A facultative association between Plebeia droryana (Friese, 1900) (Hymenoptera: Apidae: Meliponini) and a wax scale insect, Ceroplastes janeirensis (Hemiptera: Coccoidea: Coccidae).

Ants and bees (Hymenoptera) are frequently associated with scale insects (Hemiptera: Coccoidea) and other Sternorrhyncha in a mutualistic relationship. Associations with ants are best known, and they tend to clean, protect and even transport these insects in exchange for honeydew (Way, 1963). Studies between coccoids and bees are less common, although in some regions of Europe the associations between Apis sp. (Hymenoptera: Apidae) and scale insects are important for honey production (Santas, 1983; Gounari, 2006). In Brazil, the interaction between Apis mellifera and Stigmacoccus spp. (Coccoidea: Stigmacoccidae) associated to Mimosa scabrella (Fabaceae) was studied in relation to the production of molasses in Campos de Cima da Serra, Rio Grande do Sul (Witter et al., 2010). Camargo and Pedro (2002a, b) reported a new kind of mutualistic association between the Amazonian stingless bee Schwarzula coccidophila Camargo and Pedro, 2002 (Hymenoptera: Apidae: Meliponini) and Cryptostigma sp. (Hemiptera: Coccoidea: Coccidae) in which the stingless bees not only collect the honeydew, but also the waxy cover produced by the scale insect which they use as an alternative source for construction of their nests. Schwarzula coccidophila maintain the scale insect Cryptostigma sp. inside their nests providing a safe place for them, far from the reach of natural enemies (Camargo and Pedro, 2002a, b). Camargo and Pedro (2002b) also provided a review of the stingless bees Schwarzula timida (Silvestri, 1902) at Coxipó, MT, Brazil and Plebeia emerina (Friese, 1900) (at São Paulo, SP, Brazil) associated with unidentified soft scale insect (Coccidae). The coccid Cryptostigma sp. mentioned in association with S. coccidophila by Camargo and Pedro (2002a, b) was later described as a new species by Kondo (2010) who described it as Cryptostigma melissophilum Kondo. Kondo (2010) also described a second species, C. chacoensis Kondo, associated with stingless bees, which is found inside the nests of two stingless bees, S. timida and Plebeia sp. (D. Roubik, personal communication apud Kondo, 2010). In the present report, Plebeia droryana (Friese, 1900) was collected in association with Ceroplastes janeirensis Gray, 1828 (Hemiptera: Coccoidea: Coccidae) (Figure 1), in December 2007, on Myrcia cauliflora Berg. (Myrtaceae) in an urban area of Araraquara, São Paulo, Brazil, located between the coordinates 21° 58’-22° 00’ S and 47° 51’-47° 52’ W. Additional samples were collected between January and August 2009, in order to confirm this novel scale insect interaction. The scale insects and bees were stored separately in 75 and 100% ethanol respectively. The coccoid was mounted on microscopic slides following the methodology described by Gullan (1984), and identified according to Peronti et al. (2008). The bee specimens were sent to a specialist for identification. All specimens are deposited at the Universidade Federal de São Carlos, SP, Brazil. The specimens of Ceroplastes janeirensis collected had their wax test completely or almost completely removed by the bees (Figure 2). The absence of the wax test, which is responsible for protection of these coccids, causes dehydration of the coccids and facilitates the action of