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Balaustium medicagoense Meyer & Ryke (Acari: Erythraeidae) and Bryobia spp. Koch (Acari: Tetranychidae) are significant emerging pests in Australian grains and pastures. Despite this, there is limited information known on their basic biology, such as species status and reproductive modes, making it difficult to develop effective and sustainable control strategies. The species/strain status of Balaustium and Bryobia mites from southern Australia was examined using a combination of mitochondrial and nuclear DNA sequence data. In addition, the amplified fragment length polymorphism (AFLP) method was used to examine the reproductive mode and genetic diversity of Ba. medicagoense from 16 populations within southern Australia. Results indicate that there is only one species of Balaustium (Ba. medicagoense) and as many as seven species of Bryobia mites currently present in grain crops, pastures and roadsides within southern Australia. The Bryobia species complex consists of four recently described lineages (Bryobia sp. I, Bryobia sp. IV, Bryobia sp. VII, and Bryobia praetiosa Koch) and three additional genetic lineages (Bryobia sp. VIII, Bryobia sp. IX, and Bryobia sp. X) that have not been described previously. Bryobia sp. VIII, B. sp. IX, and B. sp. I seem to be the most abundant species present in Australian broadacre agriculture (i.e., land suitable for farms practicing large-scale crop [agriculture] operations). The AFLP data revealed that Ba. medicagoense reproduces asexually and that genetic diversity was low with only 10 genotypes found. These findings indicate a new complex of pest mites are present within Australian grain crops and pastures and this has implications for their control.

Nine Satsuma citrus orchards (seven conventionally sprayed and two unsprayed) in southern Alabama were sampled (mainly leaf samples) for predacious mites at eight different sampling dates from March 2005 to February 2006. At least 29 species of predacious mites from nine families (Anystidae, Ascidae, Bdellidae, Cheyletidae, Cunaxidae, Erythraeidae, Eupalopsellidae, Phytoseiidae, and Stigmaeidae) were identified. In addition, six primarily fungivorous species from three families (Parasitidae, Tydeidae, and Tarsonemidae) were recorded. Predacious mites in the families Phytoseiidae (18 species) and Stigmaeidae (one species) were the most abundant. The dominant species were Typhlodromalus peregrinus (Muma) and Proprioseiopsis mexicanus (Garman) (Phytoseiidae), and Agistemus floridanus Gonzalez (Stigmaeidae). Phytoseiid mites were most abundant in the spring with populations declining at the start of the summer and remaining at very low levels through the fall and winter. Analysis of fruit, leaf and orchard ground cover plant samples collected in fall (October) 2005 showed greater abundance of phytoseiid mites on ground cover plants than on citrus fruit and leaves, suggesting that ground cover plants may serve as overwintering reservoirs for predacious mites. In general, predacious mites were relatively more abundant in the conventionally sprayed orchards compared with the unsprayed orchards, as were the two key phytophagous species, Panonychus citri (McGregor) and Phyllocoptruta oleivora (Ashmead). The results are discussed in relation to the potential of the dominant predacious mite species as candidates for biological control of key phytophagous mites on Alabama Satsuma citrus.

Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). However, interactions between these mites and hosts in tropical environments have received little attention. In this study, we examined the prevalence and intensity of mite infestations for Neotropical harvestmen from the Caribbean island of Trinidad. Overall, the prevalence of infestation was 9.9%, with significant interspecific variation in the intensity of mite infestation and significant differences in parasitism of hosts between habitats. Harvestmen collected from lowland, crappo-cocorite forest exhibited the highest infestation rates. In our samples, the intensity of infestation varied from 1 to 17 mites per host. Examination by scanning electron microscopy revealed that harvestmen were infested by two taxa of mites, a species of Leptus and another unidentified erythraeid species. Our observations represent the first host records for erythraeid mites parasitizing harvestmen from the families Cranaidae and Manaosbiidae. Mites were found to attach preferentially to the tibia and femur of the leg (175 of 178 observations). In general, the harvestmen of Trinidad exhibited mite parasitism in a fashion similar to temperate species with respect to site of attachment and prevalence and intensity of mite infestation. In the field, we also collected an adult Cynortula sp. (Cosmetidae) that was transporting 30 gravid adults of an oribatid mite (Acariformes, Oribatida, Mixonomata). Cases of mite phoresy upon harvestmen are rare, with our observation representing the first report of phoresy by an oribatid mite upon a harvestman and the first documentation of mite phoresy upon harvestmen in the Caribbean.

The commercial apple (Malus spp.) orchard ecosystem in Quebec has a diverse fauna of predacious mites. A systematic 2-yr survey showed Amblyseius fallacis (Garman), Typhlodromus caudiglans Schuster (Acari: Phytoseiidae), and Agistemus fleschneri Summers (Acari: Stigmaeidae) to be the most abundant species. Other phytoseiids, Typhlodromus conspicuous (Garman), Typhlodromus herbertae Chant, Typhlodromus longipilus Nesbitt, Typhlodromus bakeri (Garman), Typhlodromus pyri Scheuten, Amblyseius okanagensis (Chant), and Amblyseius finlandicus (Oudemans), were found in low numbers. Two of these species, A. finlandicus and T. conspicuus, were identified for the first time in Quebec. Other occasional species included Anystis baccarum (L.) (Acari: Anystidae) and Balaustium sp. (Acari: Erythraeidae). Tetranychid mite numbers were always less than two mites per leaf throughout the study, and none of the commercial orchards required an acaricide treatment. A notable aspect of this study was that seasonal total...

Balaustium spp. mites are noted for their quickness, red color, population bursts, and ubiquity. Water balance characteristics of adults were assessed to determine their primary source of water to gain insight into the biology and physiology of these poorly studied mites. Characteristics of this mite show that it is xeric adapted, featuring a 71% body water content, 39% dehydration tolerance limit, and a modest water loss rate of 2% h−1. This species is unable to absorb water vapor from atmospheric air which is unusual for mites. This is illustrated by net water losses at water vapor activities close to saturation, failure to maintain the uptake after first day passive gains, and no detectable salt accumulation around the base of the mouthparts in scanning electron micrographs. Thus, enhanced water conservation enables this mite to withstand desiccation, and their aggressive predatory life style has apparently not necessitated evolution of an active uptake mechanism for absorption of water vapor ...

One hundred fifty-one host records obtained in 1984—85 from Washington County, Miss., are reported for Lasioerythraeus johnstoni Welbourn & Young. Thirteen insect species from three orders are recorded as hosts of the larval stage, with nymphs of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), representing 52% of all records. Attached larval mites were obtained from undisturbed old-field habitats during the period of 20 March—13 September, with most of the records obtained in July. Parasitization levels for some host species were as high as 46%. Of the attached larval mites, >90% occurred on the dorsal head and thorax, usually at a molt suture. In the laboratory, field-collected attached larval mites killed their hosts and detached within 2 d, passed through several nymphal stages, and became adults in ca. 21 d. Both the active deutonymph and adult forms were predaceous on tarnished plant bug nymphs. L. johnstoni appears to have considerable natural control potential for the tarnished plant bug.

A new genus and species of Erythraeinae (Acari: Parasitengona: Erythraeidae) is described from larvae parasitizing Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae) and other arthropods in Mississippi. The active postlarval instars (deutonymph and adult male and female) are described from reared individuals. Bochartia shirleyanneae McDaniel and Bolen and Erythraeus whitcombi Smiley are transferred to the new genus. Paraphanolophus Smiley is transferred from the Smarididae to the Erythraeinae. The terminology of Grandjean is reapplied to the Erythraeidae. A key to the active instars of North American Erythraeidae is provided.

A new species of erythraeid mite, Callidosoma metzi , is described. As a larva, this mite is parasitic on adults of Anacamptodes vellivolata (Hulst) and some other geometrids, and as a deutonymph and adult, it is predaceous on eggs of Lepidoptera. The following stages are described: larva, pupa I, deutonymph, pupa II, and adult. The stages other than larva were reared in the laboratory. It is the first time the adult stage in this genus has been reared, and the first record in the Western Hemisphere of a species of Callidosoma from a geometrid.

Larvae of an erythraeid mite, Callidosoma metzi Sharma, Drooz, and Treat, parasitized males of Platynota idaeusalis (Walker) from late May to late July in eastern West Virginia. Parasitism peaked at 29% in late June (1984). Most mites attached to moths at pleural intersegmental membranes, primarily between the thorax and abdomen and between the first two abdominal segments. Dispersion of C. metzi on P. idaeusalis approximated the negative binomial distribution, with k ranging from 0.053–0.657.

Balaustium putmani Smiley has been abundant in unsprayed fruit orchards of the Niagara Peninsula, Ontario, since 1959. The larva, like the nymph and adult, is a free-living predator of small soft-bodied arthropods on the trees; it was seen attacking all stages of the European red mite, Panonychus ulmi (Koch); all stages of the San Jose scale, Aspidiotus perniciosus Comstock; and the apple aphid, Aphis pomi De Geer, though aphids were not very suitable prey. B. putmani agrees with other Balaustium spp. in having free-living larvae; otherwise its development is typical of erythraeids in general, with apodous quiescent nymphs alternating with motile feeding stages. It has 2 generations per year.