Red Mite Research Articles

Miticidal Tools for Management of Southern Red Mites Infesting Southern Highbush Blueberries.

Tetranychid outbreaks have been detected since 2016 in southern highbush blueberries (SHB); however, it was not until 2019 that the southern red mite (SRM), Oligonychus ilicis (Acari: Tetranychidae) was confirmed as the pest causing severe bronzing and stunting, in multiple Florida and Georgia commercial blueberry plantings. To date, only three miticides (fenazaquin, fenpyroximate, and acequinocyl) have been registered for use in SHB and there are no clear guidelines on how to manage SRM in SHB. Similarly, there is no knowledge regarding the existence of natural enemies of SRM in SHB. This is the first report of naturally occurring predatory mites (Amblyseius sp. and Neoseiulus ilicis) associated with SRM in SHB. Predatory mites were recorded in blueberry bushes after treatment with seven miticides used to suppress SRM populations including spiromesifen, acequinocyl, sulfur, sulfur + molasses, bifenazate, fenpyroximate, and fenazaquin. The number of SRM recorded per leaf and averaged plant damage ratings (0 = no bronzing-4 = 100% bronzing) were used to evaluate miticide efficacy. Additionally, the presence or absence of predatory mites per sample was recorded. Fenpyroximate used as the standard miticide, significantly reduced mite numbers seven days after application, as well as acequinocyl and fenazaquin. Fenpyroximate and fenazaquin demonstrated the best performance for managing O. ilicis on SHB and treated bushes demonstrated significantly less bronzing compared with the control plants. These miticides were also safe to naturally occurring predatory mites. Lastly, the level of growers' awareness regarding SRM was assessed using surveys in 2020 to design adequate educational materials available to the grower community.

Effects of Different Diets on Biological Characteristics of Predatory Mite Amblyseius Eharai (Acari: Phytoseiidae)

In this study, we investigated the effects of different diets on the development and reproduction of the predatory mite Amblyseius eharai. The results show that feeding on citrus red mite (Panonychus citri) led to the fastest life cycle completion (6.9 ± 0.22 days), the longest oviposition period (26.19 ± 0.46 days), the greatest female longevity (42.03 ± 0.43 days), and the highest total number of eggs per female (45.63 ± 0.94 eggs). Feeding on Artemia fanciscana cysts resulted in the highest oviposition rate (1.98 ± 0.04 eggs), a high total number of eggs per female (33.93 ± 0.36 eggs), and the highest intrinsic rate of increase (rm = 0.242). The hatching rate did not differ significantly among the five types of food, and the proportion of females ranged from 60% to 65% across all diets.

Evaluation of the interaction of citral, geraniol and thymol on the poultry red mite Dermanyssus gallinae (DE GEER, 1778) under in vitro conditions

The control of Dermanyssus gallinae in small productions of laying hens is carried out by using chemical methods. However, its indiscriminate use has generated resistance and environmental pollution problems. This problem has encouraged the use of natural substances to control mites. Thus, the objective of this work was to evaluate the acaricidal activity of the bioactive citral (Ci), geraniol (Ge) and thymol (Thy) on D. gallinae under in vitro conditions using six concentrations (0.05, 1, 2, 3, 4 and 5g/mL). In addition, the interactions of the mixtures of the three bioactive were evaluated through binary (1:1) and tertiary (1:1:1) combinations. The interaction between of the combination of bioactive was performed by using CompuSyn software and calculating the combination index (CI). LC50, LC90, and LC99 with 95% confidence limits were estimated by Probit analysis. The bioactive Ci, Ge and Thy show acaricidal activity on the poultry red mite. The combination of Ge:Thy and Ci:Ge showed very strong synergism with CI of 0.084 and 0.052, whereas Ci:Thy showed strong synergism with CI of 0.122 at a concentration of 0.05g/mL. The tertiary combination in 1:1:1 showed a higher toxic effect and strong synergistic effects at low concentrations with 100% mortality at 1g/mL concentration with a CI of 0.147. The combination of natural bioactive could be an additional way to control D. gallinae without putting the welfare of the birds at risk and would be an environmentally friendly measure.

Variation of bacterial community assembly over developmental stages and midgut of Dermanyssus gallinae.

Bacterial microbiota play an important role in the fitness of arthropods, but the bacterial microflora in the parasitic mite Dermanyssus gallinae is only partially explored; there are gaps in our understanding of the microbiota localization and in our knowledge of microbial community assembly. In this work, we have visualized, quantified the abundance, and determined the diversity of bacterial occupancy, not only across developmental stages of D. gallinae, but also in the midgut of micro-dissected female D. gallinae mites. We explored community assembly and the presence of keystone taxa, as well as predicted metabolic functions in the microbiome of the mite. The diversity of the microbiota and the complexity of co-occurrence networks decreased with the progression of the life cycle. However, several bacterial taxa were present in all samples examined, indicating a core symbiotic consortium of bacteria. The relatively higher bacterial abundance in adult females, specifically in their midguts, implicates a function linked to the biology of D. gallinae mites. If such an association proves to be important, the bacterial microflora qualifies itself as an acaricidal or vaccine target against this troublesome pest.

Life Table Parameters of Tetranychus merganser Boudreaux (Acari: Tetranychidae) on Five Host Plants.

The quality of the host plant affects the life history parameters of tetranychid mites. The biology and fertility life tables of Tetranychus merganser on five host plants (Carica papaya, Phaseolus vulgaris, Capsicum annuum var. glabriusculum, Helietta parvifolia, and Rosa hybrida) were assessed under laboratory conditions at 28 ± 1 °C and 70-80% relative humidity (RH) with a photoperiod of 12:12 h (L:D). The development period of immature females differed among the tested host plants and ranged from 9.32 days on P. vulgaris to 11.34 days on H. parvifolia. For immature males, it ranged from 9.25 days on P. vulgaris to 11.50 days on H. parvifolia. The female survival rate varied from 53.97% on H. parvifolia to 94.74% on P. vulgaris. The highest total fecundity rate was recorded on P. vulgaris (125.40 eggs/female) and the lowest on H. parvifolia (43.92 eggs/female). The intrinsic rate of increase (rm) varied from 0.271 (H. parvifolia) to 0.391 (P. vulgaris). The net reproductive rate (RO) was higher on P. vulgaris than on the other host plants. The longest mean generation time (GT) was calculated on C. annuum var. glabriusculum and the shortest on Rosa hybrida. The demographic parameters suggest the unsuitability of H. parvifolia as the host for the development of red spider mites, and the best performance of T. merganser was on P. vulgaris.

Profiling of Dermanyssus gallinae genes involved in acaricide resistance

The poultry red mite (PRM), Dermanyssus gallinae, is a major threat for the poultry industry worldwide. Chemical compounds have been extensively used for PRM control, leading to selection of resistant mites. Molecular mechanisms of resistance have been investigated in arthropods, showing the role of target-site insensitivity and enhanced detoxification. Few studies are available about those mechanisms in D. gallinae, and none have yet focused on the expression levels of detoxification enzymes and other defense-related genes through RNA-seq. We tested PRM populations from Italy for their susceptibility to the acaricidal compounds phoxim and cypermethrin. Mutations in the voltage-gated sodium channel (vgsc) and in acetylcholinesterase (AChE) were investigated, detecting mutations known to be associated with acaricide/insecticide resistance in arthropods, including M827I and M918L/T in the vgsc and G119S in the AChE. RNA-seq analysis was performed to characterize metabolic resistance in fully susceptible PRM and in cypermethrin-resistant PRM exposed and unexposed to cypermethrin as well as phoxim resistant PRM exposed and unexposed to phoxim. Detoxification enzymes (including P450 monooxygenases and glutathione-S-transferases), ABC transporters and cuticular proteins were constitutively overexpressed in phoxim and cypermethrin resistant mites. In addition, heat shock proteins were found constitutively and inductively upregulated in phoxim resistant mites, while in cypermethrin resistant mites esterases and an aryl hydrocarbon receptor were constitutively highly expressed. The findings suggest that acaricide resistance in D. gallinae is due to both target-site insensitivity and overexpression of detoxification enzymes and other xenobiotic defense-related genes, which is mostly constitutive and not induced by treatment. Understanding the molecular basis of resistance could be useful to screen or test PRM populations in order to select targeted acaricides and to avoid the abuse/misuse of the few available compounds.

Blood-feeding adaptations and virome assessment of the poultry red mite Dermanyssus gallinae guided by RNA-seq

Dermanyssus gallinae is a blood-feeding mite that parasitises wild birds and farmed poultry. Its remarkably swift processing of blood, together with the capacity to blood-feed during most developmental stages, makes this mite a highly debilitating pest. To identify specific adaptations to digestion of a haemoglobin-rich diet, we constructed and compared transcriptomes from starved and blood-fed stages of the parasite and identified midgut-enriched transcripts. We noted that midgut transcripts encoding cysteine proteases were upregulated with a blood meal. Mapping the full proteolytic apparatus, we noted a reduction in the suite of cysteine proteases, missing homologues for Cathepsin B and C. We have further identified and phylogenetically analysed three distinct transcripts encoding vitellogenins that facilitate the reproductive capacity of the mites. We also fully mapped transcripts for haem biosynthesis and the ferritin-based system of iron storage and inter-tissue trafficking. Additionally, we identified transcripts encoding proteins implicated in immune signalling (Toll and IMD pathways) and activity (defensins and thioester-containing proteins), RNAi, and ion channelling (with targets for commercial acaricides such as Fluralaner, Fipronil, and Ivermectin). Viral sequences were filtered from the Illumina reads and we described, in part, the RNA-virome of D. gallinae with identification of a novel virus, Red mite quaranjavirus 1.

Screening of Suitable Castor Cultivars for Ericulture in Tamil Nadu, India

Although castor cultivation is predominant in Gujarat, Andhra Pradesh, Tamil Nadu, and few other states in India, rearing of eri silkworm, which feeds on castor is not catching up in these non-traditional states. One of the probable reasons is the non-availability of studies indicating region-specific suitable castor cultivars for different eri silkworm races. Studies on castor cultivar preference for one such better-performing race, C2 yielding better shell weight (12-15 Kg/100 DFL) in the Tamil Nadu region is lacking. Eleven castor cultivars, including local accessions, varieties, and hybrids, have been raised in Randomised Block Design (RBD) with three replicates. The worms were reared using all the grown cultivars with five replications for each cultivar (treatment) with 20 worms/replication. All the economic parameters of eri silkworm were computed and compared. Local accessions such as Krishnagiri local and Tindivanam local, Perennial castor - YTP – 1, and Hybrids such as YRCH – 1 and DCH – 519 recorded significantly better larval, cocoon, and reproductive parameters. Least larval duration and highest matured larval weight were recorded in Krishnagiri local accession. Least values of all the economic parameters were noticed in Dharmapuri local. The reason might be due to the poor leaf quality impacted due to severe whitefly (Trialeyrodes ricini) and red spider mite (Tetranychus urticae) attack.

In Vivo Evaluation of an Ivermectin and Allicin Combination Treatment for Eradicating Poultry Red Mite.

A safe and effective method for eradicating poultry red mite (PRM; Dermanyssus gallinae) is urgently needed, as existing treatments show a low efficacy or hazardous effects on chickens. We evaluated the efficacy of a combined treatment with ivermectin and allicin (IA) against PRMs in chickens and drug residues in non-target samples. The efficiency of PRM eradication by IA was compared with those of natural acaricides in vitro. Ivermectin (0.25 mg/mL) + allicin (1 mg/mL) (IA compound) was sprayed on isolator housing hens with PRMs. The PRM mortality rate, clinical symptoms, and ivermectin residue in hens were analyzed. IA showed the highest PRM-eradication efficacy among all tested compounds in vitro. The insecticidal rates of IA were 98.7%, 98.4%, 99.4%, and 99.9% at 7, 14, 21, and 28 days of treatment, respectively. After inoculating PRMs, hypersensitivity, itching, and a pale-colored comb were observed in control animals, which were absent in treated hens. No clinical symptoms from IA and ivermectin residues were found in hens. IA effectively exterminated PRMs, demonstrating its potential for industrial use to treat PRMs.

Farm Fields as Toxic Sinkhole

Farm Fields as Toxic Sinkhole

Chitinase from Streptomyces mutabilis as an Effective Eco-friendly Biocontrol Agent.

Blood sucking parasites not only cause economic loss but also transmit numerous diseases. Dermanyssus gallinae, an obligatory blood feeding ectoparasite causes huge production loss to the poultry industry. Mosquitoes act as vector for transmitting several viral and parasitic diseases in humans. Acaricide resistance limits the control of these parasites. The present study was aimed to control the parasites using chitinase that have selective degradation of chitin, an important component in exoskeleton development. Chitinase was induced in Streptomyces mutabilis IMA8 with chitin extracted from Charybdis smithii. The enzyme showed more than 50% activity at 30-50°C and the optimum activity at 45°C. The enzyme activity of chitinase was highest at pH 7.0. The kinetic parameters Km and Vmax values of chitinase were determined by non-linear regression using Michaelis-Menten equation and its derivative Hanes-Wolf plot. The larvicidal effect of different concentrations of chitinase was evaluated against all instar larvae (I-IV) and pupae of An. stephensi and Ae. aegypti after 24h of exposure. The percentage of mortality was directly proportional to the chitinase concentration. Bioassay for miticidal activity showed that chitinase had excellent miticidal activity (LC50 = 24.2ppm) against D. gallinae. The present study suggested the usage of Streptomyces mutabilis for preparation of chitinase in mosquito and mite control.

Function of glycogen synthase kinase3 in embryogenesis of Dermanyssus gallinae

In the life cycle of Dermanyssus gallinae, the embryo is a developmental stage that does not require blood meals, but needs glucose to produce adenosine triphosphate (ATP) through glycolysis or oxidative phosphorylation, providing energy for embryonic development. Glycogen synthase kinase 3 (GSK3), belonging to the serine/threonine kinase family, is a key enzyme involved in glycogen metabolism in many eukaryotes, but not be described in D. gallinae. The present study was conducted to explore the role of Dg-GSK3 in the embryogenesis of D. gallinae. The results of qPCR showed that Dg-GSK3 mRNA was expressed in different development stages of D. gallinae embryos. RNA interference (RNAi) was performed on the female mites and eggs by immersion, and it was found that lowering GSK3 expression level could significantly decrease the female egg laying rate and egg hatching rate (P < 0.05). Some eggs became shrunken and shriveled in appearance. The fecundity of female D. gallinae obtained from the rDg-GSK3-immunized group of chickens (2.56 ± 0.35 eggs per mite, P < 0.0001) decreased significantly from that of the control group (3.49 ± 0.35). The oviposition rate of rDg-GSK3-immunized group (75.94 ± 7.28 %, P = 0.0003）was significantly lower that of the control group (89.69 ± 2.63 %). In conclusion, Dg-GSK3 is a crucial gene during the embryogenesis of D. gallinae, which can affect both the female fecundity and the egg hatching, which help us understand the function of GSK3 gene in the embryogenesis of mites.

Le pou rouge du poulailler (Dermanyssus gallinae) : une cause méconnue d’urticaire

Dermanyssus gallinae is a hematophagous ectoparasite on poultry. Accidentally, this parasite could reach human, leading to itchy cutaneous rash. In dermato-allergology or allergology, red and icthy rashes are a quite usual reason for medical consultation. We describe two cases of red itchy rashes in two patients, which made us suspect the implication of ectoparasite Dermanyssus gallinae. In both cases, the parasite has been recognized by families. The source of these parasites was a chicken coop (with an intermediary vector, possible rats) and, in the other case, a nest of birds in communication to the bedroom of the child implicated. Treatment is firstly eviction of the parasite by reducing potential sources of infestation, or vectors of Dermanyssus gallinae in contact with human environment. Symptomatic treatment of pruritus could be applied (dermocorticoids and antihistamines) but these treatments will be efficient only when the parasite eradication will be effective. When a patient is addressed with the initial suspicion of allergy in a context of red and itchy cutaneous rash, diagnosis of parasite bites must be evoked. Active research of clinical elements in favor of parasite implication is fundamental. As in all allergology medical consultations, precise collection of medical history is fundamental and differential diagnoses has to be in the mind of allergology physicians.

Sex dimorphism in the deutonymphs of Dermanyssus gallinae (De Geer, 1778) based on geometric morphometrics

The lifecycle of poultry red mite (PRM), Dermanyssus gallinae,includes several stages and only the adult has been reported to have sex discrimination based on body structures and color patterns. Currently, it's still unknown how to distinguish two sexes of deutonymphs. We measured body length of 254 engorged deutonymphs and examined body size and shape variation of 104 engorged deutonymphs using geometric morphometric techniques. Our findings showed that deutonymph females (with average values of 813.08 μm) had a longer body length than deutonymph males (713.39 μm). Additionally, deutonymph females were found to had a narrow and elongated posterior body shape while deutonymph males had a suboval shape, and the former was bigger than the latter. These results suggest that there is sexual dimorphism in PRM deutonymphs, and the differentiation of deutonymph females and males based on their body length, shape, and size will facilitate a better understanding of reproductive behavior and the accurate population dynamics of PRMs.

Poultry red mite eradication potential of ivermectin and allicin combination treatment.

Existing treatments against poultry red mite (PRM; Dermanyssus gallinae) infestation have reduced efficacy or exhibit hazardous effects on chickens. Considering the economic importance of chickens, development of a safe and effective method for exterminating PRMs is necessary. Ivermectin and allicin are effective against some ectoparasites; however, their acaricidal efficacies against PRMs remain unknown. To evaluate individual and combined efficacies of ivermectin and allicin in exterminating PRMs. Different concentrations (0.10-1.0mg/mL) of ivermectin (1mL) were applied via dropping method in different insect culture dishes (ICDs), prior to transferring PRMs. For the spraying method, PRMs were transferred to ICDs, before spraying ivermectin (1mg/mL) solution (1mL). Further, the acaricidal effect of allicin on PRMs was evaluated by applying different concentrations (0.25-1.0mg/mL) of allicin (1mL). The combined acaricidal effects of ivermectin and allicin were analysed using four concentration combinations. PRM death rates were determined after 2h, 24h, 2 days, 5 days and 7 days of drug application. Ivermectin application (1mg/mL) exterminated 64% and 100% of PRMs on 1 and 5 days, respectively, and prevented their revival. Further, 0.5mg/mL ivermectin and 1mg/mL allicin individually exterminated 98% and 44% of PRMs, respectively, within 7 days of treatment. In combination, 0.5mg/mL ivermectin and 0.5mg/mL allicin exterminated 100% of PRMs within 5 d of treatment. The most effective combination was 0.25mg/mL ivermectin + 1.00mg/mL allicin. The efficacy of ivermectin-allicin combination in exterminating PRMs was demonstrated. This novel approach could be optimised for industrial applications.

Effect of the type of citrus fruit on the biological parameters of Panonychus citri (Acari: Tetranychidae) under laboratory conditions

The citrus red mite, Panonychus citri (McGregor, 1916), is considered a very important pest in most citrus-growing countries. The developmental periods, reproduction rates, and population growth parameters of P. citri were evaluated using the fruit peel under experimental conditions (25 ± 1 °C, 50 ± 5% RH and 14:10 h photoperiod) on five Citrus species: Mexican lime (C. ×aurantiifolia (Christm.) Swingle), grapefruit (C. ×paradisi Macfad.), sweet orange (C. ×sinensis (L.) Osbeck), mandarin (C. reticulata Blanco), and tangelo fruit (C. ×tangelo J.W. Ingram & H.E. Moore). The developmental period of the immature stages of P. citri averaged 26.64, 25.93 and 25.75 d for sweet orange, mandarin, and tangelo fruit, respectively. The adult stage was not achieved in Mexican lime and grapefruit. Immature survival was less than 50% in mandarin and tangelo fruit, in contrast, in sweet orange it was 57%. On average, oviposition was 3.55, 4.95 and 5.00 eggs female-1, on sweet orange, mandarin, and tangelo fruit, respectively. The intrinsic natural growth rate (rm), net reproduction rate (R0), generation time (T), and finite growth rate (λ) of P. citri showed significant differences among the tested species (p < 0.05). The rm and R0 values were 0.005 and 1.209 for sweet orange, 0.026 and 2.474 for mandarin and 0.020 and 2.000 for tangelo fruit. The results indicated that mandarin was the most suitable species for the P. citri population growth, whereas sweet orange was less suitable to proliferate. These differences are important in the integrated management of P. citri on citrus.

Effect of cues from Amblyseius largoensis (Muma) on the oviposition behavior of Raoiella indica Hirst

The ability of an organism to defend itself and protect its offspring is closely related to the evolutionary success of the organism. In this study, we examined the responses of red palm mite, Raoiella indica Hirst, to predation risk using cues from the predator Amblyseius largoensis (Muma). Females of A. largoensis were used for the production of cues for 4 h in two types of bioassays, a choice and no-choice tests. The oviposition rate of R. indica was evaluated until to 96 h. In addition, a walking behavior test was conducted (distance/time walked and resting time). For both tests, a control treatment without cues was done. In the no-choice bioassay, the oviposition rate of R. indica decreased by 55% when the cues were present. In the choice bioassay, the oviposition rate was similar to the control treatment, however most of the eggs were deposited in the site without cues. The walking behavior of R. indica was not affected by the presence of predator cues in no-choice bioassay. In choice bioassay, R. indica stayed longer in sites without cues. A. largoensis cues seem to be strong signs of predation risk affecting R. indica oviposition when there is no-choice, even after 96 h. R. indica shows that it is able to identify the cues of A. largoensis. We clearly evidenced the anti-predation behavior of R. indica, showing the trade-off between predation risk and reproduction on A. largoensis cues.

Enantioselective activity and toxicity of chiral acaricide cyflumetofen toward target and non-target organisms

Cyflumetofen (CYF), a novel chiral acaricide, exert enantiomer-specific effects on target organisms by binding to glutathione S-transferase. However, there is limited knowledge regarding the response of non-target organisms to CYF, including enantioselective toxicity. In this study, we investigated the effects of racemic CYF (rac-CYF) and its two enantiomers (+)-CYF and (−)-CYF on MCF-7 cells and non-target (honeybees) and target (bee mites and red spider mites) organisms. The results showed that similar to estradiol, 1 μM (+)-CYF promoted the proliferation and disturbed the redox homeostasis of MCF-7 cells, whereas at high concentrations (≥100 μM) it exerted a negative effect on cell viability that was substantially stronger than that of (−)-CYF or rac-CYF. (−)-CYF and rac-CYF at 1 μM concentration did not significantly affect cell proliferation, but caused cell damage at high concentrations (≥100 μM). Analysis of acute CYF toxicity against non-target and target organisms revealed that for honeybees, all CYF samples had high lethal dose (LD50) values, indicating low toxicity. In contrast, for bee mites and red spider mites, LD50 values were low, whereas those of (+)-CYF were the lowest, suggesting higher toxicity of (+)-CYF than that of the other CYF samples. Proteomics profiling revealed potential CYF-targeted proteins in honeybees related to energy metabolism, stress responses, and protein synthesis. Upregulation of estrogen-induced FAM102A protein analog indicated that CYF might exert estrogenic effects by dysregulating estradiol production and altering estrogen-dependent protein expression in bees. Our findings suggest that CYF functions as an endocrine disruptor in non-target organisms in an enantiomer-specific manner, indicating the necessity for general ecological risk assessment for chiral pesticides.

Extracts of plant residues from soursop peels in the management of palm red mite

Raoiella indica Hirst, 1924 (Prostigmata: Tenuipalpidae), is one of the main pest mites of palm and banana trees, causing significant damage in producing regions. Thus, the objective of this work was to evaluate the acaricidal effect of soursop peel extract (Annona muricata L.) on R. indica adults. The experiment was conducted in a completely randomized design using soursop peel extract, with 7 replications and 12 individuals of R. indica per replication. The experimental units consisted of discs of coconut palm leaves (4 cm in diameter), with cotton moistened at the bottom of the Petri dish (10.0 x 1.2 cm) and around the disc to maintain turgor and prevent mites from escaping. The application was carried out using an airbrush, connected to a calibrated compressor with a constant pressure of 1.3 psi and 1 mL of solution per plate. The acaricidal effect was evaluated 24, 48, and 72 hours after spraying. Mortality data were corrected and subsequently submitted to probit analysis (p≤0.05) using the statistical program R, with the LC50 and LC90 of the extract being calculated. The soursop peel extract at the maximum concentration used (15%) showed mortality of 80% of individuals of R. indica. The LC50 was 1.934%. It was concluded that extracts from soursop peel have acaricidal potential on R. indica in the laboratory.

Management of Panonychus ulmi with Various Miticides and Insecticides and Their Toxicity to Predatory Mites Conserved for Biological Mite Control in Eastern U.S. Apple Orchards

Panonychus ulmi (Koch) (Acari: Tetranychidae), commonly known as European red mite, is a polyphagous pest of various tree and small fruit crops, including apples. A field study was conducted to evaluate different pesticide options available for the management of P. ulmi, and their impact on the population of non-target predatory mite species complex consisting of Neoseiulus fallacis, Typhlodromus pyri, and Zetzellia mali in apple orchards. Pesticides were applied using a commercial airblast sprayer at the 3-5 mite/leaf recommended economic Integrated Pest Management (IPM) threshold or prophylactically in the spring ignoring IPM practices such as monitoring, reliance on biological control and economic thresholds. Effects on the motile and egg stages of P. ulmi were evaluated as were effects on the populations of predatory mites through frequent leaf counts during the season. We also recorded the subsequent overwintering eggs of P. ulmi from each pesticide treatment. The two prophylactic treatments containing a mixture of zeta-cypermethrin + avermectin B1 + 1% horticultural oil and abamectin + 1% horticultural oil provided effective control of P. ulmi population throughout the season without reducing predatory mite populations. In contrast, eight treatments applied at the recommended economic threshold of 3-5 mites/leaf were not effective in suppressing P. ulmi populations and most reduced predatory mites. Etoxazole had significantly higher number of overwintering P. ulmi eggs compared to all other treatments.