The genus Lepidocunaxoides (Acariformes: Cunaxidae) is recorded for the first time from China and the generic diagnosis is revised on the basis of both sexes of a new species, Lepidocunaxoides bomiensis Chen & Jin sp. nov.. The new species differs from the known species Lepidocunaxoides robustus Kalúz & Ermilov, 2019 by follows: palpal tibiotarsus claw unbranched apically and tibiotarsus with a proximal bifurcated seta; cheliceral seta and adoral setae absent; propodosomal shield concave anteromedially; tibia II with one bsl. Cunaxoides neopectinatusShiba, 1978 is transferred to Lepidocunaxoides based on the generic concept.

The tick Dermacentor silvarum mainly overwinters in northern China as an unfed adult entering diapause; however, little is known about the involvement of genes and pathways in summer diapause and overwintering adults of this species. Hence, we investigated the differential transcriptome profile of D. silvarum ticks' diapause and cold-responsive genes and pathways during its summer diapause, overwintering, and questing/ active stages. Through transcriptomic sequencing, a total of 136,740 unigenes were assembled, and 1,549, 2,196, and 2,125 differentially expressed genes (DEG) were identified in active and diapause, diapause and overwintering, and active and overwintering ticks, respectively. Between active and diapause ticks, 875 genes were up-regulated, while 674 genes were found down-regulated in diapause ticks. When compared with active ticks, overwintering ticks had 993 up-regulated genes and 1,132 down-regulated genes. Comparison between diapause and overwintering ticks revealed 745 up-regulated and 1,451 down-regulated genes in overwintering ticks. Gene Ontology analysis revealed that, among the active, diapause, and overwintering ticks, most of the DEGs in molecular function were enriched in catalytic activity and hydrolase activity. In the cellular component, most DEGs were assigned to the integral component of the cell membrane, whereas the oxidation-reduction process was the most enriched among biological processes. In addition, the lysosome pathway was the most enriched pathway identified in KEGG pathway analysis. The above results deepened our understanding of the mechanism underlying diapause and overwintering adaptation of ticks, which is important for integrative prevention and control of ticks and tick-borne diseases.

Lychee productivity (Litchi chinensis) has been decreasing since the appearance of the erinose mite Aceria litchii (Keifer) in the main producing regions. This mite causes erinose formation in leaflets, branches, and fruits, which affects fruit productivity and quality. This study referred to an assessment of the population dynamics of this mite associated with abiotic factors in different lychee varieties during 25 months. For the assessments, the germplasm bank of the Faculty of Agrarian and Veterinary Sciences, UNESP–Jaboticabal, state of São Paulo, with lychees in full production was used. The assessed varieties were Bengal, Americana, Brewster, Groff, and WB4. Aceria litchii occurred in lychee plants over the years, reaching the highest levels in October and November. These results are considered important for the establishment of a more adequate management program for A. litchii. In this study, we verified that the Bengal variety (widely commercialized) is one of the varieties more susceptible to the mite attack. The variety Americana showed resistance to the mite. Despite the occurrence records for the pest in this variety, the number of individuals and, consequently, the erinose was reduced. Information reported here on the relationships between lychee varieties and the main crop pest is essential to implement plant-breeding programs or even select resistant or tolerant varieties to the erinose mite.

The taxonomic status of the genus Dicondyla is discussed, and it is removed from the synonymy of Dolicheremaeus. Dicondyla fossalissp. nov., is described from litter in Yunnan Province of China. It differs from other known species of this genus by the shorter notogastral seta la pressed into a groove on notogastral surface, compared to the other notogastral setae. An identification key to all known species of Dicondyla is given.

Four new species of the feather mite genus Mesalgoides (Acariformes: Psoroptoididae: Pandalurinae) are described from passerine birds (Passeriformes) in China: Mesalgoides morrisoniasp. nov. from Alcippe morrisonia Swinhoe (Leiothrichidae), M. vinaceasp. nov. from Carpodacus vinaceus Verreaux (Fringillidae), M. flammicepissp. nov. from Cephalopyrus flammiceps (Burton) (Paridae), and M. erythacasp. nov. from Pyrrhula erythaca Blyth (Fringillidae).

Three water mite species of the genera Torrenticola (T. kumarisp. nov. and T. muranyiisp. nov.) and Monatractides (M. kontschanisp. nov.) are described from the Uttarakhand State of India (Acari: Hydrachnidia, Torrenticoliade). The number of torrenticolid water mites known from India now tallies 33 species. A key for water mite species of the genera Torrenticola and Monatractides from the Indian Subcontinent is given.

Sensitivity and elasticity analyses quantify the effect of an absolute and proportional change in demographic variables on population growth rate (λ), respectively. The methods are used to identify the variable(s) that have the largest influence on λ. Tetranychus urticae Koch is one of the most polyphagous tetranychid mites which has been collected from plenty plant species including agricultural and horticultural crops. In this study, sensitivity and elasticity analyses were used to investigate the effects of various demographic variables on λ at five different temperatures (15, 20, 25, 30 and 35 °C), using both age- and stage-structured matrix models. Considering the sensitivity of λ to age-dependent fecundity rates (f_x), it was found that starting oviposition one day earlier was associated with the highest sensitivity compared to the other age classes, irrespective of temperature. Besides, results from both age- and stage-structured matrix models indicated that λ is more sensitive to changes in survival rates than in fecundity rates at all temperatures. Furthermore, female individuals at the ages of 46, 23, 14, 11 and 7 days had the highest contribution to population growth in comparison with other ages, when reared at the above-mentioned temperatures, respectively. Also, the sensitivity of λ to the changes in survival of adults was higher than in other stages. Besides, the elasticity to fecundity rate at the age of first reproduction was considerably higher than those associated with the age of last reproduction. The survival rates (s_i) generally exhibited a higher elasticity than the transition rates (g_i). Overall, adult survival had the highest influence on λ followed by immature survival, egg survival, and female fecundity. Consequently, management efforts that aim at decreasing adult survival are likely to yield the best results with regard to reducing the growth rate of T. urticae.

Four new species, Caeculisoma allopenlineatus Xu & Jin sp. nov., Dambullaeus jianfengensis Xu & Jin sp. nov., Iguatonia seemani Xu & Jin sp. nov. and Iguatonia xinfengi Xu & Jin sp. nov. are described and illustrated based on larvae ectoparasitic on insects (Hemiptera) from Hainan Province, China. The genus Iguatonia is reported for the first in China. New data for Caeculisoma penlineatus Xu & Jin, 2019 are given. Keys to world species of larval Caeculisoma, Dambullaeus and Iguatonia are presented.

The morphological ontogeny of Limnozetes solhoyorumsp. nov. from Norway is described and illustrated. This species is most similar to L. guyiBehan-Pelletier, 1989 as adult, but differs from it mainly by the sculpture of notogaster, shorter prodorsal seta in and notogastral setae, especially p₁, and the distribution of posterior notogastral setae. The tritonymph of L. solhoyorum differs from that of L. guyi by shorter gastronotal setae c₃, dm, dp, lm and lp. In the deutonymph, tritonymph and adult of both species, setae d and l' from genu IV are absent.

During the field surveys of eriophyoid mites associated to plant species of Artemisia L. (Compositae) from semi-arid and arid environment in East Iran (Birjand, South Khorasan, Iran 2016-2017), three new Aceria spp. (Acari: Trombidiformes: Eriophyidae) were collected. They are Aceria gallartaesp. nov. on Artemisia sieberi Besser, Aceria khaniensissp. nov. on A. tournefortiana Rchb., and Aceria alghooriisp. nov. on A. scoparia Waldst. & Kitam., which are illustrated and described herein.

Rhizoglyphus species are commonly found associated with subterranean plant organs, where they may lead to direct or indirect damages. The diversity of this genus in Brazil is poorly known and the most frequently mentioned species in the country is Rhizoglyphus echinopus (Fumouze & Robin). However, this species appears on the A1 quarantine list for Brazil. The objective of the present work was to report the Rhizoglyphus species that have been collected in agricultural environments in Brazil. In this study, five species are reported: R. caladii Manson, R. columbianus Oudemans, R. robini Claparède, R. setosus Manson and R. vicantus Manson. Among these, four are new records for Brazil (R. caladii, R. columbianus, R. setosus and R. vicantus).

Five new eriophyoid mites infesting weeds of the family Poaceae are described and illustrated from Egypt. They are Abacarus stagninissp. nov. from Echinochloa stagnina (Retz.) P. Beauv., vagrants in grooves between veins on the upper leaf surface, causing discoloration of the leaves; and four new species from genus Aceria (A. echinochloaesp. nov., A. barnyardisp. nov., and A. stagninissp. nov.) from E. stagnina and E. crus–galli (L.) Beauv., and Aceria pennisetosasp. nov., from Pennisetum purpureum Schumach. These species are vagrants underneath inner surface of the leaf sheath around stem and no symptoms were observed. However, A. barnyardisp. nov. is a vagrant underneath inner surface of the leaf sheath around stem and are endoparasitic inside tissue of leaves causing rusted leaves.