The influence of different maize varieties and treatments on the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae) (original) (raw)
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Acarines: Journal of the Egyptian Society of Acarology, 2021
Field studies were carried out to evaluate six single cross maize hybrids namely; Giza 129, Giza 10 & Giza 125 (white ~1aize varieties) and Giza 168, Giza 162 & Giza 166 (yellow maize varieties) for their relative susceptibility to the twospotted spider mite, Tetranychus urticae Koch infestation, during 2008 and 2009 growing seasons at Sharkia Governorate, Egypt. Giza 125 and Giza 162 proved to be the most susceptible hybrids to spider mite infestation in white and yellow maize varieties, respectively, while Giza 129 and Giza 166 were the most tolerant in the two varieties, ~espectively. In both tested seasons, mite population reached its peak on maize during the fourth and the third weeks of July, respectively, for all tested hybrids. A significant positive correlation was found between mite infestation and both nitrogen and protein contents in maize leaves.
Maize plants produce direct resistance elicited by Tetranychus urticae Koch (Acari: Tetranychidae)
Brazilian Journal of Biology, 2017
Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays), despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested b...
Efficacy of Post-Tassel Miticide Applications Against Spider Mites and Yield Response in Corn, 2003C
Arthropod Management Tests, 2005
Banks grass mite (BGM): Oligonychus pratensis (Banks) Twospotted spider mite (TSM): Tetranychus urticae Koch Five miticides were evaluated at three application timings on field corn, (110-day maturity), planted 5 May with a John Deere Max Emerge 6 row planter at a rate of 36,000 seeds/acre in a furrow-irrigated field (Finnup no. 8) at the Southwest Research-Extension Center, Finney County, KS. The test was set up in a randomized complete block design with four replications. Plots were four rows (10 ft) wide and 50 ft long with 4-row (10 ft) borders of untreated corn on each side and 10-ft alleys at each end. The treatments were applied with a high clearance sprayer using a 10-ft boom with two nozzles directed at each row (one on each side of the row on a 16-inch drop hose). The nozzles were directed up into the plant for the first treatment and at the ear zone for the other timings. The sprayer was calibrated to deliver 14 gpa at 2 mph and 40 psi. Treatments no. 2-4 were applied 26 Jul and treatments no. 5-10 were applied 28 Jul when the corn was in the soft dough stage. An untreated check and a standard late-season miticide, Capture, were included with these dough stage treatments. Spider mites infested the plots naturally from an adjacent wheat field. During the summer, spider mites were sampled in corn by collecting half the leaves from 4 plants (4 half plants = 2 plants) from the two center rows in each plot. The sample plant material was placed in large 76-liter Berlese funnels with a 100 watt light bulb to dry the vegetation and drive arthropods down into a collecting jar containing 70% methanol. The alcohol samples were filtered on ruled white filter paper and spider mites, predator mites and thrips were counted under a binocular microscope. A subsample of spider mites (about 20 for each plot) was mounted on a microscope slide and examined to determine the proportion of BGM versus TSM. Pre-treatment spider mite samples were collected 25 Jun and post-treatment samples were collected 1 and 8 Aug. Spider mite counts were transformed with Taylor's power transformation for statistical analysis and converted to mites per 4 halfplants for presentation. On 12 Sep the plots were also rated for the number of green leaves. Grain yield was collected by machine harvesting the two middle rows from each plot and adjusting to 15.5% moisture. There was a significant yield gradient down the field that was associated with slope and furrow irrigation. We calculated the "field yield trend" by averaging the yield at each position down the field across 6 strips of plots. The position means were smoothed using rolling averages. Then this "field yield trend" was used as the covariate in the ANOVA of grain yield and number of green leaves. Spider mite populations increased to 1141 mites per 2 plants at 11-13 days post treatment and caused
Population Changes of Spider Mites (Acari: Tetranychidae) Following Insecticide Applications in Corn
Environmental Entomology, 1996
Applications of 2 insecticides, methyl parathion and permethrin, for the control of 1st-and 2nd-generation European com borer, Ostrinia nubilalis (Hubner), in com, Zea mays (L.), were evaluated in 1992, 1993, and 1994 for their effects on the population densities of twospotted spider mites, Tetranychus urticae Koch, Banks grass mites, Oligonychus pratensis (Banks), and selected mite predators such as predatory mites, lady bird beetles, pirate bugs, predatory thrips, lacewings, and spiders. Results indicated that applications of permethrin during the last week of July or early August were associated with a significant increase in the population of twospotted spider mites. However, no consistent increases in the population of Banks grass mites were observed. Predator populations were generally low throughout the study period, and no significant changes in the population of identified predators were observed between pretreatment and posttreatment sampling. KEY WORDS spider mites, outbreaks, predators, insecticides ApPLICATIONS OF PESTICIDES, including insecticides, acaricides, and fungicides have resulted in economic outbreaks of spider mites (Van de Vrie et al.
The two-spotted spider mite, Tetranychus urticae Koch, is very polyphagous and considered a serious pest worldwide. The use of relatively resistant crop cultivars may limit the negative effects of this pest; we therefore compared population growth parameters of T. urticae reared on five commonly grown bean cultivars in Iran (Derakhshan, G14, Sayyad, D81, and Talash). The life table parameters were estimated at 25±1 o C, 60±10% RH, and a photoperiod of 18:6 h (L:D). Egg hatchability, development time and survival to adult stage were similar among cultivars, but we detected significant variation in fecundity and longevity, resulting in large differences for population growth parameters like the intrinsic rate of natural increase (r m ), net reproductive rate (R 0 ), finite rate of increase (λ) and doubling time (DT). Sayyad was the most favourable host for two-spotted spider mites with r m = 0.295 (offspring/female/day), followed by G14 (0.261), D81 (0.244) and Derakhshan (0.238). The slowest population growth was observed on the Talash variety with r m = 0.214. These findings indicate that the choice of bean variety will affect how fast spider mite populations reach damaging levels in a culture.
STUDY ON THE DEVELOPMENTAL STAGES OF SPIDER MITE (TETRANYCHUS URTICAE KOCH) INFESTING COUNTRY BEAN
2008
The duration of developmental stages of Tetranychus urticae Koch was studied in different months of a year at room temperature. In addition fecundity of this mite was also observed in winter, autumn and summer seasons. T. urticae eggs hatched to larvae in the shortest duration of 1.07 ± 0.26 days and the longest duration of 11.67 ± 2.33 days in April and January, respectively. The larval period of T. urticae took the shortest time of 0.55 ± 0.50 days in May and 2.93 ± 1.07 days in December. The protonymph transformed to deutonymph in 0.89 ± 0.32 day in May and 3.71 ± 1.94 in December and January. The deutonymph required the shortest duration of 0.92 ± 0.41 days in August and the longest of 10.26 ± 1.48 days in January. The temperature played significant (P<0.001) role on the duration of developmental stages of T. urticae. The high temperature accelerated the developmental rate and reduced the duration of developmental periods. Its life cycle completed within 4.22 ± 0.46 days at 28.53 ± 3.17°C but 28.33 ± 2.36 days at 13.78 ± 2.36°C. A female T. urticae deposited 82.46 ± 4.11 eggs in autumn, 62.96 ± 12.09 eggs in summer and 58.21 ±1 3.65 eggs in winter.
Transgenic research, 2015
Crops producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), are an important tool for managing lepidopteran pests on cotton and maize. However, the effects of these Bt crops on non-target organisms, especially natural enemies that provide biological control services, are required to be addressed in an environmental risk assessment. Amblyseius andersoni (Acari: Phytoseiidae) is a cosmopolitan predator of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), a significant pest of cotton and maize. Tri-trophic studies were conducted to assess the potential effects of Cry1Ac/Cry2Ab cotton and Cry1F maize on life history parameters (survival rate, development time, fecundity and egg hatching rate) of A. andersoni. We confirmed that these Bt crops have no effects on the biology of T. urticae and, in turn, that there were no differences in any of the life history parameters of A. andersoni when it fed on T. urticae feeding on Cry1...
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%).