Blaptostethus Pallescens Poppius Research Articles

Impact of field releases of predatory bug, Blaptostethus pallescens Poppius against mites in apple in Kashmir

Impact of field releases of predatory bug, Blaptostethus pallescens Poppius against mites in apple in Kashmir

Effect of the entomopathogenic fungus, Lecanicillium lecanii, on the biology and predation rate of the anthocorid predatory bug, Blaptostethus pallescens, feeding on the flower thrips, Frankliniella schultzei Trybom (Thysanoptera: Thripidae)

BackgroundThe flower thrips, Frankliniella schultzei Trybom (Thysanoptera: Thripidae) is a notorious pest that attacks the plants of economic importance. The anthocorid bug Blaptostethus pallescens Poppius (Heteroptera: Anthocoridae) is a predator of thrips in field crops and greenhouses. Another biocontrol agent, the entomopathogenic fungi (EPF) Lecanicillium lecanii (Zimm.) (Hypocreales: Cordycipitaceae), has been effectively used in management of various insect pests. With the aim to develop an effective combination of biocontrol agents like microbial and insect predator for the management of the serious pest F. schultzei, the present studies were carried out on development, predation rate and prey preferences of the predator B. pallescens provided with the EPF (ICAR-NBAIR Vl-8)-treated thrips under laboratory conditions.ResultsThe predator, B. pallescens, could complete its life cycle on treated thrips. The nymphal duration of bugs fed on treated thrips was higher (25.25 ± 0.13 days). The Vl-8 strain did not show any negative effect on hatchability of eggs (83% hatchability in treatment; 86% in control). However, the longevity was comparatively less in bugs fed on treated thrips than that of control group The fecundity of the treated group was found to be reduced to one half of the control group. The rate of daily feeding potential of bugs on treated thrips was less (7.29 ± 0.15) than the untreated thrips (12.54 ± 0.1) throughout their lifetime. Moreover, when the F1 generation from both parents line fed on treated and untreated thrips allowed to feed on Corcyra cephalonica eggs, it did not show any difference in terms of nymphal duration which revealed that the fungi did not affect the F1 generation. When choice was given between treated and untreated thrips to different instars of this predatory bug, all the instars including adult significantly preferred the untreated thrips. However, nymphs and adult bugs were found to encounter both the treated and untreated thrips. No mortality was observed in any stage of the predator.ConclusionThis study shows that the effect of L. lecanii (ICAR-NBAIR Vl-8) on B. pallescens is not harmful. However, further field studies are required to evaluate their combined effect against this pest.

Field evaluation of Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae) in controlling Tetranychus urticae Koch on parthenocarpic cucumber under protected environments

ABSTRACT The two-spotted spider mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae) is a major pest of greenhouses and field crops worldwide. Many attempts to control T. urticae by using chemical insecticides have failed because of the development of pesticide resistance. The use of natural enemies may represent both a more effective alternative and an environmentally-safer method to that of chemical products. Here, we investigated the predation efficacy of the anthocorid bug, Blaptostethus pallescens Poppius, on eggs and active stages of T. urticae on parthenocarpic cucumber grown under a polyhouse. The use of B. pallescens at 50 nymphs per plant led to a significantly higher level of predation on the two-spotted spider mite population (76.4% in egg and 81.7% in active stage of mites) than with 40 or 30 nymphs per plant (68.9% in egg and 69.4% in active stage of mites; 66.4% in egg and 68.2% in active stage of mites), respectively. Significantly higher yields of cucumber were recorded from the plot where B. pallescens at 50 nymphs per plant (2554.8 g/ plant) were released. Results suggest that two-spotted spider mite can be effectively managed by the release of this anthocorid bug. B. pallescens as part of an IPM system for the management of T. urticae on parthenocarpic cucumber grown under polyhouse.

Potential of Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae) on Tetranychus truncatus Ehara (Prostigmata: Tetranychidae)


 Efficiency, functional and numerical responses of anthocorid bug Blaptostethus pallescens Poppius on the spider mite, Tetranychus truncatus Ehara were examined under laboratory conditions. Nymphs of B. pallescens exhibited a Hollings type II functional response when females of spider mite were offered at densities of 10, 20, 30, 40, 50, 60 and 70 mites/bug. Individual fifth instar bugs consumed up to 45.3 adult females of T. truncatus in 24 h at prey mite densities of 60 mites/ bug. Studies on numerical response revealed that the nymphs of the anthocorid bug failed to complete development when the food was restricted to mite alone. Numerical response studies on adult bugs, when offered T. truncatus at densities of 10, 20, 30, 40 and 50 females showed no significant differences in the average fecundity of the female bug. Results indicate that the anthocorid predator, B. pallescens has a very high predatory potential though with a weak numerical response.

Demographics and functional response of Blaptostethus pallescens preying on Tuta absoluta

In order to enhance the ecofriendly management of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), we studied the demographics and functional response of Blaptostethus pallescens Poppius on T. absoluta under laboratory conditions. B. pallescens completed its development on the eggs and the first two larval instar of T. absoluta, however the demographic parameters were higher on the prey eggs than on larvae. The predatory bug exhibited a type II functional response to the target prey and the demographic parameters were higher on prey eggs than on larvae. The attack rate increased and the handling time decreased with the advancement of the predator as well as the prey stage. The attack rate was the highest and handling time the lowest for the adult females on the prey eggs. Based on the results of the study, B. pallescens seems to be a promising biocontrol agent of T. absoluta, nevertheless, under field conditions, many biotic and abiotic factors can influence its performance. Hence a proper field evaluation is required before giving the final recommendation.

Biology of anthocorid predator, Blaptostethus pallescens Poppius (Heteroptera: Anthocoridae)

Biology of anthocorid predator Blaptostethus pallescens Poppius was studied on eggs of alternate host Corcyra cephalonica (Stainton). Eggs of B. pallescens, thrust within the plant tissue, hatched after a mean incubation period of 5.78 days. Nymphs, when reared on UV sterilized eggs of C. cephalonica under ambient conditions, developed normally with five instars, each having a mean duration of 2.63, 1.92, 2.01, 2.50 and 5.10 days, respectively. Females laid eggs after a pre-oviposition period of 4.2 days. Average fecundity of bugs was 134.04 eggs. Mean longevity of females was found to be higher (52.03 days) than that of males (40.18 days).

Functional Response of Three Species of Predatory Pirate Bugs to Different Densities of Blossom Thrips, <i>Frankliniella schultzei</i> Trybom (Thysanoptera: Thripidae)

The functional response of three anthocorid bugs, namely Blaptostethus pallescens Poppius, Cardiastethus affinis Poppius and Montandoniola indica Yamada (Heteroptera: Anthocoridae) was assessed by feeding them with different densities of thrips larvae of Frankliniella schultzei (Trybom) in the laboratory. Predation rate of all the three species increased with increasing prey densities. Both B. pallescens and C. affinis exhibited type-II response and M. indica exhibited type-III response. Among the predators, M. indica proved to be effective as it showed highest predation rate, higher 1/Th, higher a/Th and lowest handling time followed by B. pallescens . It is evident from the present study that M. indica and B. pallescens could be used in augmentative biological control programmes for thrips.

Evaluation of anthocorid predator, Blaptostethus pallescens Poppius against spider mite,Tetranychus urticae Koch on Okra under insect net cage condition

The present study deals with the evaluation of anthocorid bug, Blaptostethus pallescens Poppius against Tetranychus urticae Koch on okra ( Abelmoschus esculentus L.), conducted in Karif season (June-August) during 2013-2015 in the net cage condition at Entomological Research Farm, Punjab Agricultural University, Ludhiana. The 6-7 days old nymphs of B. pallescens @ 10, 20 and 30 nymphs/m 2 were released at weekly interval on the mite infested plants and these were compared with chemical control (Omite @ 300ml/acre at 10 days interval) and untreated control. The releases of predators and acaricidal spray on okra were found better than control in suppressing the population of T. urticae . The release of B. pallescens @ 30 nymphs/m 2 was found most effective with a 75.86 to 81.20 per cent reduction of mite population over control. It was statistically at par with chemical control, where 84.04 to 91.66 per cent reduction of mite population over control was recorded. There was no significant difference observed in the reduction of mite population of the plots released with 20 and 10 nymphs/m 2 of B. pallescens . The yield of okra from the plots of chemical control was recorded highest (52.70 q/acre), followed by 45.05 q/acre from the plots released with a B. pallescens @ 30 nymphs/m 2 at seven days interval. The study concluded that, integrating predator, B. pallescens @ 30 nymphs/plant along with acaricide (Omite 300 ml/acre) as a component of IPM for the management of two-spotted spider mite, T. urticae on okra under net house conditions.

Morphology and performance specifications of Blaptosthethus pallescens Poppius (Heteroptera: Anthocoridae) when reared on two alternate laboratory hosts

The present research paper provides detailed morphology and morphometrics of an anthocorid predator, Blaptostethus pallescens Poppius. To identify the alternate laboratory host to be utilized for mass production, biological parameters of the anthocorid were evaluated by rearing on UV irradiated eggs of two alternate laboratory hosts, Corcyra cephalonica (Stainton) and Sitotroga cerealella (Motsch.). Five nymphal instars were recorded on both hosts. No significant differences were observed in incubation period, nymphal duration, total developmental period and sex ratio when reared on the two hosts. However, significant differences were observed in two biological parameters i.e., adult longevity and fecundity. Longer life span and higher fecundity of B. pallescens was recorded when reared on C. cephalonica eggs in comparison to S. cerealella eggs, indicating the suitability of C. cephalonica eggs for mass rearing B. pallescens in the laboratory. B. pallescens could be reared continuously for 7 generations on C. cephalonica eggs.

Biology and feeding efficacy of the anthocorid, Blaptostethus pallescens Poppius on Oligonychus coffeae in tea

The anthocorid predator, Blaptostethus pallescens Poppius was studied for the first time on red spider mite (RSM), Oligonychus coffeae Nieter. Laboratory studies indicated that B. pallescens can be successfully reared on RSM. Incubation period was 4.4 ± 0.34 days. The total developmental period of five nymphal instars to adults was 17.1 ± 0.34 days. Blaptostethus pallescens nymphs consumed RSM in the range of 3.83 ± 0.18 to 17.37 ± 0.95/day. Female B. Pallescens consumed more mites than male. The study clearly showed B. pallescens is a promising candidate in tea plantations for the control of red spider mite.

Effect of Four Host Plants of the Two Spotted Spider Mite Tetranychus urticae on the Consumption Rates and Reproductive Biology of the Predator Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae)

Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae) is a potential predator on mites and otherinsects in Maize, Mango and grain warehouses in Egypt. The indirect effect of four vegetable crops; bean (Phaseolusvulgaris), pepper (Capsicum annuum), eggplant (Solanum melongena) and cucumber (Cucumis sativus) as host-plantsof the two spotted spider mite (TSSM) Tetranychus urticae Koch on the consumption rate and reproductive biologywere studied at 30 ±1˚C and 60 ± 10% R.H. The obtained results revealed that the type of plant had a significant effecton the daily and overall prey consumption of all the nymphal instars and total developmental nymphal periods. Thetotal predation rates of all nymphal instars of B. pallescens were higher with bean leaf plant (552.4 mites) than that ofpepper, eggplant and cucumber leaf plants (520.5, 451.8 and 349.2 mites, respectively). The major portion of mortalityduring the nymphal stage occurred during the first instar in all tested host plants and the higher mortality was recordedwhen TSSM fed on mites fed cucumber plant, and the lower one was for mites fed on bean plant. The total number ofconsumed T. urticae nymphs by B. pallescens adult females was significantly different among the four host plants;being higher in bean plant leaves (301.9 mites) and lower on cucumber plant leaves (152.4 mites). Also, the totalnumber of consumed T. urticae nymphs by B. pallescens adult males was significantly different among the four hostplants; being higher in bean plant leaves (158.8 mites) and lower on cucumber plant leaves (105.3 mites). Significantdifferences in adult longevity among the different host plants were observed, the shortest lifetime for females was 17.7days on cucumber, while the longest lifetime (22.3 days) was recorded with bean. The oviposition period was shorteston cucumber (10.5 days) and longest on bean (17.7days). Meanwhile, the greatest total lifetime fecundity (70.0 eggs/female) was observed with bean plant, which was significantly higher than on cucumber plant (22.9 eggs/female). Thesuccess of B. pallescens as a biological control agent of TSSM seems to be strongly affected by the host plants onwhich the TSSM were fed on.

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.

Molecular Characterisation of some Indian Anthocorid Predators

Anthocorid predators widely used as biocontrol agents were characterised for genetic diversity and phylogeny. Cardiastethus exiguus Poppius, Xylocoris flavipes Reuter and Blaptostethus pallescens Poppius were characterised using Cytochrome oxidase I (COI) marker to elucidate the diversity and phylogeny. The sequencing of the COI region at 650bp was compared with sequence of Orius majusculus (Reuter), available at NCBI by BLASTn. The cluster analysis based on dendogram revealed B. pallescens and O. majusculus to be more closely related, while X. flavipes and C. exiguus were distinct. The usefulness of characterisation and phylogenetic relationship among the anthocorid populations for their effective utilisation in pest management is discussed.

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.

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.

Life history traits of Blaptostethus pallescens (Hemiptera: Anthocoridae), a candidate for use in augmentative biological control in Egypt

Blaptostethus pallescens Poppius (Hemiptera: Anthocoridae) is an abundant native predator in mango orchards and other cropping systems in Egypt. To determine suitable mass-rearing conditions for this little-studied species, we assessed some of its biological characteristics. Testing its thermal response at three constant temperatures (20, 25, 30 °C), showed that immature development time and adult longevity decreased with increasing temperature. Reproductive success of individual females was greatest when reared at 25 °C (84.3 ± 3.1 eggs) rather than at 20 °C (46.6 ± 2.0 eggs) or 30 °C (65.2 ± 2.5 eggs). Although B. pallescens reared at 25 °C had a significantly higher net reproductive rate (R0), which may be attributed to their relatively rapid development and high fecundity, we argue that 30 °C seems to be more convenient for rearing B. pallescens, as mean generation time (T) and doubling time (DT) are clearly shorter, thus more individuals could be reared per unit of time at 30 °C. Mating significantly reduced male and female longevity, as unmated adults lived 25–45 % longer than mated individuals did. Unmated females did not lay eggs, suggesting that mating is a prerequisite for egg maturation. Adult males and females performed best, in terms of longevity, when fed Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs instead of non-prey diets. However, diets of plant sap or pollen could sustain adults in times of limited egg availability. Because its biology is similar to that of other subtropical anthocorids already reared for augmentative releases, B. pallescens may be amenable to mass-rearing using already established techniques. Therefore, B. pallescens could be used to improve augmentative biological control in crops such as mango or maize in Egypt where it already naturally occurs, and therefore would not engender concerns over non-target effects that an exotic, generalist biological control agent would.

Role of Blaptostethus pallescens Poppius and Xylocoris flavipes (Reuter) in the suppression of Corcyra cephalonica Stainton in stored rice grain

The predatory performance of anthocorid bugs, Blaptostethus pallescens Poppius and Xylocoris flavipes (Reuter) was evaluated against stored rice grain moth, Corcyra cephalonica Stainton. Both the predators significantly suppressed the infestation of C. cephalonica in stored rice grain. However, X. flavipes performed better than B. pallescens which was attributed to their small size enabling them to adapt to store rice grain. The higher doses of X. flavipes @ 30 nymphs/100 eggs/jar (11.9 moths/jar) and 20 nymphs/100 eggs/jar (15.5 moths/jar) were found to be most effective in suppressing the population build-up of C. cephalonica in stored rice grain. X. flavipes with respect to nymphal survival was found to be most suitable as higher number of their living nymphs (13.4 to 24.4 nymphs/jar) was recovered as compared to B. pallescens , where, negligible number of living nymphs (0–0.2 nymphs/jar) was recovered. It was concluded that X. flavipes @ 30 nymphs/jar, followed by X. flavipes @ 20 nymphs/jar was most effective in controlling C. cephalonica in stored rice grain.

Feeding preference of anthocorid predators for parasitized and unparasitized eggs of Corcyra cephalonica (Stainton) and Helicoverpa armigera (Hübner).

Laboratory studies were conducted to check the feeding preferencc of anthocorid predators, Orius tantillus (Motsch.) and Blaptostethus pallescens Poppius for unparasitized eggs of Coreyra cephalonica (Stainton) and Helicoverpa armigera (Hubner) and those parasitized by Trichogramma chilonis Ishii. In a no-choice situation, O. Tantillus and B. Pallescens nymphs devoured more than 90 per cent of the unparasitized C. Cephalonica eggs provided and only 1.6 and 10 percent, respectively, of the parasitized eggs, while such a preferential feeding was not observed in adults. Given a choice of parasitized and un parasitized C. Cephalonica eggs, nymphs and adults of both the species of anthocorids preferred to feed on unparasitised eggs. In the experiments with H. Armigera eggs, the significantly higher preference the nymphal and adult stages of both anthocorid predators for unparasitized eggs, indicated that it may be possible to integrate releases of anthocorids and trichogrammatids for biololgical control of lepidopteran pests/thrips in different crop ecosystems.

Biology and rearing requirements of an anthocorid predator, Blaptostethus pallescens Poppius (Heteroptera: Anthocoridae)

Biology and feeding potential of an anthocorid predator, Blaptostethus pallescens Pop pius were studied on the eggs of alternate host, Corcyra cephalonica (Stainton). Approximately 100 UV irradiated C. cephalonica eggs are required for rearing one nymph throughout its nymphal period of about 16 days (4-11 eggs per day) and 630 eggs for an adult throughout its longevity (3-19 eggs per day). Adult females had a greater feeding potential (943 eggs per adult) in comparison to males (381 eggs per adult). Utilising 9cc of C. cephalonica eggs , 1000 B. pallescens could be produced. The lab-reared adults had a very high longevity (38- 78 days) and fecundity (110-203 nymphs/female), indicating the suitability of C. cephalonica eggs for mass production.