The superfamily Ixodoidea includes two major families: the Ixodidae called “hard tick” and Argasidae called “soft tick”. Furthermore, Ixodidae is classified into Prostriata (Ixodidae: Ixodes), and Metastriata (Ixodidae except for Ixodes) based on their reproductive strategies. That is, species in each group have characteristic reproductive organs and systems. Ticks are important as vectors of various pathogens. Haemaphysalis longicornis belonging to the Metastriata is characterized by having both the parthenogenetic and bisexual races, and is widely distributed in Australia, New Zealand, New Caledonia, the Fiji Islands, Japan, the Korean Peninsula and northeastern areas of both China and Russia. This species is known as a vector of rickettsiae causing Q fever, viruses causing Russian spring-summer encephalitis, and protozoa causing theileriosis and babesiosis. H. longicornis, the most dominant tick in Japanese pastures, is very important in agricultural and veterinary sciences because this species also transmits piroplasmosis caused by Theileria and Babesia parasites among grazing cattle. We present here an overview reproduction in the bisexual race of H. longicornis.

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Intraspecific variation of idiosomal setal patterns was examined in field populations of eight phytoseiid species and in laboratory populations of Neoseiulus californicus and N. womersleyi. In field populations, about 6.4-16.1% of females showed setal variation, whereas in laboratory populations, this percentage was relatively low in N. californicus (5.8-14.8%) but high in N. womersleyi (8.6-36.1%). Setal variations were divided into the following categories: absent, additional, inserted, deviated, expanded, and shortened setae. An absence of setae was more common than additional or inserted setae, both in the field and laboratory populations. Expanded and shortened setae were rare. An absence of setae was frequently observed on the ventral opisthosoma, and occurred on both of its sides (left and right), mainly at ZV3 in N. womerwelyi and JV3 in Typhlodromus vulgaris. In the IG population of N. womersleyi, an absence of setae was frequently observed at ZV1 (49.5% of the total absent setae in the population) and ZV3 (37.8%), which was significantly different from the other populations. The difference in setal variation between field and laboratory populations suggests that it is not caused by accidental defects during post-embryonic development but rather is the result of heritable traits. The maintenance of the absence of setae in field populations may create a driving force from holotrichous to hypotrichous conditions, and may produce higher levels of species diversity in phytoseiid mites.

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The predation capacities of predatory mites (Acari: Gamasina) found in spinach fields against Tyrophagus similis Volgin (Acari: Acaridae), a harmful mite that affects the growth of spinach, were evaluated under laboratory conditions.
Female specimens of the following 6 species of predatory mites were studied: Ascidae sp. 1, Ascidae sp. 2, Hypoaspis (Gaeolaelaps) praesternalis Willmann, Hypoaspis (Gaeolaelaps) queenslandicus (Womersley), Macrocheles similis Krantz & Filipponi, and Cycetogamasus diviortus (Athias-Henriot). It was revealed that all these species could prey on T. similis. Large-sized species such as H. queenslandicus, M. similis, and C. diviortus showed a high degree of predatory ability; these species were found to feed on any of the different stages of T. similis, except the egg stage.
The suitable ambient temperature range for the predatory activity of H. queenslandicus and M. similis was found to be from 20°C to 30°C and that for C. diviortus was from 15°C to 30°C.

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