Toxicological and Biological studies of Some Pesticides from Different Groups on Red Mite, tetranychus urticae. Under Laboratory Conditions

The Laboratory study was administrated to evaluate the toxic and latent effect of, fenpyroximate, Lufenuron, Spinosad


INTRODUCTION
The spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is considered one of the greatest common plant pests in the world and it is responsible for significant yield damages in numerous economically essential crops in several fields and greenhouse conditions (Adesanya et al., 2021). The checklist of host plants attack by this pests includes more than 1200 species (Shukla, 2021), including food crops, vegetables, fruits, and ornamentals plants. Damage to plants can be classified as direct or indirect effects (Santamaria et al., 2020) The direct effects extend from small spots on the top side of the leaf due to chlorophyll depletion, webbing, and defoliation, even necrosis in leaves and small stems, or even plant death. Indirect effects of feeding may include a reduction in transpiration and photosynthesis and can lead to leaf color changing from yellow to white and often referred to as bronzing, causing loss of quality and yield or death of host plants (Park & Lee, 2002). In addition, mites can transmit some pathogenic fungi, bacteria, and viruses and inject systemic toxic substances into the leaf that interfere with vital processes. many of strategies include biological and chemical treatments have been applied to control T. urticae, particularly in protected crops (Badawy et al., 2018;El-Saiedy et al., 2008;Wang et al., 2015). A variety of commercially available acaricides have been used such as abamectin, bifenazate, chlorfenapyr, clofentezine, cyflumetofen, dicofol, etoxazole, fenpyroximate, hexythiazox, propargite, pyridaben, spiromesifen, and spiromesifen (Dekeyser, 2005;Van Leeuwen et al., 2015). Also, Tetranychus urticae Koch is one of the foremost polyphagous tetranychidae species and could be a major pest in many cropping systems worldwide (Nauen et al., 2001). T. urticae can increase population density very rapidly in suitable host plant and climate conditions. T. urticae outbreaks in agricultural ecosystems end in large economic loss, particularly in greenhouses where mite populations can reach very high densities, thanks to the favorable temperature and availability of excellent quality food during the year. Acaricides are widely used for mite control in greenhouses, orchards and plenty of other cropping systems. Their high reproductive potential and very short life cycle, combined with the frequent applications of acaricides usually required to keep up mite populations below economic thresholds, facilitate the event of resistance during this species . There is an increasing interest by natural pesticides which are derived from plants and microorganisms (Isman, 2006;Isman et al., 2007) because they generally gave the impression to be safer of manufactured pesticides. These concerns have resulted in a very renewed interest in searching for alternative control measures. The mineral oils employed in this study were of the second category after the precise acaricide and therefore the insecticide cyhalothrin in their toxicity to tetranychidae T.urticae. In general, oils are known to be physically effective in the various mite stages. The mineral oils were evaluated again against the various stages of mite by other authors and indicated to achieve success (Rizk et al., 1999, Gamieh et al., 2000. Said et al., (2002) also found that supermasrona caused residual effect (87.61%) against the T.urticae density in cottonplants.
The current study was to research the toxic effect of certain compounds including (fenpyroximate and Lufenuron, Spinosad and mineral oil against the egg and adult stage of the two-spotted spider mite; T. urticae. Also, to evaluate latent effect of LC50 concentration of the tested compounds on some biological aspects of spider mite; T. urticae

Culture Technique:
The culture of the two-spotted mite, Tetranychus urticae Koch (Acarina: Tetranychidae), T.urticae colonies were obtained from infested cotton plants from Be sueif governorate and reared under laboratory conditions for many generations on cotton plants, away from any contamination with pesticides before starting the experiments, cotton plants were it was planted in pots, each pot contains about 6 seeds from of cotton until grow, after about 15 days from seed planting were infested by culture of Tetranychus urticae by transferred from old to young plants by cutting heavily infested leaves into small sections which were then placed on new plants. Adult famale of Tetranychus urticae were collected from stock cultures and allowed to lay eggs overnight on cotton plant leaves, leaves with eggs placed on clean plants. Groups of plants bearing eggs laid within a 24 hours period were transferred to small cages after 16 h oviposition. The eggs and adults of uniform age were collected from the cultures for experimental use. The culture was kept at 25 +2 0C under 16 hours photoperiod to encourage plant growth, and 70 +5 R.H. the availability of 16 hrs length ensured that mites wouldn't enter diapause. Brush (No.0) was accustomed transfer mites from one plant to another. Chemicals Used: Match Lufenuron 5 % EC Ortus 5% E.C., Fenpyroximate Tracer Spinosad 24 % SC Mineral oil (KZ 95% EC) Preparation of Discs: By cutting cotton leaves using scalpel Cotton leaf discs were placed small pieces of cotton leaves are placed on a surface of cotton fibers pad -soaked by water in petri dishes.

Toxicity of Tested Insecticides:
A study the toxicity of tested insecticides to T.urticae was evaluated by leaf pieces dip technique in step with Siegler (1947). Insecticides were diluted to certain concentrations (ppm) in water. Four replicate each concentration it has five five discs of cotton leaves were dipped in each concentration for five seconds and left to dry. Then 10 adults of T.urticae were transferred to every disc and kept under controlled conditions of 25+20C & 65+5 R.H. Mortality counts were made 24,48 and 72 hours after treatment. Correction mortality was made by using Abbott's formula (1925). Data were plotted on log dosage-probit papers and statistically analyzed by the strategy of Finney (1952). LC50 and slope values were computed according to Finney (1971) and using Ldp line software according to Bakr (2000).

Toxicity of Tested Compounds to Eggs of Two-Spotted Mite T.urticae :
To investigate the effect of tested insecticides, ten adult females were placed on cotton leaf discs (2 cm diameter) on wet cotton wool in a petri dish and allowed to put eggs, The petri dish was incubated for 24hrs at 25±2ºC and 70±5%R.H. Then adult's females were removed from the leaf discs. serial concentrations were prepared, Four replicates each concentration have five discs of cotton leaves each disc include 10 eggs of T.urticae laid within a 24 hours period were transferred with gentle agitation to discs and immersed in each insecticides concentrations for five seconds and left to dry. Untreated discs were immersed in water. The tested eggs were kept at controls, in a chamber of about 25±2ºC and 70±5%R.H. Assessment of the results was made when the emergent eggs reached the protonymphal stage. Eggs that had not hatched were recorded as "dead. Egg mortality was calculated as a count was made of (a) unhatched eggs, (b) number of total eggs counted before treatment with toxicant Egg mortality = (a/b) × 100 Egg mortality was calculated and correction mortality was made using Abbott's formula (1925). LC50 and slope values were computed according to Finney (1971) and using Ldp line software according to Bakr (2000).
Latent effect of compound's on T. urticae egg deposition and egg hatching to evaluate, the latent effect of every tested chemical at LC50 level on adult mites Four replicates of each concentration it include five discs of cotton plants leaves were dipped in each LC50 concentration for five seconds and left to dry, Then 10 adult of T.urticae of known age were transferred to every disc, and were allowed to lay eggs for 24 h to test ovicidal activity of the pesticides. After that, the adult female spider mites were removed, and the eggs were counted on each leaf disc subsequently and kept under controlled conditions of 25+20C & 65+5 R.H. Number of eggs laid was counted 24, 48, and 72 hours later. The quantity of hatched eggs was also counted four days after egg deposition. Statistical Analysis: data were statistically analyzed using a one-way repeated measures analysis of variance. The least significant difference (LSD) was used to separate means using SAS program (Version 6.12, SAS Institute Inc., Cary, USA). Table (   The data shown in Tables (4) indicated that lufenuron caused the best decrease in egg (10.28) compared with the control treatment, followed by fenpyroximate with (16.18) decrease in egg deposition, Spinosad (18.93) decrease in egg deposition and kz-oil (13.87) decrease in egg deposition), compared with 58.16 on egg deposition control of female mites T.urticae. Also, data within the same table indicate lufenuron caused the best reduction in egg deposition compared with the control treatment (82.32%) reduction in egg deposition, followed by fenpyroximate with (72.18%) reduction in egg deposition, spinosad (57.45%) reduction in egg deposition and kz-oil (41.76%) reduction in egg deposition), compared with control of female mites.T.urticae. Also, data within the same table indicated that each pesticides caused a decrease in egg hatchability compared with the control treatment, however, lufenuron was the very best compound which decreased egghatchability of T.urticae with (69.88%) of egg hatchability followed by fenpyroximate gave ( 60.96%) reduction in eggs hatchability, spinosad gave (49.12 %) reduction in egg hatchability, while mineral oil, was a moderate effect where gave (31.61%) reduction in egg hatchability of T.urticae.

DISCUSSION
These results agree with the results those obtained by several investigators. (Vásquez & Ceballos, 2009). Found that the LC50 values of chlorfenapyr and abamectin against T. urticae were 59.34 and 1.50 mg/L, respectively. (El Kady et al., 2007) reported that the LC50 values of Vertemic (1.8% EC) (formulated abamectin) were 9.238 and 7.09 mg/L after 24 and 48 h of exposure, respectively against adults of T. urticae Also,  proved that the LC50 value of Vapcomic (1.8% EC) was 0.34 mg/L against adults of T. urticae. Consequently, (Arain, 2015) found that the LC50 values of Sanmite 15% EC (formulated pyridaben) were 29.85 and 11.34 mg/L after the second and third day of the treatment against adults of T. Urtica. Kumari et al (2015). cited that abamectin was found to be the most toxic to the adults (LC50= 0.39 ppm) followed by fenpyroximate (5.67 ppm), spiromesifen (12.53 ppm), chlorfenapyr (32.24 ppm), propargite (77.05 ppm) and dicofol (146.65 ppm). Hexythiazox was less toxic. to Tetranychus urticae Koch Entsar I. Rabeai (2009), showed that lambda-cyhalothrin and spinosad caused the highest toxicity against T. urticae with LC50 of 4.88 and 6.72 mg. L-1, respectively, followed by chlorpyrifos, deltamethrin and profenofos (LC50 = 11.44, 12.86 and 16.47 mg. L-1, respectively. Osman (1997) indicated that Albulium 80% EC, KZ 95% EC, Shokrona super 95% EC and Shokrona 95% EC were more toxic to adult females of E.orientalis than to T.urticae and the response of mite eggs to the oils varied according to their age. Many investigators proved that plant extracts were effective against phytophagous mites when tested in the lab The mineral oils were evaluated again against the different stages of Tetranychus urticae by other authors and indicated to be successful (Rizk et al., 1999 andGamieh et al., 2000). Said et al., (2002) found that supermasrona causing the highest residual effect (87.61%) against T.urticae density in cotton plants. Khairia M.M., (2019) showed that Abamactin 1.8% was the most effective acaricides followed by buprofezin, abamactin 5%, chlorfenapyr, hexythiazox and fenpyroximate, respectively. The LC50 values of abamectin1.8% EC, buprofezin, Abamectin 5% EC, chlorfenapyr 24% SC, hexythiazox 5% WP were 1, 5, 10, 45, 88 and 100 mg/l, respectively. Laila,E.M.S., et al (2015). Showed that cyhalothrin was the most toxic compound followed by fenpyroximate to adult females of T. urticae, while wormseed extract was the least toxic. Saenz de Cabezón , F J., et al. (2002) cited that no differences in toxicity for larvae, proto-nymphs and deutonymphs were observed, but immature stages were 3.8-times more susceptible than adults at the LC50 of triflumuron Manal, A. R., et al. (2019). cited that Abamectin 1%+Thiamethoxam 9%, Fenpyroximate, khaya and pomegranate extracts were toxic to T. urticae and safer for P. persimilis. Mousa, G. M. et al (2001) indicated that cottonseed oil was effective in its initial and residual effects against eggs of spider mite T.urticae on squash crop. Keratum (2001) indicated that fenpyroximate was the most potent compound against eggs of T.urticae, followed by vertimec. Also, Ismail et al., (2006) indicated that abamectin it was the highest toxic pesticide to egg stage of T.urticae where was the LC50 value of 2.88 ppm. Also, they indicated that cypermethrin was one of the most effective compounds on eggs of T.urticae. Also, Ismail et al., (2009) indicated that cyhalothrin and abamectin have a special effect on eggs of T.urticae it was the best pesticide that have importance in integrated mite management, while the mineral oil Nat-1 was more toxic to the eggs stage of T.urticae than black cumin extract.Also, Laila, E.M.S., et al. (2015) indicated that cyhalothrin was the foremost toxic ovicide, followed by fenpyroximate against the egg stage of T. urticae, while wormseed extract was the smallest amount toxic to eggs of T. urticae. Laila,E.M.S., et al. (2015). Showed that fenpyroximate, cyhalothrin reduced egg deposition and egg hatchability of T. urticae. Cyhalothrin was the foremost effective compound against T. urticae egg deposition and egg hatchability, while wormseed extract was the smallest amount effective one. Also, Sáenz-de F.j. Sáenz-de, F J. Cabezón1, et al. (2006). Cited that Triflumuron at LC50 caused a discount both within the percentage of eggs that developed to adults and within the survival of adult stage. Triflumuron also affected the fecundity, reproductive rate (R0), the intrinsic rate of increase (rm), and therefore the limited increase rate of treated females under in those nontreated, leading to a discount of growth. triflumuron on the biological performance of Tetranychus urticae. Sáenz-de, F J. Cabezón1 et al. (2002) cited that triflumuron exhibited ovicidal activity influenced by eggs age. 48-72 hrs. Eggs were significantly more sensitive than eggs of the opposite age classes. hatch inhibition was observed in eggs laid by treated adult females of Tetranychus urticae employing LC50 concentration at two physiological times (<12 and 48-72 h old). However, fecundity decreased in younger treated females, but it increased within the oldest ones of Tetranychus urticae Hosny et al., (2009 and2010), showed that fecundity was highly reduced by bromopropylate followed by fenpyroximate and dicofol and no significant differences among them in their effects were observed. It's interesting to notice that the results of sterilizing effect which had shown on T.cinnabrinus are clear within the present results. Sterilization means one or both of two aspects, few eggs and/or less hatchability. Discs treated by Tedion gave a lower number of eggs than on untreated discs (4.6 and 6.5 eggs/day/female), respectively. Temporary or partial sterilization for adult mites exposed to discs treated by pyrethroids might be answerable for small number of eggs laid/female/day in spite of their intermediate effect on egg hatchintg, that the same two effects may well be characterized by a sterilizing effect. The identical summary clearer by Spadafora and Lindquist (1973) indicated that benomyl at 0.03 % a.i. depressed egg hatchability of T.urticae (Koch), they found that viability was reduced by direct application to the eggs through ingestion of treated plant part by gravid females. Laila, E.M.S., et al (2015) showed that cyhalothrin produced eggs hatch to (30.16%) of T. urticae after treated with LC50 value of cyhalothrin while very reduction (67.52%) was obtained just in case of the treatment with LC50 of wormseed extract. El-Banhawy and Reda (1988) found that the susceptibility of T.urticae egg increased progressively with increasing age for synthetic pyrethroids (cypermethrin 500 ppm and pyridaphenthion 10 ppm ) while abamectin was effective only on older eggs. Correlation was found between hatchability and egg age within the cascade-treated eggs. it had been indicated that egg hatchability of T.urticae was decreased with an increase period of egg deposition on the identical disc. Park et al. (1995) found that abamectin significantly was more effective on the hatching of eggs of T.urticae at ( 0.06 -0.6 ) ppm. Four days old eggs were far more liable to abamectin than sooner or later old eggs. Abamectin at sublethal concentration (i.e., 0.012 -0.06 ppm) can be important in adjusting predator/prey ratios within the integrated management of T.urticae. Laila,E.M.S., et al. (2015). Showed that. Cyhalothrin was the foremost effective compound against T. urticae egg deposition and egg hatchability, while wormseed extract was the smallest amount effective one. Gamieh et al. (2000) found that hatching of eggs of T.cucurbitacearum treated with LC50 mineral oils increased because the eggs got older, being 45.43, 57.83 and 70.69% with KZ-oil and 44.21, 50.51 and 69.47 you tired of Supermasrona oil for one, two and three days old eggs respectively. Amer et al., (2001) found that KZ-oil was more toxic to eggs stage than female stage of T. urticae. Saadoon (2006) indicated that hatching of mites T.cucurbitacearum eggs decreased being 57.62% with challenger and 76.47% with Vapcomic.Total mortalities of immature stage were (61.66% and 45.17%) in Challenger and Vapcomic respectively. On the opposite hand, the duration of immature stages and total life cycle of this mite were prolonged when adult females were treated with LC50 of two tested compounds compared with untreated ones. Ismail (2007 and2009) indicated that cypermethrin was very toxic compound that caused the very best decrease in egg hatchability on leaf discs against eggs stage of T.urticae but etoxazole and seed cotton oil extract were of the smallest amount effective ovicidal action. (We i-dong, 2002). proved that the LC50 values of chlorfenapyr and abamectin ranged between 0.122 and 7.656 mg/L against eggs of T. urticae. (Van Pottelberge et al., 2009). (Kumari et al., 2017). reported that there was a respectable difference between chlorfenapyr, dicofol, fenproximate, hexythiazox, propargite, and spiromesifen against eggs of T. urticae using the spray method at the recommended concentration Based on the observations of the tenth day, they found that the ovicidal activity of spiromesifen (100% mortality) was followed by dicofol (7.78% mortality) and hexythiazox (6.67%). In addition, nearly no action on hatching was found in both abamectin and chlorfenapyr treatments (0.54% non-hatchability). However, all eggs treated for propargite were hatched. (Salman, 2007). Reported that abamectin was highly toxic for eggs at all ages but did not affect mite fecundity. . Reported that abamectin 1.8% EC (caused 87% mortality on egg hatching of T. urticae at 2.5 mg/L. Also, (Hosny et al.,2010) found that LC50of abamectin (1.8% EC) was 1.05 mg/L and LC50 of chlorfenapyr (36% SC) was 168.11 mg/L against eggs of T. urticae from the obtained data after 24 and 48 h of the treatment with technical compounds, abamectin showed the highest acaricidal activity against the adult females followed by chlorfenapyr while pyridaben was less toxic compound. (Van Pottelberge et al., 2009) reported. that the LC50 values were 0.4 mg/L for abamectin and 156 mg/L for pyridaben against T. urticae adults. (Herron & Rophail, 2003). found that the LC50 of chlorfenapyr and pyridaben were 0.54 and 0.29 μg/L, respectively against Russell Fox Pres-sured field strain of T. urticae. (Kumari et al., 2017). Proved that abamectin was the most toxic to the adults (LC50 =0.39 mg/L) by spray method followed by fenpyroximate (LC50=5.67 mg/L), spiromesifen (LC50=12.53 mg/L), chlorfenapyr (LC50=32.24 mg/L), propargite (LC50=77.05 mg/L), and dicofol (LC50=146.65 mg/L) however, hexythiazox was the least toxic acaricide.