Spider Mite Eggs Research Articles

PM 7/116 (1)Tetranychus evansi

PM 7/116 (1)<i>Tetranychus evansi</i>

Induced defence in lima bean plants exposed to the volatiles from two-spotted spider mite-infested conspecifics is independent of the major protein expression

Non-infested plants respond to volatiles from neighboring herbivore-infested plants, triggering induced defence responses against the threat. Information about protein expression in volatile-exposed plants after the ‘plant–plant signalling’ is scarce. We focused on the defence response and the protein expression of lima bean plants exposed to the volatiles from their conspecifics infested by the two-spotted spider mites (Tetranychus urticae) using a flow chamber. The number of eggs of spider mite was significantly reduced on the plants exposed to infested plant volatiles, suggesting defence induction in the exposed plants. A proteomic analysis on the volatile-exposed plants showed that two proteins associated with photosynthesis and an unknown protein showed a marginally significant decrease and increase, respectively. These results suggest that the induced defence caused by volatiles is essentially independent of changes in the major proteins.

Generalist red velvet mite predator (Balaustium sp.) performs better on a mixed diet

Generalist predators have the potential advantage to control more than one pest and to be more persistent than specialist predators because they can survive on different foods. Moreover, their population growth rate may be elevated when offered a mixture of prey species. We studied a generalist predatory mite Balaustium sp. that shows promise for biological control of thrips and whiteflies in protected rose cultures in Colombia. Although starting its life in the soil, this predator makes excursions onto plants where it feeds on various arthropods. We quantified life history parameters of the predator, offering high densities of three pest species: first-instar larvae of Frankliniella occidentalis, eggs of Trialeurodes vaporariorum and Tetranychus urticae, either alone or in combination. The predators completed their life cycle on each diet. The egg-to-egg period was c. 2 months. All eggs were laid in one batch in 1-2 days, indicating a pronounced semelparous reproduction pattern. In general, females reproduced earlier and laid more eggs on mixed diets, and these early reproducers consequently had higher population growth rates than late reproducers. The best diet in terms of egg-to-egg period and juvenile survival was the combination of eggs from whiteflies and spider mites. Spider mite eggs alone and western flower thrips larvae alone were the worst diets. It remains to be investigated whether mixed diets promote the population growth rate of Balaustium sufficiently for biocontrol of whiteflies and thrips in the presence of alternative prey, such as spider mites, to become effective.

Potential of the predatory mite Phytoseius finitimus (Acari: Phytoseiidae) to feed and reproduce on greenhouse pests

Phytoseiid mites of the genus Phytoseius are natural enemies of tetranychid and eriophyid herbivorous mites mostly found on hairy plants where they feed on prey, as well as on pollen. Nevertheless, the nutritional ecology and the role of these predators in biological pest control are only rarely addressed. In the present study, we evaluated the potential of Phytoseius finitimus to feed and reproduce on three major greenhouse pests, the two-spotted spider mite, the greenhouse whitefly and the western flower thrips. Additionally, we estimated the effect of cattail pollen when provided to the predator alone or in mixed diets with prey. Contrary to thrips larvae, both spider mite larvae and whitefly crawlers sustained the development of P. finitimus. In addition, females consumed more spider mite eggs and larvae, as well as whitefly crawlers than thrips larvae, but laid eggs when feeding on all prey. When provided alone, cattail pollen sustained the development and reproduction of the predator. The addition of pollen in mixed diets with prey reduced prey consumption, though it increased the predator's egg production. We discuss the implications of our findings for biological pest control.

Laboratory-based toxicity of some acaricides to Tetranychus macfarlanei and Tetranychus truncatus (Acari: Tetranychidae)

Tetranychus macfarlanei (Tm-BB) Baker & Pritchard and Tetranychus truncatus (Tt-BJ) Ehara (Acari: Tetranychidae) were recently found in Bangladesh as pests in many crops. The susceptibility of eggs of both species to 14 acaricides and of adults to 11 acaricides was examined in the laboratory, using a rotary spray tower. LC50 values in female adults of Tm-BB and Tt-BJ indicated high susceptibility to all acaricides, except chlorfenapyr; LC50 of chlorfenapyr in Tm-BB was approximately 10 times higher than the recommended concentration (492 mg/l vs. 50 mg/l). Ratios of LC90 values and the recommended concentrations (i.e. resistance factor (RF)) indicated 117.07 and 1.16 fold resistance in Tm-BB adults against chlorfenapyr and spirodiclofen, respectively, whereas Tt-BJ appeared to be resistant to tebufenpyrad (RF = 1.65). The RF value of spirodiclofen in Tt-BJ adults was 0.90, suggesting that this should not be used for control of this species, to avoid the further development of resistance. Eggs of both spider mites proved highly susceptible to all the acaricides at the LC50 level. However, RF-ratios based on assays with eggs indicated resistance against chlorfenapyr (1.43) in Tm-BB and fenpyroximate (6.03) in Tt-BJ. RF-ratios of chlorfenapyr (0.87) and milbemectin (0.74) in Tt-BJ eggs suggest these acaricides should be avoided for control of this species. Finally, acequinocyl, bifenazate, clofentezine, cyenopyrafen, cyflumetofen, etoxazole, fenbutatin oxide, hexythiazox and spiromesifen were found to be most effective for control of Tm-BB and Tt-BJ.

Efficacy of Syringa (Melia Azedarach L.) extracts on eggs, nymphs and adult red spider mites, Tetranychus spp. (Acari: Tetranychidae) on tomatoes

This study evaluated the effect of Syringa (Melia azedarach) fruit and seed extracts (SSE) on red spider mite (Tetranychus spp.) eggs, nymphs and adults. Bioassay investigations were carried at the Vegetable and Ornamental Plant Institute (VOPI) outside Pretoria in South Africa using different concentrations (0.1, 1, 10, 20, 50, 75 and 100%) of SSE. Mortalities were measured at 24, 48 and 72 h after treatment and compared to the effects of the synthetic acaricides: Abamectin, chlorfenapyr and protenofos. A completely randomized design (CRD) was used with 12 treatments. Analysis of variance (ANOVA) was used to test for effects of treatments. Differences in treatment means were identified using Fisher’s protected t-test least significant difference (LSD) at the 1% level of significance. Data were analysed using the statistical program GenStat (2003). The result of the analyses revealed that the efficacy of SSE and commercial synthetic acaricides increased with exposure time.Concentration of 50% and above SSE was as effective against red spider mite (RSM) adults, eggs and nymphs as the synthetic acaricides. Key words: Syringa fruit and seed extracts, Melia azedarach, red spider mites, acaricidal activity, tomatoes.

Positive association between thrips and spider mites in seedling cotton

Abstract In cotton fields in Texas, spider mites are sporadic pests, whereas thrips are considered as major pests on early stages (before the fourth true leaf stage). Thrips are also important predators of spider mite eggs. In the present study, we tested the hypothesis that the presence of spider mites on seedling cotton may increase the likelihood of the occurrence of thrips. Based on a greenhouse experiment, it was confirmed that seedling cotton was a suitable host for spider mites. Subsequently, we conducted a 2‐year field experiment in which we studied the likelihood of thrips infestation in cotton plants with/without experimental spider mite infestations. Spider mites established better in 2011 (dry and hot season) than in 2010 (rainy and cooler season), and there was a positive association between spider mites on cotton plants and natural thrips infestation. Thus, we showed that the probability of thrips infestation strongly increased with the presence of spider mites. To confirm the proposed hypothesis on a larger scale, a second field experiment was performed, in which one half of a field was infested with spider mites. Weekly sampling of thrips and spider mites showed a two‐fold increase of thrips immatures on plots previously infested with spider mites. The results obtained in the present study emphasize the importance of incorporating spider mite population dynamics into risk assessments of thrips infestation in seedling cotton fields in Texas and elsewhere.

Effect of Different Temperatures on Consumption of Two Spotted Mite,Tetranychus urticae, Eggs by the Predatory Thrips,Scolothrips longicornis

Environmental variables such as temperature are important factors affecting the efficacy of biological control agents. This study evaluated the predation rate of the predatory thrips Scolothrips longicornis Priesner (Thysanoptera: Thripidae) against the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) under laboratory conditions. Based on daily and total prey consumption of different life stages of S. longicornis on spider mite eggs at temperatures covering the range suitable for development and survival of the predator (15° C to 37° C, 60 ± 10% RH, 16:8 L:D), there was a significant effect of temperature on prey consumption. The number of prey consumed daily by first and second instar larvae increased linearly with increasing temperature from 15 °C to 37 °C, whereas daily consumption of preovipositing and postovipositing females was uninfluenced by temperature. Lower temperature thresholds for consumption by first and second instar larvae of S. longicornis was estimated to be 6.8 ± 0.04° C and 4.6 ± 0.03° C, respectively. The daily consumption of ovipositing females followed a nonlinear pattern, with maximum daily predation estimated at 32.8° C. From the model used to describe consumption of ovipositing females, an upper threshold for consumption of 41.4° C was estimated. The performance of S. longicornis at the different temperatures is discussed in relation to its practical use in integrated pest control programs.

DNA preparation method in eggs, immature stages, and diapausing females of Tetranychus spider mites (Acari: Tetranychidae) for diagnostic PCR-RFLP

A DNA preparation method for diapausing females, immature stages, and eggs of spider mites for diagnostic analyses using restriction fragment length polymorphisms after polymerase chain reaction (PCR-RFLP analysis) of the internal transcribed spacer (ITS) region including 5.8 S of the nucleic ribosomal DNA was developed using Tetranychus urticae Koch as a typical example of tetranychid mites. In diapausing females and deutonymphs, the method of crushing an individual mite with a glass rod was eminently successful and a useful method to obtain the DNA template for PCR. For protonymphs, larvae, and eggs older than 48 h after oviposition at 24 °C, the DNA preparation method for a single nematode, crushing a tiny sample with a filter paper chip, was also successful and a useful method to obtain the DNA template from mite individuals (eggs) for PCR. Consequently, we found a single distinctive band of an amplified DNA fragment after electrophoresis in all developmental stages, and digestion of the PCR product by a restriction endonuclease, DraI, resulted in identical banding patterns being exhibited in all developmental stages. Our findings indicate that PCR-RFLP analysis of the ITS region can be used for species identification of diapausing females, immature stages, and eggs of Tetranychus species.

EFFECT OF DIFFERENT TYPES OF FOOD ON DEVELOPMENT AND FECUNDITY OF PREDACIOUS MITE NEOSEIULUS BELLINUS WOMERSLEY (ACARI: PHYTOSEIIDAE)

Phytoseiids mites are known as cosmopolitan predators throughout the world. They have a wide range of natural foods, though preferences may be shown for certain foods on which development may be faster and egg production greater than on others. Data herein showed that Neosiulus bellinus was able to complete development and reproduce when fed on eggs of Tetranychus urticae Koch and AD-1 with a survival rate reached 90 and 60 % respectively. However, it could not survive when fed on AD-2 and AD-3 artificial diets. On the other hand, Adult female longevity of phytoseiid mite N. bellinus was found to be longer when fed on eggs of spider mites than the experimental diet AD-1 as was the oviposotion period. Female fecundity was also greatest on eggs of spider mite. While, adult was short lived when no food source offered. Moreover, the survival rates of adult females fed AD-1 after long term maintenance10, 20, and 30 days was 35, 21 and 6 %, respectively.

EFFICENCY OF SOME ACARICIDES ON PREDATION POTENTIAL OF Amblyseius gossypi AND Coccinella undesimpunctata ASSOCIATED WITH SPIDER MITE ON COTTON PLANTS .

Abamectin caused the highest decrease in prey eggs consumption (56.25 eggs) comparable to the control through the egg meal of the all days (178.80 eggs during four days). Also, Abamectin was the most effective chemical that caused decrease in adult consumption (consumption (32.55 adult during four days) comparable to the control (73.74 adult) Therefore, Abamectin reduced the adult consumption (5.75, 7.25, 9.25 and 10.50, individ. during the first, second, third and fourth days, respectively) with the percentages of 22.63, 23.35, 28.87 and 31.37 %, respectively. Etoxazole was the least effective compound in this respect, when A. gossypi fed on eggs treatment the average of total consumed eggs were 46.03 during the fourth days successively with the percentages of feeding capacity for each of the fourth days of this predator were 17.48, 28.78, 23.25 and 30.97 %, respectively. While ,when it fed on adult of T. urticae, the average consumption of A. gossypi was 42.05 individ. through fourth days successively (73.74 individ . for control ) with the percentages of 23.18, 19.61, 28.35 and 28.65 %, respectively. Laboratory studies carried out on the ladybird beetle predator showed that, it devoured 189.85 of the two spotted spider mite eggs during the shortest duration of larval stage (11.30 days ) compared with control (376.12 eggs) that was consumed in 10 days all larval instars. The fourth larval instar consumed the highest percentages of T. urticae eggs (37.42%) (treatment). On the other hand, the larvae of C. undicempunctata was fed on T. urticae adult, the duration of larval instars lasted 9.45 days, consumed during 176.75 adults in untreatment. While the treatment by Abamectin, the consumption was 104.05 adults for the four instars during 12.50 days. The 4th instar consumed relatively the highest percentages of individual offered four the fore mentioned mite, as it consumed were 13.21, 18.02, 27.63 and 41.56%, respectively. The coccinellid larval stage was completed in four instars, with a total larval duration of 10.50 days, consumed during these days 148.05 eggs. Also, the percentage of feeding capacity for each of the four larval instars of this predator were 17.73, 23.44, 28.19 and 30.90 %, respectively. Concerning the two spotted spider mite adult, the ladybird consumed 100.10 individ. during 12.24 days for the four larval instars. Thus, the most voracious instar was the fourth instar, that consumed 40.04 % out of total consumed. While the first instar was the least voracious (12.24 % out of total consumed).

Design, Synthesis, Structure, and Acaricidal/Insecticidal Activity of Novel Spirocyclic Tetronic Acid Derivatives Containing an Oxalyl Moiety

A series of novel spirocyclic tetronic acid derivatives containing an oxalyl moiety was designed and synthesized via the key intermediate 3-(2,4,6-trimethyl)-2-oxo-1-oxaspiro[4.4]-decyl-3-en-4-ol. The target compounds were identified by (1)H NMR and elemental analysis or high-resolution mass spectrum (HRMS). The results of bioassays indicated that most of the target compounds possessed excellent acaricidal activities against carmine spider mite larvae and eggs. Especially, diisopropylamino oxalyl compound 7g and piperidine oxalyl compound 7h were 1.4- and 2.3-fold as high as the activities of commercial Spiromesifen, respectively, against spider mite eggs. Moreover, most of the target compounds exhibited insecticidal activities against Lepidoptera pest. Interestingly, compounds containing alkylamino-substituted oxalyl moiety showed obvious selectivity between spider mite larvae and eggs because the activities against spider mite eggs of 7g and 7h were 25-fold those against spider mite larvae, whereas Spiromesifen had no significant differences in these activities. This meant that the introduction of an oxalyl moiety to spirocyclic tetronic acid might lead to novel biological activity characteristics.

Four New Doramectin Congeners with Acaricidal and Insecticidal Activity from Streptomyces avermitilis NEAU1069

Four new doramectin congeners, 1-4, were isolated from Streptomyces avermitilis NEAU1069. The structures of 1-4 were elucidated on the basis of spectroscopic analysis, including 1D- and 2D-NMR as well as HR-ESI-MS, ESI-MS, UV, and IR, and comparison with literature data. All compounds exhibited noticeable acaricidal and insecticidal activities. Especially compound 2 was found to be the most potent pesticide of the compounds evaluated with the IC(50) values of 10.2, 65.1 and 124.4 μg/ml against adult two-spotted spider mites (Tetranychus urticae Koch), two-spotted spider mite eggs, and Mythimna separata, respectively, which are comparable to those of commercial pesticide milbemycin A(3)/A(4) as positive reference.

Ovicidal activity of different plant extracts on two-spotted spider mite (Tetranychus urticae Koch) (Acari: Tetranychidae)

Methanol extracts of nine plant species were evaluated for their ovicidal activity against the two-spotted spider mite Tetranychus urticae Koch in a bioassay under laboratory conditions. These plants and plant parts used in the study wereXanthium strumarium L. (fruits and leaves), Anthemis vulgaris L. (flowers and leaves), Humulus lupulus L. (flower buds), Chenopodium album L. (flowers and leaves), Melia azedarach L. (fruits), Eucalyptus camaldulensis Dehn (flower buds and leaves), Solanum nigrum L. (flowers, leaves and fruits), Styrax officinalis L. (seed coats, seeds) and Lolium perenne L. (flowers and leaves). The greatest mortality was caused by E. camaldulensis leaf extract (63.26%), followed by X. strumarium fruit (59.64%), X. strumarium leaf (57.45%), S. nigrum fruit (51.57%),A. vulgaris flower (46.80%) and S. officinalis seed extract (44.25%). Lolium perenne extract (flowers, leaves) caused the least mortality (24.40%). Azadirachtin at 10 g/l concentration was used as a chemical standard and caused 10.09% mortality. Our results show that some of these plant extracts have a potential for ovicidal activity on two-spotted spider mite eggs and are worth further investigation. Key words: Tetranychus urticae, Eucalyptus camaldulensis, plant extract, ovicidal activity.

Temperature-Dependent Fumigant Activity of Essential Oils Against Twospotted Spider Mite (Acari: Tetranychidae)

Fumigant activity of 34 commercial essential oils was assessed on female adults and eggs of twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) at three temperatures (5, 15, and 25 degrees C). Common thyme, cinnamon, and lemongrass oils were equally effective on twospotted spider mite adults showing 85.8-100% mortality at 5 and 10 microl/liter air at 25 degrees C. At a lower temperature of 15 degrees C, lemongrass and peppermint resulted in > or =90% mortality of adults at 10 microl/liter air. Only lemongrass was relatively active at 5 microl/liter air, at 15 degrees C. At 5 degrees C, lemongrass and peppermint caused significantly higher adult mortality than controls but only at 10 microl/liter air. Common thyme oil showed the highest ovicidal activity at 5 microl/liter air at 25 degrees C. Among the main components of common thyme and lemongrass oils, citral was lethal to twospotted spider mite adults at all tested temperatures. Carvacrol, thymol, and citral caused the same inhibitory effects on the hatch of twospotted spider mite eggs at 25 degrees C. However, citral was more active than other compounds to twospotted spider mite eggs at 15 degrees C. Therefore, we conclude that citral has the best potential for development as a fumigant against twospotted spider mite on agricultural products harvested late in the growing season.

Estimating development and temperature thresholds of Scolothrips longicornis (Thysanoptera: Thripidae) on eggs of two-spotted spider mite using linear and nonlinear models

The development rate of the predatory thrips, Scolothrips longicornis Priesner, fed on Tetranychus urticae Koch was determined at 15, 20, 26, 30, 35, and 37°C. No development occurred at 40°C. The total development time from egg to adult emergence for females was estimated to be 48.1, 22.8, 13.6, 10.6, 8.3 and 9.6 days, respectively. The development time decreased with increasing temperature from 15 to 35°C. In the temperature range of 15–37°C, egg and larval mortality varied between 10% and 48% and 1.92% and 11.1%, respectively. The sex-ratio of S. longicornis was in favor of females at all tested temperatures and remained uninfluenced by temperature in the range of 15–35°C with an average of about 75% females. The lower temperature threshold for the entire development period and the thermal constant for female S. longicornis using the common linear model were estimated to be 11.1°C and 200 degree-days (DD), and 10.8°C and 204 DD using the Ikemoto and Takai model. Data were fitted to four nonlinear development rate models and the thermal thresholds (T min and T max) and optimal temperature (T opt) estimated. The Briere-1, Briere-2, and Ikemoto and Takai linear models provided adequate descriptions of temperature-dependent development of S. longicornis. The upper temperature threshold was estimated to be about 42°C. Temperature-dependent development data, thermal requirements and temperature thresholds can be used to predict the occurrence, number of generations and population dynamics of S. longicornis, an important biocontrol agent of T. urticae.

Effects of sucrose on survival and oviposition of the predacious insects Stethorus japonicus (Coleoptera: Coccinellidae), Oligota kashmirica benefica (Coleoptera: Staphylinidae), and Scolothrips takahashii (Thysanoptera: Thripidae)

The effects of sucrose on the survival and oviposition of predacious insects Stethorus japonicus, Oligota kashmirica benefica, and Scolothrips takahashii, under no-prey conditions, were investigated. In all three predacious insect species, adult females fed on sucrose under no-prey conditions survived significantly longer than those on only water. In addition, in S. japonicus and O. kashmirica benefica, females fed sucrose under no-prey conditions recommenced oviposition significantly earlier and required fewer spider mite (Tetranychus urticae) eggs to recommence after re-feeding on T. urticae eggs than those on only water. On the other hand, in S. takahashii, even females supplied only with water under no-prey conditions recommenced oviposition immediately after re-feeding on T. urticae eggs. Thus, sucrose had no significant effects on the recommencement of oviposition. These results suggested that sucrose was effective to maintain the populations of these predacious insect species even under no-prey conditions.

The effect of temperature and light conditions on diapause induction in a Korean population of Neoseiulus womersleyi Schicha (Acari: Phytoseiidae)

To determine the condition for diapause induction of a Korean population of Neoseiulus womersleyi, combinations of constant temperatures (14, 16, 18, 20 and 25 °C) and photoperiods (0, 8, 10, 12, 14, 16 and 24 h photophase) were used from egg to adult emergence. Diapause induction was determined by reproductive cessation of adult females. Lower temperature and shorter photophase resulted in higher diapause induction. Critical photophases for diapause induction were 10 and 12 h at 18 and 16 °C, respectively. Diapause-induced N. womersleyi adult females consumed significantly fewer eggs of the two-spotted spider mite, Tetranychus urticae, than non-induced females. Field monitoring of N. womersleyi showed that there was no egg-bearing female after 282 Julian date, while a model estimated complete diapause induction at 288 Julian date. Diapause of this predatory mite occurred approximately 2 weeks before diapause of its main prey, T. urticae, in Korean apple orchards. Further study perspectives are discussed relative to the spider mite biological control system in fruit orchards.

ミツユビナミハダニＴｅｔｒａｎｙｃｈｕｓ ｔａｋａｆｕｊｉｉ Ｅｈａｒａ ＆ Ｏｈａｓｈｉの殺ダニ剤および殺虫剤感受性

The spider mite, Tetranychus takafujii Ehara and Ohashi,2002, is known to occur mainly on weeds and black nightshade in Tokyo, Osaka, Kyoto and Hyogo prefectures on Honshu island. In 2007, T. takafujii was found to cause heavy damage to cherry tomatoes in Kagoshima on Kyushu island. To test the possibility of chemically controling this spider mite, we tested its susceptibility to 18 acaricides/pesticides available for tomato and other vegetables in the Solanaceae using a leaf dip method. Spider mite females were highly susceptible to most acaricides/pesticides, except Etoxazole SC and Spirodiclofen SC which are categorized as slow-acting. Spider mite eggs were also highly susceptible to many of treatments, except Malathion EC, Bifentrin 2.0% WP, Emamectin benzoate EC, Chlorfenapyr SC and Bifenazate SC. Egg hatchability at day 4 were ranged from 24.7% to 89.4% among the treatments, and most neonate larvae died after 1 day of Emamectin benzoate EC, Chlorfenapyr SC and Bifenazate SC treatments. Results suggest that many of the treatments tested will be effective in controlling of T. takafujii either at the egg, larval or adult stage.

Toxicity of bifenazate and its principal active metabolite, diazene, to Tetranychus urticae and Panonychus citri and their relative toxicity to the predaceous mites, Phytoseiulus persimilis and Neoseiulus californicus

Bifenazate is a novel carbazate acaricide discovered by Uniroyal Chemical (now Chemtura Corporation) for the control of phytophagous mites infesting agricultural and ornamental crops. Its acaricidal activity and that of its principal active metabolite, diazene, were characterized. Bifenazate and diazene had high toxicity and specificity both orally and topically to all life stages of Tetranychus urticae and Panonychus citri. Acute poisoning was observed with no temperature dependency. No cross-resistance was found to mites resistant to several other classes of acaricides, such as tebufenpyrad, etoxazole, fenbutatin oxide and dicofol. Bifenazate remained effective for a long time with only about a 10% loss of efficacy on T. urticae after 1 month of application in the field. All stages of development of the predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, survived treatment by both bifenazate and diazene. When adult females of the two predatory mite species were treated with either bifenazate or diazene, they showed a normal level of fecundity and predatory activity in the laboratory, effectively suppressing spider mite population growth. Even when the predators were fed spider mite eggs that had been treated previously with bifenazate, they survived. These findings indicate that bifenazate is a very useful acaricide giving high efficacy, long-lasting activity and excellent selectivity for spider mites. It is, therefore, concluded that bifenazate is an ideal compound for controlling these pest mites.