The Genus Neoseiulus Hughes (Acari: Phytoseiidae) in Shanxi, China

Simple Summary Phytoseiid mites are widely distributed on plants and in soil; they can prey on many phytophagous mites and pests and play an important role in biological control programs. The genus Neoseiulus Hughes is one of the largest genera within the Phytoseiidae family, comprising 14.6% of the family’s species worldwide. At present, there are few reports investigating Neoseiulus from Shanxi Province; however, the study on the species diversity of Neoseiulus is helpful to enrich the resource species bank of Phytoseiidae and provide more detailed basis for species identification. We report the discovery of five additional species in Shanxi, and redescribed four of them. Neoseiulus paraki (Ehara) is recorded for the first time in China, and N. neoreticuloides (Liang and Hu) is considered a new junior synonym of N. bicaudus (Wainstein). We provide a key to assist in the identification of the known species of Neoseiulus in Shanxi. Abstract The genus Neoseiulus in Shanxi Province is reviewed and seven species are recorded from the province. Four of these are redescribed and detailed taxonomic information are provided. Neoseiulus paraki (Ehara) is recorded for the first time in China and Neoseiulus neoreticuloides (Liang and Hu) is considered a new junior synonym of Neoseiulus bicaudus (Wainstein). Additionally, a diagnostic key to the known species of Neoseiulus in Shanxi is provided.

Shanxi is a province located in the northern part of China and covers a total area of 156,700 square kilometers. The majority of the province, over two-thirds, sits on the loess plateau. The climate is characterized as semiarid, with lower annual rainfall and longer dry seasons. In the south, the monthly 24 h average temperature ranges from −3 • C to 32 • C, while in the north, it ranges from −9.8 • C to 21.9 • C. The annual precipitation falls between 400 mm and 650 mm, with over 70% of the rainfall occurring between June and September. The most common natural vegetation consists of shrubs and grasses, and forested areas, mainly found on mountain slopes, only cover approximately 20% of the land area. Due to these factors, Shanxi has a lower biodiversity in comparison to areas located in southern China.
Diagnosis (female). Dorsal shield elongate oval, reticulated throughout, bearing 17 pairs of setae, 16 pairs of lyrifissures and 7 pairs of solenostomes, S4, S5, Z4 and Z5 serrated, others smooth; Z5 longer than others. Peritremes extending anteriorly to level of j1. Sternal shield reticulated, bearing three pairs of setae. Ventrianal shield approximately pentagonal, reticulated; solenostomes (gv3) posteromedian to JV2, circular. Calyx of spermathecal apparatus cup-shaped and basally stalked, and stalk approximately as long as width of atrium; atrium nodular at junction with minor duct, minor duct thread-like for a short distance and then expanded, forming a cylindrical tube. Fixed digit of chelicera with six teeth, movable digit with a tooth. Palpgenu with genu setae al1 and al2 rod-like. Leg genu II with seven setae. Only basitarsus of leg IV with a macroseta.

4.
Spermatheca ( Figures 6D and 8A-C). Calyx of spermathecal apparatus elongate trumpet-shaped, distally thickened and flaring, 50 (47-51) long; a large atrium nodular at base of calyx and without a neck, bifurcate at junction with major duct; major duct membranous and thick-walled, as wide as atrium and then gradually reduced.
Legs ( Figure
In earlier descriptions, the striation on the anterolateral margins of the dorsal shield were often overlooked, as was the case in the original description provided by Zhu and Chen (1985)  Remarks. The species was first described from Cucumis melo L. var. makuwa Makino in Kyushu, Japan, by Ehara (1972), and has since been reported in six other Asian countries including China, as well as one African country [3]. The current study documents the first record of this species in Shanxi Province.  [46]. This is the first record for China.

1.
Diagnosis (female). Dorsal shield elongate oval, strongly reticulate, bearing 17 pairs of setae, 16 pairs of lyrifissures and 7 pairs of solenostomes, all smooth except Z5 serrated; s4, Z4 and Z5 longer than others. Peritremes extending anteriorly to bases of j1. Sternal shield reticulated, bearing three pairs of setae. Ventrianal shield approximately pentagonal, loosely reticulated, solenostomes (gv3) small and rounded, posterior to JV2. Calyx of spermathecal apparatus bell-shaped and basally stalked, stalk approximately twice as long as width of atrium; atrium broadened at junction with minor duct, minor duct thread-like; major duct narrower than atrium. Fixed digit of chelicera with four-five teeth and movable digit edentate. Palpgenu with genu setae al1 and al2 rod-like. Genu II with eight setae. Genu, tibia and basitarsus of leg IV each with a macroseta.
Legs ( Figure  Remarks. The female of this species was originally described from apple trees in Sapporo, Hokkaido, Japan [16]. Subsequently, Ehara and Yokogwa (1977) provided information on the male morphology. Both sexes of N. paraki have four-five teeth on the fixed digit, while the movable digit is edentate in females but has one tooth in males [43]. While this species has also been reported in South Korea, specimens from this country have seven teeth on the fixed digit and one tooth on the movable digit, and their epigynal shield is strongly reticulated [46]. In contrast, the epigynal shield of our specimens is slightly striated. One of our specimens exhibited a structural anomaly where iv3 was positioned off the metasternal platelet on the right side.