Macrolophus pygmaeus

Identification & Distribution

Two species (Macrolophus pygmaeus and Macrolophus melanotoma) have been used for biological control in glasshouses, and several other related species (e.g. Macrolophus rubi) also occur in the wild. We give key characteristics for these species as well as for Macrolophus pygmaeus.

Adult Macrolophus species are green and have a dark bar between each of the eyes and the pronotum (see first picture below). Macrolophus pygmaeus has the third antennal segment only about 1.75 times as long as the fourth (cf. Macrolophus rubi which has the third antennal segment at least twice as long as the fourth). The clavus is entirely green (cf. Macrolophus rubi which has a clear black mark at the apex of the clavus). The adult has the first antennal segment black (cf. Macrolophus melanotoma, formerly Macrolophus caliginosus, which usually has a white central band on that segment). The immatures of Macrolophus pygmaeus (see second picture below) have the first antennal segment a greenish brown.

Note:

There is considerable confusion in the literature between Macrolophus pygmaeus and Macrolophus melanotoma because the colour pattern on the first antennal segment does not always reliably differentiate the two species (Perdikis et al., 2003). We know of no studies directly comparing the biocontrol potential of each species. Since it is not always possible to know to which species the publication refers, we have included both species in our literature review.

Both pictures above copyright Skipper & Tolsgaard (2013) under a Creative Commons Attribution 4.0 International License.

Macrolophus pygmaeus is zoophagous and phytophagous. Its plant host is hedge woundwort (Stachys sylvatica), where it feeds on plant juices. Its animal prey comprise a variety of small invertebrates including aphids, whitefly, leaf miners, moth eggs and spider mites.

Biology & Ecology:

Host plant preference

Ingegno et al. (2011) explored the relationship between Macrolophus pygmaeus and different host plants. The host plants compared were red pepper (Capsicum annuum), marigold (Calendula officinalis), sage (Salvia officinalis), pellitory (Parietaria officinalis) and black nightshade (Solanum nigrum). Among tested plants, pellitory was the least attractive under laboratory conditions. Furthermore the availability of prey was crucial for the successful establishment of Macrolophus pygmaeus on tested plants, suggesting the inability of nymphs to complete development to adulthood on a strictly phytophagous diet. Nevertheless, Macrolophus pygmaeus seemed to prefer plants where phytophagy provides a fitness benefit. Note that it is not clear why its preferred host, hedge woundwort, was not included as one of the plants in this study.

Gaspari (2007) investigated the effect of water extract of 'annual nettle' (Urtica urens) on the biological characteristics and population parameters of Myzus persicae and Macrolophus pygmaeus on eggplants. Three applications were made at 5-day intervals using the nettle extract, with deionized water as the control. Their results showed that the application of nettle extract significantly reduced the fecundity of Myzus persicae but did not result in a substantial lowering in its intrinsic rate of population increase. The predator's biological characteristics and population parameters were not affected by the application of this plant extract. The authors discussed the importance of these results for the use of nettle extract in the management of Myzus persicae along with its compatibility with the use or conservation of Macrolophus pygmaeus.

Most aphid predators and parasitoids feed on plant-provided food (nectar, pollen) or engage in herbivory during at least part of their life stages. Plant feeding by these insects plays an important role in driving predator-herbivore dynamics. Thus, understanding the effects of plant feeding on omnivores could be an important element in improving biological control strategies. Unlike other predators that need to seek out accessible nectar to meet their carbohydrate requirements, mirid bugs can access the plant's carbohydrate resources by feeding directly on plant tissues. Leaf and stem feeding could be seen as a nutritional surrogate that allows mirids to become independent of nectar availability. However, to date, feeding experiments had not considered nectar feeding by these mirid predators. In this study Portillo et al. (2012) demonstrate that Macrolophus pygmaeus survival is prolonged on broad bean plants featuring extrafloral nectar as compared to broad bean with extrafloral nectaries removed, irrespective of the presence of pollen. Survival on extrafloral nectar was comparable to the survival by individuals kept on broad bean provided with eggs of Ephestia kuehniella (mediterranean flour moth) as prey. Also, a greater proportion of mirid females laid eggs when extrafloral nectar was available as compared to those confined on nectarless plants without supplemental food.

Prey preference

Enkegaard et al. (2006) carried out a comparative study between direct prey preference and odour-mediated preference of Macrolophus caliginosus. The mirid bugs showed a stronger response to odours from infested plants than to odours from clean plants. The mirids did not, however, seem to exploit odours emitted directly from the prey themselves. They further demonstrated that Macrolophus caliginosus prefers Myzus persicae to Tetranychus urticae (a spider mite) in a direct two-choice consumption test. This preference was, however, not reflected in a similar odour-mediated preference between plant volatiles induced by either of the two preys.

Fantinoua et al. (2008) addressed the fascinating issue of prey killing without consumption ('fox in a henhouse' behaviour) addressing the question of whether Macrolophus pygmaeus shows adaptive foraging behaviour. Several predators exhibit a killing behaviour that might not result in prey consumption after prey death. This behaviour includes killing without consumption and/or partial prey consumption. The hypotheses tested included whether or not the predatory behaviour of Macrolophus pygmaeus is affected by the prey density or prey size. The nymphal instars of Myzus persicae were used as prey. The experiments were conducted at three different temperatures. The frequency of non-consumptive mortality was higher with larger and overall less-preferred prey instars. Predators that foraged at low temperatures appeared to be less selective, killed more frequently, and left more prey unconsumed. Killing behaviour, however, was not found to increase with prey density. Instead, non-consumptive prey mortality was associated with intermediate prey densities and was dependent on temperature and the prey instar. Fantinoua et al. believed that this behaviour corresponded to a foraging predator's strategy for optimal exploitation of the available prey.

Fantinoua et al. (2009) examined preference and prey consumption of Macrolophus pygmaeus when offered mixed-instar assemblages of Myzus persicae. They examined the effects of changes in the prey frequency and abundance upon prey selection among the four instars of Myzus persicae under laboratory conditions. The central hypothesis was that Macrolophus pygmaeus would become more selective as prey density increases. It was also observed that Macrolophus pygmaeus can occasionally abandon a prey item that had already been killed (non-consumptive prey mortality). It was assumed that the frequency of this behavior would increase with the prey size and prey density. For these purposes prey-selection was evaluated by simultaneously presenting all instars of Myzus persicae to the predator in equal proportions and at increasing densities. Macrolophus pygmaeus showed a higher predation rate and a higher preference for smaller prey instars at all prey densities. However, if the predation rate by the predator is expressed in terms of biomass consumed, then biomass gain was higher when feeding on the larger instars of Myzus persicae. The prey selectivity was indicated by the total prey mortality (consumptive plus non-consumptive prey mortality) as well as by the non-consumptive prey mortality, was associated with relatively high prey densities, depending on the prey instar. The authors argued that the predatory impact of Macrolophus pygmaeus on the various instars of the aphid depends not only on prey traits but also on their relative abundance in a patch. Observed decreases in biomass gain from larger prey were likely the result of high prey availability at densities before saturation, which might have caused confusion in the predator's prey selection.

Predator survival, development and predation rate

Perdikis et al. (1999) studied the effect of temperature and photoperiod on the rate of predation by nymphs and adults of Macrolophus pygmaeus using Myzus persicae feeding on egg-plant and pepper plants. Predation rate was affected by photoperiod on pepper but not on egg-plant. Females and fifth instar nymphs were the most voracious stages, followed by third and fourth instar nymphs and males. First and second instar nymphs consumed far fewer aphids. Predation rate was higher on leaves of pepper than egg-plant.

Perdikis & Lykouressis (2000) studied nymphal development and survival of Macrolophus pygmaeus on various host plants, in the presence and absence of various insect prey, and on bee pollen (pollen balls from honeybee workers), and on pollen from 'squirting cucumber' (Ecbalium elaterium), in various combinations. Results demonstrated that Macrolophus pygmaeus can successfully complete its development on tomato, eggplant, cucumber, pepper, and green beans in the absence of insect prey. In the presence of insect prey, Macrolophus pygmaeus had the shortest period of nymphal development on eggplant with whitefly (Trialeurodes vaporariorum) followed by the aphids Myzus persicae, Macrosiphum euphorbiae and Aphis gossypii and the spider-mite Tetranychus urticae. Mortality of Macrolophus pygmaeus nymphs was higher in the absence than in the presence of prey on various host plants, but was not considered a factor restricting predator establishment. Macrolophus pygmaeus completed its development, even in the absence of prey, under a range of temperatures from 15 to 30°C on tomato, with optimum development at 30°C. Bee pollen and pollen from cucumber, when offered separately, were sufficient to support successful predator nymphal development and survival. Bee pollen contributed considerably to the development and survival of the nymphs when it was included in diets containing other food sources, such as eggplant leaves and Myzus persicae.

Perdikis & Lykouressis (2002) studied the life table and biological characteristics of Macrolophus pygmaeus when the bugs were fed with Myzus persicae feeding on eggplant, and with Trialeurodes vaporariorum (the glasshouse whitefly) feeding on tomato plants. The intrinsic rate of increase of Macrolophus pygmaeus was highest at 27.5 °C, with similar values on eggplant and tomato. Doubling time was shortest at 27.5 °C and, also, finite rate of increase was highest at 27.5 °C. Their results show that the predator Macrolophus pygmaeus develops well on the aphid Myzus persicae, or on the whitefly Trialeurodes vaporariorum, both of which are important pests of vegetable crops. This predator is also well adapted to the temperatures that occur both in greenhouses and in the open field in the Mediterranean region. Compared to other natural enemies of whiteflies such as Encarsia formosa (a chalcidoid wasp parasitoid, often used to control greenhouse whitefly), Macrolophus pygmaeus populations can increase at relatively low temperatures.

Lykouressis et al. (2007) investigated the predation rate of the polyphagous predator Macrolophus pygmaeus when offered two aphid species, Myzus persicae and Macrosiphum euphorbiae. The predation rate of Macrolophus pygmaeus was always higher on Myzus persicae than on Macrosiphum euphorbiae. However, biomass consumption was highest when instars of Macrosiphum euphorbiae were offered in unequal numbers. The predator showed a strong preference and higher biomass consumption of first and second instar Myzus persicae. In tests where Macrosiphum euphorbiae was the prey, preference and biomass consumption were almost always higher for the first instar. Therefore, first and second instar Myzus persicae and first instar Macrosiphum euphorbiae provide optimal prey for Macrolophus pygmaeus.

Intraguild predation

Perdikis et al. (2014) investigated intraguild predation and sublethal interactions between two zoophytophagous mirids, Macrolophus pygmaeus and another mirid, Nesidiocoris tenuis (tomato bug, also a general predator, see picture below), on tomato.

Nesidiocoris tenuis, copyright Guney Baloglu under a Creative Commons Attribution 4.0 International License.

The two predators showed a different distribution pattern on the tomato plants, with Nesidiocoris tenuis exploiting mostly the upper part, whereas Macrolophus pygmaeus were mostly observed on the 5th to the 7th leaf from the top. However, when the predators co-occurred, Nesidiocoris tenuis or Macrolophus pygmaeus individuals were recorded with increased numbers on the lower or the higher part of the plant, respectively. In the presence of Nesidiocoris tenuis adult young nymphs of Macrolophus pygmaeus completed their development to the adult stage when alternative prey (lepidopteran eggs) were present on the plant, but 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 Nesidiocoris tenuis. However, large 4th instar nymphs of Macrolophus pygmaeus were much less vulnerable to Nesidiocoris tenuis than younger individuals. The behavior of Nesidiocoris tenuis was affected by the presence of Macrolophus pygmaeus, but at a rate similar to that when two individuals of Nesidiocoris 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 Macrolophus pygmaeus and Nesidiocoris tenuis do occur, but are not intensive.

Biological control:

Mass rearing

Vandekerkhove & De Clercq (2010) looked at pollen as an alternative or supplementary food for the mirid predator Macrolophus pygmaeus. For the mass production of this bug, eggs of the Mediterranean flour moth Ephestia kuehniella are routinely used as an effective but expensive alternative food. In the current study, the potential of pollen as a supplementary food for Macrolophus pygmaeus was investigated. In a first experiment, the minimum number of Ephestia kuehniella eggs needed for optimal development and reproduction was determined to be 40 eggs per individual per 3 days. Insects reared on only 10 Ephestia kuehniella eggs per 3 days suffered higher mortality, developed slower and had lower adult weights and oocyte counts than insects reared on 40 eggs or 10 eggs supplemented with pollen. When the nymphs were fed only pollen, survival rates and oocyte production were lower than when both pollen and flour moth eggs were provided. On pollen alone, ca. 80% of the nymphs successfully reached adulthood; their adult weights and oocyte counts were, respectively, 12% and 32% lower compared with individuals fed optimal amounts of flour moth eggs. When an egg yolk-based artificial diet was supplemented with bee pollen, development and fecundity were better than on the artificial diet alone.

Effects of Insecticide

Arnas & Gabarra (2011) evaluated the lethal and sublethal side effects of three of the insecticides most widely used to control Tuta absoluta on the predators Macrolophus pygmaeus: azadirachtin (a limonoid, from neem seeds), spinosad (an insecticide from the bactera Saccharopolyspora spinosa) and indoxacarb (an oxadiazine pesticide for lepidopteran larvae). Seven days after applying the treatment at the maximum recommended field rates, the mortality produced by indoxacarb ranged from 28% for nymphs of Macrolophus pygmaeus to 77% for females of Nesidiocoris tenuis and were significantly higher than those produced by azadirachtin, spinosad and the control (<13%). However, indoxacarb did not affect the number of descendants of females exposed to residues during the last days of their preimaginal (preadult) development. In contrast, spinosad significantly reduced the offspring of Macrolophus pygmaeus, and azadirachtin significantly reduced the offspring of Nesidiocoris tenuis females. The sublethal effects of azadirachtin and spinosad on predator reproduction should therefore not be ignored. This information could be useful when selecting the most appropriate insecticide to control Tuta absoluta in greenhouses and field crops in which Macrolophus pygmaeus and Nesidiocoris tenuis are used as biological control agents.

Martinou et al. (2014). evaluated the lethal and behavioural effects of six insecticides and a fungicide on Macrolophus pygmaeus nymphs exposed to the pesticides through three routes of exposure: direct, residual and oral. Chlorantraniliprole (a selective insecticide) and emamectin-benzoate (from the soil actinomycete Streptomyces avermitilis) caused less than 25% mortality to Macrolophus pygmaeus and were classified as harmless according to the International Organization for Biological Control rating scheme. In contrast, thiacloprid (a neonicotinoid) and metaflumizone (a broad-spectrum semicarbazone insecticide) caused 100% and 80% mortality, respectively, and were classified as harmful. Indoxacarb and spinosad resulted in close to 30% mortality to the predator, and were classified as slightly harmful, while the fungicide copper hydroxide caused 58% mortality and was rated as moderately harmful. Chlorantraniliprole and thiacloprid were selected for further sublethal testing by exposing Macrolophus pygmaeus to two routes of pesticide intake: pesticide residues, and feeding on sprayed food. Thiacloprid led to an increase in resting and preening time of the predator, and a decrease in plant feeding. Chlorantraniliprole resulted in a decrease in plant feeding, but no other behaviours were affected. In addition, thiacloprid significantly reduced the predation rate of Macrolophus pygmaeus, whereas chlorantraniliprole had no significant effect on predation rate. The results of the study suggest that thiacloprid is not compatible with Macrolophus pygmaeus, while further research needs to be carried out for metaflumizone and copper hydroxide. All other products seem to be relatively compatible with Macrolophus pygmaeus, though studies on their sublethal effects will shed more light into their safety.

Control of aphids

Lykouressis, et al. (2000) looked at the effects of natural enemies on aphid populations on tomato in Central Greece. Two species of aphids, Macrosiphum euphorbiae and Myzus persicae were the only ones which developed populations on tomato in a two year study conducted in central Greece. The aphid population structure showed that Macrosiphum euphorbiae was much more abundant than Myzus persicae in both years. The former species peaked in August whilst the latter did not show any particular peak over the two successive years. Some species of natural enemies were recorded. Orius niger (an anthocorid) was found in low numbers scattered over a long period, but mainly towards the end of the growing season, and it did not correlate with the aphid population. The rate of parasitism of Macrosiphum euphorbiae by the parasitoids Aphelinus abdominalis and Praon volucre was very low, and it seemed that they did not have any particular effect on the aphid population suppression. Macrolophus pygmaeus was the key natural enemy and the most abundant and effective among the predators found. Its highest numbers occurred towards the end of the growing season following the aphid population peak, suggesting a numerical response of this species to its prey. A proportion of the population of Macrolophus pygmaeus occurring on tomato plants after fruit harvesting, might he collected and subsequently released in crops such as tomato, pepper and eggplant, to biologically control greenhouse pests like aphids and whiteflies, thus contributing to the production of healthy vegetable products.

Perez-Hedo & Urbaneja (2005) examined the potential of the omnivorous predatory mirids Nesidiocoris tenuis, Macrolophus pygmaeus, and Dicyphus maroccanus as biocontrol agents of aphids in sweet pepper crops. Laboratory work demonstrated that females of the three species of predatory mirids were strongly attracted to the odour of plants infested with Myzus persicae. The three species actively preyed on Myzus persicae, with Dicyphus maroccanus the most voracious species preying on both young and mature nymphs. Finally, the capacity of the three omnivorous predators to reduce Myzus persicae on heavily infested plants was determined in semi-field conditions. The three species of mirids could reproduce on aphids and establish on sweet pepper plants. Mirids significantly reduced the number of Myzus persicae per leaf, reaching levels of aphid reduction close to 100% when compared to the untreated control. These results suggest that mirids might play a major role in aphid management in sweet peppers.

Messelink et al. (2011) evaluated the effects of inoculative releases of the generalist predatory bugs Orius laevigatus, Orius majusculus (omnivorous anthocorids used for biocontrol) and Macrolophus pygmaeus on Myzus persicae and western flower thrips (Frankliniella occidentalis) in a greenhouse-grown sweet pepper crop. They found that, compared to the two Orius species, Macrolophus pygmaeus was by far the best predator for controlling aphids. Several releases of aphids did not result in an establishment of this pest in the plots with Macrolophus pygmaeus, whereas aphids attained high densities in the Orius laevigatus or Orius majusculus treatments, causing serious crop damage. Thrips were controlled by all predators, but compartments with Macrolophus pygmaeus initially showed some thrips damage on the fruits. Currently, Orius laevigatus is the predator used most in inoculative releases in sweet pepper in Europe, but the data suggested that, when control of both thrips and aphids is required, it might be better to use Macrolophus pygmaeus instead of Orius laevigatus - or in addition to it.

Messelink et al. (2014) reported increased control of thrips and aphids in greenhouses with two species of generalist predatory bugs involved in intraguild predation. The combined release of species of generalist predators can enhance multiple pest control when the predators feed on different prey, but, in theory, predators may be excluded through predation on each other. This study evaluated the co-occurrence of the generalist predators Macrolophus pygmaeus and Orius laevigatus and their control of two pests in a sweet pepper crop. Both predators consume pollen and nectar in sweet pepper flowers, prey on thrips and aphids, and Orius laevigatus is an intraguild predator of Macrolophus pygmaeus. Observations in a commercial sweet pepper crop in a greenhouse with low densities of pests showed that the two predator species coexisted for 8 months. Moreover, their distributions in flowers suggested that they were neither attracted to each other, nor avoided or excluded each other. A greenhouse experiment showed that the predators together clearly controlled thrips and aphids better than each of them separately. Thrips control was significantly better in the presence of Orius laevigatus and aphid control was significantly better in the presence of Macrolophus pygmaeus. Hence, combined inoculative releases of Macrolophus pygmaeus and Orius laevigatus seem to be a good solution for controlling both thrips and aphids in greenhouse-grown sweet pepper. The predators are able to persist in one crop for a sufficiently long period and they complement each other in the control of both pests. The study provided further evidence that intraguild predation does not necessarily have negative effects on biological control.

Messelink et al. (2015) aimed to select a suitable mirid predatory bug for aphid control in sweet pepper. Four species were compared: Macrolophus pygmaeus, Dicyphus errans, Dicyphus tamaninii and Deraeocoris pallens. They were assessed on their establishment on sweet pepper plants with and without supplemental food (eggs of the flour moth Ephestia kuehniella and decapsulated cysts of the brine shrimp Artemia franciscana and on their effects on aphids with releases before and after aphid infestations. None of the predator species was able to control an established population of aphids on sweet pepper plants; however, the predators Macrolophus pygmaeus and Dicyphus tamaninii could successfully reduce aphid populations when released prior to an artificially introduced aphid infestation. The best results were achieved with Macrolophus pygmaeus in combination with a weekly application of supplemental food. The results demonstrated that the order and level of plant colonization by mirid predators and aphids determines how successful biological control is.

De Backer et al. (2015) evaluated the effectiveness of Macrolophus pygmaeus in controlling Myzus persicae by testing different combinations of aphid and predator densities in cage-experiments under greenhouse conditions. The impact of the presence of an alternative supplementary prey (Ephestia kuehniella eggs) was also investigated. Macrolophus pygmaeus, at densities of four individuals/plant, caused rapid decline of newly established aphid populations. When aphid infestations were heavy, the mirid bug reduced the aphid numbers but did not fully eradicate aphid populations. The availability of an alternative prey did not influence Macrolophus pygmaeus predation on aphids. Preventive application of Macrolophus pygmaeus, along with a supplementary food source, was recommended to control early infestations of aphids.

Control of whiteflies

Alomar et al. (2006) reported on an investigation that aimed to evaluate the effectiveness of releases of the omnivorous predator Macrolophus caliginosus in the control of Bemisia tabaci (silverleaf whitefly, see picture below) on greenhouse melon.

Bemisia tabaci, USDA, public domain.

Two greenhouse trials were performed, one in spring and one in summer. Adults of Macrolophus caliginosus were released at two release rates (two and six per plant) in an initial infestation of 10 adult whitefly per plant. The high release rate did control the whitefly populations. The lower release rate did not work in the second trial, presumably due to excessive pruning of the crop that may have affected predator establishment. No damaged fruits were recorded. Laboratory trials were also done to examine the effects of plant and variable prey availability on predator fertility and survivorship. Results showed that low-prey availability significantly reduced survivorship and fertility of Macrolophus caliginosus, and explained why predator establishment was the same for both predator release rates.

Gabarra et al. (2006) studied the efficacy of using two natural enemies, Eretmocerus mundus and Macrolophus caliginosus, either individually or in combination to control Bemisia tabaci on greenhouse tomatoes in spring and autumn crop cycles. Eretmocerus mundus was effective in reducing whitefly populations in both crop cycles. However, the greatest reduction in terms of both adults and nymphs of Bemisia tabaci was achieved with the combined use of Eretmocerus mundus and Macrolophus caliginosus, especially in spring and with high whitefly populations. Releases of both natural enemies prevented adult whitefly emergence and the establishment of predators prevented subsequent crop colonization by whitefly.

Control of tomato leafminer

The tomato leafminer (Tuta absoluta, see picture below) is a pest, native to South America, that produces significant damage to tomato crops. It was first detected in Europe in late 2006, and is now found over much of Europe and North Africa.

Tuta absoluta, copyright Patrick Clements under a Creative Commons Attribution 2.0 License.

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.

As a first step to discovering the extent to which two indigenous mirid predators, Macrolophus pygmaeus and Nesidiocoris tenuis can adapt to this invasive pest, Molla et al. (2011) evaluated the prey suitability of eggs and larval instars of Tuta absoluta under laboratory conditions. Both predators preyed actively on Tuta absoluta eggs and all larval stages, although they preferred first-instar larvae. Secondly, in a greenhouse trial both mirids were separately inoculated on tomato plants to evaluate their predation on Tuta absoluta. After its installation in the crop, Nesidiocoris tenuis was highly effective in controlling Tuta absoluta under these experimental conditions, with reductions of up 97% infestation of leaflets and of 100% of fruits. Macrolophus pygmaeus was also effective on this new pest, although its efficacy was lower in comparison to Nesidiocoris tenuis (76% and 56% reductions of leaflet and fruit infestation). Their results demonstrate that both mirids can adapt to this invasive pest, contributing to their value as biological control agents n tomato crops. A challenge for future studies will be to investigate how both predators, especially Nesidiocoris tenuis, can be used in biological control programs targeting Tuta absoluta.

Suppliers of Macrolophus pygmaeus

Macrolophus pygmaeus is available commercially from various sources including Fargro (Britain), Biobest (Belgium) and Koppert (Netherlands).

Acknowledgements We especially thank Hadlow College for their kind assistance, and permission to sample. For identifying mirid bugs we have used Southwood & Leston (1959) and British Bugs to aid in identification and for the key characteristics. For aphids we have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994) and Blackman & Eastop (2006) supplemented with Blackman (1974), Stroyan (1977), Stroyan (1984), Blackman & Eastop (1984), Heie (1980-1995), Dixon & Thieme (2007) and Blackman (2010). We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

Useful weblinks

References Alomar, O. et al. (2006). Macrolophus caliginosus in the biological control of Bemisia tabaci on greenhouse melons. Biological Control, 36(2), 154-162. Abstract Arnas, J. & Gabarra, R. (2011) . Side effects of selected insecticides on the Tuta absoluta (Lepidoptera: Gelechiidae) predators Macrolophus pygmaeus and Nesidiocoris tenuis (Hemiptera: Miridae). Journal of Pest Science 84(4), 513-520 Abstract De Backer, L. et al. (2015). Evaluation of Macrolophus Pygmaeus (Heteroptera: Miridae) as biocontrol agent against aphids. MSc thesis. Universite de Liè Full text De Backer, L. et al. (2015). Predation of the Peach Aphid Myzus persicae by the mirid predator Macrolophus pygmaeus on sweet peppers: Effect of prey and predator density. Insects 6, 514-523. Full text Enkegaard, A. et al (2006). Odour-mediated preference and prey preference of Macrolophus caliginosus between spider mites and green peach aphids. 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