Spider Mite Populations Research Articles

Mathematical Model for Two-Spotted Spider Mites System: Verification and Validation

This paper presents and compares four mathematical models with unique spatial effects for a prey-predator system, with Tetranychus urticae as prey and Phytoseiulus persimilis as predator. Tetranychus urticae, also known as two-spotted spider mite, is a harmful plant-feeding pest that causes damage to over 300 species of plants. Its predator, Phytoseiulus persimilis, a mite in the Family Phytoseiidae, effectively controls spider mite populations. In this study, we compared four mathematical models using a numerical simulation. These models include two known models: self-diffusion, and cross-diffusion, and two new models: chemotaxis effect model, and integro diffusion model, all with a Beddington-De Angelis functional response. The modeling results were validated by fitting experimental data. Results demonstrate that interaction scheme plays an important role in the prey-predator system and that the cross-diffusion model fits the real system best. The main contribution of this paper is in the two new models developed, as well as the validation of all the models using experimental data.

Efficiency of Two Predatory Mites Amblyseius swirskii and Cheletogenes ornatus Early Release in Controlling the Two Spotted Spider Mite, Tetranychus urticae Koch on Soybean Plants in Sharkia Governorate.

The two predatory mites, Amblyseius swirskii Athias-Henriot and Cheletogenes ornatus Canestrini & Fanzago were evaluated as early release to control Tetranychus urticae (Koch) on Soybean plants in Sharkia governorate during the period from 15th June to 7th September 2016. Three release levels (2, 4 and 6 predators/leaf) were conducted when population of spider mite was 1-3 individual/leaf. There was no significant difference between the efficiency of the two predators all over the experiment. Reduction percentages were recorded as 54.3, 69.7 and 78.9% for A. swirskii while it was 48.7, 61.8 and 69% for C.ornatus at three rates of release, respectively. Efficiency increased significantly with predator release rate increase. There was no significant differences between the reduction percentages of 4 and 6 predators/plant. Starting release at low level of infestation to have good control in very short time after releasing is amust.

Biocontrol of Spider Mites in California Strawberry Production

ABSTRACTField experiments were conducted in 2013 and 2014 to evaluate the predation efficacy of four commercially available predatory mites (Phytoseiidae): Phytoseiulus persimilis, Neoseiulus californicus, N. fallacis, and Amblyseius andersoni, for control of twospotted spider mite (Tetranychus urticae Koch) and Lewis spider mite (Eotetranychus lewisi) in strawberries. In the 2013 experiment, a grower standard treatment (P. persimilis and N. californicus) was compared to single treatments of each phytoseiid species. The 2014 experiment excluded N. fallacis as a treatment, but all other treatments are the same as in 2013. For both seasons, all treatments decreased both two-spotted and Lewis spider mite populations immediately after releases equivalently. However, none of the treatments tested were able to keep twospotted and Lewis spider mite populations below the economic threshold level. These findings indicate that several releases will be needed throughout the growing season in order to maintain spider mite levels below the economic thresholds.

Screening of spider mites (Acari: Tetranychidae) for reproductive endosymbionts reveals links between co-infection and evolutionary history.

Reproductive endosymbionts have been shown to have wide-ranging effects on many aspects of their hosts’ biology. A first step to understanding how these endosymbionts interact with their hosts is to determine their incidences. Here, we screened for four reproductive endosymbionts (Wolbachia, Cardinium, Spiroplasma and Rickettsia) in 28 populations of spider mites (Acari: Tetranychidae) representing 12 species. Each of the four endosymbionts were identified in at least some of the tested specimens, and their infection patterns showed variations at the species-level and population-level, suggesting their distributions can be correlated with both the phylogeny and ecology of the hosts. Co-infections of unrelated bacteria, especially double infections of Wolbachia and Cardinium within the same individuals were common. Spiroplasma and Rickettsia infections were specific to particular host species, respectively. Further, the evolutionary histories of these endosymbionts were inferred by comparing the phylogenies of them and their hosts. These findings can help to clarify the interactions between endosymbionts and arthropods.

Interactions between natural enemies: Effect of a predatory mite on transmission of the fungus Neozygites floridana in two-spotted spider mite populations

Introducing the predatory mite Phytoseiulus persimilis into two-spotted spider mite, Tetranychus urticae, populations significantly increased the proportion of T. urticae infected with the spider mite pathogen Neozygites floridana in one of two experiments. By the final sampling occasion, the number of T. urticae in the treatment with both the predator and the pathogen had declined to zero in both experiments, while in the fungus-only treatment T. urticae populations still persisted (20–40 T. urticae/subsample). Releasing P. persimilis into crops in which N. floridana is naturally present has the potential to improve spider mite control more than through predation alone.

The Influence of <i>Tetranychus urticae</i> Koch (Acari: Tetranychidae) Life Table and Reproductive Parameters by Applying Si on Bean at Library Condition

Two-spotted spider mite, Tetranychus urticae Koch, is one of the important pests of bean, which can cause severe damages on it. Silicon is one of the micronutrient elements, as its spray on the leaves can decrease the population of the pest. In this research, the impact of four different doses of Si (0, 1, 1/5, 2 ppm) was investigated on biological and population growth parameters of T. urticae. The experiments were carried out in Petri dishes in an incubator at 25°C ± 2°C, 65% ± 5% RH and 16 L: 8 D. The duration of developmental stage was significantly affected by Si dose. The longest immature period, the shortest longevity of females and the shortest oviposition period were obtained at 2 ppm. In addition, Si dose significantly affected population growth parameters of the mite. The intrinsic rate of natural increase (rm) of the mite ranged from 0.246 to 0.215 day which lowest and the highest values were at 2 ppm and control plants, respectively. The lowest net reproductive rate (R0) and finite rate of increase (λ) of the mite and the highest value of mean generation time (T) and doubling time (DT) were estimated at 2 ppm. The results of this peruse represented that 2 ppm had better potential for decreasing the population of the two-spotted spider mite, and it can be used in the mite integrated pest management programs.

Effect of two-spotted spider mite population (Tetranychus urticae Koch) on growth parameters and yield of the summer apple cv. Katja

Warabieda W. (2015): Effect of two-spotted spider mite population (Tetranychus urticae Koch) on growth parameters and yield of the summer apple cv. Katja. Hort. Sci. (Prague), 42: 167–175. The effect of two-spotted spider mite populations (Tetranychus urticae Koch) on the yield and growth parameters of the early-season apple cv. Katja was evaluated during a 3-year study. In the case of the colonisation of apple trees exceeding 1,462, 2,760 and 1,548 cumulative mite days (CMDs) in the subsequent years of research, a significant reduction of the cumulative yield (14 kg/tree) and of the cumulative trunk cross sectional area increase (5.7 cm2) was observed. No significant effect of spider mites on the average weight of the fruit was observed, while the pest affected fruit colouration. The calculated values of economic injury level were 60.5, 155.5 and 51.8 CMDs in subsequent years of the study, respectively. These values are much lower than the action threshold recommended in Poland and elaborated for the European red mite – Panonychus ulmi (Koch) on apple trees. The results suggest that the tolerance of early-season apple cultivars to T. urticae may be lower when compared to late-season varieties infested with P. ulmi; therefore, the decision to implement pest management for two-spotted spider mite should be taken at a lower infestation threshold than previously thought.

Phenology and structure of a phytoseiid community in an insecticide-free apple orchard.

Commercial orchards have acarine communities that are reduced in biological diversity compared to their undisturbed counterparts. Examining the phenology of an unsprayed orchard allows for the examination of non-pesticide factors that drive changes in populations. This study examined the mite community in a largely unsprayed research orchard in 2013–2014. The phytoseiids Galendromus flumenis (Chant), Amblydromella caudiglans (Schuster), Kampimodromus corylosus Kolodochka, and Galendromus occidentalis (Nesbitt) were found, in addition to Zetzellia mali (Ewing) and Aculus schlechtendali (Nalepa). Although G. occidentalis is typically the dominant phytoseiid in commercial orchards, G. flumenis was much more abundant in this unsprayed block. Aculus schlechtendali appeared to be the main source of prey for all predator species. The availability of this prey item and the lack of pesticides are likely the factors that allowed for G. flumenis to reach high abundances. Tetranychids were scarce, emphasizing the role of these mites as induced pests; without the application of disruptive sprays, the predatory mite community was able to maintain biological control. This study demonstrates that the species complex of generalist phytoseiids that is present in orchard systems undisturbed by pesticides is sufficient to maintain spider mite populations below damaging levels throughout the season.

Development of a model for mass production of <em>Neoseiulus longispinosus</em>, a phytoseiid predator of spider mites

The two spotted spider mite (Tetranychus urticae Koch.) is a serious pest in greenhouses as well as on field grown crops. The predatory mites are important in regulating spider mite populations and should be conserved whenever possible due to their great predatory potential. The pyhtoseiid predator Neoseiulus (Amblyseius) longispinosus (Evans) has a wide distribution and has the ability to adapt to warm temperature inside poly houses under South Indian conditions. This study was undertaken to develop an efficient mass multiplication model for N. longispinosus. To determine the highest yield of predatory mite N. lonigispinosus, both the prey (T. urticae; 5 and 10 per leaflet) and predator mites (2 and 4 per leaflet) were released at two different ratio on French bean (FB) plants at four different growth stages as a tri trophic system. The treatments were imposed with three replicates in a factorial arrangement. Prey mites were released at 20, 25, 30 and 35 days after sowing (DAS) and predatory mites were released 10 days after prey mite release. The number of eggs, immature stages and adults of spider mites as well as predatory mites in each sample was recorded from 35 DAS. Two models where ten spider mites were released per leaflet on 20 DAS with 2 and 4 predatory mites released at 30 DAS, and the third model where release of spider mites at 25 DAS with two predators per leaflet were released, gave the highest yields of the predator. The first model was the most suitable, where the predators harvested was 1,087,130 (55 DAS), 1,362,600 (60 DAS) and 2,000,700 (65 DAS) per 300 pots, at a cost of production of Indian Rupees (INR) 7.5, 6.4 and 4.63 for 1000 predators, respectively. When four predators were used in the above model, 146,230, 325,840, 700,110 and 1,083,700 predators were harvested per 300 pots in 35, 40, 45 and 50 DAS, respectively. The costs of the 1000 predators were INR 40.39, 19.85, 10.04 and 7, respectively. The present models were based on two repeated cycles (two times) and the information generated may be insufficient to draw a solid conclusion. Hence, these models need to be tested thoroughly to stabilize predator production.

Repellency and oviposition deterrence of wild tomato leaf extracts to spider mites, Tetranychus urticae Koch

Glandular trichomes on the leaves of wild tomato, Lycopersicon hirsutum f. hirsutum Mull, also known as Solanum habrochaites (Solanaceae) synthesize and accumulate high levels of methyl ketones (MKs). The potential of using MKs as alternatives to synthetic acaricides for controlling the twospotted spider mite, Tetranychus urticae Koch, is explored in this study. Plants of L. hirsutum accession LA 407 having high concentrations of MKs were grown from seeds under greenhouse conditions. The main objective of this investigation was to conduct bioassays that are quick and easy to implement, consistent over time (repeatable) with the ability to utilize small amounts of test material for testing repellency and fecundity (number of eggs laid by a female mite) of MKs in pure forms and in LA 407 crude extracts. Four MKs (2-tridecanone, 2-undecanone, 2-dodecanone, 2-pentadecanone) and their mixture were screened for their repellency and ability to alter fecundity of spider mites. All MKs repelled spider mites at the two periods tested. Following spraying of tomato leaf extracts prepared in ethanol (ethanol extracts), average number of eggs laid per female mite on bean leaf discs dropped from 0.8 to 0.3 and from 0.9 to 0.3 at 4 and 24 h after exposure representing 65 and 68% reduction, respectively. However, spraying of tomato leaf extracts prepared in water (water extracts) reduced number of eggs laid per female mite from 1.7 to 0.7 and from 2.6 to 0.9 at 4 and 24 h after exposure representing 60 and 67% reduction, respectively. We concluded that all MKs have repellent and egg laying deterrence activities against spider mites. This investigation suggests that ethanol and water extracts of LA 407 have a potential for repelling female spider mites and reducing their laid eggs which might be explored under field conditions for managing populations of spider mites, which could reduce reliance on synthetic acaricides.

A reservoir weed for mites: Datura stramonium L. (Solanaceae) in the vicinity of cultivated solanaceous plants in Turkey

Twenty-six phytophagous, predacious and generalist mite species were found on the weed species Datura stramonium in the vicinity of solanaceous vegetables from two locations in Turkey during 2009–2010. Of seven species of phytophagous mites, Tetranychus urticae was the predominant species on the weed leaves. Additionally, 15 predacious mite species from seven families were identified: Phytoseiidae, Anystidae, Stigmaeidae, Bdellidae, Ascidae, Ameroseiidae and Iolinidae. Phytoseiidae (nine species) and Iolinidae (one species) were the most abundant predacious mites in the families. The dominant predacious species were Cydnodromus californicus and Pronematus ubiquitus. The Shannon index (H′), a biodiversity parameter of the predacious mites was very high compared to that of phytophagous mites that occurred at a high density. Among four generalist species from three families (Tydeidae, Acaridae and Oribatidae), one species, Zygoribatula microporosa, was found in the Turkish mite fauna. In Ankara, the population density of spider mites on the weed leaves began to increase in early July and peaked three times in late July, early September and mid-October in 2009–2010. In Bursa, the mites emerged in early June and peaked four times in early July, early August, early September and early October in 2010–2011. Cydnodromus californicus and Typhlodromus Anthoseius recki exhibited efficient numerical responses to spider mite populations from early August to early September. However, in Bursa, Sorenson’s coefficient confirmed that there were positive predator–prey associations among spider mites and these predacious mites. Although this weed is a source of predacious species when it is located in the vicinity of tomato fields, D. stramonium may play a role as a reservoir plant for phytophagous mites and permit increasing pest population in areas used for the cultivation of solanaceous vegetables due to predators’ delayed response to spider mite populations.

Incorporation of Biorational Insecticides with Neonicotinoids to Combat Resurgence ofTetranychus urticae(Prostigmata: Tetranychidae) on Rose

Rose plants were treated with 2 neonicotinoids (imidacloprid and acetamiprid), 3 biorationals (spinosad, emamectin benzoate, and Beauveria bassiana [Bals.-Criv.] Vuill. [Hypocreales: Cordycipitaceae]), and combinations of neonicotinoids and biorationals to control two-spotted spider mites (Tetranychus urticae Koch; Prostigmata: Tetranychidae) on rose. Toxicity bioassays revealed that imidacloprid drench, imidacloprid foliar applications, and acetamiprid treatments significantly increased spider mite numbers, whereas treatments with spinosad or with emamectin either alone or in combinations with imidacloprid and acetamiprid resulted in significantly fewer spider mites compared with the untreated control. Beauveria bassiana was least effective in controlling the spider mite population. The fecundity experiment indicated that the imidacloprid drench and foliar treatments significantly increased the number of mite eggs produced during observation days up to 9 d after treatment (DAT) for the drench treatment and up to 7 DAT for the foliar treatments. Acetamiprid did not induce any significant changes in spider mite egg production. Spinosad, emamectin, and B. bassiana alone or in combinations induced significant reductions in egg numbers compared with the control at almost all observation days. Both preference and non-preference tests indicated that the drench and the foliar applications with imidacloprid resulted in significantly more spider mites on treated leaf discs at 5 and 7 DAT than on untreated leaves. In conclusion, spinosad and emamectin in combinations with the neonicotinoids can be incorporated into the integrated pest management of the two-spotted spider mite on roses.

Evolution of meteorological factors on incidence of red spider mite of tea,Oligonychus coffeae (Nietner) under the natural conditions of Assam

The incidence of red spider mite, Oligonychus coffeae on tea crop was maximum during the month of April to May-June and September-October (2011). The minimum number of mites were recorded from July-August and November (2011) to February (2012). The data taken from 1 st week of April, 2011 to last week of March, 2012. That population build up of O. coffeae showed a significant positive correlation with the maximum temperature and minimum temperature (r = 0.320 and r = 0.268, respectively). Whereas, the red spider mite population was negatively correlated but significant with average relative humidity (r = -0.357). Rainfall had a negative non-significant correlation with the mite population (r = -0.049).

Reproductive parameters of Tetranychus urticae (Acari: Tetranychidae) affected by neonicotinoid insecticides.

Two-spotted spider mite is a major pest of many agricultural and ornamental crops worldwide. Some reports have indicated that application of neonicotinoid insecticides may lead to increased fecundity of this pest. If this is found to be true, the use of these pesticides may cause an outbreak of spider mite populations. Sublethal effects of three neonicotinoids, namely thiacloprid, acetamiprid and thiamethoxam were studied on T. urticae adults at field recommended doses. The experiments were carried out using bean leaf pieces in plastic Petri dishes. The adult mites were treated using two methods: (1) drench application and (2) spraying of leaves with Potter Spray Tower. Our results indicated that all neonicotinoids tested increased T. urticae population. In both treatment methods, acetamiprid treated mites had the highest intrinsic rate of population increase (rm) and finite rate of population increase (λ); and the lowest mean generation time (T) and doubling time among the treatments. If similar results are obtained from greenhouse and field trials, the use of these insecticides requires necessary precautions such as avoiding repeated use of neonicotinoid insecticide for controlling insect pests.

Organic fertilization and botanical insecticides to control two-spotted spider mite in strawberry

Strawberry fields receive several pesticides spraying and residues in fruits are recurrent. Development and application of methods that avoid applying pesticides mostly during fructification period are imminent needs. Comparison of population of two-sppoted spider mite (TSSM) Tetranychus urticae Koch. in organic and mineral fertilized plants (as used by growers) and treated with alternative products were done. Plants were grown in vessels in a greenhouse infested with local population of TSSM. Extracts of Tephrosia voggeli (Hook), neem oil (Azadirachta indica A. Juss.), and lime sulfur were applied three times against TSSM in ten days intervals. Assessments were done three times after each spraying. Interaction between fertilization and spraying alternatives was also assessed but was not significant. TSSM population was about 44% lesser in organic fertilized plants than those in inorganic fertilized. T. voggeli extracts reduced in large amounts TSSM; neem oil reduced in some assessments and an intermediate reduction was found for sulfur lime. Organic fertilization and T. voggeli extracts are potential strategies to manage TSSM and additional studies are proposed to enable wide utilization

Do mites evolving in alternating host plants adapt to host switch?

A fluctuating environment may be perceived as a composition of different environments, or as an environment per se, in which it is the fluctuation itself that poses a selection pressure. If so, then organisms may adapt to this alternation. We tested this using experimental populations of spider mites that have been evolving for 45 generations in a homogeneous environment (pepper or tomato plants), or in a heterogeneous environment composed of an alternation of these two plants approximately at each generation. The performance (daily oviposition rate and juvenile survival) of individuals from these populations was tested in each of the homogeneous environments, and in two alternating environments, one every 3 days and the other between generations. To discriminate between potential genetic interactions between alleles conferring adaptation to each host plant and environmental effects of evolving in a fluctuating environment, we compared the performance of all lines with that of a cross between tomato and pepper lines. As a control, two lines within each selection regime were also crossed. We found that crosses between alternating lines and between pepper and tomato lines performed worse than crosses between lines evolving in homogeneous environments when tested in that environment. In contrast, alternating lines performed either better or similarly to lines evolving in homogeneous environments when tested in a fluctuating environment. Our results suggest that fluctuating environments are more than the juxtaposition of two environments. Hence, tests for adaptation of organisms evolving in such environments should be carried out in fluctuating conditions.

Effects of Bt+CpTI transgenic cotton on the performance of <em>Tetranychus</em><em> turkestani</em> (Acari: Tetranychidae)

Transgenic cotton is very effective in controlling targeted pests such as cotton bollworm (Helicoverpa armigera). However, increases in spider mite (Acari: Tetranychidae) populations have been reported in fields of transgenic cotton. The objectives of our laboratory experiments were (i) to determine host plant preference (transgenic or non-transgenic cotton) of T. turkestani females and (ii) to compare the life table parameters of T. turkestani females reared on transgenic or non-transgenic cotton. Enzyme-linked immunosorbent assays indicated that T. turkestani females reared on transgenic cotton leaves contained 14.9±0.23 μg Bt toxic protein per gram fresh weight, about 57.4% toxin in the transgenic cotton leaves. Results of dual-choice disc tests showed that T. turkestani females preferred to feed and lay eggs on non-transgenic cotton. Food source (transgenic or non-transgenic cotton) had no significant effect on the life table parameters of T. turkestani females. We conclude that increases in the population of spider mites in fields of transgenic cotton cannot be attributed to host plant preference or to the effects of Bt toxic protein on the non-targeted arthropods life cycle. Additional studies should be done to determine if the increases are due to less insecticide application or less competition with primary insects in transgenic cotton fields.

Influence of certain climatic factors on some major pepper pests under Egyptian conditions

Pepper crop (Capsicum annuum,l) is considered one of the most important vegetable crops, under greenhouse conditions. This work aim to study influence of certain environmental factors (Temperature and relative humidity) on population of pepper pests i.e. aphid (Aphis gosspii), white fly (Bemisia tabaci) and spider mites (Tetranychus urticae), through growing seasons 2012 and 2 013, at two different regions (El-Dokki region, Giza governorate and El-Nobria region, Beheria governorate), Egypt. Population of white fly was the most severity compared with other pests, but population of aphid was moderately severity and population of spider mites was less severity. While, population of tested pests were more severity in El-Nobria region (Beheria governorate) than El_Dokki region (Giza governorate). However, population of tested pepper pests were increased with increasing the temperature through studied seasons. Also, population of tested pests were the most severity during the period from May to June compared with the period from January to March for to growing seasons and two regions. Population of all pepper pests were the most severity during may in El_Nobria region (Beheria governorate) during may-june in El-Dokki region (Giza governorate) Meanwhile, relative humidity was less effectively on population of tested pepper pest through this study.

Bahasa Indonesia

Red spider mite Tetranychus sp. is one of the most important pests attacking leaves of Jatropha curcas. The objective of this study was to elucidate life history parameters and abundance of spider mite on two J. curcas cultivars. Field studies were carried out in BALITTRI Pakuwon Sukabumi, and laboratory experiments were conducted at the Department of Plant Protection, Bogor Agricultural University, from June to November 2008. Cultivars significantly affected several life history parameters of the spider mite. Spider mite reared on IP1-P cultivar have longer oviposition period and higher fecundity than those on IP2-P (7.00 days and 25.56 eggs against 5.00 days and 10.00 eggs). The sex ratio of spider mite was 3.2 : 1 on IP1-P and 2.5 : 1 on IP2-P. Intrinsic rate of increase was also higher on IP1-P. However, field studies indicated that the spider mite were less abundant on this cultivar. These might be due to the presence of other arthropods which were higher on IP1-P. In general, the highest population of spider mite occurred in August and the lowest in October–November. Predatory mite Family Phytoseiidae was found associated with spider mite, however its role as natural control agent was not significant.

Efficacy of five acaricides against the two-spotted spider mite Tetranychus urticae Koch and their side effects on some natural enemies

Five acaricides, Challenger, Ortus, Vertimec, Delmite and Bioca were investigated for controlling phytophagous mite, Tetranychus urticae Koch and their side effects on the predatory insects, mites and spiders at the El-Fayoum Governorate of cotton seedlings during the late season of 2007 and 2008. At the early seedling time, the application of the five tested compounds induced an average of 81.55%, 80.62%, 75.94%, 65.35% and 54.57% reduction in the population of spider mite during the 2007 season, and then changed to 79.72%, 77.92%, 72.54%, 60.05% and 47.97% reduction during the 2008 season. However, at the late season (fruiting time), the application of these compounds induced 83.24%, 84.11%, 76.34%, 56.29% and 59.57% reduction during the 2007 season changed to 84.78%, 84.94%, 77.31%, 55.58% and 58.68% reduction during 2008, respectively. As to the natural enemies, the highest reduction in the population after using the tested compounds was noticed for effect of Delmite during 2007 (33.79%), while the lowest ratio recorded when Ortus was used in the second season 2008 (18.53%). The side effect of the most important tested compounds (Challenger) was investigated in the laboratory against the predatory phytoseiid mite, Euseius scutalis.