrolophus pygmaeus is commercially employed in the biological control of greenhouse and field vegetable pests. It is morphologically undistinguishable from the cryptic species M. melanotoma, and this interferes with the evaluation of the biological control activity of M. pygmaeus. We analysed the potential of cuticular hydrocarbon composition as a method to discriminate the two Macrolophus species. A third species, M. costalis, which is different from the other two species by having a dark spot at the tip of the scutellum, served as a control. Sex, diet and species, all had significant effects in the cuticular hydrocarbon profiles, but the variability associated to sex or diet was smaller than among species. Discriminant quadratic analysis of cuticular hydrocarbons confirmed the results of previous molecular genetic studies and showed, using cross-validation methods, that M. pygmaeus can be discriminated from M. costalis and M. melanotoma with prediction errors of 6.75% and 0%, respectively. Therefore, cuticular hydrocarbons can be used to separate M. pygmaeus from M. melanotoma reliably.
Cristina Castane - One of the best experts on this subject based on the ideXlab platform.
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elliptic fourier analysis in the study of the male genitalia to discriminate three Macrolophus species hemiptera miridae
Insects, 2017Co-Authors: A M Jauset, Cristina Castane, Nuria Agusti, E Edotena, Pere M Parescasanova, Oscar AlomarAbstract:Within the genus Macrolophus (Heteroptera: Miridae), the species M. costalis (Fieber), M. melanotoma (Costa) and M. pygmaeus (Rambur) are present in the Mediterranean region on a wide variety of plant species. While M. costalis can easily be separated from the other two by the black tip at the scutellum, M. pygmaeus and M. melanotoma are cryptic species, extremely similar to one another in external traits, which has resulted in misidentifications. M. pygmaeus is an efficient biological control agent, both in greenhouse and field crops. The misidentification of these cryptic species could limit the effectiveness of biological control programs. Although the morphology of the left paramere of the male genitalia has been used as a character for identification of these two cryptic species, there is controversy surrounding the reliability of this character as a taxonomic tool for these species. Using geometric morphometric techniques, which are a powerful approach in detecting slight shape variations, the left parameres from these three Macrolophus species were compared. The paramere of M. costalis was larger and had a different shape to that of M. melanotoma and M. pygmaeus; however, no differences in size or shape were found between the left paramere of M. melanotoma and that of M. pygmaeus. Therefore, our results confirm that this character is too similar and it cannot be used to discriminate between these two cryptic species.
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Tomato belowground–aboveground interactions: Rhizophagus irregularis affects foraging behavior and life history traits of the predator Macrolophus pygmaeus (Hemiptera: Miridae)
Arthropod-Plant Interactions, 2017Co-Authors: Juliana Durán Prieto, Cristina Castane, Cinta Calvet, Amelia Camprubi, Donatella Battaglia, Vincenzo Trotta, Paolo FantiAbstract:In recent years, studies on arbuscular mycorrhizal fungi (AMF) have been revealing that the belowground symbiosis can influence the performance of aboveground herbivores and their natural enemies through its effects on the host plant. In this study, we tested whether the colonization of tomato plants by the arbuscular mycorrhizal fungus Rhizophagus irregularis (Syn. Glomus intraradices Schenk and Smith) (Glomeromycota: Glomeraceae) affects the performance of the zoophytophagous mirid bug Macrolophus pygmaeus Rambur (Hemiptera: Miridae). Mycorrhizal colonization in tomato plants positively influenced the predator host-plant acceptance for feeding and oviposition, as well as nymphal survival and female weight. We hypothesize that AMF can modify mirid bug foraging behavior and performance.
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tomato belowground aboveground interactions rhizophagus irregularis affects foraging behavior and life history traits of the predator Macrolophus pygmaeus hemiptera miridae
Arthropod-plant Interactions, 2017Co-Authors: Juliana Durán Prieto, Cristina Castane, Cinta Calvet, Amelia Camprubi, Donatella Battaglia, Vincenzo Trotta, Paolo FantiAbstract:In recent years, studies on arbuscular mycorrhizal fungi (AMF) have been revealing that the belowground symbiosis can influence the performance of aboveground herbivores and their natural enemies through its effects on the host plant. In this study, we tested whether the colonization of tomato plants by the arbuscular mycorrhizal fungus Rhizophagus irregularis (Syn. Glomus intraradices Schenk and Smith) (Glomeromycota: Glomeraceae) affects the performance of the zoophytophagous mirid bug Macrolophus pygmaeus Rambur (Hemiptera: Miridae). Mycorrhizal colonization in tomato plants positively influenced the predator host-plant acceptance for feeding and oviposition, as well as nymphal survival and female weight. We hypothesize that AMF can modify mirid bug foraging behavior and performance.
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comparative cytogenetic study of three Macrolophus species heteroptera miridae
Comparative Cytogenetics, 2015Co-Authors: Ana Maria Jauset, Eva Edotena, Cristina Castane, Nuria Agusti, Oscar Alomar, Snejana GrozevaAbstract:Macrolophus pygmaeus (Rambur, 1839) (Insecta, Heteroptera, Miridae) is a predator of key vegetable crop pests applied as a biocontrol agent in the Mediterranean region. Macrolophus pygmaeus and Macrolophus melanotoma (A. Costa, 1853) are cryptic species with great morphological similarity which results in their misidentification and negative consequences for the conservation of their populations on greenhouse and outdoor crops. In order to find out specific markers for their separation we studied the karyotype, male meiosis and heterochromatin composition of these species and additionally of a third species (as a reference one), Macrolophus costalis Fieber, 1858. We demonstrate here that all the three species share achiasmate male meiosis and sex chromosome pre-reduction. On the other hand, the species differ in karyotype, with 2n=28 (26+XY) in Macrolophus pygmaeus, 2n=27 (24+X1X2Y) in Macrolophus costalis, and 2n=34 (32+XY) in Macrolophus melanotoma, and heterochromatin distribution and composition. In addition, the species differ in sperm morphology: sperm cells of Macrolophus costalis are significantly longer with longer head and tail than those of Macrolophus melanotoma and Macrolophus pygmaeus, whereas sperm cells of Macrolophus melanotoma have a longer tail than those of Macrolophus pygmaeus. All these characters can be used as markers to identify the species, in particular the cryptic species Macrolophus melanotoma and Macrolophus pygmaeus.
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taxonomic identification of Macrolophus pygmaeus and Macrolophus melanotoma based on morphometry and molecular markers
Bulletin of Entomological Research, 2013Co-Authors: Cristina Castane, Nuria Agusti, Judit Arno, Rosa Gabarra, Jordi Riudavets, J Comas, Oscar AlomarAbstract:Two Macrolophus species, M. melanotoma ( =M. caliginosus ) and M. pygmaeus , have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants ( Dittrichia viscosa and tomato) through crossing experiments. Then, using multivariate morphometric analysis, we proposed a linear discriminant function that combines head measurements separating males from the two species without error. Finally, we designed specific primers for a mitochondrial DNA region that were able to distinguish field-collected Macrolophus individuals through conventional PCR. In conclusion, the tools developed in the present study will allow reliable identification of the Macrolophus species present in crops and in the native flora that are the source of populations that colonise them. They will also allow correct identification of mass reared Macrolophus to be introduced in greenhouse crops in inoculative releases.
Dionyssios Ch Perdikis - One of the best experts on this subject based on the ideXlab platform.
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Macrolophus pygmaeus hemiptera miridae foraging on tomato leaves from different plant strata
Phytoparasitica, 2019Co-Authors: Nomi Sarmah, Anjumoni Devee, Dionyssios Ch PerdikisAbstract:This study investigates the foraging activity of the generalist predator Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) on tomato leaves of different vertical plant strata (apex, top, middle and lower). On a leaflet of each tested leaf, ten 2nd instar nymphs of the aphid Myzus persicae were established with the aid of harmless glue, as prey. It was observed that prey consumption was highest on the lower leaves. There was no significant difference in prey consumption between middle and top leaves but it significantly reduced on the apex leaves as compared to the top and the lower leaves. Behavioural observations were conducted to assess the time budgets (i.e. time spent in each activity such as searching, resting, grooming) of the foraging predator on leaves of each plant strata. The predator spent significantly more time in grooming on apex than on lower leaves whereas it showed a higher tendency to fall off from the apex leaves than the leaves of the other plant strata. The apex leaves had the highest trichome density and this may impede movement of the predator. In the third experiment, the prey consumption of M. pygmaeus nymphs was reduced with the increase of distance between its release point and the prey patch on a tomato plant. In conclusion, M. pygmaeus nymphs are most efficient in foraging on the middle or lower leaves of young tomato plants whereas their prey searching efficiency is influenced by the distance between their release point and the prey patch. Therefore, the efficacy of M. pygmaeus nymphs in pest control may be benefited if released close to prey patches but not on the apex leaves.
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intraguild predation and sublethal interactions between two zoophytophagous mirids Macrolophus pygmaeus and nesidiocoris tenuis
Biological Control, 2014Co-Authors: Dionyssios Ch Perdikis, D. Maselou, Eric Lucas, Nikolaos Garantonakis, Athanassios Giatropoulos, P Kitsis, S Panagakis, P Lampropoulos, A Paraskevopoulos, Dionyssios P LykouressisAbstract:The omnivorous predators Macrolophus pygmaeus and Nesidiocoris tenuis (Hemiptera: Miridae) are important biological control agents of pests on tomato crops. In this study, potential intraguild predation (IGP) interactions between the two species were investigated on tomato. We examined: (a) the within plant distribution of both species in the field, (b) the within plant distribution of each predatory species when co-occurred at high densities on tomato caged plants, (c) their behavioral interactions when enclosed in experimental arenas and (d) the development young and old nymphs of M. pygmaeus when enclosed together with N. tenuis adults. Results revealed that the two predators showed a different distribution pattern on the plants, with N. tenuis exploiting mostly the upper part, whereas M. pygmaeus were mostly observed on the 5th to the 7th leaf from the top. However, when the predators co-occurred, N. tenuis or M. pygmaeus individuals were recorded with increased numbers on the lower or the higher part of the plant, respectively. In the presence of N. tenuis adult young nymphs of M. pygmaeus completed their development to the adult stage, when alternative prey (lepidopteran eggs) was present on the plant, however failed to reach adulthood in the absence of alternative prey. A high percentage of the dead nymphs found with their body fluids totally sucked indicating predation by N. tenuis. However, large 4th instar nymphs of M. pygmaeus were much less vulnerable to N. tenuis than younger. The behavior of N. tenuis was affected by the presence of M. pygmaeus, but at a rate similar to that when two individuals of N. tenuis were enclosed together. Contacts between the predators were recorded in a similar frequency in mono- and heterospecific treatments, whereas aggressive behavior was not observed. This study shows that intraguild interactions between M. pygmaeus and N. tenuis occur but are not intensive. The potential implications of the outcomes for biological control are discussed.
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ecological relationships between non cultivated plants and insect predators in agroecosystems the case of dittrichia viscosa asteraceae and Macrolophus melanotoma hemiptera miridae
Acta Oecologica-international Journal of Ecology, 2007Co-Authors: Dionyssios Ch Perdikis, Dionyssios P Lykouressis, Charalampos Favas, Argyro A. FantinouAbstract:Abstract Species of the genus Macrolophus (Hemiptera: Miridae) are thought to be effective predators in reducing the numbers of several pests in vegetable crops. These predators are omnivorous as in addition to prey they also utilize plant sap for growth and development. Populations of these predators build in non-crop host plants and provide inoculum that augments natural control of insect pests in adjacent crops. However, to enhance their effectiveness in crops requires knowledge of their trophic relationships with host plants. In this study, the ecological relationships between the predator Macrolophus melanotoma (Costa) ( = M. caliginosus Wagner) and its most important natural host plant Dittrichia viscosa L. (W. Greuter) (Asteraceae) were investigated in the laboratory and in field studies. A 2-year field study of M. melanotoma populations on D. viscosa was made using the percentage of plants infested by C. inulae as a measure of aphid prey abundance. The field studies revealed that M. melanotoma populations were present throughout the year on D. viscosa reaching highest numbers in June and July despite very low levels of aphid infested plants. Laboratory life table studies were used to compare the survival and reproduction of the predator on D. viscosa leaves alone and leaves plus aphid prey (Capitophorus inulae (Passerini)). Predators reared on D. viscosa leaves plus aphid prey had an average developmental time of 16.73 days, fecundity was 69.55 eggs/female and the intrinsic rate of population increase was 0.0614/day. When fed only leaves, the developmental time was 21.13 days, fecundity was 10.80 eggs/female and the intrinsic rate of population increase was 0.0229/day. The results of the two studies suggest an important role for D. viscosa in conserving and augmenting M. melanotoma in agro ecosystems, and in the development of natural control augmentation strategies in vegetable crops.
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Macrolophus pygmaeus hemiptera miridae population parameters and biological characteristics when feeding on eggplant and tomato without prey
Journal of Economic Entomology, 2004Co-Authors: Dionyssios Ch Perdikis, Dionyssios P LykouressisAbstract:Abstract The population parameters and biological characteristics of the predator Macrolophus pygmaeus Rambur when feeding on eggplant, Solanum melongena L., and tomato, Lycopersicon esculentum (Miller) (both Solanaceae), without access to prey, were investigated at several temperatures. The experiments were conducted at 15, 20, 25, and 30°C, 65 ± 5% RH, and a photoperiod of 16:8 (L:D) h. Females oviposited on both plant species at all temperatures, with the exception of tomato at 30°C. Fecundity was highest at 20°C (21.55 and 8.28 eggs per female on eggplant and tomato, respectively). Adult longevity on both host plants was greatest at 15°C, reaching 38.72 and 34.20 d for females and 92.88 and 62.80 d for males, on eggplant and tomato, respectively. The estimated values of population parameters showed that this predator increased its numbers on eggplant at all temperatures tested, but the highest intrinsic rate of increase occurred at 25°C (0.0401 d−1). On tomato, this predator could not increase in numb...
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discrimination of the closely related biocontrol agents Macrolophus melanotoma hemiptera miridae and m pygmaeus using mitochondrial dna analysis
Bulletin of Entomological Research, 2003Co-Authors: Dionyssios Ch Perdikis, John T Margaritopoulos, Costas Stamatis, Zissis Mamuris, D P Lykouressis, J A Tsitsipis, Apostolos PekasAbstract:The separation of the closely related predatory species Macrolophus melanotoma Costa (= M. caliginosus Wagner) and Macrolophus pygmaeus (Rambur) based exclusively on the different colour pattern of the first antennal segment (white central band in M. melanotoma and entirely black in M. pygmaeus) is rather precarious and their taxonomic status is still in doubt. In the present study their taxonomic status was evaluated by DNA confirmatory analysis and hybridization experiments between M. pygmaeus and a Macrolophus taxon, resembling M. melanotoma, with a first antennal segment entirely black or with a white central band collected from Dittrichia viscosa (L.) W. Greuter (Asteraceae) in southern Greece. Adult females from Dittrichia plants hybridized with males of M. pygmaeus and vice versa did not produce viable eggs. The Macrolophus species from Dittrichia irrespective of the first antennal segment coloration differed from M. pygmaeus in digestive patterns generated by AseI, XbaI, and MseI on 16S rRNA and in RAPD profiles produced by the primers OPA-18 and OPA-20. These results demonstrate that on Dittrichia plants there is a distinct dimorphic taxon, M. melanotoma, as it is the only species of the genus Macrolophus bearing a first antennal segment with a central white band. Given the limitation of the coloration pattern, the mtDNA genetic markers are the appropriate method for the identification of M. melanotoma and M. pygmaeus.
Nicolas Desneux - One of the best experts on this subject based on the ideXlab platform.
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combined thermal and insecticidal stresses on the generalist predator Macrolophus pygmaeus
Science of The Total Environment, 2020Co-Authors: Michele Ricupero, Nicolas Desneux, Khaled Abbes, Khalid Haddi, Alican Kurtulus, Agatino Russo, Gaetano Siscaro, Antonio BiondiAbstract:Abstract Ecotoxicological risk assessments of pesticides on non-target arthropods are often carried out under constant and optimal temperature regimes. However, living organisms rarely experience these conditions in real field situations. Understanding the impact of pesticides on non-target beneficial arthropods under temperature stresses is especially important in terms of global warming. We assessed the lethal and sublethal effects of four modern insecticides (chlorantraniliprole, cyantraniliprole, spinetoram, spinosad), on the generalist predator Macrolophus pygmaeus (Hemiptera: Miridae) under a range of temperatures (from 10 to 40 °C) frequently experienced in a real field scenario. A reduction coefficient (Ex) was calculated by summarizing the mortality and predator reproductive capacity and, the chemicals were classified according to the International Organization for Biological Control (IOBC) toxicity classes. The insecticides showed a marked synergistic effect with temperature, as the predator mortality and reproductive outputs were significantly correlated with increasing temperatures. Spinosyns interacted significantly with temperature causing the highest mortality and lowest fertility rates. Anthranilic diamides showed a safer ecotoxicological profile compared to spinosyns, with cyantraniliprole being more harmful than chlorantraniliprole. These results suggest that temperature should be taken into account in pesticide ecotoxicology studies within the framework of integrated pest management and the recent climate changes.
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Side effects of insecticides commonly used against Tuta absoluta on the predator Macrolophus basicornis
Journal of Pest Science, 2019Co-Authors: Marianne Araujo Soares, Nicolas Desneux, Luis C Passos, Mateus R. Campos, Lara J. Collares, Geraldo Andrade CarvalhoAbstract:Macrolophus basicornis (Stal) (Hemiptera: Miridae) is a promising biological control agent against tomato pests, mainly the South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). Nevertheless, the amount of pesticides used in tomato crops could compromise the effectiveness of M. basicornis in pest control. Thus, the present research aims to evaluate the lethal and sublethal effects of five insecticides (spinetoram, chlorantraniliprole + abamectin, triflumuron, tebufenozide, and abamectin) commonly used in tomato crops on M. basicornis . Third instar nymphs were exposed to dry residues of insecticides on tomato seedlings, and adults were directly sprayed using a Potter precision tower. Abamectin caused the highest mortality rate (79.98%) of M. basicornis nymphs. Females exposed to spinetoram during the nymphal stage showed a reduction in tibia length. Except for spinetoram, all other insecticides significantly influenced adult longevity. All insecticide treatments caused a reduction in female offspring. However, the growth of males and females ( F _1 generation) issued from adults treated did not differ significantly from the control. In the predator flight bioassay, males in the first evaluation showed a reduction in flight activity following exposure to chlorantraniliprole + abamectin and to tebufenozide. Overall, all insecticides tested caused negative effects on M. basicornis .
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life history traits of Macrolophus pygmaeus with different prey foods
PLOS ONE, 2016Co-Authors: Serigne Sylla, Thierry Brevault, Karamoko Diarra, Philippe Bearez, Nicolas DesneuxAbstract:Macrolophus pygmaeus Rambur (Hemiptera: Miridae) is a generalist predatory mirid widely used in augmentative biological control of various insect pests in greenhouse tomato production in Europe, including the invasive tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera, Gelechiidae). However, its biocontrol efficacy often relies on the presence of alternative prey. The present study aimed at evaluating the effect of various prey foods (Ephestia kuehniella eggs, Bemisia tabaci nymphs, Tuta absoluta eggs and Macrosiphum euphorbiae nymphs) on some life history traits of M. pygmaeus. Both nymphal development and adult fertility of M. pygmaeus were significantly affected by prey food type, but not survival. Duration of nymphal stage was higher when M. pygmaeus fed on T. absoluta eggs compared to the other prey. Mean fertility of M. pygmaeus females was greatest when fed with B. tabaci nymphs, and was greater when offered M. euphorbiae aphids and E. kuehniella eggs than when offered T. absoluta eggs. Given the low quality of T. absoluta eggs, the efficacy of M. pygmaeus to control T. absoluta may be limited in the absence of other food sources. Experiments for assessing effectiveness of generalist predators should involve the possible impact of prey preference as well as a possible prey switching. (Resume d'auteur)
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Nitrogen and water limitations in tomato plants trigger negative bottom-up effects on the omnivorous predator Macrolophus pygmaeus
Journal of Pest Science, 2015Co-Authors: Philippe Bearez, Stephane Adamowicz, Anne-violette Lavoir, Edwige Amiens-desneux, Nicolas DesneuxAbstract:Omnivorous Heteroptera predators play important roles in biological control of a wide range of pest insects. Their predation could be influenced by various biotic or abiotic factors. Here we examined the effects of nitrogen and water inputs to tomato plants ( Solanum lycopersicum L.) on the predation strength of the omnivore Macrolophus pygmaeus Wagner (Hemiptera: Miridae) on eggs of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). We tested the hypothesis that a change in plant status, manipulated by sub-optimal nutrients and water inputs, may influence predation on E. kuehniella by the predator M. pygmaeus . Nitrogen and water restrictions depressed the predation of E. kuehniella eggs by M. pygmaeus . Moreover, we observed a 30 % reduction in predator longevity on plants under low water inputs. Therefore, the negative bottom-up effect of nitrogen and water limitations (in tomato plants) toward M. pygmaeus may be detrimental for mirid predator-based IPM programs in tomato crops.
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foraging behaviour of the parasitoid eretmocerus eremicus under intraguild predation risk by Macrolophus pygmaeus
Pest Management Science, 2015Co-Authors: Maria Concepcion Velascohernandez, Antonio Biondi, Ricardo Ramirezromero, Carla Sanchezhernandez, Alejandro Munozurias, Nicolas DesneuxAbstract:BACKGROUND Intraguild predation (IGP), predation between species that use a common resource, can affect the populations of a pest, of the pest's natural enemy (IG prey) and of the predator of the pest's natural enemy (IG predator). In this study, we determined whether the parasitoid Eretmocerus eremicus (Hymenoptera: Aphelinidae) (IG prey), modifies its foraging behaviour under the risk of IGP by Macrolophus pygmaeus (Hemiptera: Miridae) (IG predator). Parasitoid behaviour was analysed using two bioassays (choice and no-choice) with the following treatments: (i) control, tomato leaf infested with whitefly nymphs; and (ii) PEP, tomato leaf infested with whitefly nymphs and previously exposed to the IG predator; and (iii) PP, tomato leaf infested with whitefly nymphs, with both, the IG predator and the IG prey present. RESULTS In both bioassays, we found that E. eremicus did not significantly modify the number of ovipositions, time of residence, duration of oviposition or behavioural sequence. However, in the no-choice bioassay, the number of attacks was higher and their duration shorter in the PEP treatment than in the control. CONCLUSION Our results indicate that the parasitoid may detect IGP risk to a certain extent, but it did not significantly modify its foraging behaviour, suggesting that simultaneous release of the two natural enemies can be successfully employed. © 2014 Society of Chemical Industry
Rosa Gabarra - One of the best experts on this subject based on the ideXlab platform.
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taxonomic identification of Macrolophus pygmaeus and Macrolophus melanotoma based on morphometry and molecular markers
Bulletin of Entomological Research, 2013Co-Authors: Cristina Castane, Nuria Agusti, Judit Arno, Rosa Gabarra, Jordi Riudavets, J Comas, Oscar AlomarAbstract:Two Macrolophus species, M. melanotoma ( =M. caliginosus ) and M. pygmaeus , have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants ( Dittrichia viscosa and tomato) through crossing experiments. Then, using multivariate morphometric analysis, we proposed a linear discriminant function that combines head measurements separating males from the two species without error. Finally, we designed specific primers for a mitochondrial DNA region that were able to distinguish field-collected Macrolophus individuals through conventional PCR. In conclusion, the tools developed in the present study will allow reliable identification of the Macrolophus species present in crops and in the native flora that are the source of populations that colonise them. They will also allow correct identification of mass reared Macrolophus to be introduced in greenhouse crops in inoculative releases.
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intraguild interactions between the predator Macrolophus pygmaeus and the parasitoid eretmocerus mundus natural enemies of bemisia tabaci
Biocontrol Science and Technology, 2012Co-Authors: Sonia Malo, Judit Arno, Rosa GabarraAbstract:Abstract The native parasitoid Eretmocerus mundus Mercet and the predator Macrolophus pygmaeus Rambur are widely used to control Bemisia tabaci (Gennadius) in Mediterranean tomato greenhouses. An optimal biological control strategy for B. tabaci should take into account intraguild interactions between these natural enemies. In this study, predator's prey preferences and prey consumption were studied when offered different parasitoid and whitefly stages. The effect of the host plant on the adults of both natural enemies was also examined. M. pygmaeus preferred to consume B. tabaci over E. mundus when immature stages and adults of B. tabaci and E. mundus were offered. They consumed a larger amount of healthy B. tabaci nymphs and adults than of parasitised nymphs or E. mundus adults. The predator M. pygmaeus interfered with the reproduction of E. mundus females on cotton but not on tomato. However, B. tabaci nymphal mortality on tomato associated with parasitoid host feeding was also lower when the adult par...
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Side effects of selected insecticides on the Tuta absoluta (Lepidoptera: Gelechiidae) predators Macrolophus pygmaeus and Nesidiocoris tenuis (Hemiptera: Miridae)
Journal of Pest Science, 2011Co-Authors: Judit Arno, Rosa GabarraAbstract:Tuta absoluta is a pest native to South America that produces significant damage to tomato crops and was first detected in Europe in late 2006. Data obtained during 2008 from commercial tomato crops in which IPM was applied suggested that good pest control was possible through the combined action of the predatory mirid bugs Macrolophus pygmaeus and Nesidiocoris tenuis and the use of selective insecticides. The aim of our study was to evaluate the lethal and sublethal side effects of three of the insecticides most widely used to control T. absoluta on these predators: azadirachtin, spinosad and indoxacarb. Seven days after applying the treatment at the maximum recommended field rates, the mortality produced by indoxacarb ranged from 28% for nymphs of M. pygmaeus to 77% for females of N. tenuis and were significantly higher than those produced by azadirachtin, spinosad and the control (
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colonization of tomato greenhouses by the predatory mirid bugs Macrolophus caliginosus and dicyphus tamaninii
Biological Control, 2004Co-Authors: Cristina Castane, Oscar Alomar, Marta Goula, Rosa GabarraAbstract:Colonization of tomato greenhouses by native predatory mirid bugs at the end of the spring cycle is common in the western Mediterranean area when no broad-spectrum insecticides are applied. Due to their polyphagy, these predators interact with pest populations and also with other natural enemies present in the crop. In this work we evaluate the abundance and timing of greenhouse colonization by these predators and their interaction with the greenhouse whitefly Trialeurodes vaporariorum, a key crop pest, and its introduced parasitoid Encarsia formosa. Although quite unpredictable, natural colonization of greenhouses by Macrolophus caliginosus and Dicyphus tamaninii, the two predominant species in our location, usually leads to the establishment of predator populations in the crop that subsequently prey on greenhouse whitefly. No preference for parasitized pupae was observed in greenhouse samples, while laboratory experiments revealed a marked tendency to avoid parasitoid pupae. In our area, IPM programs for greenhouse tomatoes and other vegetables should take advantage of the presence of this predator complex by allowing the immigration and establishment of its populations without disturbing them with highly toxic and non-selective insecticides.
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residual toxicity of some insecticides on the predatory bugs dicyphus tamaninii and Macrolophus caliginosus
Biocontrol, 1999Co-Authors: Marc Figuls, Cristina Castane, Rosa GabarraAbstract:Chlorpyrifos, formetanate, methamidophos, imidacloprid and endosulfan were tested in the laboratory for their effects upon the mirid bugs Dicyphus tamaninii and Macrolophus caliginosus, which are polyphagous predators used for IPM programs in some vegetable crops. The mortality of third-fourth instar nymphs was checked 24 and 48 hours and 7 days after exposure to 1-, 3-, 8-, 21- and 30-day residues of the treatments on tomato leaflets. The reproductive capacity of surviving females also was evaluated for 15 days and compared with females that had not been exposed to insecticides. Chlorpyrifos, formetanate and methamidophos are considered persistent because they remained toxic to both mirid species for 30 days. Imidacloprid is moderately persistent, becoming harmless by 21 days after treatment for M. caliginosus and by 30 days after treatment for D. tamaninii. Endosulfan is moderately persistent for M. caliginosus, becoming harmless by 21 days after treatment, and is short lived for D. tamaninii, becoming harmless by 3 days after treatment. There were no effects on the reproductive capacity of females that were exposed as nymphs to the insecticides tested. Of all the insecticides, only endosulfan is marginally compatible with the use of D. tamaninii.
