A scientific note on the association of Haptoncus luteolus (Coleoptera: Nitidulidae) with colonies of multiple stingless bee species

Abstract

Different Nitidulid beetles can be found in social bee colonies (Ellis et al. 2008) andmay range from harmless associates (e.g.,Cychramus luteus , Neumann andRitter 2004) to damaging parasites (e.g., Aethina tumida , Neumann and Elzen 2004). Haptoncus luteolus (Coleoptera: Nitidulidae, Figure 1a, b) is a fruit pest (Yunus andHo 1980; Audisio et al. 1990) and has been reported as an associate of honeybee, Apis mellifera , colonies (Atkinson and Ellis 2011a, b). Here, we report for the first time its association with colonies of multiple stingless bee species. In July 2013, beetle larvae (N =6) were manually collected using entomological forceps from a thriving colony of the local stingless bee Trigona thoracica in Kelantan, Malaysia. The larvae were only found near and in multiple-punctured pollen pots in a bottom corner (Figure 1c). The pollen pots looked distorted oval and collapsed, which contrasts to the normal elongated oval shape in this stingless bee species (Michener 2013). No adult beetles were observed. In December 2013, adult beetles (N =21) were manually collected using entomological forceps from a thriving Heterotrigona itama , another local stingless bee. These beetles were hiding in the corners or under the brood comb of the colony. No beetle larvae was found. In January 2014, adult beetles (N >100), larvae (>100), and pupae (N >100) were manually collected using entomological forceps from the colony of a different local stingless bee, Tetragonula laeviceps . Several brood, honey, and pollen pots were infested by the larvae and adults (see Michener 2013 for respective details on the nesting biology of stingless bees). Interestingly, we observed distinct bulges on the surface of the nesting material. Careful dissections revealed that those apparently served as pupation sites (Figure 1d). This heavily infested T. laeviceps colony collapsed. All beetle samples were transported to the Biology Laboratory, Universiti Malaysia Kelantan. The adults were identified as H. luteolus (Coleoptera: Nitidulidae) [synonym—Epuraea luteola ] based on definitive morphological characteristics (see Gillogly 1982; Figure 1a). Then, a successful standard laboratoryrearing program for small hive beetles was established using plastic containers [18×12×6 cm, with a pin-holed lid (O=~1 mm), allowing for sufficient air circulation] and a diet consisting of pollen/honey/protein powder (Nutrilite®, Amway) in a 1:1:2 volume ratio (Neumann et al. 2013), thereby confirming that H. luteolus is able to successfully reproduce on bee products. Our observations show that H. luteolus can be associated with colonies of at least three different species of stingless bees. Taken together with earlier reports in honeybee, A. mellifera , colonies (Atkinson and Ellis 2011a, b), this suggests that this beetle species can exploit a variety of different social bee species. This is similar to the small hive beetle, which can infest colonies of honeybees (Neumann and Elzen 2004), bumblebees Bombus impatiens (Spiewok and Neumann 2006), Corresponding author: K. Krishnan, kumara_k2001@yahoo.com Manuscript editor: James Nieh Apidologie (2015) 46:262–264 Scientific note