Orius Species Research Articles

Buckwheat as a companion plant in soybean fields: Implications for management of major pests

Abstract Many studies have explored the potential of companion plants to manage pests through top–down or bottom–up effects in agricultural fields. Buckwheat is known as a good candidate for companion planting with various crops to enhance pest management, but rarely in soybeans. We investigated the impact of planting buckwheat as a new companion plant on the population dynamics of major soybean pests and their natural enemies in soybean fields in Andong, Republic of Korea. We recorded numbers of pests and natural enemies at 9–10‐day intervals from 20 soybean plants each in eight small experimental fields throughout the cropping season. Significant reduction in pests, such as Riptortus pedestris (F.) (Hemiptera: Alydidae) adults, and a significant increase in natural enemies, such as Orius species (Hemiptera: Anthocoridae) and crab spiders (Araneae: Thomisidae), were observed in the buckwheat treatment plots. However, there were significant increases in other pests, such as leafminers and leafhoppers, in the buckwheat treatment plots. While we observed effects on R. pedestris adult density, we did not find significant effects on other developmental stages of this pest or its parasitoids. Although there were some concerns in the buckwheat treatment plots, the positive effects of buckwheat in soybean fields appear to outweigh the drawbacks. Buckwheat is likely a suitable companion plant for use in soybeans to manage pests.

Control effect and field application of four predatory Orius species on Megalurothrips usitatus (Thysanoptera: Thripidae).

Megalurothrips usitatus (Bagrall) is one of the most important pests of cowpea, Vigna unguiculata (Linn.) Walp in South China. Four Orius species, including Orius minutus (L.), Orius nagaii (Yasunaga), Orius sauteri (Poppius), and Orius strigicollis (Poppius), have been commercially produced and widely used as natural enemies of pests in China. In this study, we evaluated the control efficiency of these Orius species on M. usitatus in tropical Hainan Province, China, by recording the survival rates, developmental times, and predation effects in laboratory and semi-field conditions. Laboratory experiments showed that all these 4 Orius species preyed on M. usitatus under the experimental temperatures (25, 30, and 35 °C), and O. strigicollis exhibited the highest survival rate and predation effect. Semi-field cage experiments showed that the control effect of 4 Orius species on M. usitatus was significantly higher than that under normal chemical control, with O. strigicollis having the highest effect. Greenhouse experiments in Hainan Province, China, confirmed that O. strigicollis had a significant control effect on M. usitatus. Our study indicated that O. strigicollis has a significant potential for the control of M. usitatus in cowpea fields in southern China.

Demography and predatory potential of Orius strigicollis on eggs of Plutella xylostella at two temperatures.

The polyphagous predatory bug Orius strigicollis Poppius (Heteroptera: Anthocoridae) is an active predator used to control many insect pests of agricultural crops. Orius species are significantly affected by the type of food and temperature. A study of O. strigicollis feeding on Plutella xylostella L. (Lepidoptera: Plutellidae) eggs in climate chambers at 28 and 32°C, 70 ±5% relative humidity, 16:8 photoperiod, was conducted to determine the effects of different temperatures on the predation activity, biological characteristics and demographic parameters of O. strigicollis. Twosex-MS Charts were used to determine the age-stages and characteristics of this species. The results showed that the daily consumption of pre-adults on eggs of P. xylostella was highest at 28°C, and at this temperature, there was a greater probability that O. strigicollis would survive to adulthood (42.5%) than at 32°C (25.0%). It has also been found that at 28°C there was a long oviposition period (9.38 days) and the greatest female fecundity (44.2 eggs/female) In addition to the highest life expectancy of O. strigicollis (16.96 days) at 28°C, the intrinsic rate of increase (0.087 d-1) was also highest. According to our results, O. strigicollis has the potential to grow and develop on the eggs of P. xylostella at 28°C and, therefore, could potentially be used as a biological control agent in integrated pest management (IPM) programs.

An analysis of predatory bugs (Orius spp., Hemiptera: Anthocoridae) and pest insects on some crop plants: Their distributions, abundance and population developments

Seasonal distributions and population dynamics of predatory bugs, Orius (Hemiptera: Anthocoridae) species with some harmful insects in crop plants in 2019-2020 Turkey were investigated in Turkey. A total of four Orius species were identified, these are; Orius laevigatus,(Fieber) Orius niger (Wollf) Orius albidipennis (Reuter) and Orius vicinus (Ribaut). The most common species was O. laevigatus, constituting 78.36% of the total adult individuals. Both O. laevigatus and O. niger were relatively more abundant on broad beans and beans than those numbers found in fruit trees and field crops. Very few Orius individuals were recorded on the fruit trees. Orius and thrips individuals were collected mainly from the flowers of the plants, and their population patterns depended on the flowering phenology patterns of the plants. Orius individuals were recorded together with the pest thrips on plants particularly summer and winter vegetables sampled. The total prey (thrips, aphids and leafhoppers) numbers per Orius were lower on broad bean and bean plants. Finally, the number of prey per Orius was 5.83 in the broad bean and 14.33 in the bean plant, indicating thrips in particular had high predation risks due to Orius attacks in these two plant species.

Frozen lepidopteran larvae as promising alternative factitious prey for rearing of Orius species

Frozen lepidopteran larvae as promising alternative factitious prey for rearing of Orius species

Considering the Geographic Diversity of Natural Enemy Traits in Biological Control: A Quantitative Approach Using Orius Predators as an Example

The desirable characteristics of effective natural enemies and the causes for failure of biological control efforts have been discussed extensively in the literature, yet predicting which collection site may yield efficient natural enemies remains a challenge. Insect characteristics, such as morphology, physiology, life history and behavior, often vary across geographic cline and location. These variations may reflect phenotypic plasticity across environments, or genetically based local (demic) adaptation. Parameters such as body size, photoperiod response, thermal tolerance and genetic diversity may greatly influence the outcome of biological control efforts. Therefore, geographic variation in such characteristics may be used to optimize the collection site of efficient enemies to be employed in biological control programs. The first step towards this goal is compilation of data on the trait diversity of promising natural enemies across their geographic distribution range. For example, we used published information to compile a database on the geographic distribution of various traits of 92 Orius species (Heteroptera: Anthocoridae), a genus known for its potential contribution to biological control in IPM systems. We discuss how the widespread distribution of this genus in different ecozones should enable the collection of species and populations that differ in various geographically dependent traits relevant to biological control. Finally, we suggest a quantitative method to optimize collection efforts of natural enemies. This approach balances the effects of several natural enemy traits that vary geographically. Lastly, we demonstrate the use of this method by evaluating the potential employment of two geographically distinct populations of O. albidipennis.

Effects of Nutritional Composition of Different Prey Eggs on Development and Reproduction of the Predatory Bug, Orius sauteri (Hemiptera: Anthocoridae).

Orius sauteri (Poppius) is an important predator of many economically important insect pests. The mass rearing of O. sauteri is difficult, limiting its application in pest control. Here we assessed the nutritional quality of eggs of Sitotroga cerealella (Olivier), Agrotis ypsilon (Rottemberg), or Spodoptera litura (Fabricius), and their potential for rearing O. sauteri in the laboratory for two generations. Of species tested, S. cerealella eggs resulted in the highest survival and reproduction of O. sauteri compared to the other two lepidopteran species. Eggs of A. ypsilon were a suitable diet for the nymphal stage, which developed faster on A. ysilon eggs than those of S. cerealella eggs. Conversely, eggs of S. litura were not a suitable diet for O. sauteri, and they disrupted the development and reproduction of O. sauteri. Sitotroga cerealella eggs showed advantages in all the nutritional components evaluated. Orius sauteri fed S. litura eggs contained significantly lower protein levels than those fed on the other eggs tested. Spodoptera litura eggs significantly enhanced the CAT activity in O. sauteri, which suggests that some components from S. litura eggs harmed the development and reproduction of O. sauteri. Based on these results, we suggest using a combined diet for mass rearing of the pirate bug, feeding the nymphs and adults with A. ypsilon eggs and S. cerealella eggs, respectively. This study contributes to the discovery of artificial diets for mass rearing O. sauteri and other Orius species in the future.

Investigation of predatory Orius species (Hemiptera: Anthocoridae) in Balcalı District of Adana Province, Turkey

Bu çalışma ile Adana ili Balcalı yöresinde değişik kültür bitkilerinde 2019-2020 yıllarında Orius türleri (Hemiptera: Anthocoridae) türleri araştırılmıştır. Sörvey çalışmaları, bazı yazlık ve kışlık sebzeler, tarla bitkileri ile meyve ağaçlarında yürütülmüştür. Örnekleme ünitelerinde tek yıllık otsu kültür bitkilerinden 20 bitki, çok yıllık odunsu kültür bitkilerden ise 10 bitki tesadüfi olarak seçilmiştir. Örneklemelerde özellikle bitkilerin çiçekleri dikkate alınmıştır. Otsu bitkilerin üst kısımları, meyve ağaçlarının ise çiçekli sürgünleri kap içerisine silkelerek böcekler toplanmıştır. Çalışma sonucunda; Orius niger Wolff, Orius laevigatus (Fieber), Orius albidipennis (Reuter) ve Orius vicinus Ribaut (Hemiptera: Anthocoridae) türleri saptanmış olup, toplam birey sayıları 211 adet olarak kaydedilmiştir. Orius laevigatus %69.67 oran ile en yaygın bulunan avcı tür olmuştur. Bu türü, toplam erginlerde %29.39 bulunma oranı ile O. niger izlemiştir.

Prey preference of Orius minutus and its functional response in comparison that of O. laevigatus, on Tetranychus urticae

• Orius minutus preferred Frankliniella intonsa the most in choice or no-choice test. • Both O. minutus and O. laevigatus exhibited a Type III response. • O. minutus can be an biocontrol agent of both Tetranychus urticae and F. intonsa. Orius species (Hemiptera: Anthocoridae) are generalist predators of small insects, including thrips, mites, aphids, and scales. Here, we evaluated the prey preference of Orius minutus (L.) on five prey species by comparing it with Tetranychus urticae Koch (Acari: Tetranychidae) as a standard prey. Among five prey species tested, Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) and Hyalopterus pruni (Geoffroy) (Hemiptera: Aphididae) were preyed on more than T. urticae by O. minutus in a four hour choice test. In a four hour no-choice test, F. intonsa was the most frequently consumed prey, followed by H. pruni , T. urticae , Amphitetranychus viennensis (Zacher) (Acari: Tetranychidae), Eriococcus sp. (Hemiptera: Eriococcidae), and Stephanitis pyrioides Scott (Hemiptera: Tingidae). The functional response of O. minutus in response to various densities of adult T. urticae on kidney bean leaf was compared with that of the commercialized species Orius laevigatus (Fieber). Different numbers of adult T. urticae (5, 10, 20, 40, 80, and 120) were offered to females of both predators for 24 h in a controlled environment of 25.0 ± 0.5 °C, 71.2 ± 5.0% RH, and a 16: 8 h (L: D) photoperiod. Both O. minutus and O. laevigatus exhibited a Type III response according to a logistic regression model. Despite the similar attack rate or handling time found between the two species, predation rate was higher on O. minutus than on O. laevigatus . These results indicate that O. minutus could also play an important role in the biological control of T. urticae as well as F. intonsa and H. pruni .

Residual selectivity of some pesticides on the predatory bug, Orius minutus (Hemiptera: Anthochoridae)

ABSTRACT Orius species are predators of mites and many small insects such as aphids, scales, thrips, and insect eggs. Five insecticides (buprofezin, flonicamid, sulfoxaflor, flupyradifurone, and spirotetramat) and two acaricides (spiromesifen and emamectin benzoate) with low toxicity to natural enemies that are being used to control those pest groups were evaluated for their acute toxicity against adult females of Orius minutus (L.) (Hemiptera: Anthocoridae) and Orius laevigatus (Fieber) in a glass vial assay. Among the seven pesticides, spirotetramat and spiromesifen were the least acute toxic to both predators. In an experiment on sublethal toxicity of spirotetramat and spiromesifen against only O. minutus, we found that neither material negatively affected any of the life history parameters of O. minutus except for fecundity. A potted plant experiment was also conducted to confirm the efficacy of the combined use of spiromesifen and O. minutus against Tetranychus urticae Koch (Acari: Tetranychidae), and this combination was found to reduce the T. urticae population significantly more than the single treatment or untreated control. Therefore, we conclude that spiromesifen is a selective acaricide with less negative effect on biological parameters of O. minutus compared to other pesticides tested.

The predatory bug Orius strigicollis shows a preference for egg-laying sites based on plant topography.

BackgroundOviposition site selection is an important factor in determining the success of insect populations. Orius spp. are widely used in the biological control of a wide range of soft-bodied insect pests such as thrips, aphids, and mites. Orius strigicollis (Heteroptera: Anthocoridae) is the dominant Orius species in southern China; however, what factor drives its selection of an oviposition site after mating currently remains unknown.MethodsHere, kidney bean pods (KBPs) were chosen as the oviposition substrate, and choice and nonchoice experiments were conducted to determine the preferences concerning oviposition sites on the KBPs of O. strigicollis. The mechanism of oviposition behavior was revealed through observation and measurement of oviposition action, the egg hatching rate, and the oviposition time.ResultsWe found that O. strigicollis preferred the seams of the pods for oviposition, especially the seams at the tips of the KBPs. Choice and nonchoice experiments showed that females did not lay eggs when the KBP tail parts were unavailable. The rates of egg hatching on different KBP parts were not significantly different, but the time required for females to lay eggs on the tip seam was significantly lower. Decreased oviposition time is achieved on the tip seam because the insect can exploit support points found there and gain leverage for insertion of the ovipositor.DiscussionThe preferences for oviposition sites of O. strigicollis are significantly influenced by the topography of the KBP surface. Revealing such behavior and mechanisms will provide an important scientific basis for the mass rearing of predatory bugs.

Preference of Orius insidiosus and Orius tristicolor (Hemiptera: Anthocoridae) for Host Plants in Olfactometry and Free-Choice Experiments

The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a key pest of sweet pepper cultivation, where it causes feeding damage, excretes phytotoxic substances, and transmits important viruses. Control with chemical insecticides often is ineffective because endophytic oviposition and the cryptic habits of the pest provide protection. In Uruguay, the biological control program of this pest in sweet pepper crops is at risk due to the low settlement rate and high dispersal of releases of predator Orius insidiosus (Say) (Hemiptera: Anthocoridae). Previous studies have ruled out an antibiosis effect as the cause of dispersal; therefore, we hypothesized antixenosis (non-preference) for the sweet pepper plants as the cause of poor biological control by O. insidiosus. The effect of olfactory stimuli from different structures of strawberry, corn, and sweet pepper plants (lamuyo and blocky type) on the behavior of O. insidiosus was evaluated in olfactometry and free-choice cage experiments. Since Orius tristicolor (White) (Hemiptera: Anthocoridae) occurs naturally in the area, it was included also in the study with the aim of assessing whether there are differences in behavior between the species. Orius tristicolor may act as a complementary biocontrol agent or competitor on sweet pepper. Y-tube experiments showed no preference for plant volatiles in any combination, and response to volatile stimuli generally was poor. However, in the free-choice cage experiment, females of both species of Orius preferred the flowering strawberry plants over the flowering sweet pepper plants, which could explain the low establishment of O. insidiosus when released on pepper with neighboring strawberry fields. Given that horticultural greenhouses in Uruguay and in many other countries are open, this information can be very useful in designing the spatial and temporal management of different crops on a production field, which enhances the effectiveness of these predatory species.

Selection for larger body size in Orius laevigatus: Intraspecific variability and effects on reproductive parameters

Different characters of natural enemies can affect their performance in biological control programs. Among them, body size may play a significant role, as has been associated with increased fitness. No specific studies on body size have been carried out in any Orius species, important predators widely used in biological control. Therefore, the aim of this work was to study the variation in body size in wild and commercial populations of O. laevigatus, and artificially select a strain with larger body size. The parameters of the life table of populations showing different body sizes was investigated. We found a significant variability in body size among wild populations of O. laevigatus, with commercial populations within the natural range. From this variation we started a selective breeding programme for larger body size, successfully obtaining a strain with a significant larger body size. Our selected strain showed higher fecundity when provided a nutritionally superior food (Ephestia kuehniella eggs), and increased fecundity and longevity when fed a nutritionally inferior food (honey bee pollen). Despite a slightly slower development time, the overall reproductive potential was similar or superior to that of the commercial and unselected populations. We hypothesize that the enhanced characteristics of the selected large strain are based on a superior ability to exploit nutritional resources, conferring stronger resilience under stresses (low food quality or quantity) typically found in agricultural ecosystems, improving its performance as biological control agent.

Development and Fecundity of Orius minutus (Hemiptera: Anthocoridae) and O. laevigatus Reared on Tetranychus urticae (Acari: Tetranychidae).

The polyphagous predator Orius species is a dominant predator of thrips, mites, and aphids. Orius laevigatus (Fieber) is a well-known commercialized and effective biological control agent, whereas Orius minutus (L.) distributed widely over the world has not been commercialized. To assess potentials of developing O. minutus as a commercial biological control agent, we compared the biological parameters of O. minutus with O. laevigatus when reared on mixed stages of Tetranychus urticae Koch at 27.5°C. Nymphal development of O. laevigatus was shorter (11.30 d) than that of O. minutus (12.25 d), but there was no significant difference in survivorship between the two species. Also, no significant difference was found in either the preoviposition or oviposition periods, lifetime fecundity, or longevity between the two species. However, O. minutus eggs had a higher hatch rate (0.77) than O. laevigatus (0.71). In life table analysis, no difference was found in any parameters, i.e., R0, rm, λ, T, and DT, between O. laevigatus and O. minutus in two-tailed t-tests. In a predation bioassay, O. minutus consumed 1.39 times more adult T. urticae in 24 h than did O. laevigatus, although the predation rate on T. urticae eggs was similar between the two species. These results suggest that O. minutus native to Korea could be developed as a biological control agent against T. urticae.

Distribution and seasonal abundance of predatory bugs, Orius spp. (Hemiptera: Anthocoridae) in Adana Province, Turkey

Orius species are considered effective biological control agents of thrips both in fields and greenhouses worldwide. The seasonal abundance and distributions of Orius and thrips species were determined from different arable crops and weeds in Adana Province in 2015-2016. In this study, a total of six species of genus Orius namely, Orius albidipennis (Reuter,1884), Orius horvathi (Reuter,1884), Orius laevigatus (Fieber, 1860), Orius minutus (L., 1758), Orius niger (Wolff, 1881) and Orius vicinus (Ribaut, 1923) (Hemiptera: Anthocoridae) were identified. Orius niger was the most common predatory Anthocorid species with 1944 specimens, and followed by O. laevigatus with 447 specimens. While, O. laevigatus and O. niger were found to be active throughout the year, O. vicinus was only active in spring and summer, and the other Orius spp. were collected in summer. The predatory bugs were mostly found with the pestiferous thrips, Frankliniella occidentalis Pergande, 1895 and Thrips hawaiiensis (Morgan, 1913) (Thysanoptera: Thripidae) in diverse agricultural areas. Alfalfa, faba bean and sunflower were determined as a crucial host plant for Orius spp. Also, sesame could be potential companion (trap or banker) plant to support the predatory bugs in augmentative and conservative biological control strategies. Of the weeds sampled, Glebionis segetumFourr. and Sinapis arvensis L. were the most colonized by Orius spp. From results it is concluded that O. niger and O. laevigatus are well adapted to the geographical conditions and plant biodiversity in Adana Province. Therefore, these predatory bugs could be crucial biological control agents of thrips species in field crops.

Three new species of the flower bug genus Orius (Hemiptera: Heteroptera: Anthocoridae) from Nepal

Abstract Three new species of the flower bug genus Orius Wolff, 1811 (Anthocorinae: Oriini) are described as new, namely Orius (Orius) ekaii sp. nov., O. (Orius) nigromaritus sp. nov., and O. (Xylorius) paveli sp. nov., all from Nepal. The plant association and habitat are documented for each new species. Habitus images of live individuals and scanning electron micrographs are also provided to aid in proper recognition of their identities. A checklist of Orius species known from South Asia (SAARC nations) is incorporated; Orius indicus (Reuter, 1884) is herein placed in the subgenus Dimorphella Reuter, 1884.

Orius (Heterorius) linnavuorii (Hemiptera: Heteroptera: Anthocoridae), a New Species from Iran

A new species, Orius (Heterorius) linnavuorii Moulet, Ghahari & Ostovan sp. nov. (Hemiptera: Heteroptera: Anthocoridae), is described from Semnan Province (Iran). The species was collected on Acer velutinum, and confirmed as a predator of Asterobemisia atraphaxius. A checklist of 18 Iranian Orius species is provided.

A new species of the flower bug genus Orius Wolff (Hemiptera: Anthocoridae) cryptically inhabiting Hibiscus tiliaceus L. (Malvaceae).

A new species of the anthocorid genus Orius Wolff (subgenus Heterorius Wagner), O. (H.) hibiscus sp. n., is described, based on specimens recently found from the coastal area of Okinawa Island, Ryukyus, Japan. This new species, evidently most related to Orius (Heterorius) strigicollis (Poppius), was found to prefer cryptic habitat, or bract and flower bud of Hibiscus tiliaceus (L.) (Malvaceae) planted at urbanized zones in Naha City. Diagnostic characters of the new species are described, comparing with those of other Japanese members of Heterorius, based on detailed observation using a SEM. An updated checklist and revised key are provided to aid in identification of all known Japanese Orius species.

Variation in susceptibility and selection for resistance to imidacloprid and thiamethoxam in Mediterranean populations of Orius laevigatus

AbstractImidacloprid and thiamethoxam are neonicotinoids that have been tested in several Orius species, including Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), but not the variability in their effect among Orius populations of a single species. In this study, the variation in susceptibility to imidacloprid and thiamethoxam in 30 Mediterranean wild populations and four commercial populations of O. laevigatus was investigated in the laboratory using a standard dip bioassay method. Lethal concentration values (LC50) and the mortality of adults at the maximum field rate (MFR) were calculated. The range of LC50 of thiamethoxam was from 0.7 to 5.9 mg l−1, an 8.4‐fold variability, obtaining mortality at MFR (100 mg l−1) of >89.1% in all populations. The baseline obtained a value of 2.1 mg l−1, which is very low compared to the MFR. For imidacloprid, the LC50 varied from 7.7 to 94.7 mg l−1 (12.3‐fold variability). Mortalities at the MFR (150 mg l−1) were 57.7–99.2%, that is, more variable than for thiamethoxam. The LC50 value of the baseline was 48.7 mg l−1, also low compared to the MFR. This variation was exploited to select two populations resistant to thiamethoxam and imidacloprid, respectively. Artificial selection for on average 40 cycles significantly increased the resistance to thiamethoxam (LC50 = 149.1 mg l−1) and imidacloprid (LC50 = 309.9 mg l−1). Mortalities at the MFR in the thiamethoxam‐ and imidacloprid‐resistant populations were 44.5 and 36.9%, respectively. These results demonstrate that resistance can be enhanced in biocontrol agents by artificial selection under laboratory conditions, starting with populations showing no or very low tolerance. Our neonicotinoid‐resistant populations might enhance the wider adoption of biological control by allowing punctual or hotspot applications of neonicotinoids to control several main and secondary pests.

Effect of Two Oviposition Feeding Substrates on Orius insidiosus and Orius tristicolor (Hemiptera: Anthocoridae)

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is one of the most significant pests of commercial vegetables, fruits, and ornamental crops worldwide, causing both direct and indirect damage. Chemical control is the most common methodology for dealing with F. occidentalis, but this pest lays its eggs inside plant tissues, and adults and larvae feed in concealed locations, which can make chemical control of this pest difficult. As an alternative to chemical control, research attention has been focused on biological control through inoculative augmentation using anthocorid flower bugs of the genus Orius (Hemiptera: Anthocoridae). Although Orius insidiosus (Say) (Hemiptera: Anthocoridae) is an effective predator used worldwide for suppressing populations of western flower thrips, its use on pepper crops in Uruguay (Salto) has not achieved favorable results to date. Taking into account that O. insidiosus can supplement its diet by feeding on pollen and plant tissues, the aim of this study was to assess the effects of pepper fruits compared to bean pods, a vegetable substrate widely used for multiplying this predator, on the duration of the embryonic and nymph developmental stages, survival, fertility, and longevity of this species. Since Orius tristicolor (White) (Hemiptera: Anthocoridae) is present also in the horticultural region of Salto, this species was incorporated into the study in order to evaluate if significant differences exist between these 2 species. When biological parameters were measured, pepper fruits proved to be a more appropriate substrate than bean for the 2 Orius species studied. We reject the hypothesis that an antibiosis effect would explain the difficulties for the establishment of O. insidiosus in the greenhouses of Salto. These results show the need to examine other factors contributing to low establishment of these predatory bugs in greenhouses in Uruguay. Resumen El trips occidental de las flores, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), es una de las plagas mas importantes de hortalizas comerciales, frutas y cultivos ornamentales en todo el mundo, causando dano tanto directo como indirecto. El control quimico es la metodologia mas comun para el control de F. occidentalis, pero esta plaga pone sus huevos dentro de los tejidos vegetales y los adultos y las larvas se alimentan en lugares ocultos, lo que puede dificultar el control quimico de esta plaga. Como una alternativa al control quimico, mucha de la atencion de la investigacion se ha enfocado en el control biologico a traves del aumento inoculativo usando insectos antocoridos del genero Orius (Hemiptera: Anthocoridae). Aunque Orius insidiosus (Say) (Hemiptera: Anthocoridae) es un depredador eficaz utilizado en todo el mundo para suprimir poblaciones de trips occidental de las flores, su uso en cultivos de pimiento en Uruguay (Salto) no ha dado buenos resultados hasta la fecha. Teniendo en cuenta que O. insidiosus puede complementar su dieta alimentandose de polen y de tejidos vegetales, el objetivo de este estudio fue evaluar los efectos de los frutos de pimiento, en comparacion con las vainas de frijol (un sustrato vegetal ampliamente utilizado para multiplicar este depredador), en la duracion de las etapas de desarrollo embrionario y ninfal, supervivencia, fertilidad y longevidad de esta especie. Como Orius tristicolor (White) (Hemiptera: Anthocoridae) esta presente tambien en la region horticola de Salto, esta especie se incorporo al estudio para evaluar si existian diferencias significativas entre estas dos especies. Cuando se midieron los parametros biologicos, los frutos de pimiento probaron ser un sustrato mas apropiado para las dos especies de Orius estudiadas que las vainas de frijol. Rechazamos la hipotesis de que un efecto de antibiosis explicaria las dificultades para el establecimiento de O. insidiosus en los invernaderos de Salto. Estos resultados muestran la necesidad de examinar otros factores que contribuyen al bajo establecimiento de estos insectos depredadores dentro de los invernaderos en Uruguay. Key Words: biological control; omnivory; plant-feeding predators; pepper; Frankliniella occidentalis; oviposition substrates View this article in BioOne https://doi.org/10.1653/024.102.0216