The larva of the ixodid tick Dermacentor parumapertus Neumann, chiefly a parasite of hares and rabbits, is redescribed using scanning electron micrographs of seven specimens derived from two engorged females collected from two black-tailed jackrabbits, Lepus californicus, at the Black Gap Wildlife Management Area, Brewster County, southwestern Texas. The use of chaetotaxy for separating the genera of Ixodidae is discussed, and a morphological key is provided for separating the larvae of D. parumapertus from those of five other Dermacentor species with partly sympatric geographic ranges.

Amblyomma varanense (Supino) (Ixodida: Ixodidae) is a reptile-associated bont tick native to the Oriental and Australasian zoogeographic regions. This species is primarily ectoparasitic on monitor lizards (Varanidae) and snakes but has been reported to occasionally occur on turtles and mammals. Prior to the research described here, only one collection of A. varanense had been reported from the Philippines. Herein, we present a second Philippines collection of A. varanense as well as updated host records across this tick's geographic range and an overview of associated microbes with zoonotic potential.

Information on the morphological ontogeny of oribatid mites of the family Oribatulidae is very scarce, and the juveniles of most species are unknown yet. In this work, the ontogenetic instars of the semicosmopolitan species, Zygoribatula excavata Berlese, 1916 are studied. The juvenile instars of this species are morphologically similar to those of the other species of Zygoribatula, and this genus can be included among those in which species are difficult to distinguish based on juvenile characteristics alone. As information on the morphological ontogeny of most species of Oribatulidae is still insufficient or unknown, a comparison on the juvenile characteristics of the families belonging to the superfamily Oripodoidea is given based on our own data and available literature sources. The major characteristics of juvenile instars of 10 families and 21 genera are presented. There are few characters, such as body shape and size, pattern of cuticle, excentrosclerites at gastronotic setae, size and morphology of setiform organs, such as bothridial as well as gastronotic setae that distinguish the families or genera of Oripodoidea.

The female and male of a new species, Brachytydeus elongatus sp. nov., are described from leaves of common reed (Phragmites australis) in Tyumen Oblast of Russia. Brachytydeus obnoxius (Kuznetsov and Zapletina) is recorded from Russia for the first time; B. inconstans (Kaźmierski) and B. ferulus (Baker) are recorded from Western Siberia for the first time. An unusual type of secondary sexual dimorphism in Brachytydeus elongatus sp. nov. is discussed.

Two new species of Tuberemaeus (Oribatida, Scheloribatidae)—T. salavatulini sp. nov. and T. bifossatus sp. nov.—are described, based on adults collected from tree branches of Haldina cordifolia in Cat Tien National Park, southern Vietnam. The generic diagnosis of Tuberemaeus is revised. An identification key to known species of Tuberemaeus is given.

Phytoseiulus persimilis is a specialist predator of spider mites, with promising control effects. Its population generally has a stable sex ratio. Under appropriate conditions, the proportion of female offspring can reach 80%. But the mechanisms of sex determination in P. persimilis is still unclear. Sex-lethal (sxl) is an important gene in studying sex regulation mechanisms in insects. In the model organism Drosophila melanogaster, it has been proved to be a switch controlling sex determination. Herein, we screened one sex-lethal gene ortholog in the genome of P. persimilis (Ppsxl). We separated male and female offspring successfully based on the order of the egg laid, and found Ppsxl is expressed in both sexes at different stages. The expression peak was found in females 10 h after mating, and it was also highly expressed in eggs that developed into males. RNA interference was used to study the function of Ppsxl. When Ppsxl was interfered, all female individuals remained fertile. However, their cumulative fecundity decreased by 18.0%, daily fecundity decreased by 13.4%, and the proportion of female offspring decreased by 22.7%. This study showed that Ppsxl gene has a certain influence on the reproduction of P. persimilis, but its influence on sex determination may not be as critical as that in D. melanogaster. The regulation of sxl on P. persimilis was different from that in D. melanogaster.

A new species of Scirula, S. artemisae sp. nov. (Acari: Cunaxidae), is described and illustrated based on females collected from Semnan Province, Iran. In addition, we report for the second time Cyta kreiteri Barbar & Ueckermann, 2017 and Armascirus hastus Shiba, 1986, as well as update an identification key for known species of Scirula.

Antennoseius (Antennoseius) brasiliensis Martin & Castilho sp. nov. is described based on the morphology of adult females collected from litter/soil of a pasture of the Caatinga biome (relatively hot and dry), in Alagoas state, northeastern Brazil. A key for the separation of females of the 40 recognizable world species of Antennoseius (Antennoseius) is provided.

Eriophyoid mites are characterized by high host plant specificity—roughly 80% named species infesting only one host plant species. However, sympatric species, i.e. two or more eriophyoid mites infesting the same host, were consistently reported. In this study, we described and illustrated one new species, Abacarus horseshoex sp. nov. on Bambusa sp., and re-described two sympatric species, Abacarus fuzhoubambusae nom. nov. and Knorella bambusae (Kuang & Feng, 1989) on Bambusa multiplex (Lour.) Raeusch. ex Schult. (Poaceae). Abacarus bambusae Kuang & Zhuo, 1987 now is Abacarus fuzhoubambusae nom. nov. All three eriophyoid mite species are vagrants causing no apparent symptom to their host plants. We further provided mitochondrial gene (cox1, 12S rRNA) and nuclear gene (18S rRNA, 28S rRNA) sequences for the new species and mitochondrial gene (cox1) for the other two species.

This study is based on Scapheremaeus materials collected from leaves, branches and bark from Haldina cordifolia and Dipterocarpus alatus in Cat Tien National Park, southern Vietnam in November–December 2022. Six species are recorded; of these, two new species—S. kudrini sp. nov. and S. globulus sp. nov.—are described, based on adults.

Amblyseius andersoni and Neoseiulus barkeri, two species of phytoseiid mites that are widely used for the control of small sucking pests, were found to co-occur on Chinese wolfberry in Inner Mongolia. We investigated the possibility of intraguild predation (IGP) between A. andersoni and N. barkeri to explore the interactions and coexistence of these two species. Predation and oviposition of the two predators on heterospecific juveniles were measured and compared with Tetranychus truncatus or Typha pollen as food, or without alternative food. The mortality rate of N. barkeri juveniles was not affected by the diet treatment, but that of A. andersoni juveniles was reduced by the presence of spider mites. The presence of spider mites also increased oviposition by A. andersoni but not by N. barkeri, and the presence of pollen had no influence on the oviposition of the two predators. Thus, according to the IGP criteria for gaining benefits from predation on heterospecific juveniles, it was concluded that IGP between A. andersoni and N. barkeri occurred, with A. andersoni as intraguild predator and N. barkeri as intraguild prey when spider mites were present. In a further choice test in which heterospecific juveniles and T. truncatus juveniles were provided for each predator, female A. andersoni preferred to prey on N. barkeri rather than on spider mites, whereas female N. barkeri preferred to feed on spider mites rather than on A. andersoni. These findings indicate that the higher preference of N. barkeri on T. truncatus might result in its lower predation on the other predator species compared with A. andersoni and, thus, increased the possibility of the coexistence of the two predator species. Therefore, the occurrence of IGP between A. andersoni and N. barkeri appears to be influenced by the availability and type of the diet and the prey preference of the predators.

During field surveys of eriophyoid species associated with rosaceous plants in Zagros forests of Iran, three new species were discovered and described including Eriophyes cotosarica sp. nov. from Cotoneaster hissaricus Pojark., Eriophyes cratameyeris sp. nov. from Crataegus meyeri Pojark. and Eriophyes pyrusyriaca sp. nov. from Pyrus syriaca Boiss. All species cause galls on their host plant's leaves. In addition, a list of Eriophyes species found on Rosaceous plants in Iran and a supplementary description of Eriophyes pyri (Pagenstecher, 1857) are provided.