Search

The abundance and diversity of eriophyid and phytoseiid mites in south and central Florida were assessed in six citrus orchards under three different pest management systems, conventional, organic, and untreated. Tree canopy, ground cover, and leaf litter were sampled every two months in two groves each under conventional, organic, and untreated pest management from April 2019 to February 2021. The citrus rust mite, Phyllocoptruta oleivora (Ashmead) was identified from 95-99% of the samples from study groves except 45% in one untreated orchard (n = 938). The pink citrus rust mite, Aculops pelekassi (Keifer) was present in organic and untreated orchards at 5% and 28%, respectively, but absent from conventional orchards (n = 134). Twenty-nine species of phytoseiid mites were identified from 1,778 specimens. Thirteen species were present in the canopy, fifteen in the ground cover, and eighteen in the leaf litter with some common species among these habitats. In the tree canopy, Typhlodromalus peregrinus (39%), Euseius spp. (25%), and Iphiseiodes quadripilis (19%) were the dominant species. Typhlodromalus peregrinus (43%), Typhlodromips dentilis (25%), and Proprioseiopsis mexicanus (13%) were the major species in the ground cover. Species richness was lower in organic orchards (3.0) compared to conventional and untreated orchards (5.0 and 4.7, respectively). In the leaf litter, Amblyseius curiosus (26%), Proprioseiopsis carolinianus (15%), Chelaseius floridanus (14%), and A. tamatavensis (12%) were the most common species. Shannon index was significantly higher in conventional orchards (1.45) compared to organic and untreated orchards (1.02 and 1.05, respectively). Evenness was also higher in conventional orchards (0.86) compared to organic and untreated (0.72 and 0.68, respectively). Finding of several phytoseiids in abundance across pest management programs suggest the need for identifying their role in pest suppression particularly mites.

The genus Thyreophagus is distributed worldwide, containing species occurring in stored food, house dust, bark, subcortical habitats, scale insect associations, and nests of wasps and bees. As species of this genus prefer concealed habitats, the actual species diversity is currently underappreciated. In addition, some described taxa are poorly known and their species boundaries are not entirely clear. Only a few species are known from both adult and deutonymphal stages. Using high-resolution light microscope and scanning electron microscopy, we describe a new partenogenetic species, Thyreophagus calusorum sp. n. from Florida (USA) based on adult stage (female) and heteromorphic deutonymph. This species was reared in the lab and its morphological variation was also studied. We did not find any substantial variation in the shape of the female spermatheca, but in the heteromorphic deutonymph, we did find extensive variation in the shape of tibial setae hT I (a taxonomically important character). Furthermore, we summarized taxonomic data and compiled an annotated checklist of species of Thyreophagus, with 35 species-level taxa. We clarified the following nomenclatorial questions: type species designation in Monieziella Berlese, 1897 was done by A. Berlese in G. Leonardi 1900 (Tyroglyphus entomophagus Laboulbène) not by A. Jacot (1936) as it was though previously; Monieziella mali Berlese, 1897 is an unjustified emendation and junior objective synonym of the name Acarus malus Shimer, 1868, currently Hemisacoptes malus (Shimer, 1868). Three subspecies of Thyreophagus were elevated to the species status due to their distinct morphology: Thyreophagus italicus Vacante, 1989, stat. nov. (=Thyreophagus entomophagus italicus Vacante, 1989); Thyreophagus mauritianus (Fain, 1982), stat. nov. (=Michaelopus gallegoi mauritianus Fain, 1982), and Thyreophagus ponticus Kadzhaya, 1973, stat. nov. (=Thyreophagus entomophagus ponticus Kadzhaya, 1973).