Are Pesticides Used to Control Thrips Harmonious with Soil-Dwelling Predatory Mite Cosmolaelaps sabelis (Mesostigmata: Laelapidae)?

Edaphic predatory mites could be introduced in pest management programs of pests that live, or spend part of their life cycle, in the soil. Some mesostigmatic mites have been widely used for the management of different species of thrips (Thysanoptera), especially in protected cultivation. The edaphic predator Cosmolaelaps sabelis (Mesostigmata: Laelapidae) was a model species in this study, being exposed to the most applied insecticides for the control of thrips in Brazil. After lethal, sublethal and transgenerational effects were evaluated. The pesticides acephate, acetamiprid + etofenprox, azadirachtin, spinetoram, formetanate hydrochloride, and imidacloprid were classified according to the IOBC/WPRS (International Organization for Biological Control-West Paleartic Regional Section) recommendation, considering the acute toxicity and the effects on adult females' reproduction, in the maternal and first generation. The pesticides acetamiprid + etofenprox and azadirachtin were classified as slightly harmful (Class 2), while spinetoram was classified as moderately harmful (Class 3). Acephate and formetanate hydrochloride were classified as harmful (Class 4). Only imidacloprid didn't cause negative effects on the females. Regarding effects on the first generation, acetamiprid + etofenprox, azadirachtin, and spinetoram caused reduction in the oviposition rates. Therefore, we suggest that complimentary bioassays should be done under semi-field and field conditions using the pesticides that were considered harmful in this study, to assess their effects on this predator in other environments prior to recommending not to use them in integrated programs to manage soil-based pests using chemical and biological tools.

Two new species of Afrodacarellus (Acari: Mesostigmata: Rhodacaridae) from Brazil and a key to the world species of the genus.

Within a project to determine the edaphic predatory mites from the Brazilian Alagoas state, two new species of Afrodacarellus Hurlbutt (Rhodacaridae) were found, namely Afrodacarellus alagoensis Santos & Castilho n. sp. and Afrodacarellus xucurukariri Santos & Castilho n. sp.. These are here described based on the morphology of adult females. A key for the separation of females of the 31 recognisable world species of Afrodacarellus is provided, including the newly described species.

Diversity of edaphic Rhodacaroid mites (Acari: Mesostigmata: Rhodacaroidea) in natural ecosystems in the state of São Paulo, Brazil / Diversidade de ácaros edáficos Rhodacaroidea (Acari: Mesostigmata) em ecossistemas naturais no estado de São Paulo

Avaliou-se neste estudo a diversidade de ácaros Rhodacaroidea em amostras de folhedo e solo coletadas em ecossistemas conhecidos como “Mata Atlântica” e “Cerrado” do estado de SãoPaulo. O total de 969 Rhodacaroidea adultos foi coletado, 913 na Mata Atlântica e 56 no Cerrado. Foram encontrados representantes de três famílias de Rhodacaroidea: Ologamasidae, Rhodacaridae eDigamasellidae. Ologamasidae foi a mais numerosa na Mata Atlântica, enquanto Rhodacaridae foi a mais numerosa no Cerrado. Os Rhodacaroidea de ambos ecossistemas representaram 12 gêneros deOlogamasidae, dois de Rhodacaridae e um de Digamasellidae. O total de 13 gêneros foi encontrado em amostras de folhedo e sete em amostras de solo da Mata Atlântica. Os gêneros mais comuns neste ecossistema foram Neogamasellevans Loots & Ryke e Ologamasus Berlese, em folhedo, e Rhodacarus Oudemans, em solo. Foram coletadas 31 morfoespécies, sendo Rhodacarus sp.1, Neogamasellevanssp.1 e Neogamasellevans sp.6 as mais abundantes. Foram encontrados três gêneros de Rhodacaroidea em cada substrato do Cerrado, Rhodacarus e Rhodacarellus Willman sendo os mais abundantes. Das cinco morfoespécies encontradas neste ecossistema, a mais abundante foi Rhodacarus sp.1. Asmorfoespécies coletadas na Mata Atlântica apresentaram mais alta eqüitabilidade na freqüência de ocorrência quando comparadas àquelas do Cerrado, especialmente em amostras de folhedo. As espécies de planta amostradas na Mata Atlântica foram divididas em dois grupos distintos, de acordo com as morfoespécies de Rhodacaroidea a elas associadas: 1) Astrocaryum aculeatissimum (Schott), Bactris setosa Mert. e Attalea dubia (Mert.); e 2) Syagrus romanzoffiana (Cham.) e Euterpe edulis Mert.

This study was conducted to evaluate the diversity of rhodacaroid mites in litter and soil samples from “Mata Atlântica” and “Cerrado”, e ecosystems of the state of São Paulo, Brazil. A total of 969 adult rhodacaroids were collected, 913 in the Mata Atlântica and 56 in the Cerrado. Representativesof three rhodacaroid families were from: Ologamasidae, Rhodacaridae and Digamasellidae. Most numerous groups were ologamasids in the Mata Atlântica and rhodacarids in the Cerrado. Mites from both ecosystems represented 12 genera of Ologamasidae, two of Rhodacaridae and one of Digamasellidae.A total of 13 genera were found in litter samples and seven in soil samples of Mata Atlântica. The most common genera in this ecosystem were Neogamasellevans Loots & Ryke and Ologamasus Berlese in litter, and Rhodacarus Oudemans in soil samples. Thirty-one morphospecies were recovered, the most abundant being Rhodacarus sp.1, Neogamasellevans sp.1 and Neogamasellevans sp.6. Threerhodacaroid genera were found in each substrate of Cerrado, the most abundant being Rhodacarus and Rhodacarellus Willman. Of the five morphospecies found in this ecosystem, the most abundant was Rhodacarus sp.1. Morphospecies collected in Mata Atlântica displayed a higher equitability in frequency of occurrence than those of Cerrado, especially in litter samples. The plant species sampled in Mata Atlântica comprised two distinct groups in terms of the rhodacaroid morphospecies associated with them: 1) Astrocaryum aculeatissimum (Schott), Bactris setosa Mart. and Attalea dubia (Mart.); and 2)Syagrus romanzoffiana (Cham.) and Euterpe edulis Mart.