Role of Stethours gilvifrons (Mulsant) as Biological Control Agents of the Two Spotted Spider Mite Tetranychus urticae Koch (original) (raw)
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Egyptian Academic Journal of Biological Sciences, F. Toxicology & Pest Control
Ecological studies had been carried out in cotton plants to investigate the population density and effect of certain weather factors on the two-spotted spider mite, Tetranychus urticae Koch; Phytoseiulus persimilis, and Tarsonemidae. and some insect predators, Stethorus gilvifrons (Mulsant), Orius insidiosus and Chrysoperla carnea (Stephens), in two successive seasons, 2021 and 2022 at Mansoura district. There were two peaks in 2021 for T. urticae whereas three peaks in 2022. That highest peak was found in 2021 during the first week of July (1040 individuals /25 leaves), while that was in the last week of July (1043.3 individuals / 25 leaves) in 2022. The results indecated that P. persimilis had first seen in the second week of May in both seasons of the study. The highest peak was found during the second week of Jun (5.5 individuals /25 leaves) in 2021, but, in 2022, that was in the first week of July (4.0 individuals / 25 leaves). In addition to that, family Tarsonemidae was first seen in the second week of May 2021 and 2022. It recorded two peaks in 2021 and one beak in 2022. These peaks were found in the first and second week of July recording (2.3 individuals) in 2021. The beak in 2022 was at the last week of July with the same density as 2021 (2.3 individuals). Predatory insect S. gilvifrons had one peak in the 2021 whereas two peaks in 2022. The highest density was found during the first week of July (5.8 individuals) in 2021. While, O. insidiosus had only one peak in each season of the study, the highest density was in 2021 at the first week of July (6.0 individuals). C. carnea was first seen in the first week of May during the two seasons of the study. It recorded one peak in both seasons. 2022, recorded high density in the third week of July, (5.5 individuals). The statistical analysis showed that there was no significant correlation between most pests and temperature parameters in 2021. both T. urticae and Tarsonemidae there was positive significant for both maximum and average temperature in 2022. While a slight negative effect in 2021 for P. persimilis. a moderately significant correlation between the average temperature and the number of S. gilvifrons during the season of 2022. The statistical analysis showed that there was a highly significant positive correlation between the temperature parameters and the number of O. insidiosus during the season of 2022. While C. carnea had a non-significant correlation with temperature parameters in the two seasons of study.
In microcosm set-ups we investigated whether combined releases of the predatory thrips Scolothrips longicornis Priesner and two phytoseiid species, Neoseiulus californicus (McGregor) and Typhlodromus bagdasarjani Wainstein & Arutunjan provide better biological control of Tetranychus urticae Koch on cucumber plants than releases of each predator species alone. Results showed that control of T. urticae populations was equivalent under all predator combinations as in single predator release, indicating that no additive or synergistic effects among three predatory species had occurred in the control of the prey. In addition, the densities of each predator species under different combinations were similar, indicating that the three predators did not prey on each other during the observation period. Overall, our results showed that all three predator species are effective predators of T. urticae under microcosm conditions and suggest that they can be used in combination without decreased efficacy through intraguild predation.
University Journal of Zoology, Rajshahi University, 2009
Three predators Scolothrips sexmaculatus Pergande, Phytoseiulus persimilis Athias - Henriot and Stethorus punctillum Weise were used to control two-spotted spider mite, Tetranychus urticae Koch on potted bean plants. Mite population increased exponentially on the untreated plants, but on the predator treated plants, increase of mite population was checked and remained within minimum number. Early release of predator checked the mite population earlier and kept it lower than on late released plants. All the three predators may be used as bio-control agents against two-spotted spider mite. Key words: Control, Tetranychus urticae, Scolothrips sexmaculatus, Phytoseiulus persimilis, Stethorus punctillum and bio-control agents. Â doi:10.3329/ujzru.v27i0.1954 Univ. j. zool. Rajshahi Univ. Vol. 27, 2008 pp. 51-54
The effect of prey stages of the two-spotted spider mite Tetranychus urticae on the functional response of the coccinellid predator Stethorus gilvifrons was studied at 25±1 °C, 65±10% rh, and 16:8 h (L:D photoperiod). The functional response of S. gilvifrons female, to increasing prey stage density from 10−100 preys per patch, was of the curvilinear shape depicting Roger's type II response with the highest consumption rate of larval prey stage. Results of the maximum likelihood analyses confirmed this type. By plotting a type II functional response model and polynomial logistic regression model to the numbers and proportions of consumed stages of T. urticae, respectively, the resulting regression lines fitted the data well. However, a composite waving form that appeared to be a decelerating (type II) response at low to medium prey densities and an accelerating (type III) response at high prey densities. We assume that the small size of experimental arena or predator feeding behaviour at low and high prey densities may have induced the modified type II response. A sensitivity analysis of the functional response model shows the crucial effect of prey stages on predation rates by S. gilvifrons. Theoretically, based on the lowest handling time for S. gilvifrons on larval stage of T. urticae, the maximum numbers of mites that could consume by a single female of S. gilvifrons within 24 h period were 77.42 larvae. These results improve our understanding of the interaction among S. gilvifrons and T. urtica stages and provide insights into the control of T. urticae.
Scolothrips longicornis Priesner is a native predator insect in Iran and it is an active biological control agent in bean, cucumber and eggplant fields. The aim of this study was to determine functional response and mutual interference of the predatory thrips, S. longicornis under laboratory conditions (25 °C, RH 65% and a photoperiod of 16 h light: 8 h dark) fed on Tetranychus urticae Koch on cucumber. The functional response was measured by offering eggs and nymphs of T. urticae at seven densities (2, 4, 8, 16, 32, 64 and 128) to an adult female of thrips separately and the mutual interference was calculated by five densities (1, 2, 4, 8 and 16) of adult female predators on 250 nymphs of T. urticae. Both experiments were done during 24-h period. The values of the attack rate (a) and handling time (T h ) were estimated using the Royama-Rogers' model. The logistic regression showed a type II response of the predator to different densities of eggs and nymphs of T. urticae. Both parameters (a, T h ) were very similar between eggs (0.1107 and 2.4038 h, respectively) and nymphs (0.1034 and 2.4691 h, respectively). The per capita searching efficiency decreased significantly from 0.040 to 0.024 with increasing predator density from 1 to 16 females. Also the per capita predation decreased significantly from 9.800 to 4.983 with increasing predator density from 1 to16. The results revealed the high predation potential of S. longicornis, which it can be used as a sufficient biological control agent on T. urticae.
Biological Control, 2007
The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important pests of many crops in temperate and tropical climates. Chemical control is the main method of combating this mite, but it is less preferred due to the development of resistance as well as environmental problems associated with the use of pesticides. Biological control of spider mites has been tried as a logical alternative method for chemical control. Studies have been conducted in different countries to assess the effect and potential of natural enemies for controlling the pest. The predatory mite Phytoseiulus macropilis (Banks) (Acari: Phytoseiidae) was found associated with spider mites in strawberry crops in the state of Minas Gerais, Brazil. Earlier studies suggested that P. macropilis was able to control spider mites, but predation and oviposition rates have not been measured so far. We measured predation and oviposition on strawberry with spider mites as prey in the laboratory. The predator fed on all prey stages and showed capacity to control local prey populations on leaf disks. The oviposition rate of P. macropilis is similar of the most used predatory mite Phytoseiulus persimilis and the predation rate is higher than that of the latter. Our results suggest that P. macropilis is a promising candidate to control two-spotted spider mites in the tropics and other areas.
The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is a very serious pest of many crops in temperate and tropical climates. Several of the attempts to control this mite by using chemical insecticides have failed mainly because of development of pesticide resistance. Though several natural enemies have been recorded as potential predators of T. urticae, the predator used most often has been the phytoseiid mite Phytoseiulus persimilis Athias-Henriot. Earlier studies have also indicated that anthocorid predators are effective biological control agents of spider mites. An anthocorid predator Blaptostethus pallescens Poppius (Heteroptera: Anthocoridae) was collected from the field and successfully multiplied on the eggs of the rice moth Corcyra cephalonica Stainton. Laboratory studies indicated that B. pallescens could feed on 190 and 116 T. urticae nymphs during its nymphal and adult stages, respectively. In the net house studies, there was a 78% reduction in th...
Control of the Two-Spotted Spider Mite, Tetranychus urticae Koch on kidney Bean and Pea Plants
The effect of the two predatory species (Phytosiulus persimilis Athias-Henriot and Typhlodromips swirskii Athias-Henrio), fungal entomopathogen (Beuvaria bassiana) and the Biochemical compound Abamectin (Vapcomic) were investigated against the two-spotted spider mite, Tetranychus urticae Koch on kidney bean (Paulista) and sugar snap pea (Snow wind) in a greenhouse at Behaira Governorate during 2013 season. The average number of spider mite population was significantly different among the different treatments on Paulista (F 4,99 = 39.025; P < 0.001; Table 1), and on Snow wind (F 4,99 = 32.17; P < 0.001). The mean reduction percentage of the spider mite populations on both plant varieties by P. persimilis was significantly highest (95.2%). Followed by treating with Vapcomic (90.0 %) and the fungus B. bassiana (84.8%); T. swirskii caused the least (71.9%).
Compatibility of two predator species for biological control of the two-spotted spider mite
Experimental and Applied Acarology
Because predators may interfere with each other, an important step towards the implementation of successful release of multiple predators in biocontrol programs requires resolving how predators respond to the presence of heterospecific competitors. Several species of predatory mites are important biocontrol agents and the species Phytoseiulus macropilis and Neoseiulus californicus are used to control the two-spotted spider mite, Tetranychus urticae, an important pest in agriculture worldwide. We investigated their compatibility showing that the two predators do not avoid plants on which the other species is present together with their common prey, and demonstrated that their oviposition rates are not affected by the presence of the other species. However, the distribution of the eggs on leaf discs was affected by the presence of the heterospecific predator. This behaviour might weaken possible interference between these two biocontrol agents, which, in turn, may enable their persist...