The predatory mite Neoseiulus bicaudus (Mesostigmata: Phytoseiidae), a promising biocontrol agent of whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) 

2020 ◽  
Vol 25 (12) ◽  
pp. 2273-2285
Author(s):  
Guo-dong Han ◽  
Jie Su ◽  
Ke Zhang ◽  
Jing Chen ◽  
Jian-ping Zhang

Neoseiulus bicaudus (Wainstein) (Acari: Phytoseiidae) is a native predatory mite species in Xinjiang, China, and a biological control agent for some small pests, such as Tetranychus turkestani (Acari: Tetranychidae) and Thrips tabaci (Thysanoptera: Thripidae) in greenhouse. However, little is known whether N. bicaudus could be an effective natural enemy of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). A series of laboratory and greenhouse experiments were conducted to evaluate the efficiency of N. bicaudus on B. tabaci. The present data showed that each stage of N. bicaudus demonstrated type II functional response when fed on B. tabaci. The adult females showed the highest consumption rate and attack rate, and the shortest handling times were obtained when they preyed on eggs and 1st instar nymphs. The 1st instar of B. tabaci was preferred for the feeding of N. bicaudus adult females than eggs, followed by 2nd instar nymphs of B. tabaci. Under greenhouse conditions, this predator effectively suppressed the population growth of B. tabaci throughout the experimental period. Accordingly, N. bicaudus could be an efficient predator for B. tabaci.

2020 ◽  
Vol 25 (9) ◽  
pp. 1531-1540
Author(s):  
Firdevs Ersin ◽  
İsmail Döker ◽  
Ferit Turanli

This study was conducted to reveal the toxicity of sulfoxaflor and the four modern fungicides (ametoctradin +dimethomorph, isopyrazam, mandipropamid and propamocarb-HCl+fluopicolide) on various developmental stages of a non-target predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). The maximum recommended concentrations of the pesticides were applied to eggs, larvae and adult females of the predator in order to obtain detail knowledge of their toxicity at worst-case scenario under laboratory conditions. Results indicated that mortality rates vary between the life stages and the larva was the most sensitive. The highest egg mortality was found for isopyrazam (20.44%) followed by propamocarb+fluopicolide (17.55%) and ametoctradin+dimethomorph (15.77%) at 72 h after the treatments. Sulfoxaflor, ametoctradin+dimethomorph and propamocarb+fluopicolide were proven to be harmful to the larvae as they caused significantly higher mortality than the control, and their mortality reached 80.00, 77.50 and 60.00% at 168 h after treatment, respectively. In the case of adult females, respective mortality rates of propamocarb+fluopicolide, sulfoxaflor, ametoctradin+dimethomorph and isopyrazam were found 30.00%, 25.83%, 21.66% and 16.66% after 120 h after treatment, respectively. In addition, mandipropamid and sulfoxaflor caused a drastic decrease in fecundity of the predator. Accordingly, isopyrazam may be compatible with A. swirskii in intergraded pest management programs where it is released as biological control agent. Due to their high toxicity to at least one developmental stage of the predator, further experiments are needed in order to clarify the toxicity of the other pesticides under field or semi-field conditions.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 588
Author(s):  
Charles A. Braman ◽  
Adam M. Lambert ◽  
A. Zeynep Özsoy ◽  
Ellen N. Hollstien ◽  
Kirsten A. Sheehy ◽  
...  

Arundo donax (giant reed) is invasive in Mediterranean, sub-, and tropical riparian systems worldwide. The armored scale Rhizaspidiotus donacis is approved for biocontrol in North America, but an adventive population was recently discovered in southern California. We documented this population’s distribution, phylogeny, phenology, potential host spillover to Phragmites spp., and potential for parasitism by a common biocontrol parasitoid of citrus scale. The adventive scale was found within a single watershed and is genetically closest to Iberian scale genotypes. Rhizaspidiotus donacis developed on Phragmites haplotypes but at much lower densities than Arundo. The adventive population is univoltine, producing crawlers from March-June. Aphytis melinus parasitoids exhibited sustained interest in R. donacis during choice and no-choice trials and oviposition resulted in a small second generation. Rhizaspidiotus donacis appears limited in distribution by its univoltinism and sessile adult females. This presents challenges for broad biocontrol implementation but allows for targeted application. The genetic differentiation between imported biocontrol samples and adventive populations presents an opportunity for exploring benefits of hybrids and/or alternative genotypes where establishment has been difficult. While unlikely to occur in situ, spillover to vulnerable endemic Phragmites or deleterious parasitoid effects on scale biocontrol agents warrants consideration when planning use of R. donacis.


2013 ◽  
Vol 13 (1) ◽  
pp. 18
Author(s):  
W. Setiawati ◽  
N. Gunaeni ◽  
T. S. Uhan ◽  
A. Hasyim

Bemisia tabaci (Gen.) (Homoptera: Aleyrodidae) is one of the most serious pests on tomato. It is mainly controlled by chemi-cal means, requiring some 25 sprays during the average growing season. The extensive and repeated use of insecticides has dis-rupted the natural balance between this pest and its natural enemies. In this study, Menochilus sexmaculatus F. was evalu-ated as a possible biological control agent of B. tabaci and its effect on Gemini virus infestation. The study was conducted at the experimental station of the Indonesian Vegetables Research Institute (IVeGRI) in Lembang, West Java (1,250 m above sea level) from August to December 2008. The experimental plots consisted of 0.35 ha of tomato (± 100 m2 per plot) and spatially separated with four rows of maize (a minimum of 1 m) inter-plot distance to prevent cross-contamination among plots. The experiment was arranged in completely randomized block design with eight treatments and four replications. M. sexmaculatus were released at 24 days after planting. The treatments were designed according dosages and schedules at three released populations (i.e. 10 predators per plot, 20 predators per plot, and 10 predators per plot at vegetative stage followed by 20 predators per plot at generative stage); two places of release (center and edge of the plot); and two schedules of release (weekly and biweekly). Efficacy of the predator was measured in terms of the density of B. tabaci, both before and after release of the predator and its effect on Gemini virus infestation. The result indicated the potential use of M. sexmaculatus to control B. tabaci and its effect on Gemini virus infestation on tomato. Reductions in B. tabaci populations and subsequent tomato yields were significant. B. tabaci population in plots receiving 10 predators showed 73.62% and 75.75% reductions by the end of experiment. The incidence and intensity of Gemini virus were consistently and significantly lowest and tomato yield gain was observed when 10 predators were released at weekly intervals. It is suggested that release of M. sexmaculatus against B. tabaci on tomato may be offered as an alternative solution to increase implementation of biologically-based B. tabaci management. <br /><br />


2022 ◽  
Vol 154 ◽  
Author(s):  
Desh Deepak Chaudhary ◽  
Bhupendra Kumar ◽  
Geetanjali Mishra ◽  
Omkar

Abstract In the present study, we assessed functional response curves of two generalist coccinellid beetles (Coleoptera: Coccinellidae), specifically Menochilus sexmaculatus and Propylea dissecta, using fluctuating densities of aphid prey as a stimulus. In what may be the first such study, we investigated how the prey density experienced during the early larval development of these two predatory beetle species shaped the functional response curves of the late instar–larval and adult stages. The predators were switched from their rearing prey-density environments of scarce, optimal, or abundant prey to five testing density environments of extremely scarce, scarce, suboptimal, optimal, or abundant prey. The individuals of M. sexmaculatus that were reared on either scarce- and optimal- or abundant-prey densities exhibited type II functional response curves as both larvae and adults. However, individuals of P. dissecta that were reared on scarce- and abundant-prey densities displayed modified type II functional response curves as larvae and type II functional response curves as adults. In contrast, individuals of P. dissecta reared on the optimal-prey density displayed type II functional response curves as larvae and modified type II functional response curves as adults. The fourth-instar larvae and adult females of M. sexmaculatus and P. dissecta also exhibited highest prey consumption (T/Th) and shortest prey-handling time (Th) on the scarce-prey rearing density. Thus, under fluctuating-prey conditions, M. sexmaculatus is a better biological control agent of aphids than P. dissecta is.


Oecologia ◽  
2019 ◽  
Vol 192 (1) ◽  
pp. 29-41 ◽  
Author(s):  
Sophie Le Hesran ◽  
Thomas Groot ◽  
Markus Knapp ◽  
Tibor Bukovinszky ◽  
Jovano Erris Nugroho ◽  
...  

AbstractThe ability of an organism to adapt to short-term environmental changes within its lifetime is of fundamental importance. This adaptation may occur through phenotypic plasticity. Insects and mites, in particular, are sensitive to changes in temperature and humidity, especially during the juvenile stages. We studied the role of phenotypic plasticity in the adaptation of eggs to different relative humidity conditions, in the predatory mite Phytoseiulus persimilis, used worldwide as a biological control agent of the spider mite Tetranychus urticae. The biocontrol efficacy of P. persimilis decreases under dry conditions, partly because P. persimilis eggs are sensitive to drought. We exposed P. persimilis adult females from two different strains to constant and variable humidity regimes and evaluated the hatching rate of their eggs in dry conditions, as well as the survival and oviposition rates of these females. Whereas the eggs laid by P. persimilis females exposed to constant high humidity did not survive in dry conditions, females exposed to constant low humidity started laying drought-resistant eggs after 24 h of exposure. Survival and oviposition rates of the females were affected by humidity: females laid fewer eggs under constant low humidity and had a shorter lifespan under constant high and constant low humidity. The humidity regimes tested had similar effects across the two P. persimilis strains. Our results demonstrate that transgenerational phenotypic plasticity, called maternal effect, allows P. persimilis females to prepare their offspring for dry conditions.


2007 ◽  
Vol 42 (4) ◽  
pp. 481-495 ◽  
Author(s):  
Juang-Horng Chong ◽  
Ronald D. Oetting

Anagyrus sp. nov. nr. sinope Noyes and Menezes (Hymenoptera: Encyrtidae) is a candidate biological control agent against the Madeira mealybug, Phenacoccus madeirensis Green (Hemiptera: Pseudococcidae). This study reported on the components of the oviposition behavior of Anagyrus sp. nov. nr. sinope in relation to 6 developmental stadia of P. madeirensis: crawlers, second-instar nymphs, third-instar immature females, third-instar immature males, prereproductive adult females, and ovipositing adult females. A behavioral sequence and a time budget were prepared for Anagyrus sp. nov. nr. sinope, indicating that the parasitoids foraging in a patch containing third-instar and prereproductive adult females had the highest probability to encounter and eventually parasitize a host. The parasitoids attacking third-instar and prereproductive adult females also spent the largest proportion of total foraging time in oviposition (67 and 69%, respectively) and had the longest handling time (997 and 655 sec per event, respectively). No third-instar immature males, which were wrapped in thick tests constructed of wax filaments, were parasitized by the parasitoids. Anagyrus sp. nov. nr. sinope did not avoid superparasitism. Parasitoids foraging in patches of third-instar and adult females had a higher self-superparasitism rate (27–33%) than crawlers and second-instar nymphs (8–14%). The clutch sizes in the superparasitized mealybugs were slightly larger than those in the mealybugs parasitized only once, but the difference was only significant in the ovipositing female P. madeirensis. Older and larger mealybugs exhibited more vigorous defensive behaviors by walking away and flipping abdomens. However, such behavioral defenses were not effective against the persistent parasitoids.


2004 ◽  
Vol 94 (2) ◽  
pp. 159-167 ◽  
Author(s):  
S. Jess ◽  
J.F.W. Bingham

AbstractIn small-scale experiments, the predatory mites, Hypoaspis aculeifer (Canestrini) and H. miles Berlese, applied at 700 mites m−2, and the entomopathogenic nematode, Steinernema feltiae (Filipjev) applied at 3 × 10−6 nematodes m−2 controlled sciarids and phorids in mushroom compost and casing substrates. For both mite species, earliest application to the growing substrate following sciarid infestation reduced sciarid emergence. In contrast, later application of each biological control agent provided more effective control of phorid emergence. The behaviour of adult mites suggested that H. aculeifer were more positively geotactic than H. miles although both species could penetrate compost and casing substrates to a depth of 2–12 cm. A majority of S. feltiae nematodes resided at a depth of 2–4 cm in both substrate types. Independent application of H. aculeifer provided more comprehensive control of sciarids and phorids than the other biological agents studied, owing to its better dispersal within compost and casing, and ability to attack larvae of differing ages.


2020 ◽  
Vol 25 (6) ◽  
pp. 1147-1157
Author(s):  
Rosenya Michely Cintra Filgueiras ◽  
Jairo De Almeida Mendes ◽  
Francisco Wesller Batista Da Silva ◽  
Eduardo Pereira De Sousa Neto ◽  
José Wagner Da Silva Melo

Raoiella indica Hirst (Acari: Tenuipalpidae) is a polyphagous pest widely dispersed worldwide and a particular threat to crops from the Arecaceae family. Control measures are still being evaluated in recently invaded countries. A possible control strategy for this pest is the use of predatory mites. A recent study has suggested Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a potential biological control agent of R. indica. In the present study we determined the prey stage preference of N. barkeri when offered different stages of R. indica besides its functional response and numerical over its prey stage preferred. The predatory mite N. barkeri showed a marked preference for eggs over other stages of the prey. The regression analysis indicated that the predatory mite N. barkeri exhibited a Type II functional response. The prey density needed to start the oviposition was 10 R. indica eggs. The number of eggs laid by N. barkeri females increased with an increase in the prey density and tended to stabilize when prey availability was greater than 80 R. indica eggs, with average oviposition of 2 eggs/female. Our study suggests that N. barkeri shows potential to reduce populations of R. indica, especially at low prey densities. However, further studies are needed to investigate whether R. indica supports the development of immature stages of N. barkeri.


Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 619 ◽  
Author(s):  
Ibrahim Sani ◽  
Siti Izera Ismail ◽  
Sumaiyah Abdullah ◽  
Johari Jalinas ◽  
Syari Jamian ◽  
...  

Whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), consists of genetically diverse species known to cause significant destruction in several crops around the world. Nymphs and adults of B. tabaci cause damage to plants during feeding, and they can act as a virus vector, thus causing significant yield loss to crops in the tropical and subtropical regions. Chemical pesticides are widely used to control B. tabaci due to their immediate action, but this approach has several drawbacks including food safety issues, insecticide resistance, environmental pollution, and the effect on non-target organisms. A biological control agent using entomopathogenic fungi (EPF) has therefore been developed as an alternative against the conventional use of chemical pesticides in an integrated pest management (IPM) system to effectively control B. tabaci. It is apparent from this review that species of hyphomycetes fungi are the most common EPF used to effectively control B. tabaci, with the second instar being the most susceptible stage of infection. Therefore, this review article focuses specifically on the control of B. tabaci with special emphasis on the use of EPF as biological control agents and their integration in IPM.


Author(s):  
El-laithy A.y. M., E, M.elseedy ◽  
Hoda E. Hussein

A field experiment was carried out to evaluate the efficacy of the native predatory mite Cydnoseius negevi (Swirski and Amitai) (=Typlodromus negevi) as a biological control agent for Bemisia tabaci (Gennadius) complex, Onion thrips Thrips tapaci (Lindeman) and Tetranychus urticae (Koch). The efficacy of Phytoseiulus persimilis (Athias-Henriot) against these pests was also evaluated. The data obtained revealed reduction in population density of the above-mentioned pests in the experimental plots for P. persimilis and C. negivi compared to the control plot. Mean population density of each of the pests ranging from 32.2–0.5, 284.4–2.0 and 441.8–2.0 individuals / leaf for T. urticae, in the three plots respectively. The mean values of B. tabaci fluctuated between 41.1–2.1, 16.2–1.0 and 57.3–3.6. individuals / leaf and T. tabaci between 20.1–2.6, 13.7–1.4 and 24.9–1.9 individuals / leaf respectively. A slight non-consumptive negative effect is shown by P. persimilis against the pests B. tabaci and T. tabaci. This preliminary experiment hopefully will enhance the role of the native predator C. negevi to play a role in bio-control and its mass augmentation.


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