Hector Alonso Escobar-Garcia

The genus Agistemus Summers (Acari: Stigmaeidae) comprises predatory mites widely distributed in various agroecosystems. Agistemus manjilicus Khanjani, Hajizadeh and Zarei was described from Iran and differentiated from related species based on subtle morphological traits. However, a detailed comparison with A. mendozensis Simons reveals substantial overlap in diagnostic characters. In this study, we re-evaluated the taxonomic status of A. manjilicus through a comparative analysis of morphological characteristics, idiosomal dorsal setae measurements, diagnostic ratios, and leg chaetotaxy. Our results indicate that all distinguishing characters fall within the range of intraspecific variation of A. mendozensis. No consistent differences were found in key diagnostic traits such as dorsal setae morphology, diagnostic ratios, and leg chaetotaxy. Based on these findings, Agistemus manjilicus Khanjani, Hajizadeh and Zarei n. syn. is herein considered a junior subjective synonym of A. mendozensis Simons. This synonymy contributes to a more stable taxonomy within the genus and highlights the importance of comprehensive morphological comparisons in species delimitation.

Brevipalpus yothersi Baker is one of the main mite pests in citrus orchards in Southeastern Brazil, causing significant losses in fruit production. Spirodiclofen, an acetyl‐CoA carboxylase inhibitor, is a synthetic acaricide widely used for its control. However, continuous application of a single compound can select for resistant populations. The potential evolution of spirodiclofen resistance in B. yothersi raises concerns about field efficacy and the long‐term sustainability of its use. Monitoring resistance levels across citrus‐growing regions is therefore essential for developing effective management strategies. This study estimated spirodiclofen resistance in 19 field populations of B. yothersi to provide data supporting resistance management programmes. Female mites were exposed to spirodiclofen for 7 days in a direct‐contact bioassay. Toxicity was determined by estimating LC ₅₀ and LC ₉₅ values, and data were spatially analysed in ArcGIS for geographic visualization of resistance ratios. LC ₅₀ values ranged from 1.12 to 236.63 mg L ⁻¹ , while LC ₉₅ values ranged from 12.36 to 160,047.00 mg L ⁻¹ . Resistance ratios varied from low to very high, reaching up to 80.56‐fold at LC ₅₀ and 12,124.77‐fold at LC ₉₅ among populations. These findings reveal wide variation in spirodiclofen resistance among B. yothersi populations from the Brazilian citrus belt. Such information is critical for guiding resistance management programmes. The rotation of acaricides with different modes of action should be prioritized, particularly in areas with high levels of resistance.

BACKGROUND: Brevipalpus yothersi Baker (Acari: Tenuipalpidae), the citrus leprosis mite, is currently the most economically significant mite pest in commercial citrus orchards, serving as the vector of citrus leprosis virus C (CiLV‐C, Cilevirus leprosis ). Its control has traditionally relied on the intensive use of synthetic acaricides, raising concerns regarding field efficacy and resistance development. To support integrated pest management (IPM) and resistance management strategies, monitoring the susceptibility of field populations is essential. Cyflumetofen, an acaricide that inhibits mitochondrial complex II electron transport, offers a distinct mode‐of‐action (MoA) for mite control. This study aimed to characterize the susceptibility of B. yothersi populations to cyflumetofen to evaluate its potential use in sustainable resistance management and prolong its efficacy in commercial applications. RESULTS: Field populations exhibited high susceptibility to cyflumetofen, with median lethal concentration (LC ₅₀ LC₅₀) values ranging from 0.36 to 1.31 mg L ⁻¹ and 95% lethality (LC ₉₅ ) values from 1.22 to 4.99 mg L ⁻¹ . Resistance levels were low, with resistance ratios below 2.79‐fold at LC ₅₀ and below 3.06‐fold at LC ₉₅ , relative to a susceptible reference population. CONCLUSION: Cyflumetofen proved effective against B. yothersi in the surveyed regions, with field populations showing high susceptibility. To maintain its efficacy and extend its commercial longevity, rotation with other synthetic acaricides featuring different MoAs is recommended as part of a resistance management plan. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The citrus leprosis mite (CLM), Brevipalpus yothersi Baker (Acari: Tenuipalpidae), is an important mite pest in Brazilian citrus orchards, with control mainly dependent on synthetic acaricides. However, frequent applications can lead to resistance development, compromising long-term efficacy. The objective of this study was to estimate resistance levels to the acaricide hexythiazox in different CLM populations from Brazil’s citrus belt and evaluate potential fitness costs associated with resistance. Populations were collected from commercial sweet orange orchards, and direct-contact bioassays were conducted by exposing eggs to hexythiazox for 10 d to determine resistance levels, based on resistance ratios (RRs) estimated at LC50 and LC95. Additionally, biological parameters were evaluated, including egg incubation period, duration of developmental stages, preoviposition period, and demographic parameters (R₀, rm, T, and Dt). Populations showed resistance levels ranging from low to very high, with LC50 RRs between 0.33- and 17.15-folds and LC95 between 0.41- and 643.38-folds. The resistant population exhibited a significantly longer egg incubation and deutochrysalis period, while deutonymph duration and preoviposition period were significantly shorter. No significant differences in demographic parameters were observed between the resistant and susceptible population. Overall, hexythiazox resistance remains low in most populations, with only one showing moderate resistance based on RR50, which may be associated with higher selection pressure from hexythiazox. To preserve the efficacy of hexythiazox and ensure continued control of CLM in Brazil’s citrus belt, rotation of synthetic acaricides with different modes of action is recommended.

The genus Aegyptobia is recorded from South America for the first time, with the description of a new species collected from the branches of a native forest tree, Neltuma piurensis (Fabaceae), from Department of Piura in north-western Peru. The species A. pennatulae Baker & Tuttle was also collected from the same host, and is redescribed based on the types and new material. Observations during summer and autumn revealed A. pennatulae as the predominant species, and that N. piurensis is likely an accidental host for A. peruensis sp. nov.

Tuckerella ornata, Tuckerella knorri (Acari: Tuckerellidae) and Brevipalpus yothersi (Acari: Tenuipalpidade) were found associated with the native South American Cannon-ball tree, Couroupita guianensis, for the first time in Brazil. The trees were observed throughout their flowering season in spring for two consecutive years. The highest population densities of peacock and flat mites were located on the raceme-type inflorescences. Throughout this survey, no mites were detected on the fruits.

A new species of Neotropical Camerobiidae from Brazil, Neophyllobius (Neophyllobius) unespensis n. sp., is collected and described from the raceme-type inflorescences of a native South America forest tree, Cannonball tree, Couroupita guianensis Aubl. (Lecythidaceae), description based on females, a protonymph, and a larva. The new stilt-legged mite was found during two springs for two consecutive years, which coincides with the inflorescence period of this tree.