Apidologie 34 (2003) 563-568
DOI: 10.1051/apido:2003056

Suppression of ovarian development of Bombus terrestris workers by B. terrestris queens, Psithyrus vestalis and Psithyrus bohemicus females

Carlos H. Vergara^a, Stefan Schröder^b, Maria Teresa Almanza^c and Dieter Wittmann<sup>b

a</sup>  Departamento de Química y Biología, Universidad de las Américas-Puebla, Santa Catarina Mártir, Puebla, 72820, Mexico
^b  Institut für Landwirtshaftliche Zoologie und Bienenkunde, Rheinische Friedrich-Wilhelms-Universität Bonn, Melbweg 42, 53127 Bonn, Germany
^c  Facultad de Ciencias Biología Aplicada, Universidad Militar Nueva Granada, cra 11 N° 101-80, Bogotá, Colombia

(Received 6 May 2002; revised 3 December 2002; accepted 7 April 2003)

Abstract
Ovarian development was studied in workers of Bombus terrestris under four different treatments, which produced different levels of ovarian development. Psythirus females of both specific (P. vestalis) and non-specific (P. bohemicus, which is the specific parasite of B. lucorum) species were able to inhibit worker ovarian development and to reproduce in B. terrestris colonies. The effect of P. vestalis females on ovarian development of workers was statistically not different from the effect of B. terrestris queens (positive control) and significantly different from ovarian development inhibition measured in groups of workers alone (negative control). Ovarian development inhibition by P. bohemicus was not statistically different both from the positive and the negative control, indicating that this non-specific parasite is able to affect the ovarian development of workers, but not to the same extent as the queens of the same species or the females of the specific parasite.

Key words: Bombus terrestris / Psithyrus spp. / cuckoo bumblebee / ovarian development / social parasitism

Correspondence and reprints: Carlos H. Vergara cvergara@mail.udlap.mx

© INRA, EDP Sciences, DIB, AGIB 2003