Report of the mite Lasioseius prorsoperitrematus Abo-Shnaf, Sánchez & Moraes, 2016 (Acari: Blattisociidae) in Brazil associated with the insect Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae)

The sugarcane weevil, Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae), is a pest of sugarcane in Brazil. Lasioseius prorsoperitrematus Abo-Shnaf, Sánchez & Moraes, 2016 (Acari: Blattisociidae), described from the Dominican Republic, is reported from Brazil in association with S. levis in Iracemápolis, São Paulo state. The actual role of each organism in this association needs to be verified. A key to species of Lasioseius Berlese, 1916 recorded from Brazil associated to Coleoptera is provided.

The sugarcane weevil, Sphenophorus levis Vaurie, 1978 (Coleoptera: Curculionidae) is a key pest of sugarcane in Brazil, where annual losses attributed to this insect can reach 20-30 ton/ha (Degaspari et al. 1987;Dinardo-Miranda et al. 2006;Leite et al. 2012). It is usually found in four Brazilian states, namely Mato Grosso do Sul, Minas Gerais, Paraná and São Paulo (Moraes & Ávila 2013;Dinardo-Miranda 2014). Eggs of this species are laid at the base of sugarcane stalks, and larvae tunnel toward the rhizome (Cerda et al. 1999). It is presently controlled with the use of pesticides, not always successfully, mainly because of the secluded behaviour of the juveniles (Zarbin et al. 2003). Promising results have been obtained in its control with the use of entomopathogenic nematodes (Giometti et al. 2011;Leite et al. 2012), but other biological control agents have been searched for. Predatory mites of the order Mesostigmata are commonly found in the soil, where they feed on a range of organisms, including other mites, nematodes, small insects and other invertebrates (Moraes et al. 2015).
Given the limited ability to disperse, predatory mites usually use insects as carriers to move between patches of ephemeral habitats, a process named phoresis, known for mesostigmatid mites of the families Laelapidae and Macrochelidae, families of a mesostigmatid group called Uropodina, and others (e.g. Hoffmann & López-Campos 1995;Krantz 1998;Bajerlein & Witalinski 2014). In this process, the transported organism is benefited, but it causes no damage to the carrying species.
The present study reports the first record in Brazil of the association between a species of Lasioseius Berlese, 1916 on a beetle.
A mesostigmatid mite was recently found on the body of adults of S. levis collected from sugarcane fields in Iracemápolis (22°34'53''S, 47° 31' 11'' W), São Paulo state, Brazil ( Fig. 1). They were most often found between coxae I and II of the insects, but also occasionally near the base of antennae. The mites were removed from S. levis with a brush, mounted on microscope slides with Hoyer's medium and examined under phase (Leica, DMLB) and interference (Nikon, Eclipse 80i) contrast microscopes. Voucher specimens of the mite were deposited in the Acarology Collection of Departamento de Entomologia e Acarologia, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (ESALQ/USP), Piracicaba, São Paulo. Nothing is known about the biology of this mite species. The sugarcane weevil was identified based on the description study (Vaurie 1978).
Preliminary observations in the laboratory showed mites to leave the carrier and move onto eggs recently laid by the latter, tapping the surface continuously, as if trying to feed, leaving the egg after 10-12 hours (Fig. 4). It is possible that the association be only phoretic, with mites riding the insect in search of their actual prey or other types of food, as fungi (Moraes et al. 2015). But it could also cause some type of damage to S. levis, or even attack nematodes, some of which could be pathogenic to the insect. Further studies are necessary, to demonstrate the type of relation between L. prorsoperitrematus and S. levis.
Differences between Brazilian Lasioseius associated with beetles can be seen in the dichotomous key provided in this note.