<div>Background: Two-spotted spider mite,&nbsp;Tetranychus urticae Koch (Acari: Tetranychidae) is a destructive, polyphagous and cosmopolitan pest infesting a wide range of vegetables. Farmers frequently use acaricides in the vegetable ecosystem for mite management leading to increased probability for the development of resistance against acaricides in mite species. Literature about resistance in T. urticae to novel acaricides is scanty from this region. Hence, this study was aimed to evaluate the magnitude of acaricide resistance in T. urticae populations on vegetable crops from Southern districts of Tamil Nadu against seven acaricides. The role of detoxification enzymes in conferring bio-chemical resistance in the mite species was also studied.&nbsp; 
 
Methods: The laboratory experiments were conducted at completely randomized design (CRD) during 2019-2021 in central instrumentation laboratory, Department of Agricultural Entomology, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai. The level of resistance in T. urticae populations to fenazaquin, propargite, spiromesifen, buprofezin, fenpropathrin, diafenthiuron and chlorfenapyr was evaluated following the leaf dip bioassay technique. The activity of the detoxifying enzymes viz., Glutathione S Transferase (GST), Mixed Function Oxidase (MFO) and Carboxylesterase (CarE) were estimated.&nbsp; 
 
Result: Fenazaquin was highly toxic to T. urticae, which recorded a low level of resistance (2.00 to 8.62-fold).&nbsp;T. urticae exhibited a low to moderate level of resistance to fenpropathrin (1.86 to 37.28-fold), moderate to a high level of resistance to diafenthiuron (15.81 to 50.53-fold), high level of resistance to propargite (45.16 to 65.10-fold) and chlorfenapyr (54.67 to 100.14-fold) and extremely high level of resistance to spiromesifen (193.04 to 452.61-fold) and buprofezin (377.97 to 514.44-fold). Among all the test populations, the highly resistant DAmRg population exhibited the highest specific activity of the detoxifying enzymes, viz., GST (26.98 nmoles ml-1 min-1 mg of protein-1), MFO (5.07 nmoles ml-1 min-1 mg of protein-1) and CarE (827.90 nmoles ml-1 min-1 mg of protein-1). The CarE activity was found to be positively correlated with highly resistant acaricide, propargite (r = 0.995) and MFO activity with buprofezin having an extremely high level of resistance (r = 0.997). This preliminary knowledge would be instrumental in framing the acaricide resistant management (ARM) strategies.</div>

Magnitude of Resistance and Metabolism of Acaricides in Two-spotted Spider Mite, Tetranychus urticae Koch on Vegetables in Southern Districts of Tamil Nadu

<div>Background: Hyalomma ticks are the major ticks prevalent in Gujarat state which are mainly controlled with chemical acaricides. The control strategies are complicated by emergence of resistance against chemical acaricides. Development of resistance against these acaricides has compelled scientists to explore the acaricidal properties of constituents other than chemicals.&nbsp; 
 
Methods: Resistance status of Hyalomma anatolicum collected from Gujarat (India) against deltamethrin was assessed by larval packet test, which revealed level I resistance against deltamethrin. The crude ethanolic extracts of leaves of Cymbopogon citratus, Citrus aurantiifolia, Annona squamosa, Carica papaya and Catharanthus roseus were assessed for their acaricidal activity against larvae of deltamethrin resistant H. anatolicum. The efficacy was assessed by measuring per cent larval mortality and determination of LC50 values.&nbsp; 
 
Result: Various ethanolic extracts emanated a concentration dependent increase in larval tick mortality. The highest mortality (93.01 &plusmn; 0.35%) was observed with the 100mg/ml concentration of ethanolic extract of leaves of C. aurantiifolia. Overall, C. aurantifolia, A. squamosa and C. citratus were found to have significant acaricidal properties with LC95 values of 1.07x102 mg/ml, 6.09x102 mg/ml and 3.62x103 mg/ml respectively. Results of the present study indicated that these plant extracts have potential to be developed as herbal acaricides.</div>

<div>Acaricidal Properties of Herbal Extracts against Deltamethrin Resistant Multi-host Cattle Tick Hyalomma anatolicum</div>

<div style="text-align:justify">Background: Tick population in India has developed resistance against all commonly available acaricides and there have been only limited research activities to develop novel acaricides due to the enormous costs involved. Therefore, alternative therapy is need of the hour to tackle the acaricidal resistance. 
 
Methods: The present study envisages Annona squamosa seed based synthesis of ZnO nanoparticles (ZnO-NPs) for its acaricidal potential. Mean size of ZnO-NPs was 292.75 nm as per scanning electron microscope. Zeta potential of ZnO-NPs was (-) 38.9 mV. ZnO-NPs showed characteristic intense peaks in XRD analysis at 2&theta; of 31.89&deg;and 45.64&deg; due to its crystalline nature. In FTIR, the peak observed at 3754.73 cm-1 may be due to (-) OH stretching and deformation. ZnO NPs showed a strong absorbance peak at 300 nm confirmed the stability of nanoparticles. 
&nbsp; 
Result: Critical analysis of reproductive index study with ZnO-NPs revealed consistent acaricidal property of 2% ZnO-NPs even in the next generation of tick. Cytotoxicity evaluation revealed absence of aggregation as well other morphological changes of RBC, which indicated safer use of synthesized ZnO NPs on the animal body.</div>

Green Synthesized ZnO Nanoparticles (ZnO-NPs) and Its Acaricidal Action against Rhipicephalus (B). microplus

<div>Background: Tick infestation particularly, of Riphicephalus microplus is a costly affair for farmers particularly in times of emerging resistance. Biological control using plant extracts will serve as environment friendly and cost-effective method. The present study was taken up to investigate the phytoconstituents and acaricidal activities of ethanolic extract of Calotropis gigantea flowers.&nbsp; 
 
Methods: The acaricidal efficacy of ethanolic extracts of Calotropis gigantea flowers against engorged adult females of R. microplus were accessed by measuring mortality, inhibition of oviposition, hatching rate and larval mortality through Adult Immersion and Larval Packet Test. Gas chromatography-Mass spectrometry (GC-MS) analysis was done to reveal various compounds found in the flowers of Calotropis gigantea to justify their acaricidal activity. 
 
Result: As per the results of the in vitro tests (adult immersion test and larval packet test), there was adult mortality of 56.67%, RI of 0.17, IO of 66% and larval mortality of 60.33% at concentration of 100 mg/ml. LC50 values were found to be 83.18 mg/ml. The GC-MS analysis revealed the presence of two major phytocompounds: dibutyl phthalate and n-Hexadecanoic acid in the extracts suggesting&nbsp; potential acaricidal properties. Results of the present study revealed the ethanolic extracts of Calotropis gigantea flower have potential anti-tick activity against both larval and adult stage of Rhipicephalus microplus.</div>

​In vitro Acaricidal Activity and Phytochemical Screening of Calotropis gigantea Flowers against Riphicephalus microplus

<div>Background: The pigeonpea eriophyid mite, Aceria cajani Chan., vector of sterility mosaic disease in pigeonpea, causes economic damage of up to 90% during the early stages of crop growth. The major element in deploying management practice is to know the population dynamics of the pest. Generally, the vectors of disease causing agents were managed with the synthetic chemical. So we have taken studies to know efficacy of insecticides and acaricides in its control on pigeonpea. 
 
Methods: The population dynamics of A. cajani Chan. was monitored in field plots from January 2021 to December 2021. For efficacy of insecticides and acaricides studies in control of A. cajani a completely randomized design was organized. Twelve treatments (insecticides/acaricides) were tested against A. cajani on pigeonpea [var. ICP 8863 (Shree Maruti]. 
 
Result: This study found that mite population reached a peak in the summer (March) and another peak in the post-monsoon period (October), whereas the lowest populations were recorded in winter (January). Correlation studies exhibited a significant positive correlation with both maximum and minimum temperature. The insecticide and acaricide trials on A. cajani found that all chemicals used were effective and entomopathogenic formulations were comparatively less effective.</div>

Temperature Predicts the Population of Aceria cajani Chan. (Acari: Eriophyidae) and Efficacy of Insecticides and Acaricides in its Control on Pigeonpea [Cajanus cajan (L) Millsp.]

Background: Brinjal is an important vegetable crop grown throughout the country and a number of insect and non- insect pest are reported causing loss in quality and quantity of this crop. Tetranychus urticae (Koch) the two spotted mite is the most notorious non insect pest responsible for significant yield losses in brinjal crops next to shoot and fruit borer. Phytophagous mites are minute and not easily visible by naked eye making it very important create awareness among farmers of its occurrence and management practices. The present work was undertaken to understand status of phytophagous mites and associated natural enemies in brinjal farmers field along with to develop economically feasible management strategy. 
 
Methods: Survey was conducted in four villages each of two district of North Bihar Samastipur and Muzaffarpur on presence of phytophagous mites, natural enemies in farmers brinjal field and efficacy of novel acaricides was also evaluated against these phytophagous mites. The survey on phytophagous mites and their natural enemies on brinjal crops was carried out in 31 farmers&rsquo; field of Chandauli, Harpur, Naranyanpur and Gopalpur Thara villages of Samastipur and Lautan, Mirapur, Ittha and Muraul villages of Muzaffarpur district at fortnightly interval from January to June 2022. 
 
Result: In our study we found wide spread presence of&nbsp; two species of tetranychid mites, predatory mites and six predatory insects viz., Tetranychus urticae, T. neocaedelonicus, Amblyseius indicus, A. tetranychivorous, Coccinellids, green lacewing, anthocorid bugs, mirid bugs, scolothrips and black ants. Efficacy of various acaricides resulted in lowest population in plot sprayed with chlofenapyr 10SC and spiromesifen 240EC and highest active mites were found in azadirachtin 1.9 EC treated plots. The highest per cent reduction over control was observed in plots treated with spiromesifen and the lowest per cent reduction over control was observed in plot treated with azadirachtin. This study has helped in understanding increase in&nbsp; mites infestation in changing climate scenario strategy for management.

Survey of Phytophagous Mites, its Associated Natural Enemies on Brinjal and its Management Through Acaricides in North Bihar

<div>Background: Ticks are destructive ectoparasites that feed on the blood of domestic animals and the spread of ticks causes significant losses in meat, milk and leather production. About 800 species of ticks are known around the world, Hyalomma dromedarii is one of the ticks that attack camels as their main host. The objective of this study was to identify the acaricidal activity of Laurus nobilis and Croton tiglium seeds extract against H. dromedarii ticks and comparison with some drugs used against external parasites. 
 
Methods: A study was performed to evaluate the acaricidal activities of methanolic extracts of two medicinal plants, namely the seeds of C. tiglium and L. nobilis, against H. dromedarii using an adult immersion test and larval bundle test. Five graduated concentrations of extracts, 6.25, 12.5, 25, 50 and 100 mg/ml, were tested at different periods and changes over time in the viability of ticks were registered for 24 hr. Distilled water and cypermethrin (0.1%) were used as a negative and positive control, respectively. 
 
Result: From 30 min after exposure, a concentration of 100 mg/ml of C. tiglium seed extract resulted in higher mortality (p&lt;0.05) compared with cypermethrin. A significant rise in tick mortality began 2 hr after exposure to a concentration of 100 mg/ml of C. tiglium seed extract and cypermethrin. At 24 hr after exposure, cypermethrin and concentrations of 50 and 100 mg/ml of C. tiglium extract induced significantly higher tick mortality compared to the rest of the concentrations. A significant increase in tick mortality began 3 hr after exposure to cypermethrin and concentrations of 50 and 100 mg/ml of Laurus nobilis extract and 12 hr after exposure to concentrations of 6.25, 12.5 and 25 mg/ml L. nobilis extract. At 24 hr after the exposure time, concentrations of 50 and 100 mg/ml of the extract and cypermethrin had a comparable higher tick mortality effect compared to the remaining concentrations below 25 mg/ml (p&lt;0.05). The lower concentration (6.25 mg/ml) resulted in notably higher mortality of adult ticks and larvae compared to the negative control (distilled water) at 24 hr exposure to both extracts. At 24 hr after the exposure period, the tick mortality of all estimated plant extracts also increased with raised exposure time and concentration. Therefore, studied plants can be used against H. dromedarii as a potential alternative to commercially available medicines. Further studies should include more research on separating each component and validating the materials.</div>

In vitro Assessment of the Acaricidal Activity of Laurus nobilis and Croton tiglium Seeds Extract against Hyalomma dromedarii Ticks

<div>The two-spotted spider mite is a destructive phytophagous of agricultural and horticultural crops. The disruptive selection had fulfilled on T. urticae females in 20 inbred generations. The selection of individual female genotypes was carried out according to a lethality rate of diagnostic concentrations of each acaricides. Malathion and fenpyroximate strains performed for comparative toxicity to five acaricides belonging to different chemical groups: dimethoate, bifenthrin, pyridaben, brompropylate and abamectin. The results allow us to conclude the malathion and fenpyroximate in mites with resistance alleles to one of these acaricides showed that, normalization of biochemical processes on the mitochondrial membrane depends on the function of the transport plasma membrane system. The expression of the malathion resistance gene was completely suppressed by the butyphos esterase inhibitor, while fenpyroximate resistance gene &nbsp;was not manifested in the inhibition of PBO activity of monooxygenases enzymes.</div>

<div>Comparative Toxicity and Synergism in Two-Spotted Spider Mite (Tetranychus urticae) Under Disruptive Selection</div>

<div>Background: Tick infestation in cattle is commonly controlled using chemical acaricides producing acaricidal resistance, environmental pollution and hazards to human health. Biological control of ticks using entomopathogenic fungi can be an alternative to chemical acaricides and can be used in conjunction with chemical control in integrated pest management.&nbsp; 
 
Methods: The isolation of entomopathogenic fungi was carried out from naturally infected ticks in Durg district of Chhattisgarh. The species confirmation of fungal isolates was conducted by Polymerase chain reaction (PCR) using ITS gene as a molecular marker. In vitro efficacy of entomopathogenic fungi at various concentrations against engorged (adult) female ticks and unfed (Nymphs), egg laying capacity and egg hatchability of treated Rhipicephalus microplus was assessed in laboratory.&nbsp; 
 
Result: The entomopathogenic fungi isolated from naturally infected ticks was confirmed as Fusarium beomiforme by morpho- molecular analysis. The efficacy of F. beomiforme against adult female and nymphs of R. microplus at the concentration of n x 108 spores ml-1 showed 100% mortality. The 100% reduction of egg laying capacity of treated female ticks and no hatchability of eggs treated with F. beomiforme at the concentration of n x 107 spores ml-1 and n x 108 spores ml-1 was observed.</div>

Pathogenicity of Entomopathogenic Fungi Fusarium beomiforme against Rhipicephalus microplus Tick Infestation in Cattle

<div style="text-align: justify;">Field experiments were conducted to ascertain the efficacy of seven different chemicals (one botanical insecticide and six acaricides) viz., azadirachtin (multineem), dicofol (hiltol), fenazaquin (acegold), propargite (simbaa), wettableSulphur (mitsul), diafenthurion (derby), and spiromesifen(oberon) against Sterility Mosaic Disease (SMD) in pigeonpea under field conditions. Comprehensive analysis of data demonstrated that WettableSulphur50 WP (3 g/1) treated plot recorded the lowest incidence (7.00% and 7.30%) followed by Dicofol 18.5 EC (2.5 ml/1) which recorded an incidence of 13.02 and 11.6 per cent, respectively, &nbsp;at 45 and 60 days after first and second sprayfor SMD incidence as compared to 46.1 per cent in untreated control which accounted for the disease reduction of 78.14 per cent.Wettablesulphur50 WP (3 g/1) spray reduced the mite (Aceria cajani) population by 93.72 per cent followed by Dicofol 18.5 EC (2.5 ml/1) with the population reduction of 83.72 per cent. Wettablesulphur50 WP (3 g/1) spray also influenced to record the highest yield of 16.25 q ha1 as against 3.56q ha1in untreated plot and therefore, WettableSulphur and Dicofolcould be the best alternative for the management of SMD in pigeonpea under field conditions.</div>