EXPERIMENTAL AND APPLIED ACAROLOGY

Behavior of Typhlodromus (Anthoseius) recki confronted to a combination of plants and food: pollen, Tetranychus urticae and Aculops lycopersici for companion plant use
Tixier MS, Charalabidis A, Douin M and Feugnet S
Typhlodromus (Anthoseius) recki feeds on pest mites on tomato plants and its introduction into crops via companion plants, Mentha suaveolens and Phlomis fruticosa, has been recently investigated. This study aims at assessing the predator arrestment behavior, through lab choice tests to determine the effects of (i) prey (Aculops lycopersici and Tetranychus urticae) vs Typha angustifolia pollen deposited on companion plant or Solanum nigrum, (ii) T. urticae vs A. lycopersici on S. nigrum and (ii) M. suaveolens vs P. fruticosa using pollen as food source. The predator position, the number of eggs laid and the number of T. urticae eggs consumed were assessed during 4 days. The predator was more observed on leaf discs with A. lycopersici vs pollen when the pollen was deposited on S. nigrum and M. suaveolens, but was more found on leaf discs with pollen on P. fruticosa. It was equally found on leaf discs with T. urticae vs pollen for all the plants tested. No difference in predator arrestment behavior was noted between A. lycopersici and T. urticae, but a higher proportion was observed on leaf discs with A. lycopersici at the beginning of the experiment than at the end. Finally, the predator was more observed on leaf discs of P. fruticosa than of M. suaveolens. The highest fecundity was observed in systems with pollen and A. lycopersci + pollen, and the lowest with T. urticae + pollen; T. urticae consumption was not different with pollen or A. lycopersici. The predator less arrested on pollen vs A. lycopersici that provides a high fecundity; however, surprisingly it was more attracted to pollen vs a prey T. urticae, questioning the cues perceived by T. (A.) recki. The strong preference for P. fruticosa without prey vs S. nigrum with prey or M. suaveolens with pollen, suggests for the second time for Phytoseiidae, direct effects of plant (may be via odors) and questions the ecological advantages of such a behavior. For practical issues, M. suaveolens would be a better bank plant than P. fruticosa; an arrestment on patches of A. lycopersici within tomato plant is expected even if pollen is present and in case of T. urticae infestation a low dispersal to this prey will probably occur, questioning the interest to use T. (A.) recki in combination with other Phytoseiidae species, specialized in T. urticae predation, as Phytoseiulus persimilis.
Effects of variable mating opportunity, delay, and male mating experience on the lifespan, female reproductive traits, and offspring traits of Phytoseiulus persimilis (Acari: Phytoseiidae)
Chen X, Zhang K and Zhang ZQ
The balance between mating benefits and costs shapes reproductive strategies and life history traits across animal species. For biological control programs, understanding how mating rates influence life history traits is essential for optimising population management and enhancing predator efficacy. This study investigates the impact of mating opportunity availability, delayed mating, and male mating history (copulation frequency) on the lifespan (both sexes), female reproductive traits (duration of oviposition and of pre- and post-oviposition periods, and lifetime oviposition), and offspring quality (egg size and offspring survival) of the predatory mite Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae), an important biological control agent against spider mites. We examined three mating treatments-no mating, limited mating opportunity (24-h access), and continuous lifetime access-to assess their effects on lifespan (both sexes), female reproductive traits, and offspring quality. Further analyses examined the impact of delayed mating and male copulation history on female reproductive success and offspring traits. Our results showed a sexually differentiated response to repeated mating: females with continuous access to mates had similar lifespans in comparison with those mated for only 24 h, while males with continuous mating access exhibited significantly shorter lifespans. Both unlimited mating and delayed mating prolonged the female pre-oviposition period. However, neither varied mating opportunities, delayed mating, nor male copulation had any significant effect on other female reproductive traits or offspring quality. This suggests that repeated mating provides no reproductive advantage and imposes no observable costs on P. persimilis females.
Is it worth paying attention to actinedid mites in agricultural fields?
Gergócs-Winkler V, Flórián N, Tóth Z, Sipőcz L and Dombos M
Agricultural management increases the seasonal dynamics of soil-dwelling organisms compared to natural habitats. Our knowledge is very poor about the relationship between seasonal changes of soil microorganisms and the microbivorous soil arthropods. To reveal these connections, we have to know more about the seasonal changes of soil-dwelling microarthropods in croplands. Actinedid mites are rarely the subject of synecological studies, however, this group regularly reaches the dominant part of mite assemblages in agro-ecosystems. In this study, we investigated the seasonal density changes of actinedid mites from two independent studies of agricultural fields. Soil samples were taken from maize and wheat fields for two years, and from newly established meadows for one year in summer and autumn in Hungary. Soil-dwelling mites were enumerated and identified at the suborder level and soil parameters were measured. Actinedid mites dominated most of our soil samples. The density of Endeostigmata was the highest in the summer and the density of Heterostigmata was the highest in the autumn within one year among different crop species, soil types, and years. Endeostigmatid mites had negative relationships with soil nitrogen parameters and positive with soil moisture. Heterostigmatid mites had various relationships with soil moisture. The ecology of actinedid mites is under-examined but their high number in agricultural fields may justify the fact that they should receive more attention. We assume that Actinedida, mainly Endeostigmata and Heterostigmata are worth to investigate in croplands as a starting point to reveal the connection between the seasonality of soil mites and soil microbiota.
Correction: Exploration of bioactive molecules from Sesbania grandiflora (L.): identification of squalene as an effective compound against the two-spotted spider mite, Tetranychus urticae Koch, through molecular docking
Joshi SSP, Sumathi E, Murugan M, Haran R, Priya SS, Shandeep G, Mohankumar S, Uma D and Nelson A
Biopesticide transplant dips and foliar acaricide applications for control of cyclamen mite (Phytonemus pallidus) in strawberry
Renkema JM
Cyclamen mite (Phytonemus pallidus) causes injury to new growth of strawberry plants and is difficult to control because it is protected by folded leaves and plant crowns. Since cyclamen mite is easily transferred from strawberry nurseries to fruiting fields, dipping transplants in biopesticides may reduce initial populations. However, cyclamen mite numbers at 1 and 3 months-after-planting, and yield and cyclamen mite injury to fruit in the following season did not differ among transplants immersed for 30 s in Captiva® Prime, EcoTrol® EC, Landscape Oil, SuffOil-X® or Kopa Insecticidal Soap or the untreated control. Cyclamen mite is primarily controlled with foliar applications of acaricides, but there are few registered products. In greenhouse experiments, fenazaquin and pyridaben reduced cyclamen mite numbers by more than 90% in new leaves compared to the control, similar to that of the standard abamectin. New leaf injury ratings were reduced from 1 on average (scale of 0-3; 0 = no injury) pre-application to 0.25-0.5 for fenazaquin, pyridaben, and abamectin-treated plants compared to increasing to 2 for control plants 2 weeks after application. Spiromesifen and chlorfenapyr reduced cyclamen mite numbers in folded leaves in one greenhouse experiment. In the field, all acaricides reduced cyclamen mite numbers by 90-99% at 2- and 6-weeks post-application and by 75-90% at 10 months post-application. Abamectin and pyridaben resulted in 0.5-1.0% of strawberries with cyclamen mite damage compared to 3.0% for the control. All acaricides except chlorfenapyr improved strawberry yield and size. Overall, fenazaquin, pyridaben and spiromesifen should help diversify the chemical toolbox for cyclamen mite in field strawberry.
Behavioral and acaricidal effects of the chlorfenapyr and acequinocyl on the predatory mites, Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae)
Sehat-Niaki N, Zahedi Golpayegani A, Torabi E, Amiri-Besheli B and Saboori A
The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is a major pest of various plants with a worldwide distribution. Extensive use of chemical pesticides has led to the development of resistance in this pest, making biological control agents a viable alternative for its management. The predatory mites, Neoseiulus californicus (McGregor) and Phytoseiulus persimilis Athias-Henriot (Acari: Phytoseiidae) are the most important predators of the two-spotted spider mites. In this study, the toxicity of two acaricides chlorfenapyr and acequinocyl, on these predators was evaluated, and the walking behavior of predatory mites after exposure to residues of the pesticides was assessed using a video tracking system. Based on the results, the LC values of both acaricides was estimated to be higher than their field concentration, and chlorfenapyr was found to be five-fold more toxic than acequinocyl. In the behavioral assay, both acaricides significantly affected the distance and speed of walking, resting time, and frequency of stops of both predatory mites. In the escape assay, both compounds had an irritable effect on both predatory mites, as the mites avoided areas contaminated with pesticide residues and their presence in the untreated area was significantly longer than in the treated area (P < 0.05). However, the study found no correlation between toxicity and irritability. According to the results of this study, N. californicus and P. persimilis possess the ability to detect the presence of pesticide residues in their environment and try to avoid them. Moreover, both compounds are at low risk to these mites, but acequinocyl is much safer and is a suitable option for use in integrated pest management.
A novel genotype of Babesia microti-like group in Ixodes montoyanus ticks parasitizing the Andean bear (Tremarctos ornatus) in Ecuador
Santodomingo A, Enríquez S, Thomas R, Muñoz-Leal S, Félix ML, Castellanos A, Bermúdez S and Venzal JM
Babesia species (Piroplasmida) are hemoparasites that infect erythrocytes of mammals and birds and are mainly transmitted by hard ticks (Acari: Ixodidae). These hemoparasites are known to be the second most common parasites infecting mammals, after trypanosomes, and some species may cause malaria-like disease in humans. Diagnosis and understanding of Babesia diversity increasingly rely on genetic data obtained through molecular techniques. Among hard ticks, several Ixodes species are known vectors of Babesia microti-like species in the Northern Hemisphere. Recently, Ixodes and Amblyomma ticks have been recorded parasitizing the Andean bear (Tremarctos ornatus) in Ecuador. Previous reports have suggested babesiosis in a fatal case of this threatened bear species in that country. This study aimed to detect Piroplasmida DNA in hard ticks collected from Andean bears at two sites in Ecuador. This species plays a critical role as an ecological engineer and a seed disperses, contributing significantly to the maintenance and health of Andean ecosystems. Twelve ticks screened with conventional PCR and Piroplasmida DNA was amplified from one Ixodes montoyanus tick collected from a free-living female Andean bear at Llanganates National Park. Two Babesia sequences were characterized: one for the 18 S ribosomal rRNA gene and another for the cytochrome c oxidase 1 gene. Phylogenetic analyses for both loci placed these sequences within the B. microti-like clade. This study reports a novel B. microti-like genotype identified in an I. montoyanus parasitizing a female Andean bear, contributing to the knowledge of the diversity of this group in South America. Given their conservation status, future epidemiological surveillance of Babesia and other tick-borne infectious agents in Andean bears is needed.
In silico screening and immunogenic features of putative tick cement protein PA107 from Ixodes ricinus tick
Mihaljica D, Repac J, Božić B, Marković D, Radulović Ž, Mulenga A, Sukara R, Veinović G, Nedeljković BB and Tomanović S
Tick salivary proteins are crucial for efficient and successful tick feeding. Most of them are still uncharacterized, especially those involved in the formation of tick cement. Tick salivary protein PA107 is a putative cement protein, which is transcribed in salivary glands during the initial phase of tick feeding. It is a tick-unique protein, with homologs described in several tick genera. In this study, a detailed in silico analysis of its primary and tertiary structure was performed, along with the immunogenicity assessment for the PA107 protein from Ixodes ricinus species. The screening of the primary structure placed it to the glycine-rich protein family, revealing in parallel an overlapping 15mer at the C-terminus and borderline homology to non-tick proteins with antimicrobial activity. The analysis of tertiary structure revealed a high degree of intrinsic disorder for monomeric PA107, in contrast to highly ordered structures for different oligomeric states that might correlate with the putative role in the tick cement formation process. Regarding in silico PA107 immunogenicity inference, obtained results were inconclusive, which aligns with the in vitro findings showing definitely the lack of humoral response induction in experimentally infested rats and persons bitten by the I. ricinus ticks. The results represent new pieces of a huge puzzle depicting a complex tick-host relationship, but also identify PA107 as a possible compound of novel formulations to be used in biomedicine as bioadhesives, and as a target for new anti-tick strategies, by interfering with the cement cone formation and stability, i.e. tick attachment and feeding.
The status of pyrethroid resistance mutation frequencies in Varroa destructor populations in the most important beekeeping areas of Türkiye
Celikkol E and Dogac E
The Varroa destructor (hereafter referred to as Varroa) is a major pest of honeybees that is generally controlled using pyrethroid-based acaricides. However, resistance to these insecticides has become a growing problem, driven by the acquisition of knockdown resistance (kdr) mutations in the mite's voltage-gated sodium channel (vgsc) gene. Resistance mutations in the vgsc gene, such as the L925V mutation, can confer resistance to pyrethroids like flumethrin and tau-fluvalinate. Monitoring genotypic resistance through molecular mutation screening is crucial for tracking and mitigating resistance spread. In this study, the frequency of resistance mutations in the vgsc was examined using a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) approach in Varroa populations sampled throughout the Mediterranean, Aegean, and Black Sea regions of Türkiye. Considering all the samples analyzed, the results demonstrated a mean resistance allele frequency of 83.29%, indicating a relatively high frequency of resistant alleles. We observed 94.58%, 85.71%, and 69.58% resistant allele frequencies in populations sampled from the Mediterranean, Aegean, and Black Sea regions, respectively, in our study. The results of our investigation demonstrated substantial regional variations in the frequencies of resistant alleles among Varroa populations throughout Türkiye, with notably elevated resistance levels observed in the Mediterranean and Aegean regions. Due to the significant resistance mutation frequency differences between both provinces and regions, long-term monitoring of resistance alleles and the planning of regional control strategies are required for effective control of this pest.
Suitability of Rosaceae fruit tree species for Panonychus citri (McGregor) (Acari: Tetranychidae)
Shao J, Hu J, Li B, Zhang W, Liu Y, Men X and Yin S
The citrus red mite (CRM), Panonychus citri (McGregor) (Acari: Tetranychidae), a worldwide pest chiefly infesting Citrus plants, has spread from Southern China to Northern China. Little information is known about the population performance of CRM on the plants except for citrus trees and pear trees. In order to evaluate the extent of damage might caused by CRM to the fruit trees cultivated in Northern China, the performance of CRM on four Rosaceae species, including three main fruit tree species (pear-Pyrus pyrifolia Nakai cv. Shannongsu, apple-Malus pumila Mill. cv. Fuji, peach-Prunus persica (L.) Batsch cv. Zhongyou 4) cultivated in Shandong Province, Northern China, and one rootstock for grafting apples (crabapple-Malus micromalus Makino) was determined using the age-stage, two-sex life table at laboratory conditions (25 ± 1 °C, 75 ± 5% RH and L16: D8 h photoperiod). The results showed that CRM could complete the whole life cycle on all the four plant species. The development time of larva, protonymph and deutonymph and the survival of immature stage of CRM did not vary among the four plant species. Differences on the egg incubation period explained the total duration of the immature stage among the four plants. The total duration of the immature stage was shorter on pear and peach than on crabapple and apple, but no difference was observed between pear and peach. The mites reared on pear and peach exhibited a higher fecundity, net reproductive rate (R), intrinsic growth rate (r) and finite rate of increase (λ) and longer longevity of the adult females than on crabapple and apple, but no significant differences between pear and peach, crabapple and apple. The mean generation time (T) of CRM reared on crabapple was the longest, which did not differ significantly on pear, peach and apple. In summary, the cultivars of pear, peach, apple and crabapple used in this study, especially that of peach and pear were suitable for the development and reproduction of CRM. CRM might be a serious risk for the main Rosaceae fruit species in Northern China.
Identification, seasonal prevalence, and preferred attachment sites of ixodid tick species infesting cattle in four municipalities of the province of Tiaret, northwest Algeria
Hamza A, Mokhtaria K, Ammar SSM and Taha B
Ixodid ticks are important disease vectors that significantly impact animal health and cause considerable economic losses, particularly in tropical and subtropical countries. The aim of the present study was to determine the identity, seasonal distribution, and preferred attachment sites of adult ixodid tick species of cattle in four municipalities (Aïn El Hadid, Sidi Bakhti, Mechraa Safa, and Sidi Hosni) of the Province of Tiaret (north-west Algeria) between May 2022 and May 2023. A total of 317 cattle were randomly selected and examined for tick infestation; 108 (34.07%; 95% CI 28-39) were found to be infested by one or more species of ticks. The mean intensity of tick infestation was 16.22 ± 18.45 ticks per individual, while the mean abundance was 5.53 ± 13.21 ticks per examined cattle. Overall, 1,752 adult ixodid ticks were collected and identified, including 1,353 males and 399 females. Three genus and nine tick species were identified, including, H. excavatum (43.78%), H. marginatum (20.15%), H. lusitanicum (18.32%), H. scupense (8.73%), R. bursa (7.53%), H. impeltatum (0.74%), R. (Boophilus) annulatus (0.46%), R. sanguineus sensu lato (0.23%), and D. marginatus (0.06%). The highest discrepancy indices (D) were recorded for H. impeltatum (0.98), while the lowest was observed for H. excavatum (0.88). The overall discrepancy (D) values range from 0.88 to 0.98, indicating significant seasonal variability in the aggregation of ixodid ticks. The highest infestation rate recorded was in Ain El Hadid at 100%, followed by Sidi Bakhti at 79.76%, Mechraa Safa at 10.53%, and Sidi Hosni at 9.79%. H. excavatum, H. marginatum, H. lusitanicum, H. scupense, H. impeltatum, R. bursa, and R. (Boophilus) annulatus displayed significant variation across municipalities (p < 0.001). Seasonally, the highest abundance of adult ixodid tick infestations occurred in summer (38.01%), while the lowest was observed in autumn (17.29%). Significant seasonal variations were observed in the abundance of H. excavatum, H. marginatum, H. lusitanicum, and R. bursa (p < 0.001). Tick distribution was highest in zone 5 (95.43%), which includes the sternum, abdomen, udder, scrotum, and inner sides of the hind legs, while the lowest occurrence was in zone 1 (0.06%), which includes the head and ears. H. excavatum and H. lusitanicum showed a significant preference for Zone 5 (p < 0.001). The findings from the current study serve as a foundation for creating effective strategies to control tick populations on cattle in the Tiaret province.
Does the use of engorged adult ticks of Rhipicephalus microplus as substrate modifies the acaricidal behavior of Metarhizium anisopliae?
Fernández-Salas A, Romero-Pérez JB and Alonso-Díaz MÁ
Entomopathogenic fungi (EPF) is one of the most promising alternatives to regulate tick populations. However, these fungi may lose acaricidal effectiveness over time, due to the storage period and/or successive cultivation on artificial media. It is known that using arthropod pests as a substrate for EPF could potentially alter their acaricidal behavior over time, however, studies using ticks for this purpose are scarce. Hence, the aims of this research were: (1) to isolate strains of Metarhizium anisopliae from paddocks of cattle farms, (2) to evaluate the effect of engorged adult ticks of Rhipicephalus microplus as a substrate on the tickicide behavior of Metarhizium anisopliae strains, and (3) to determine the lethal time of each M. anisopliae strain to kill 50% (LT50) and 99% (LT99) of engorged ticks. First, the natural acaricidal effect of 10 strains of M. anisopliae sensu lato isolated from soils of cattle farms on R. microplus was evaluated. Second, the influence of substrate (R. microplus, Galleria mellonella and Sabouraud dextrose agar [SDA]) on the acaricidal activity and virulence index (lethal time) of each strain during four generations was evaluated. Strains MaV69, MaV60 and MaV67 showed more than 90% mortality at day 20 post-treatment. The use of engorged adult ticks as substrate increased the virulence of five M. anisopliae s.l. strains. Larvae of G. mellonella and SDA as substrate did not modify the acaricidal behavior of the 10 strains evaluated. Seven of ten EPF decreased their LT50 and three decreased their LT99 as an index of their virulence enhancement.
Mite fauna (Acari: Erythraeidae and Otopheidomenidae) associated with hawkmoths (Lepidoptera: Sphingidae) in northeastern Brazil
da Costa TRAA, Lima MFS, Furtado IP and Duarte M
The current understanding of ectoparasitic mites, especially those belonging to Otopheidomenidae, has been constrained by limited data derived primarily from museum specimens. To bridge this knowledge gap, we undertook a study to investigate mite infestations on freshly captured hawkmoths (Lepidoptera: Sphingidae). From August 2016 to July 2018, we collected samples in the Chapada do Araripe area in the municipality of Santana do Cariri (7°12'33''S, 39°43'22''W, 750 m a.s.l.), Ceará, Northeast Brazil. We attracted and captured sphingids using an artificial light source and then gathered mites from them. Among the 3,690 sphingid specimens collected from 37 species of both sexes, 119 individuals from 18 species were found to be mite-infested-a prevalence rate of 3.3%. We identified four mite species: Prasadiseius donahuei (Prasad), Prasadiseius cocytes (Prasad) (Otopheidomenidae), Callidosoma selmae Costa, Klompen, Santos, Favretto & Pepato, and an unidentified Caeculisoma species (Erythraeidae). Our data revealed the importance of seasonality for both host and parasite populations, and we observed no specific preference for infestation sites. This research recorded several first-time observations: a sphingid infested by two species of otopheidomenid mites, C. selmae parasitizing sphingids, and mites recorded from the legs of sphingids. The species Erinnyis ello ello (Linnaeus) was not only the most abundant but also the most frequently parasitized. This host presented the highest parasitism descriptors. Among the 662 mites identified, 506 were P. donahuei, predominantly infesting E. ello ello. We recommend further research to explore the potential for coevolutionary dynamics between mites and their hosts, examining how host defenses and mite adaptations influence each other over time.
Assessment of occupational exposure of soldiers to Lyme disease and Borrelia miyamotoi disease in selected military training areas from northern Poland
Gajda-Sawicka E, Kowalec M, Sieńko A, Ochab A, Żuk M, Bielat U, Krzowski Ł, Dwużnik-Szarek D and Bajer A
Ixodes ricinus tick is a vector of bacteria of Borreliella genus and Borrelia miyamotoi. Exposure to ticks constitutes occupational risk to soldiers, but the current knowledge on this subject is still limited. Therefore, the aim of this study was to evaluate tick abundance and prevalence of infection with Borreliella spp. and/or B. miyamotoi. Ticks were collected from vegetation on Drawsko, Ustka and Orzysz military training areas. Additionally, ticks infesting soldiers were also obtained. Ticks were examined by nested PCR and sequencing of flaB gene fragment. General Linear Models of One Variable was used for analysis of mean tick abundance and Maximum Likelihood technique based on log-linear analysis of contingency tables was used for analysis of prevalence of pathogens in ticks. Molecular phylogenetic analyses were also performed. 852 I. ricinus were collected from vegetation from three military areas. The overall mean abundance of ticks was almost 4 ticks/100 m. Season of study had a significant effect on density of total ticks, infected nymphs and females and infected nymphs, which were higher in spring-early summer. Total prevalence of pathogens was 25.7% in 711 questing ticks, and 16.0% in 282 I. ricinus collected from soldiers. Six species of Borreliella and Borrelia were identified with predominance of B. afzelii. It should be assumed that there is a risk for soldiers of acquiring infection after tick bite. The awareness of presence of pathogens in ticks should be raised in military.
The effect of synergists on the inhibition of detoxification enzyme activities and acaricide sensitivity in Rhizoglyphus robini
Samadieh H, Khajehali J and Izadi H
The saffron bulb mite, Rhizoglyphus robini Claparede (Acari: Acaridae), is the most important pest of the saffron crop in Iran. This pest attacks and feeds on saffron corms. For this reason, the corms are treated with acaricides before planting. The high activity of detoxification enzymes in arthropods may reduce their pesticide sensitivity. Diethyl maleate (DEM) is an inhibitor of glutathione S-transferases (GSTs), piperonyl butoxide (PBO) is an inhibitor of cytochrome P450 monooxygenases, and triphenyl phosphate (TPP) is an inhibitor of esterase activity. A filter paper method was used to determine the efficiency of these synergists in inhibiting the activity of detoxifying enzymes of R. robini. Adult mites were treated with these three synergists for 6, 12, 24, and 48 h, respectively. The activity of each detoxifying enzyme was measured and compared to the control treatment, and the inhibition percentage was calculated each time. The results showed that DEM reduced GST activity by 59.9% after 48 h, PBO inhibited cytochrome P450 activity by 30%, and TPP suppressed esterase activity by 38.5%. The most statistically significant inhibition occurred 24 h after pretreatment with each synergist. Bioassays with 24 h pretreatment showed that the sensitivity of R. robini to propargite increased by 1.6 times with PBO, 1.7 times with TPP, and 2.5 times with DEM. In conclusion, synergists and efficient inhibition of detoxifying enzymes can play a significant role in increasing the sensitivity of agricultural pests to pesticides and can be considered in managing pesticide resistance.
New finding on a migratory bird, the fowl tick Argas (Persicargas) persicus (Oken, 1818), in Italy
Menegon M, Casale F, Mancuso E, Di Luca M, Severini F, Monaco F and Toma L
Migratory birds reach Europe from sub-Saharan Africa, and some avian species may harbor and transport infected ectoparasites, mainly ticks, native to the territories of departure. In 2022, a project focused on identifying the introduction of pathogens in Italy from Africa via migratory birds represented an important opportunity to investigate this particular route of tick dispersal. Among ticks collected from migratory birds on the island of Ventotene, Latium Region, we found one larva of a soft tick on a common whitethroat (Curruca communis) that was morphologically and molecularly identified to the species level as Argas (Persicargas) persicus (Oken 1818). This study reports the fifth detection of this species in Italy; therefore, it is considered very rare. Further monitoring programmes should be implemented to better monitor the spread of this species and possibly update its distribution.
Teratological abnormalities in hard ticks (Acari: Ixodidae) from Pakistan
Akbar E, Ullah S, Almutairi MM, Liaqat I, Adnan M, Alouffi A, Tanaka T and Ali A
Studying teratological abnormalities in ticks are taxonomically important because this poorly understood biological phenomenon causes difficulties in tick's identification. Globally, reports regarding these abnormalities in ticks, reasons of their causes and their impacts are scarce. According to the available published data, there are no studies regarding teratological abnormalities in ticks from Pakistan. Herein, ticks examined for these abnormalities were museum deposited, collected from buffalos, cattle, camels, goats and sheep in 17 districts of Pakistan during 2017-2023. The abnormalities were observed in 88 out of 3279 (2.68%) ticks, representing eight ixodid species (Rhipicephalus microplus, Rhipicephalus turanicus, Rhipicephalus haemaphysaloides, Haemaphysalis bispinosa, Haemaphysalis montgomeryi, Hyalomma anatolicum, Hyalomma scupense, Hyalomma dromedarii). Among abnormal ticks, 67 abnormalities were characterized as local, 12 as general and nine as a combination of both. Local abnormalities were observed in the scutum, palpal segments, anal aperture, spiracular plates, ventral plates, caudal appendage, festoons and posterior grooves. Also, the constrictions and excavations of body parts were observed. General abnormalities included irregular idiosoma and lateral idiosomal bifurcation. This study, for the first time, highlights the diversity of teratological abnormalities in Pakistani ticks, and are reported in in Hy. anatolicum, Ha. bispinosa and Ha. montgomeryi for the first time.
New records of ticks (Acari: Ixodida) and Rickettsia species in El Salvador
Romero LE, Alvarenga F, Binder LC, Serpa MCA, Muñoz-Leal S and Labruna MB
The tick fauna of El Salvador is currently represented by 10 species of hard ticks (family Ixodidae) and 2 species of soft ticks (family Argasidae). This study aimed to report new and additional records of ticks and rickettsiae in El Salvador. During 2019-2021, a total of 216 specimens of ticks were collected from eight host species (domestic and wild animals) and in the environment among 15 geographic localities of El Salvador. Combining morphological and molecular analyses, tick specimens were identified into the following 11 tick species: Amblyomma dissimile, Amblyomma longirostre, Amblyomma mixtum, Amblyomma ovale, Amblyomma cf. parvum, Amblyomma sabanerae, Amblyomma scutatum, Dermacentor panamensis, Ixodes boliviensis, Ornithodoros puertoricensis, and Otobius megnini. In addition, one free-living nymph was morphologically and molecularly identified as Ixodes sp., although closely related to Ixodes brunneus and Ixodes silvanus. Three rickettsial agents of the spotted fever group were identified: Rickettsia rhipicephali in D. panamensis; a Rickettsia endosymbiont in Ixodes boliviensis; and Rickettsia amblyommatis in A. cf. parvum. This study reports the first records of A. longirostre, D. panamensis, I. boliviensis, O. puertoricensis and O. megnini in El Salvador. In addition, the agents R. rhipicephali and Rickettsia sp. endosymbiont of I. boliviensis are also reported for the first time in the country. With the present study, the current tick fauna of El Salvador increases to 17 species, being 13 Ixodidae and 4 Argasidae, including the addition of one genus to each of these two families (Ixodes and Otobius, respectively).
Evaluation of three mitochondrial DNA markers for species identification, genetic diversity assessment, and phylogenetic positioning of five Hyalomma tick species from Tunisia
Jomli A, Amairia S, Sebai E, Zamiti S, Mhadhbi M, Darghouth MA and Ben Said M
Hyalomma ticks are important vectors of pathogens affecting human and animal health. This study aimed to assess the outputs of three molecular markers (16S, 12S rRNA, and COI) for accurate tick species molecular identification, genetic diversity assessment, and phylogenetic positioning of Hyalomma tick specimens from Tunisia. A total of 20 tickspecimens were collected from different hosts including cattle, camels, and turtles in nine Tunisian governorates. Morphological diagnosis confirmed five Hyalomma species: H. scupense, H. marginatum, H. excavatum, H. aegyptium, and H. dromedarii. Molecular analysis confirmed species' identification and revealed varying levels of genetic diversity within each species. Within the H. scupense and H. aegyptium species, low genetic diversity was observed, with no variable sites detected in the 16 S and 12 S rRNA markers, except for a single site in H. aegyptium's COI marker. H. marginatum isolates showed moderate diversity, with no variable sites in the 16S and 12S rRNA markers, and four variable sites in the COI marker. In contrast, H. excavatum and H. dromedarii isolates exhibited higher diversity, with variable sites identified in all three markers (16S, 12S rRNA, and COI). Phylogenetic analysis revealed that, with the exception of H. scupense, the COI marker exhibited superior discriminatory power compared to the 16 S and 12 S rRNA markers. This enabled the discernment of distinct genetic clusters within each species. These findings underscore the importance of utilizing multiple molecular markers for confirming morphological diagnosis and specifically highlight the significance of the COI marker in assessing the genetic diversity and phylogenetic relationships of Hyalomma ticks. By employing these markers, particularly COI, valuable insights into the evolutionary dynamics and epidemiological significance of Hyalomma ticks can be gained, facilitating targeted control measures against tick-borne diseases.
Sublethal effects of chlorfenapyr and acequinocyl on the functional and numerical responses of the predatory mites Phytoseiulus persimilis and Neoseiulus californicus (Acari: Phytoseiidae) feeding on Tetranychus urticae (Acari: Tetranychidae)
Sehat-Niaki N, Zahedi Golpayegani A, Torabi E, Saboori A, Amiri-Besheli B and Fathipour Y
Tetranychus urticae Koch, commonly known as two spotted spider mites, is a major agricultural pest that causes significant economic loss. Predatory mites, such as Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus (McGregor) are important biological control agents for this pest. However, the efficacy of these predators can be compromised by pesticide application. This study investigated the impact of two acaricides, chlorfenapyr and acequinocyl, on the functional and numerical responses of P. persimilis and N. californicus feeding on T. urticae. Bioassay tests were conducted using a leaf disk dipping method at various pesticides concentrations. Chlorfenapyr exhibited approximately five times higher toxicity than acequinocyl for both predatory mite species and N. californicus exhibited higher tolerance to both acaricides compared to P. persimilis. Functional response experiments assessed the predation rates of 10-day-old predatory mites on different densities of T. urticae nymphs. Analysis of functional response data indicated a Type II response across all treatments. The sublethal concentrations of both acaricides negatively affected the predatory efficiency of both species by reducing attack rate and daily prey consumption and increasing handling times. The numerical response data showed a reduction in egg production correlating with increased pesticide concentrations. Additionally, the efficiency of conversion of ingested food (ECI) decreased with increasing pesticide concentrations. These findings highlight the detrimental effects of pesticides on beneficial arthropods and emphasize the need for integrated pest management strategies that minimize the reliance on chemical control.
Exploration of bioactive molecules from Sesbania grandiflora (L.): identification of squalene as an effective compound against the two-spotted spider mite, Tetranychus urticae Koch, through molecular docking
Praveen Joshi SS, Sumathi E, Murugan M, Haran R, Priya SS, Shandeep G, Mohankumar S, Uma D and Nelson A
Two-spotted spider mite (TSSM), Tetranychus urticae Koch is a devastating polyphagous mite causing considerable economic loss. Acaricides are showered in crops to manage this pest. The pest is known for developing resistance to several classical acaricides. The study was aimed at the exploration of botanical acaricide for the management of TSSM, T. urticae. Adulticidal action of ethyl acetate, ethanol and water extracts of leaves of Sesbania grandiflora (Fabaceae) were tested on T. urticae. The results showed that ethyl acetate extract showed the maximum mite mortality of 94.44 per cent, followed by ethanol extract at 87.78 per cent at 5 per cent concentration. LC of ethyl acetate and ethanol extracts were 1.00 and 4.19 per cent, respectively. The aqueous extract gave 94.44 per cent mortality at a very high concentration of 15% with LC of 8.57%. Molecules from the GC-MS analysis of S. grandiflora ethyl acetate leaf extract were subjected to molecular docking using acetylcholine esterase as the target molecule. The major phytomolecules identified in the ethyl acetate leaf extract of S. grandiflora were stigmasterol (15.45%), phytol (13.60%), beta-amyrone (8.72%), and squalene (7.51%). Squalene, a biomolecule with the lowest binding energy was selected from the docking result. The toxicity of squalene was evident from the fact that it caused 81.11, 85.55 and 87.78 per cent mortality at 1800, 2000 and 2200 ppm, respectively at 48 h after treatment. After, 72 h, 100 per cent mortality was recorded at 1800 ppm. This study reveals that squalene can be formulated and used as the best alternative to tackle T. urticae.