SCIENTIFIC NOTE Technique for Restoration of Mite (Acari) Preparations in Deteriorated Hoyer’s Medium FC JACINAVICIUS, JC BADARI, DG RAMIREZ, RHP MORAES, VC ONOFRIO, DM BARROS-BATTESTI Lab Especial de Coleções Zoológicas, Instituto Butantan, São Paulo, SP, Brasil Abstract Keywords Microscope slide restoration, mite collection, mounting technique Correspondence DM Barros-Battesti, Lab Especial de Coleções Zoológicas, Instituto Butantan, Av. Vital Brasil 1500, 05503-900, São Paulo, SP, Brasil; dbattesti@butantan.gov.br Edited by Gilberto J de Moraes – ESALQ/USP Received 1 November 2012 and accepted 28 February 2013 Published online 22 March 2013 * Sociedade Entomológica do Brasil 2013 The Acari Collection of Instituto Butantan (IBSP), São Paulo, Brazil, includes many types and other identified mite specimens that were mounted in Hoyer’s medium, mainly in the first part of last cen- tury. An effort to restore degraded preparations was initiated in 1996. In this process, an improved technique was developed, allowing the adequate cleaning of specimens mounted up to 50– 70 years before. Types and other identified specimens of Trombidiformes (Harpirhynchidae and Trombiculidae), Sarcoptiformes (Acaridae, Atopomelidae, Listrophoridae, and Psoroptidae) and Mesostigmata (Dermanyssidae, Ixodorhynchidae, Laelapidae, Macronyssidae, and Spinturnicidae) deposited at IBSP Collection have been satisfactorily restored. Because of their usually small sizes, mite specimens are usually mounted in Hoyer´s medium on microscope slides (Krantz & Walter 2009) for taxonomic examination under optical microscope. A common problem with this proce- dure is that preparations using that medium very often deteriorate, mainly when the sealant is ruptured, exposing the medium (Brown 1997). Even when the sealant is intact, mite preparations often become opaque or precipitated with time (De Lillo et al 2010). Not much has been published in terms of techniques to be used for the restoration of slides with deteriorated Hoyer’s medium. One of the main problems in this process is the possibility of breaking important taxonomic struc- tures, mainly setae. Thus, curators often prefer maintaining the original preparations, even when dark and deteriorat- ed, to running the risk of losing important specimens, especially type specimens, while remounting them. The Acari Collection of Instituto Butantan (IBSP), São Paulo, Brazil, was established in 1931 by Flávio da Fonseca, who was responsible for it until 1961 (Barros-Battesti & Knysak 1999). Most types and other identified specimens of this collection were mounted in Hoyer’s medium in the first part of last century. Because of their precarious con- ditions, we initiated a major effort in 1996 to restore those preparations. In this process, we developed a new tech- nique, improving the results even when dealing with mites mounted 50–70 years before. That new technique and ex- amples to illustrate its efficiency are subsequently described. The first recommended procedure is to copy the data shown on the label of the slide to be processed or to photograph it, so as to keep record of the original infor- mation provided, in case the label is damaged during the process. Place the slide inside a Petri dish (ca. 9 cm in diameter) with distilled water and a drop of neutral deter- gent. In order to prevent the evaporation of the distilled water, close the Petri dish and keep it at 55°C. Check the slide periodically to determine when the coverslip loosens up (it may take from a few hours to 24 h or longer), adding water as necessary. It is important to wait for the complete detachment of the coverslip to avoid damaging the specimen. When the specimen is free, remove it carefully with micro pin to avoid damage. If the specimen is observed to be sufficiently clean, then proceed with remounting by the usual mounting procedure. Depending on the degree of deterioration, sometimes the specimen still stay fixed to pieces of dirty material. In this case, place it inside a small Petri dish with distilled water and add three drops of Neotrop Entomol (2013) 42:328–329 DOI 10.1007/s13744-013-0129-1