A New Species of Chigger (Acari: Trombiculidae) from Indonesia and Current Differentiation of Trombicula Berlese, 1905 Sensu Stricto Group.

BACKGROUND: Two new species of chiggers in the two genera (Chiroptella Vercammen-Grandjean, 1960 and Rudnicula Vercammen-Grandjean, 1964) have been described in Indonesia since 2020. The checklist of all known bat-infesting chiggers has also been compiled for Indonesia. It summarizes 16 species in 9 genera of chiggers parasitizing 12 bat species belonging to 5 families collected on 8 Indonesian islands. Nine specimens collected in 2020 on Nusa Penida Island were not included in the checklist because of their uncertain taxonomy. In the current paper, we resolve the taxonomy of these specimens belonging to Trombicula sensu stricto group. We also revise the existing characters of this group and provide new characters helping with the clear definition of this taxa. METHODS: Hosts and chiggers were captured in February 2020 in Nusa Penida Islands in Indonesia using standard bat-capturing and parasite-collecting methods. For the specimens examined in this study were provided drawings, measurements, and microscopy images. This type material is deposited in the Slovak and Czech National museums. RESULTS: In the paper, we describe a new species parasitizing diadem leaf-nosed bat in the Goa Peteng cave on Nusa Penida Island (Lesser Sunda Islands, East Indonesia). This new species differs from all related species by the presence of a very long tarsala I (S1). A key to the larvae of all seven known Trombicula s. s. species is provided. The differentiation of Trombicula s. s. group is based on leg segmentation fsp = 6.6.6, rugose scutum with complete AM, AL and PL setation, and fT = 5B, 5BN or 4B2N. CONCLUSION: A new species within the genus Trombicula, group minor has been described. The new species also increases the number of known chiggers in Indonesia and the number of species parasitizing the host species Hipposideros diadema. Trombicula s. s. has also been revised and more clearly defined.

Eutrombicula cochinocaensis infestation in llamas (Lama glama) in the Puna region of Argentina.

This paper aims to describe a case of trombiculosis in llamas from the Puna region of Argentina caused by Eutrombicula cochinocaensis. Trombiculosis is a parasitic infestation caused by the larval form of trombiculid mites, commonly known as chigger mites. Six adult llamas out of eighteen (33%) were infested and showed dermatitis, hyperemia, and crusts together with an orange-dotted pattern. The chigger mites were found mainly in the hind limbs and the abdomen. Microscopic identification of E. cochinocaensis was made by phase-contrast microscopy. Then, a histopathological study of the affected animals' skin was performed. Histological findings included dermatitis withmainly lymphocytic infiltrate, pustules, crusts, hyperkeratosis, and the mites' stylostomes in the dermis and epidermis. This is the first report of trombiculosis caused by E. cochinocaensis in llamas from Argentina. Mites of the family Trombiculidae are vectors of certain diseases to humans and animals and are therefore of sanitary and productive importance.

Blankaartia sinnamaryi (Trombidiformes: Trombiculidae) parasitizing birds in southeastern Brazil, with notes on Rickettsia detection / Blankaartia sinnamaryi (Trombidiformes: Trombiculidae) parasitando aves no sudeste do Brasil, e notas sobre a detecção de Rickettsia

Abstract The larvae of the family Trombiculidae are ectoparasites of vertebrates, including birds. The bite of some species can cause deep lesions and severe skin reactions in the host, these can lead to dermatitis, popularly known as trombiculiasis. A morphological study of chiggers collected on birds from the state of Minas Gerais in Southeastern Brazil discovered Blankaartia sinnamaryi-infestation on Passeriformes birds. Molecular studies of the disclosed the 18S rDNA sequences of the mite, and the detection of a Rickettsia sp. in this chigger mite species.

Resumo As larvas da família Trombiculidae são ectoparasitas de vertebrados, incluindo aves. A picada de algumas espécies pode causam lesões profundas e reações cutâneas graves no hospedeiro, estas podem levar a dermatites, popularmente conhecidas como trombiculíases. Por meio de um estudo morfológico dos espécimes coletados parasitando aves do estado de Minas Gerais, Sudeste do Brasil relatou a infestação por Blankaartia sinnamaryi em aves Passeriformes. Além disso, nós fornecemos sequências de rDNA 18S desses ácaros e a detecção de uma espécie de Rickettsia sp. nesta espécie de trombiculídeo.

Trombiculiasis in domestic goats and humans in the state of Maranhão, Brazil / Trombiculíase em caprinos domésticos e humanos no Estado do Maranhão, Brasil

Abstract Trombiculiasis is an infestation caused by larval mites (chiggers) of the family Trombiculidae. Here, we provide the first report on parasitism by the chigger species Eutrombicula alfreddugesi (Oudemans) and Eutrombicula batatas (Linnaeus) in goats and humans on farms in the state of Maranhão, northeastern Brazil. Severe itching and dermatitis caused by the chiggers' bites were seen. From a total of 779 examined goats, 214 of them showed clinical signs of infestation, as well as family members of three farms of the region. Most of the cases occurred during the rainy season, from March to September.

Resumo Trombiculíase é uma infestação causada por larvas de ácaros da família Trombiculidae. Nós reportamos pela primeira vez parasitismo por ácaros das espécies Eutrombicula alfreddugesi (Oudemans) and Eutrombicula batatas (Linnaeus) em cabras e humanos em fazendas no estado do Maranhão, nordeste do Brasil. Foram observadas dermatite e coceiras severas causadas pelas picadas de trombiculídeos. De um total de 779 cabras examinadas, 214 delas apresentaram sinais clínicos de infestações, assim como membros de três famílias de fazendeiros da região. A maioria dos casos ocorreu durante a estação chuvosa, de março a setembro.

Larval Chigger Mites Collected from Small Mammals in 3 Provinces, Korea

A total of 9,281 larval chigger mites were collected from small mammals captured at Hwaseong-gun, Gyeonggi-do (Province) (2,754 mites from 30 small mammals), Asan city, Chungcheongnam-do (3,358 mites from 48 mammals), and Jangseong-gun, Jeollanam-do (3,169 for 62 mammals) from April-November 2009 in the Republic of Korea (= Korea) and were identified to species. Leptotrombidium pallidum was the predominant species in Hwaseong (95.8%) and Asan (61.2%), while Leptotrombidium scutellare was the predominant species collected from Jangseong (80.1%). Overall, larval chigger mite indices decreased from April (27.3) to June (4.9), then increased in September (95.2) and to a high level in November (169.3). These data suggest that L. pallidum and L. scutellare are the primary vectors of scrub typhus throughout their range in Korea. While other species of larval chigger mites were also collected with some implications in the transmission of Orientia tsutsugamushi, they only accounted for 11.2% of all larval chigger mites collected from small mammals.

Serosurveillance of Scrub Typhus in Small Mammals Collected from Military Training Sites near the DMZ, Northern Gyeonggi-do, Korea, and Analysis of the Relative Abundance of Chiggers from Mammals Examined

Comprehensive quarterly serosurveillance on scrub typhus in small mammals collected from military training sites located near the Demilitarized Zone (DMZ), northern Gyeonggi-do (Province), ROK was conducted to determine the potential rodent-borne and associated ectoparasite disease risks to military personnel. A total of 1,196 rodents and insectivores representing 8 species, Apodemus agrarius (87.3%, n = 1,044), Mus musculus (5.4%, n = 65), Crocidura lasiura (3.3%, n = 40), Microtus fortis (2.6%, n = 31), Micromys minutus (0.3%, n = 4), Tscherskia triton (0.3%, n = 4), Rattus norvegicus (0.3%, n = 4), and Myodes regulus (0.3%, n = 4) were assayed for the presence of antibodies to Orientia tsutsugamushi. O. tsutsugamushi antibodies were detected in 6 of 8 species and seroprevalence determined; A. agrarius (45.6%), M. musculus (23.1%), M. fortis (48.4%), M. minutus (50.0%), T. triton (50.0%), and R. norvegicus (25.0%). A total of 31,184 chigger mites collected from 508 rodents and insectivores were slide-mounted and 10 species belonging to 4 genera were identified. Leptotrombidium pallidum (53.4%) was the most frequently collected, followed by L. palpale (15.7%), Neotrombicula tamiyai (14.3%), L. orientale (10.7%), L. zetum (3.1%), Walchia fragilis (2.1%), and L. gemiticulum (0.8%), while the remaining 3 species, L. subintermedium, N. gardellai, and Euschoengastia koreaensis were rarely observed (prevalence < 10%). In contrast to previous surveys, higher chigger indices of the primary scrub typhus vectors, L. pallidum (165.4), L. orientale (45.0), and L. palpale (21.4), were observed during the spring season.

Caamembecaia gratiosus n. gen., n. sp. (Acari: Trombiculidae), from Trinomys gratiosus (Gunter) (Rodentia: Echimydae), of Atlantic Forest in Southeastern Brazil

From June 1999 to May 2001, small mammals were captured in three areas of the Atlantic Forest in Southeastern Brazil and examined for ectoparasites. Analysis of ectoparasites revealed the presence of a new chigger genus and species, Caamembecaia gratiosus, from Trinomys gratiosus. This is the first record of a chigger from T. gratiosus.