Oscar Alomar

• PhD Biology
• IRTA Institute of Agrifood Research and Technology

Simple Summary The tomato russet mite (TRM) is a significant problem in greenhouse tomato crops, and it has recently become more prevalent in Europe. The few acaricides available for its control are not specific and their effectiveness is limited. Several predatory mites have been tested for regulating TRM populations. Although these predators cons...

Agricultural intensification is affecting the biological control of insect pests, an important component for sustainable crop production. To understand the changing patterns of insect abundance within an agroecosystem, it is necessary to disentangle the trophic interactions between species, and metabarcoding is an excellent alternative to show them...

Agricultural intensification is affecting the biological control of insect pests, an important component for sustainable crop production. To understand the changing patterns of insect abundance within an agroecosystem, it is necessary to disentangle the trophic interactions between species, and metabarcoding is an excellent alternative to show them...

Our work reports on the establishment of the neotropical parasitoid Dolichogenidea gelechiidivoris Marsh (Hymenoptera: Braconidae) for the first time in Europe. This larval parasitoid has been recorded in samples collected in commercial tomato crops in Catalonia (North‐eastern Spain) from 2016 to the present. Dolichogenidea gelechiidivoris is consi...

Conservation biological control involves manipulation of the environment to enhance the effectiveness of natural enemies in controlling crop pests. In this study, we combined historical data, sticky trap sampling of tomato greenhouses and beat sampling of adjacent vegetation to identify which greenhouse characteristics, habitat management practices...

We assess the effects of changing land use and crop management on alfalfa insect abundance by comparing it in 50 alfalfa fields when they were inserted in landscapes with different proportions of arable crops and orchards. Land use in a buffer of 500 m was assessed, and alfalfa insect abundance was estimated with sticky yellow traps. The number of...

To understand trophic interactions and the precise ecological role of each predatory species, it is important to know which arthropod and plant resources are used by generalist predators in agroecosystems. Molecular approaches, such as the use of high-throughput sequencing (HTS), play a key role in identifying these resources. This study develops a...

Our study aimed to assess the contribution of natural parasitism due to Necremnus tutae Ribes & Bernardo (Hymenoptera: Eulophidae) to the biological control of Tuta absoluta (Meyrick) (Lepidopera:Gelechiidae) in commercial plots where an IPM program based on the use of predatory mirid bugs was implemented. During the samplings, the presence of anot...

Knowing which arthropod and plant resources are used by generalist predators in agroecosystems is important to understand trophic interactions and the precise ecological role of each predatory species. To achieve this objective, molecular approaches, such as the use of high-throughput sequencing (HTS) platforms are key. This study develops a multi-...

The β-aminobutyric acid (BABA) is a plant defense priming compound highly effective in controlling important tomato diseases and plant-parasitic nematodes. It has also been shown to induce resistance against phytophagous insects such as aphids. This study examines the effect of BABA on the performance of the tomato pest Bemisia tabaci (MEAM 1, prev...

Implementation of landscape approaches to conservation biological control programs requires the confirmation of putative sources that contribute to predator colonization of crops. Several predator species are known to play an important role in biological control programs in orchards worldwide. This study optimizes a DNA mark-capture procedure based...

Diverses espècies de l'ordre dels tisanòpters, coneguts com a trips, són plagues de diversos cultius hortícoles i fruiters de l'àrea mediterrània, entre les que destaquen Frankliniella occidentalis (trips de les flors), Thrips spp., Pezothrips kellyanus i Chaetanaphothrips orchidii (trips de l'orquídia). Totes elles causen danys directes sobre els...

First we describe the different types of biocontrol used in greenhouses and present examples of each type. Next we summarize the history of greenhouse biocontrol, which started in 1926, showed a problematic period when synthetic chemical pesticides became available after 1945, and flourished again since the 1970s. After 1970, the number of natural...

Zoophytophagous mirid species, that feed and develop either on prey or plant resources, are often found simultaneously on the same host. Hence, these species can engage in both intraguild predation and cannibalism, which can pose a threat to mirid eggs. Ovipositing females may respond to such risks of predation on their eggs by reducing the number...

Development of conservation biological control programs requires the identification of sources that contribute to predator colonization of crops. Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) is an efficient polyphagous predator used in biological control programs in vegetable crops in Europe. We have developed a marking method based on sprayi...

La genitalia es una estructura que se utiliza en la determinación de especies. Tradicionalmente, se ha usado la microscopia de campo claro para la obtención de imágenes. El microscopio láser confocal permite la obtención de imágenes tridimensionales, lo que permite detectar diferencias más sutiles entre las formas. Las tres especies de míridos que...

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 sp...

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 sp...

Predatory bugs (essentially Miridae and Anthocoridae) are used since years as biocontrol agents in greenhouses. These bugs occur naturally in the Mediterranean area. They are found colonizing vegetable crops, if they are not disturbed by chemical treatments. They are omnivorous predators which can feed on various arthropod preys as well as plant sa...

The feeding habits of the generalist arthropod predators in agroecosystems are often difficult to determine, as they are small, mobile and live among the vegetation or in the soil. DNA-based gut-content analysis is a powerful tool that enables the study of arthropod predator–prey interactions. Predation on two of the main pests of Mediterranean let...

Background The aphid Nasonovia ribisnigri (Mosley) (Hemiptera: Aphididae) and the thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) are common pests in Mediterranean lettuce crops, where Orius spp. are common generalist predators. Predation by Orius spp. was studied in a lettuce plot by conventional PCR and real-time PCR analys...

Despite wide acceptance of the importance of integrated pest management, pest control in most cropping systemsdepends on the extensive use of pesticides, with detrimental effects on environmental and human health. Theseeffects have led to many pesticides being removed from use, increasing demands for the rapid development ofalternative solutions. B...

Macrolophus pygmaeus (Rambur, 1839) (Insecta, Heteroptera, Miridae) is a predator of key vegetable crop pests applied as a biocontrol agent in the Mediterranean region. M. pygmaeus and M. melanotoma (A. Costa, 1853) are cryptic species with great morphological similarity which results in their misidentifica-tion and negative consequences for the co...

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 fem...

Media monitoring for emerging risks has become an essential tool in public health. This approach also has the potential to deliver early warning of emerging risks to plant health. The European Food Safety Authority (EFSA) has launched a project in collaboration with the Joint Research Centre (JRC) of the European Commission to make use of the Medic...

Background Hoverflies (Diptera: Syrphidae) are generalist predators of a great variety of pests. Nasonovia ribisnigri (Hemiptera: Aphididae) and Frankliniella occidentalis (Thysanoptera: Thripidae) are two common pests in Mediterranean lettuce crops, where they occur alongside alternative prey (e.g., Collembola). A semi-field experiment was conduct...

Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) (western flower thrips, WFT) is a key pest in a range of crops worldwide. Anthocorid species (Hemiptera) are important natural enemies of thrips. Several experiments were undertaken to determine whether a thrips lure, methyl isonicotinate (MI), affected the behaviour of WFT and anthoco...

Biological pest control in greenhouse crops is usually based on periodical releases of mass-produced natural enemies, and this method has been successfully applied for decades. However, in some cases there are shortcomings in pest control efficacy, which often can be attributed to the poor establishment of natural enemies. Their establishment and p...

The larvae of many hoverflies (Diptera: Syrphidae) are important polyphagous predators used in integrated pest management programs. Because the accurate identification of preimaginal stages by morphological characters is difficult, we have developed a multiplex PCR to identify the immature and/or adult stages of the most common syrphid species in M...

The species of the genus Orius Wolff are well known as generalist predators able to control pest outbreaks in several agroecosystems. Correct species identification can be problematic given their similarities, particularly in the immature stage. A pair of primers previously designed from the internal transcribed spacer-1 (ITS-1) region was able to...

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...

Modified atmospheres (MAs) are safe and environmentally friendly alternatives to control pests in stored products. However, to accommodate the requirements of the food industry, the control of insects by a MA can be a too lengthy process. This paper describes the potential of sulphur dioxide as an additive to reduce the long lethal exposure of modi...

Habitat manipulation and increasing biodiversity are important approaches that enhance biological control of pests, but it is important to evaluate the relative benefits of specific plant species when designing conservation programs. Orius insidiosus Say (Hemiptera: Anthocoridae) is an important predator of thrips and aphids that also feeds on plan...

In conservation biological control programs, provision of the required resources (shelter, food, oviposition sites) can be achieved by means of the use of insectary plants. This is especially important in the case of omnivorous predators that feed on prey and plant materials, and where the availability of plant resources plays a significant role in...

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...

The relationship between the oviposition site preferences of predators in the face of intraguild competitors has received little attention, but it likely shapes the reproductive ecology of predatory species. In this study, oviposition intensity and the within-plant distribution of Orius insidiosus (Heteroptera:Anthocoridae) and Nabis americoferus (...

The use of plant-feeding predators for biological pest control has traditionally been neglected, mainly due to the risk of them feeding on crop plants and causing economically significant damage. Yet, these predators offer advantages for biological pest control. They are mostly generalist predators that have an impact on several crop pests. They ma...

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Spontaneous colonization of crops by natural enemies contributes to the biological control of pests. However, in order to develop successful Conservation Biological Control programs it is also necessary to provide the required resources (shelter, food, oviposition sites, etc.). In the case of omnivorous predators, that alternatively feed on prey an...

DNA-based techniques have proved to be very useful methods to study trophic relationships between pests and their natural enemies. However, most predators are best defined as omnivores, and the identification of plant-specific DNA should also allow the identification of the plant species the predators have been feeding on. In this study, a PCR appr...

The development of alternative treatments for pest control in food commodities is an increasing demand from the food industry, which should meet consumer demands for the reduced use or elimination of pesticides. The use of carbon dioxide (CO2) at high pressure is one of the most rapid options for arthropod pest control among current commercial trea...

Intraguild predation (IGP) among predatory species can influence many plant-arthropod associations. However, the relevance of IGP is poorly understood for truly omnivorous species such as those that can complete development on both animal and plant diets. Here we test the hypothesis that IGP among two omnivorous mirids is more common when extraguil...

Modified atmospheres based on high carbon dioxide (CO2) content offer an alternative to fumigation for arthropod pest control in durable commodities. The present study aimed to establish the efficacy of using modified atmospheres during packaging (MAP) to control a wide spectrum of pests and their respective developmental stages that affect final f...

The development time for eggs and nymphs and female fertility were determined for Nesidiocoris tenuis Reuter (Het., Miridae: Dicyphini) at 15, 20, 25, 30, 35 and 40 +/- 1 degrees C, using tomato, Solanum esculentum (Miller), as substrate and eggs of Ephestia kuehniella Zeller as substitute prey. At 40 degrees C, N. tenuis was unable to develop and...

are considered key pests of greenhouse cucumbers, causing loss of crop yield, sooty mould, scarring and malformation of fruits. In previous trials, the polyphagous mirid bug Dicyphus tamaninii reduced these pest populations, but no data were available when both preys coexist in the crop. A treatment with a predator:prey ratio of 3:10 considering bo...

Greenhouse whitefly and western flower thrips are considered key pests of greenhouse cucumbers, causing loss of crop yield, sooty mold, scarring and malformation of fruits. In previous trials, the polyphagous mirid bug Dicyphus tamaninii reduced these pest populations but no data were available when both preys coexist in the crop. A treatment with...

Macrolophus caliginosus is a polyphagous mirid bug native to the Mediterranean area where it is widely used as a biological control agent, both in protected and open-field vegetable crops. Its reproductive biology remains largely unknown and a better understanding of it will improve mass rearing and release strategies. In the present work, we studi...

The zoophytophagous mirid bug Macrolophus caliginosus is an important biocontrol agent of whiteflies in the Mediterranean region. Periods of low productivity in commercial breeding units and unsuccessful establishment in greenhouses prompted this study of mating behaviour. Here we describe copulation behaviour, the diel mating periodicity and post-...

The mirid Macrolophus caliginosus Wagner (Hemiptera: Miridae), and the syrphids, Sphaerophoria rueppellii (Wiedemann), Sphaerophoria scripta (L.), and Episyrphus balteatus (DeGeer) (Diptera: Syrphidae), belong to the aphidophagous guild, feeding on aphids (Hemiptera: Aphididae) in Mediterranean vegetable crops. The direction, symmetry, and intensit...

This book, intended for the scientific community involved in biological control and integrated pest management, commercial companies producing biological control agents, risk assessors and regulatory authorities, compiles the current methodologies used for assessing the environmental impacts of invertebrate biological control agents and guidelines...

Late instar nymphs ofDicyphus tamaniniiWagner (Heteroptera: Miridae) were released in a 1:10 and a 3:10 ratio of the predator to prey in a high initial infestation of 5 adult thrips per leaf and in a low initial infestation of 1 adult thrips per leaf in greenhouse cucumbers. The 3:10D. tamaninii:Frankliniella occidentalis(Pergande) ratio kept thrip...

This work presents the results of an investigation that aimed to evaluate the effectiveness of releases of the omnivorous predator Macrolophus caliginosus Wagner (Heteroptera, Miridae) in the control of Bemisia tabaci Gennadius (Homoptera, Aleyrodidae) on greenhouse melon. Two greenhouse trials were performed, one in spring and one in summer. Adult...

Mediterranean vegetable growing areas are landscapes characterized by the coexistence of several annual crops, grown on rather small farms, and with a variety of species grown simultaneously all year round. Vegetable production is highly intensive, with up to 3 crops being produced on the same piece of land each year. The periodic destruction of no...

The objectives of this study were to describe the copulatory behaviour and maturation of the sexual organs of the predator M. caliginosus with the aim of implementing its use in augmentative releases in greenhouses. Males actively pursued females but that courtship was almost non-existent; more mating took place during night hours and in the first...

Selecting candidate plants to enhance predators for conservation biological control not only has to consider their contribution to enhancement of predators, but also avoid the risk of acting as reservoirs of potential pests or diseases. Mirid bugs are effective biological control agents of tomato pests and the introduction of insectary plants has b...

been used as an alternative treatment to methyl bromide for the control of stored product pests. In this study, two different methods were chosen to apply carbon dioxide (CO2): modified atmosphere packaging and high pressure treatments. The aim of our research was to compare the mortality of a range of stored product pests when treated with the two...

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 abu...

Some Mediterranean greenhouses are inserted in a landscape of open fields, non-agricultural and woody habitats. Both the greenhouse whitefly and its polyphagous predators are well adapted to protected and field crops. The phenology and intensity of whitefly and predator exchange between greenhouses and surrounding habitats were investigated in two...

Mirid bugs are important predators in vegetable crops in the Mediterranean basin, and M. caliginosus is of particular relevance. The object of this paper is to summarize our present knowledge on conservation and augmentation of this predator, examine the gaps to be filled to ensure more effective biological control, and discuss future lines of rese...

Mirid bugs are used in inoculative and conservative biological control strategies on several crops in the Mediterranean area. Due to their zoophytophagous habits, this may imply some risk of crop damage, as has been shown with tomatoes and gerberas. In this work, we studied the potential risk of damage that Macrolophus caliginosus and Dicyphus tama...

A correct taxonomic identification of predators is of paramount importance in biological control for both research and the transfer of results to integrated pest management (IPM) technicians. Dicyphus spp. are zoophytophagous mirid bugs that are well known for their role in the control of several horticultural crop pests in Europe. The genus is org...

The aim of our research is to provide the food industry with alternatives to methyl bromide and other pesticide treatments that are highly toxic and harmful to the environment. The application of carbon dioxide under pressure and preservation by modified atmospheres with high carbon dioxide concentrations are two control methods useful for the agro...

These proceedings contain nearly 200 keynote, oral and poster papers and contributions highlighting the work on the pests and diseases that cause spoilage, adverse health effects and crop losses after harvest, and discussing new techniques for safe, effective and environmentally friendly management of stored commodities. The contents cover the futu...

In northeast Spain, the most common predators found in tomato fields and greenhouses are the mirids Macrolophus caliginosus Wagner and Dicyphus tamaninii Wagner. Natural colonization occurs during the growing season and both species prey on whiteflies. Because D. tamaninii can damage tomato fruits during periods of prey scarcity, a semifield experi...

Macrolophus caliginosus (Wagner) is currently commercialized in Europe for the control of whiteflies in tomato greenhouses. Another mirid predator, Dicyphus tamaninii Wagner, spontaneously colonizes Mediterranean greenhouses. The impact of the presence of D. tamaninii on predation of the greenhouse whitefly (Trialeurodes vaporariorum Westwood) by M...

Dicyphus tamaninii and Macrolophus caliginosus are predatory bugs that significantly contribute to control of pests in tomato crops following early colonisation in spring from winter refuges. This paper aimed to determine the influence of the richness of nearby potential predator sources at the time of arrival, amount and establishment of the mirid...

Bemisia tabaci is an extremely polyphagous pest that causes direct damage and can act as a vector of viral plant diseases. The activity of natural enemies can be exploited by employing proper conservation and augmentation techniques. In addition to use of extant fauna, importation of parasitoids belonging to the genera Encarsia and/or Eretmocerus a...

The zoophytophagous predator Macrolophus caliginosus (Wagner) (Heteroptera: Miridae) has previously been identified as a potential prey for the intraguild zoophytophagous predator Dicyphus tamaninii Wagner. Its value as an intraguild prey was tested for D. tamaninii nymphal development and adult survival. In the laboratory, plant (red tomato fruit,...

Our research on the use of the predatory bug Dicyphus tamaninii for the biological control of greenhouse cucumber pests (the greenhouse whitefly Trialeurodes vaporariorum, the western flower thrips Frankliniella occidentalis and the cotton aphid Aphis gossypii) is reviewed. The predator was able to provide a good control of whiteflies and to greatl...

Results of a survey in IPM tomato greenhouses provide field evidence that suggests that the exotic facultative autoparasitoid E. pergandiella interferes with the primary parasitoid E. formosa released for control of whitefly (Trialeurodes vaporariorum).

Predation rate and nymphal development time were determined for four predatory bugs (Dicyphus tamaninii Wagner andMacrolophus caliginosus Wagner [Het.:Miridae],Orius laevigatus (Fieber) andO. majusculus (Reuter) [Het.:Anthocoridae], on cucumber withAphis gossypii Glover (Hom.:APhididae) as prey and for both mirids also on tomato withMacrosiphum eup...

The effectiveness was evaluated of releasing Aphelinus abdominalis in order to control aphids (mainly Macrosiphum euphorbiae) in unheated greenhouses growing spring tomatoes in Spain. Although aphid populations developed in some foci, no sooty mould appeared. A. abdominalis did establish in the crop, altogether with indigenous predators (Aphidolete...

Predation rate and nymphal development time were determined for four predatory bugs (Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner [Het.: Miridae], Orius laevigatus (Fieber) and O. majusculus (Reuter) [Het.: Anthocoridae], on cucumber with Aphis gossypii Glover (Hem.: Aphididae) as prey and for both mirids also on tomato with Macrosi...

Predation rate and nymphal development time were determined for four predatory bugs (Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner [Het.: Miridae], Orius laevigatus (Fieber) and O. majusculus (Reuter) [Het.: Anthocoridae], on cucumber with Aphis gossypii Glover (Hom.: Aphididae) as prey and for both mirids also on tomato with Macrosi...

Several species of mirids are native polyphagous predators in the Mediterranean basin, and among them, Dicyphus tamaninii is of particular interest. In this paper, the main biological features, prey range and consumption rates of D. tamaninii preying on whiteflies (Trialeurodes vaporariorum and Bemisia tabaci), Frankliniella occidentalis and aphids...

Field studies were carried out during 1987-90 in Spain on 24 fields of tomatoes to examine the use of the predator Dicyphus tamaninii against Trialeurodes vaporariorum. The damage to tomatoes by D. tamaninii was related to a shortage of alternative insect prey. The use of a decision chart to minimize damage is discussed.

Descriptions, drawings and colour photographs are given of Macrolophus pygmaeus, M. caliginosus, Cyrtopeltis tenuis, C. geniculata [C. modesta], Dicyphus tamaninii and D. errans. These mirids were found to be the most common predators in tomato fields in Catalonia, Spain, and play an important role in integrated pest management of tomato. A key is...

An integrated pest management programme was developed for outdoor tomato crops in Spain. The native mirids Macrolophus caliginosus and Dicyphus tamaninii were conserved up to a level where they excessively controlled Trialeurodes vaporariorum and began to damage the crop. Implementation of the programme in commercial fields reduced pesticide usage...