Anthocoridae Research Articles

Compatibility of Orius laevigatus and Cheiracanthium pelasgicum for predation on Helicoverpa armigera eggs: effects of density and day/night activity on intraguild predation

Intraguild predation (IGP) among predatory arthropods can impair pest control efforts and endanger the joint-action compatibility of groups of natural enemies. The present study used plant microcosms to examine IGP of Cheiracanthium pelasgicum (C. L. Koch) (Araneae: Miturgidae) on minute pirate bugs Orius laevigatus (Fieber) (Hemiptera: Anthocoridae), two of the major lepidopteran-egg predators in southern Spanish cotton fields, and its effects on the control of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) eggs. Intensive unidirectional IGP of C. pelasgicum on O. laevigatus was observed under plant arena conditions: over 90 % of minute bugs were killed by spiders in the first 24 h. However, no negative interaction between C. pelasgicum and minute pirate bugs was found under different egg-density conditions with Orius alone, and the combination of two predator treatments displayed significantly higher predation rates than the spider-alone treatment after 24 h. Increased egg density did not affect control by predators, nor did it prompt a significant reduction in IGP. During a day–night bioassay, negative interaction between the two predators was found under night conditions, impacting on egg predation rates due to the combination of two predators. Predation of spiders on H. armigera eggs took place mainly at night, while predation by minute bugs was recorded both by day and by night. Finally, IGP by C. pelasgicum on minute pirate bugs was significantly higher by night. These outcomes demonstrate that diurnal and more intensive nocturnal IGP by spiders on minute pirate bugs had a moderate impact on the early control of H. armigera, with no negative effects after 24 h.

Predation capacity, development and reproduction of the southern African flower bugs Orius thripoborus and Orius naivashae (Hemiptera: Anthocoridae) on various prey

The little-studied species Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) have potential as biological control agents of thrips pests in southern Africa, but may also hold promise for the control of other harmful arthropods. In this study, the predation capacity, development, reproduction and growth rates of both predatory species on the key pests Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), Tetranychus urticae Koch (Acari: Tetranychidae) and Myzus persicae nicotianae Blackman (Hemiptera: Aphididae) were examined under laboratory conditions. Female adults of O. thripoborus and O. naivashae fed on 24 and 18 F. occidentalis 2nd instars, and 15 and 21 T. urticae eggs per day, respectively. Developmental and reproductive parameters of both Orius species were most favorable on F. occidentalis. Their intrinsic rates of increase (rm) were highest when fed on F. occidentalis, averaging 0.123 and 0.131 females/female/day for O. thripoborus and O. naivashae, respectively. On the other prey, O. thripoborus showed significantly higher rm-values than O. naivashae. Overall, rm-values on M. persicae nicotianae were higher than on T. urticae, although differences were only significant for O. thripoborus. For O. naivashae, the estimated intrinsic rates of increase on the tested non-thrips prey were slightly negative. Our findings indicate the potential of both Orius spp. as biocontrol agents of thrips, whereas only O. thripoborus appears to hold promise for the suppression of aphids and spider mites as well.

Impacts of azadirachtin and chlorantraniliprole on the developmental stages of pirate bug predators (Hemiptera: Anthocoridae) of the tomato pinwormTuta absoluta(Lepidoptera: Gelechiidae)

Conservation of natural enemies is an important approach for enhancing biological control. Selective insecticides have become important for managing arthropod pests, and the prospects for their use in combination with biological control agents are increasing. In addition, progress has been made in recent decades to develop reduced-risk insecticides that have novel modes of action and, therefore, likely to have a minimum non-target effect. In this study, we use a series of laboratory bioassays to investigate the impact of two reduced-risk insecticides, azadirachtin and chlorantraniliprole, on the egg, nymph and adult stages of two predatory pirate bugs, Amphiareus constrictus (Stal) and Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae), important predators of the tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). All three stages were exposed to the label recommended field rate of these two insecticides, which is indicated for the control of T. absoluta. Neither azadirachtin nor chlorantraniliprole affected the mortality of adult predators or their egg hatchability, suggesting a safe acute toxicity for these stages. However, azadirachtin and chlorantraniliprole negatively decreased the capacity of predator nymphs to reach the adult stage. This decrease can directly affect the size of the predator population in the next generation, and may undermine the biological control of pests such as T. absoluta. In general, our results call for caution when using these reduced-risk insecticides in integrated programs of chemical and biological control of this pest.

Functional Response of Three Species of Predatory Pirate Bugs Attacking Eggs of Tuta absoluta (Lepidoptera: Gelechiidae).

The functional response and predation parameters of three species of predatory pirate bugs Amphiareus constrictus (Stal), Blaptostethus pallescens Poppius, and Orius tristicolor (White) (Hemiptera: Anthocoridae) were evaluated at four different densities of eggs of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). Experiments were conducted in Petri dishes containing a tomato leaf disk infested with the pest eggs, and maintained inside growth chamber with environmental conditions of 25 ± 2 °C, 70 ± 10% relative humidity, and a photoperiod of 12:12 (L:D) h. A. constrictus and B. pallescens showed a type III functional response where predation increased at a decreasing rate after egg density was higher than 12 per leaf disk, reaching an upper plateau of 18.86 and 25.42 eggs per 24 hours, respectively. By contrast, O. tristicolor showed a type II functional response where the number of eggs preyed upon increased at a decreasing rate as egg density increased, reaching an upper limit of 15.20 eggs per 24 hours. The predator equations used in this study estimated handling time of 1.25, 0.87, 0.96 h for A. constrictus, B. pallescens, and O. tristicolor, respectively. The lower handling time and possible higher attack rate of B. pallescens suggests a higher efficiency and probably greater impact on the pest population. If conservation or classical biological control of T. absoluta is to be implemented, then prioritizing which natural enemy species is the most efficient is an important first step.

Plant‐sex‐biased tritrophic interactions on dioecious willow

Plant sex effects on herbivores are well studied, but little is known about these effects on predators and predator–herbivore dynamics. Here we take a holistic approach to study, simultaneously, plant sex effects on herbivore and predator preference and performance, as well as population densities and predation pressure in the field. For dioecious Salix cinerea (grey willow) we found that male plants represented higher host plant quality than females for an omnivorous predator (Anthocoris nemorum, common flower bug), while host plant quality for its herbivorous prey (Phratora vulgatissima, blue willow beetle) was not sex‐biased. The herbivore strongly preferred the host plant sex (female) that was suboptimal for the predator, which in turn followed its prey to female plants, leading to plant‐sex‐biased predation. These results provide new insight into the far‐reaching effects of plant sex on insect communities, and open up novel opportunities for improving biocontrol of the herbivore in Salix short rotation coppice.

Azadirachtin-mediated reproductive response of the predatory pirate bug Blaptostethus pallescens

The little-known pirate bug Blaptostethus pallescens Poppius is a biocontrol agent observed in tropical tomato fields in Brazil regulating fruit borer populations. In this study, the lethal response of B. pallescens to the bioinsecticide azadirachtin and to two synthetic insecticides, chlorpyrifos and deltamethrin, was assessed. The mild effect of the azadirachtin label rate (0.006 mg a.i. ml−1) on the predator (median lethal time (LT50) of 27 days), relative to label rates of deltamethrin (0.02 mg a.i. ml−1) and chlorpyrifos (1.44 mg a.i. ml−1) (with LT50 of 25 and 60 min, respectively) led to the assessment of its potential sublethal effects. Azadirachtin did not cause behavioral avoidance in the pirate bug, but the daily fecundity, adult progeny production and sex ratio were impaired when both male and female parents were exposed. These effects reduced the population growth of the predator in subsequent generations. Therefore, although safer than the conventional synthetic insecticides tested, the bioinsecticide azadirachtin does impair predator reproduction requiring attention when used in fields with this biological control agent.

Differential gene expression profiles in the salivary gland of Orius laevigatus

To determine differential gene expression profiles in the salivary gland of a predatory flower bug species, Orius laevigatus (Hemiptera: Anthocoridae), a subtractive cDNA library was constructed by suppression subtractive hybridization. The major transcripts encoding trypsins [30.4% of the total expressed sequence tags (ESTs)] were eliminated from the library in silico, and the remaining salivary gland-specific genes were investigated. A total of 501 ESTs were clustered and assembled into 126 contigs (63 multiple sequences and 63 singletons). Approximately 58% of them were matched to insect genes. In total, 29 contigs (163 ESTs) in the library were determined to be differentially transcribed in the salivary gland. A hemolysin-like protein populated 8.2% (42 ESTs) of the library. Hemolysin is known to destruct cells, including blood cells, by forming pores on the cell membrane, likely facilitating O. laevigatus feeding. Digestive enzymes and antimicrobial proteins were also identified from the salivary gland-specific library. Genes related to homeostasis, antioxidation, anticoagulation and neuropeptide or peptide hormone processing were also found to be transcribed in the O. laevigatus salivary gland. Several major contigs encoded putative secretory salivary proteins, but their functional assignments were not identified in existing protein databases. The discovery of salivary gland-specific genes supports further studies on biologically active components in the saliva of O. laevigatus.

Comparative suitability of aphids, thrips and mites as prey for the flower bug Orius sauteri (Hemiptera: Anthocoridae)

The predatory bug Orius sauteri (Poppius) (Hemiptera: Anthocoridae) is an important biological control agent in Asia that is often released on field crops and in greenhouses to control pests on vegetable and ornamental plants. This study compared the developmental and reproductive performance of O. sauteri on monotypic diets of four aphid species, western flower thrips, and two-spotted spider mite. Thrips emerged as the optimal prey type, consistent with findings for many other Orius spp. A diet of Frankliniella occidentalis (Pergande) yielded the fastest development, largest adult body size, shortest pre-oviposition period, and highest fecundity and longevity. Tetranychus urticae (Koch) was the next most suitable prey by most performance measures. Among aphids, Myzus persicae (Sulzer) was the most suitable and Aphis gossypii Glover the least suitable, with Aphis craccivora Koch and Megoura japonica (Matsumura) intermediate. Female O. sauteri were larger than males and female body mass varied more with prey type than did that of males. Despite the variation in performance among prey, all prey species yielded equally good juvenile survival and none would be expected to negatively impact the numerical response of O. sauteri in biological control applications where these arthropods form part of the prey complex.

Insecticide toxicity and walking response of three pirate bug predators of the tomato leaf miner Tuta absoluta

Abstract The tomato leaf miner Tuta absoluta is a key pest of the tomato and is of global significance. Insecticide is the primary method for controlling this pest, requiring a search for compounds with a low toxicity to nontarget organisms. We assessed the toxicity of eight insecticides to T. absoluta and its pirate bug predators Orius tristicolor, Amphiareus constrictus and Blaptostethus pallescens (Hemiptera: Heteroptera: Anthocoridae). We also assessed the effect of insecticide synergists on their toxicity to the predators, as well as their walking response to insecticide exposure. All insecticides, with the exception of methamidophos, exhibited the minimum efficacy threshold required by the Brazilian legislation (80% efficacy) at concentrations lower than the registered label rates. Indoxacarb and chlorantraniliprole exhibited a lower toxicity to the pirate bug predators than to the tomato leaf miner. The results obtained with the synergized insecticides suggest the involvement of cytochrome P450‐dependent monooxygenases as the primary detoxification enzymes minimizing insecticide toxicity in the pirate bug predators. The insecticides led to a reduction in predator walking activity, especially abamectin and indoxacarb, which significantly minimized predator exposure. The results of the present study indicate that novel insecticides, especially chlorantraniliprole, are better suited to sustainable integrated management programmes of the tomato leaf miner.

Interference by Western Flower Thrips in rearing Asian citrus psyllid: Damage to host plants and facultative predation

An infestation of Western Flower Thrips (WFT), Frankliniella occidentalis (Pergande), recently developed on young citrus trees in a greenhouse devoted to rearing Asian citrus psyllid (ACP), Diaphorina citri Kuwayama. Large numbers of young flush leaves were killed which negatively impacted ACP, as ACP is dependent on flush for oviposition and nymph development. Further, WFT predated on immature ACP killing a large proportion of young nymphs. Two experiments were subsequently conducted to assess WFT damage to two ACP rearing host plants, orange jasmine [Murraya exotica (L.)] and sweet orange [Citrus sinensis (L.) Osbeck]. Direct comparisons of WFT damage to the two host plants were not made because the plants were not studied at the same time and the age of adults used in the experiments was not known. An infestation of ten adult WFT per flush shoot caused significant damage to orange jasmine: most (73%) flush shoots were killed, and shoots not killed were significantly growth retarded. Ten adult WFT per flush shoot caused little damage to sweet orange. A third experiment showed that five adult WFT per 90 ACP eggs predated on large numbers of eggs and 1st instar ACP − only 13% of the eggs hatched and developed beyond the 1st nymphal instar (WFT did not attack later instars). Predation on ACP immatures in this experiment included an evaluation of a minute pirate bug [Orius insidiosus (Say), regarded as effective against WFT] also at five adults per 90 ACP eggs. All ACP eggs were killed by this predator before eclosion. O. insidiosis might be useful for reducing infestations of WFT on citrus or other ACP host plants, but the predator would be incompatible with rearing ACP.

甘長ピーマンの害虫アザミウマ類に対するアカメガシワクダアザミウマとヒメハナカメムシ類による防除

甘長ピーマンの害虫アザミウマ類に対するアカメガシワクダアザミウマとヒメハナカメムシ類による防除

Novel Strain of Spiroplasma Found in Flower Bugs of the Genus Orius (Hemiptera: Anthocoridae): Transovarial Transmission, Coexistence with Wolbachia and Varied Population Density

Spiroplasma, a group of small, wall-less, helical, and motile bacteria belonging to the Mollicutes, contains species with diverse life histories. To date, all the Spiroplasma strains that are known to be transmitted vertically in arthropod lineages belong to either the Spiroplasma ixodetis group or the Spiroplasma poulsonii group. Here, we found that a unique strain of Spiroplasma vertically transmitted in predatory flower bugs of the genus Orius belongs to the Spiroplasma insolitum group, which is a group of bacteria phylogenetically closely related to S. insolitum derived from the tickseed sunflower, Bidens sp. (Asterales: Asteraceae). The infection frequencies in natural populations were16.0% in Orius sauteri (n = 75), 40.5% in Orius nagaii (n = 37), and 8.0% in Orius minutus (n = 87). Orius strigicollis was not infected with Spiroplasma (n = 147). In the early stage of oogenesis (i.e., within the germarium), a large number of bacteria with the typical morphology of Spiroplasma existed, keeping a distance from Wolbachia bacteria. The Spiroplasma population seemed to increase during host development but Wolbachia population did not.

Impact Assessments of Transgenic cry1Ab Rice on the Population Dynamics of Five Non-Target Thrips Species and Their General Predatory Flower Bug in Bt and Non-Bt Rice Fields Using Color Sticky Card Traps

A 2-yr field study was conducted to assess the effects of transgenic japonica rice (KMD1 and KMD2) with a synthetic cry1Ab gene from Bacillus thuingiensis Berliner on population dynamics and seasonal average densities of five thrips species including Stenchaetothrips biformis (Bagnall), Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Haplothrips aculeatus (Fabricius), Haplothrips tritici (Kurd) and their general predatory flower bug, Orius similis Zheng as compared to the parental control rice line using the white, blue and yellow sticky card traps. Population dynamics and seasonal average densities of these five thrips species and their general predatory flower bug were not significantly affected by rice type. Additionally, the white sticky card trap was suggested to be the most suitable for monitoring the population of these five thrips species and their general predator. These results show that our tested Bt rice lines do not interrupt the population of non-target thrips species and their general predatory flower bug in the field, and also cannot result in more occurrence of these thrips species in the rice ecosystem.

Light intensity and wavelength influence development, reproduction and locomotor activity in the predatory flower bug Orius sauteri (Poppius) (Hemiptera: Anthocoridae)

Light wavelength and intensity are physical factors that can affect arthropod development and reproduction. The present study examined the development, reproduction and locomotor activity of the predatory flower bug, Orius sauteri (Poppius) (Hemiptera: Anthocoridae), under five light intensities (1000, 2000, 3000, 4000 and 5000 lux) and five wavelengths [red (678.5 nm), green (620.0 nm), yellow (581.7 nm), blue (478. 1 nm) and white (all wavelengths)] at constant temperature (25 °C) and RH (70 %). The duration of nymphal development was extended at lower light intensities, primarily due to effects on the first three instars. Under white, yellow and green light, O. sauteri completed development in 18.0 days, but blue light extended development by 3.2 days and red light extended it by 7.4 days. Although lower light intensities extended the preoviposition period and reduced fecundity, they improved egg fertility. Both red and blue light negatively affected preoviposition period, fecundity and egg fertility. Whereas adult female mean walking speed over a five min period was reduced at lower light intensities, longer wavelengths (yellow and red) increased it, ostensibly reflecting an avoidance response. The respiration quotient of adult O. sauteri females was also elevated under red light conditions. These findings are informative for optimizing O. sauteri mass-rearing procedures and maximizing its efficacy as a biological control agent in greenhouse cultures.

Annotated catalog, biological notes and diagnoses of the flower bugs (Heteroptera: Anthocoridae sensu lato) in the Korean Peninsula

The flower bugs or minute pirate bugs, Anthocoridae sensu lato, are represented by 12 genera and 24 species in the Korean Peninsula. The present catalog includes three newly recorded species to the fauna: Anthocoris confusus Reuter, Bilia japonica Carayon et Miyamoto, and Montandoniola pictipennis (Esaki). Distributional data and bibliographical references of each taxon are included. Biological notes (habitats, prey types, etc.) and diagnoses based on the local materials of the Korean Peninsula are also presented for the field of applied entomology.

Optimization an optimal artificial diet for the predatory bug Orius sauteri (hemiptera: anthocoridae).

BackgroundThe flower bug Orius sauteri is an important polyphagous predator that is widely used for the biological control of mites and aphids. However, the optimal conditions for mass rearing of this insect are still unclear, thus limiting its application.MethodologyIn this study, we investigated the optimal ingredients of an artificial diet for raising O. sauteri using a microencapsulation technique. The ingredients included egg yolk (vitellus), whole-pupa homogenate of the Tussah silk moth (Antheraea paphia), honey, sucrose, rapeseed (Brassica napus) pollen and sinkaline. We tested 25 combinations of the above ingredients using an orthogonal experimental design. Using statistical analysis, we confirmed the main effect factors amongst the components, and selected five optimal combinations based on different biological and physiological characters.Principal FindingsThe results showed that, although different artificial diet formats significantly influenced the development and reproductive ability of O. sauteri, the complete development of O. sauteri to sexual maturity could only be achieved by optimizing the artificial diet according to specific biological characters. In general, pupae of A. paphia had more influence on O sauteri development than did artificial components. The results of a follow-up test of locomotory and respiratory capacity indicated that respiratory quotient, metabolic rate and average creeping speed were all influenced by different diets. Furthermore, the field evaluations of mating preference, predatory consumption and population dispersion also demonstrated the benefits that could be provided by optimal artificial diets.ConclusionsA microencapsulated artificial diet overcame many of the difficulties highlighted by previous studies on the mass rearing of O. sauteri. Optimization of the microencapsulated artificial diet directly increased the biological and physiological characters investigated. Successive physiological tests and field investigations were used to evaluate the outcome of different artificial diet combinations on the quality of the reared O. sauteri.

Implications of alternative prey on biocontrol of pests by arthropod predators in strawberry

A range of naturally occurring predator species or commercially produced predators can be used in biocontrol strategies for pests. However, multiple potential prey species or other alternative food sources are often present for predatory insects at any one time. The availability of this ‘alternative’ prey may affect specific pest control by predators and thus influence the release rates of predators required for economic pest control. Strawberry aphid (Chaetosiphon fragaefolii), western flower thrips (Frankliniella occidentalis) and European tarnished plant bug (Lygus rugulipennis) are important and damaging pests in strawberry. In this study, laboratory, glasshouse and field experiments were undertaken to assess the effects of the availability of multiple prey species on biocontrol of specific pests. Results indicated that two of the predators tested showed preferences for prey species such that biocontrol of a particular pest was often less effective when a combination of pest species was present than would have been expected from results of experiments with single prey species alone. The experiments indicated that Orius laevigatus preferred C. fragaefolii to F. occidentalis or to L. rugulipennis, and preferred L. rugulipennis to F. occidentalis. Chrysoperla carnea was shown to prefer C. fragaefolii to L. rugulipennis, and C. fragaefolii over F. occidentalis. Therefore, it is important to consider the effects of alternative prey on suppression of pest species when deciding on management strategies and release rates of predators.

Toxicity and sublethal effects of seven insecticides to eggs of the flower bug Orius insidiosus (Say) (Hemiptera: Anthocoridae)

The predatory bug Orius insidiosus is an important biological control agent of several insect pests, and is one of the most commonly used species in biological control programs worldwide. This study assessed the lethal and sublethal effects of insecticides on this species through life table, and classified the insecticides according to the definitions of toxicity given by the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC). A bioassay was carried out using a completely randomized design with eight treatments and 40 replicates. Eggs of O. insidiosus laid naturally in plant stems were immersed in aqueous solutions of the chemical products. Egg viability, duration of the embryonic period, survival of nymphs, and duration of the nymphal period were assessed daily. Insects that reached adulthood were paired and their reproduction assessed. The number of eggs produced and the survival of adults were assessed daily. The insecticides abamectin, cartap hydrochloride, spirotetramat+imidacloprid, and flubendiamid were classified as harmful. Pyriproxyfen and rynaxypyr were categorized as harmless and pymetrozine was classified as slightly harmful. Pyriproxyfen affected the population parameters rm, GT, DT, and λ, whereas other insecticides did not.

Evaluation of Imidacloprid and Cyantraniliprole for Suitability in Conservation Biological Control Program forOrius insidiosus(Hemiptera: Anthocoridae) in Field Pepper

Evaluation of Imidacloprid and Cyantraniliprole for Suitability in Conservation Biological Control Program for<i>Orius insidiosus</i>(Hemiptera: Anthocoridae) in Field Pepper

Enemigos naturales de las moscas de los estigmas del maíz: Euxesta stigmatias (Loew), Chaetopsis massyla (Walker) y Eumecosommyia nubila (Wiedemann) en Guasave Sinaloa, México

El complejo de moscas de los estigmas Euxesta stigmatias (Loew), Chaetopsis massyla (Walker) y Eumecosommyia nubila (Wiedemann) han adquirido importancia como plagas en el cultivo de maíz en Sinaloa, y sus daños están asociados a pudriciones que afectan la calidad del elote y el rendimiento del grano. Este trabajo tiene por objetivo presentar el resultado de la búsqueda de enemigos naturales (parasitoides, depredadores y nematodos entomopatógenos) con potencial para el control biológico de este complejo de moscas. El trabajo se realizo durante el ciclo agrícola primavera verano de 2011. Se hicieron 8 muestreos semanales con red entomológica y colecta de frutos, en la etapa de fructificación y maduración del grano en lotes de maíz sembrados con el hibrido Asgrow Garañon, predominando dos avispas del orden Hymenoptera de las familias Pteromalidae y Eurytomidae, que parasitan a la mosca de los estigmas en el estado de pupa; Spalangia spp., se observó con mayor frecuencia ejerciendo un parasitismo natural del 47 % sobre Euxesta stigmatias (Loew) durante las etapas de fructificación y maduración de los frutos. La chinche pirata Orius insidiosus (Say) estuvo presente durante los meses de marzo a julio depredando a huevecillos y larvas de la mosca. Por otro lado, se realizaron muestreos de suelos para aislar e identificar poblaciones de nematodos entomopatógenos, utilizando al insecto trampa Galleria melonella (L)., se aislaron poblaciones en tres sitios sembrados con maíz localizados en el CIIDIR-IPN Unidad Sinaloa, en los ejidos Guasave y Maximiliano R. López, todos ubicados en el municipio de Guasave. Los nematodos encontrados en los sitios pertenecen a especies de la familia Rhabtitidae, la identificación a nivel de género está en proceso. Los enemigos naturales encontrados se caracterizan por tener potencial para evaluarse como agentes de control biológico del complejo de moscas de los estigmas. .