In Vitro Rearing of Stingless Bee Queens and Their Acceptance Rate Into Colonies Charles Fernando Dos Santos, Patrick Douglas De Souza Dos Santos, Betina Blochtein
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In vitro rearing of stingless bee queens and their acceptance rate into colonies Charles Fernando dos Santos, Patrick Douglas de Souza dos Santos, Betina Blochtein To cite this version: Charles Fernando dos Santos, Patrick Douglas de Souza dos Santos, Betina Blochtein. In vitro rearing of stingless bee queens and their acceptance rate into colonies. Apidologie, Springer Verlag, 2016, 47 (4), pp.539-547. 10.1007/s13592-015-0398-2. hal-01532302 HAL Id: hal-01532302 https://hal.archives-ouvertes.fr/hal-01532302 Submitted on 2 Jun 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Apidologie (2016) 47:539–547 Original article * INRA, DIB and Springer-Verlag France, 2015 DOI: 10.1007/s13592-015-0398-2 In vitro rearing of stingless bee queens and their acceptance rate into colonies Charles FERNANDO DOS SANTOS, Patrick Douglas de SOUZA DOS SANTOS, Betina BLOCHTEIN Departamento de Biodiversidade e Ecologia, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Av. Ipiranga, 6681, Porto Alegre, RS, Brazil Received 2 June 2015 – Revised 18 August 2015 – Accepted 29 September 2015 Abstract – The in vitro rearing of queen bees can improve the management and conservation of pollinator insects. Here, we have developed an in vitro queen-rearing protocol for Plebeia droryana (Apidae, Meliponini). Firstly, we evaluated the amount of food offered naturally to P. droryana queen larvae. After, we grafted P. droryana larvae onto acrylic plates which were kept in constant darkness at 25 °C and different relative humidity along larval development. We also compared intertegular distance of P. droryana queens reared in vitro and naturally. We then tested whether queens reared in vitro would be accepted into new colonies with older and/ or callow workers. We found that P. droryana larvae developed into queens if fed with 66 μL of larval food. The survival rate of P. droryana queens was >75 %. The queens reared in vitro are similar in size to naturally produced ones. Finally, colonies only containing callow workers are more likely to accept queens reared in vitro. This queen-rearing technique may improve beekeeping practices in the Neotropical Region. bees / beneficial arthropods / caste determination / crops / pollinators / queen production / virgin queens 1. INTRODUCTION Thus, this concern becomes even more serious because the main bee species globally responsible Bees provide an important ecological service as for agricultural pollination, A. mellifera ,issuffer- the main pollinators of wild plants and crops ing increasing death of its colonies due to colony (Kevan and Baker 1983; Klein et al. 2007). collapse disorder (VanEngelsdorp et al. 2009). However, in current years, native bee populations Honeybees therefore cannot be relied on in the have declined worldwide, threatening this pollina- future as the most effective pollinators of many tion service (Freitas et al. 2009; Potts et al. 2010). crops throughout the planet, and we shall have to The causes of this decline may include habitat loss depend much more on native bee species for and/or fragmentation, intense use of agrochemi- effective pollination (Freitas et al. 2009; cals, pathogens, alien bee species and climate Garibaldi et al. 2013; Witter et al. 2015). change (Freitas et al. 2009; Potts et al. 2010). Further honeybees, few bee species can be These pressures may well lead to a global deficit traditionally managed in hives (as bumblebees in the availability of pollinators for food produc- and stingless bees) or elsewhere (solitary bees) tion even of honeybees Apis mellifera Linnaeus (e.g. Freitas and Pereira 2004;Cortopassi- (Aizen and Harder 2009). Laurino et al. 2006; Velthuis and van Doorn 2006), albeit there are about 20,000 bee species worldwide (Michener 2007). In the Neotropical Region, the stingless bees (Apidae: Meliponini) Corresponding author: B. Blochtein, [email protected] are an important group of highly eusocial bees that Manuscript editor: James Nieh have been identified as a viable alternative which 540 C. Fernando dos Santos et al. may help to mitigate the pollination deficit in desirable if queen-rearing techniques could devel- many natural and crop systems (Freitas et al. op most stingless bees and be made available to 2009; Garibaldi et al. 2013). beekeepers and researchers. To date, we have The rearing of stingless bees in hives lesser than five stingless bee species with queen- (meliponiculture) is a highly sustainable activity rearing techniques published like Frieseomelitta because beekeepers can work near native forests, varia (Lepeletier), Scaptotrigona depilis (Moure) as well as help conserve endemic bee species, in and S. Postica (Latreille) (e.g. Hartfelder and order to obtain bees’ products (pollen, honey, Engels 1992; Baptistella et al. 2012; Menezes propolis) and promote effective agricultural polli- et al. 2013). nation (Cortopassi-Laurino et al. 2006;Slaaetal. Here, we tested a queen-rearing method and the 2006; Contrera et al. 2011). Stingless bees can add introduction of these queens into small colonies high economic value to crops (Giannini et al. for Plebeia droryana (Friese). This stingless bee 2015). They have been identified as effective pol- species is of particular interest because it inhabits linators of fruit, vegetables and seed crops such as a wide geographic range in the Neotropical tomato, coffee, strawberry, citrus, avocado, onion, Region including Argentina, Bolivia, Brazil and cucumber and canola (Heard 1999; Slaa et al. Paraguay (Camargo and Pedro 2013). 2006; Witter et al. 2015). Furthermore, P. droryana is one of the few sting- Nevertheless, meliponiculture faces the prob- less bee species that exhibit diapause during lem of multiplying hives from core colonies which colder periods (lasting at least 3 months) in south- often hold only a few virgin queens (except ern South America (Santos et al. 2014). It de- Melipona Illiger geuns) for successful colony mands management and conservation multiplication (Imperatriz-Fonseca and Zucchi programmes for this species since this diapause 1995). Therefore, the management and propaga- behaviour probably makes it more vulnerable to tion of stingless bee colonies may be greatly com- anthropogenic disturbances, such as climate promised because there are not sufficient queens warming, than other stingless bee species that do to head new colonies (Jaffé et al. 2015). Thus, the not face such physiological restrictions (Santos mass rearing of virgin queens may offer a means to et al. 2015). overcome the low natural production of virgin queens in most stingless bee genera, and therefore 2. MATERIALS AND METHODS increase the number of new colonies that can be used to restore adequate pollination in natural 2.1. Bees and study area ecosystems or crops (Cortopassi-Laurino et al. 2006;Contreraetal.2011; Jaffé et al. 2015). All larval P. droryana and larval food were harvest- Queen-rearing techniques for stingless bees are ed from colonies in the stingless bee apiary of the based mainly on the overfeeding of female larvae Laboratory of Entomology at the Pontifícia in vitro (Baptistella et al. 2012; Menezes et al. Universidade Católica do Rio Grande do Sul 2013), since castes determination system in most (PUCRS), Porto Alegre, Brazil, between November stingless bee genera depends mainly on trophic 2014 to March 2015. factors (Darchen and Delage-Darchen 1971). Female larvae destined to become queens receive 2.2. Amount of larval food more larval food in the bigger (royal) cells than female larvae destined to become workers reared We quantified and compared the amount of larval in smaller brood cells (Darchen and Delage- food in queen brood cells (n =7) with that in worker Darchen 1971). brood cells (n =33 from three colonies) taken from Because of the potential of stingless bees as naturalcolonieskeptinPUCRS’sapiary.Forthis,we crop pollinators (Heard 1999;Slaaetal.2006; used an Eppendorf micropipette (10 μL) to calibrate Garibaldi et al. 2013; Witter et al. 2015) and the microcapillary tubes (40 μL) and used them to collect large number of species in the taxon (more than larval food from individual brood cells. We had to 300) (Camargo and Pedro 2013), it would be slightly aspirate the microcapillaries because the end In vitro rearing of bee queens 541 portion of the larval food mass is pasty due to the higher wooden stick tipped with an entomological pin modi- concentration of pollen grains. fied into a spoon shape. We added an extra 10 % of the same larval food to (d) The queen-rearing plates were placed into hermetic larvae destined to become queens (following Menezes plastic containers (7×11×17 cm) and kept in an incuba- et al. 2013) in order to ensure sufficient sustenance for tor at 25 °C (model Luca-161/04, LUCADEMA®,São the full span of larval queen development and an appro- Paulo, Brazil), in constant darkness (0L:24D). priate size. (e) The relative humidity inside the plastic container was maintained between 98 and 65 % during the whole period of larval development using a saturated solution 2.3. Queen rearing of potassium chloride (KCl) in distilled water as neces- sary (Table I). Temperature and humidity data were Before commencing the rearing procedure, all tools collected using Datalogger devices (model U23-001 and equipment were washed with distilled water and HOBO Pro v2, version3.6.2, ONSET®, Mato Grosso, then sanitized using ethanol. We then established the Brazil) placed in the plastic containers. larvae as follows: (a) In the apiary, we chose some populous P. droryana 2.4. Acceptance of queens into new colonies colonies with recently built brood combs containing only eggs and larval food.