Histopathology as diagnostic tool for Ascosphaera apis infection in apparently healthy honey bees (Apis mellifera ligustica)

Abstract

Paola Maiolino , Francesca Carella , Giovanna De Leva , Laura Rinaldi , Giuseppe Cringoli , Manuela Martano

Objective: Chalkbrood is a fungal disease of honey bee brood caused by Ascosphaera apis. This disease is now found around the world and there are some indications that the incidence has increased in recent years. The diagnosis of Chalkbrood is based on the recognition of typical clinical symptoms and on the identification of the causative agent. Despite the numerous methods available for the detection of A. apis, the diagnosis of this pathology is not always easy. Methods: Between June and July 2011 an increase in mortality of honey bees was observed to some apiaries of the Caserta province (Campania region, southern Italy). Larvae from brood samples without signs of disease and adult honey bees from the same colonies were collected and submitted to our laboratory for routine histologic evaluation. Results and Conclusions: We demonstrate that histopathology is a sensitive and specific method for the detection and identification of Ascosphaera apis infection and has the additional advantage of being able to provide a diagnosis in larvae without signs of disease.