ThetrachealmiteLocustacarusbuchneriinSouthAmericannativebumble bees (Hymenoptera: Apidae)

abstract Article history:Received 11 April 2013Received in revised form 5 June 2013Accepted 11 July 2013Available online 18 July 2013Keywords:ArgentinaBombusNeotropicsPodapolipidaePollinator Asinother regionsoftheworld,bumblebees(Bombusspp.)areimportant pollinators intheneotropics. Despiteits relevance, knowledge on their health is still limited in the region. While external acari are known to occur intheseinsects,presenceoftheinternal,trachealmiteLocustacarusbuchneriisherereportedforfirsttime.Aftertheexamination of 2,508 individuals of eight Bombus species from Argentina, two workers of Bombus bellicosus andone of Bombus atratus were found parasitized by L. buchneri in localities within San Luis and Buenos Airesprovinces, respectively. The rare occurrence recorded agrees with findings from elsewhere in the world.© 2013 Elsevier Ireland Ltd. All rights reserved. Bumble bees of genus Bombus reach more than 250 species world-wide and nearly 40 in the neotropics. The importance of these insectsaspollinatorsiswell known throughouttheworld,andit is particularlyrelevant in some crops as tomato and red clover [1]. Bombus specieshave an annual life cycle in which mated queens hibernate commonlyinthesoilandemergeduringwarmerweather.Knowledgeaboutbum-ble bee health in South America was virtually inexistent until recentyears when the emergent microsporidium Nosema ceranae was discov-eredparasitizing three Bombus species in Argentina [2]. Also after inva-sion of the exotics Bombus terrestris and Bombus ruderatus in thatcountry,surveyswereintensifiedanddifferentpathogensandparasitesweredetected [3–6].Inaddition,avarietyofexternalmitesisassociatedwith Bombus species.Thesemitesaregenerallymildandtheyoftenlivein association with the bee's nest using the insect mainly as a dispersalagent.Seven species of external mites, Kuzinialaevis,Kuziniaamericana ,Parasitellusfucorum,Pneumolaelapslonganalis,Pneumolaelapslongipilus,Scutacarus acarorum ,andTyrophagus putrescentiae, are known to bepresent in Argentina [6]. Internal mites are less common and moreharmful than external ones [7,8]. The purpose of this communicationis to present the first report of a tracheal mite associated with SouthAmerican native bumble bees.Samplings were conducted at 65 localities throughout Argentina.Bumblebeeswerecapturedwithentomologicalnetswhileforagingbe-tween early spring and early autumn. Soon after collection, they werefrozen (−32 °C). Once in laboratory, insects were identified, dissected,and examined under the stereoscopic microscope (×10–×40)tocheckfor pathogens and parasites [1,9]. When mites were observed, theywere extracted with a pipette or fine-point tweezers. Upon isolation,mitesweredepositedinPetridisheswithone-quarter-strengthRinger'ssolution [10]. Initial observations were performed in a stereoscopic mi-croscope. After that isolated individuals (including eggs) were clearedin lactophenol and mounted in slides to be observed under the com-pound microscope (×400, ×1000) [6]. Measurements were takenwith an ocular micrometer.A total of 2,608 adult bumble bees of eight Bombus species wereexamined. We scrutinized individuals of Bombus atratus (n = 1,713),B. terrestris (704), Bombus bellicosus (105), Bombus morio (45),ombus Bopifex (25), B. ruderatus (8), Bombus tucumanus (6), and Bombusdahlbomii (2) (see Appendix for details). Only two (Bombus brasiliensisand Bombus baeri) out of the ten species of Bombus known to inhabitArgentina [1] could not be collected (for supplementary information,see Tables A1 and A2).Twoworkersof B.bellicosus andoneofB.atratuswerefoundparasit-ized by internal mites. Parasitized B. bellicosus were from El Amago(32°42′33″S; 66°09′34″W), between the localities of La Carolina andSan Francisco, San Luis province in the center of the country duringthe firsthalf of March2012. The parasitized B.atratuswas from ColoniaUrquiza (34°56′24″S; 58°04′54″W), northeastern Buenos Aires prov-ince in late January 2012 (Fig. AI). None of the three bumble beesappeared to show obvious external signs or symptoms of parasitism.Two and six physogastric females were found in each of the twoB. bellicosus, respectively, and eight in B. atratus. Physogastric females