Histological Estimates of Ovariole Number in Honey Bee Queens,Apis mellifera, Reveal Lack of Correlation with other Queen Quality Measures

Abstract

Published estimates of the number of ovarioles found in the ovaries of honey bee, Apis mellifera L. (Hymenoptera: Apidae) queens range from 100 to 180 per ovary. Within the context of a large-scale study designed to assay the overall quality of queens obtained from various commercial sources, a simple histology-based method for accurate determination of ovariole number was developed and then applied to a sample of 75 queens. Although all 10 commercial sources evaluated provided queens with ovariole numbers within the expected range, ovariole number was found to vary significantly across sources. Overall, and within most of the individual samples, there was no correlation of ovariole number with other morphological attributes such as thoracic width, wing length, or wet weight. Queens from two of the sources, however, displayed a significant negative relationship between wet weight and ovariole number. This study provides baseline data on ovariole number in commercial honey bee queens in the United States at a time when honey bee populations are declining; the method described can be used in studies relating ovariole number in queens to egg production and behavior.

Survey of the Health Status of Some Honey Bee Queens in Italy

“…Ovariole numbers from this study were lower that those reported in the literature (Jackson et al, 2010;Gauthier, 2011) especially when young queens were considered. Low ovariole numbers can be the result of defective genetic characteristics and/or of poor rearing conditions and can lead to rapid queen supersedure.…”

“…The number of ovarioles was estimated with a method derived from Jackson et al (2010). The ovary was dissected in a saline solution and removed.…”

“…The queen's fully developed reproductive system is formed by: -2 ovaries, which take up almost all the room in the abdomen. The ovaries are composed overall by 300 -400 ovarioles, and each of them can give 3 -5 eggs per day (Jackson et al, 2010;Gauthier, 2011;Porporato and Laurino, 2013). This means that every day, the queen could lay up to 2000 eggs, which in weight, correspond to the average weight of the very queen (Büchler et al, 2013).…”

Standard methods forApis melliferaanatomy and dissection

“…One can use this measure for spermatheca volume to calculate the theoretical maximum storage capacity and percentage filled for spermatheca (see Tarpy et al, 2011).…”

Preparation of honey bee specimens for histopathological studies, including a technique for the preparation of whole sections

“…Typical techniques used to create specimens are usually examined through fixation, sectioning, staining and observation of a targeted organ (e.g., brain, testis, etc.). In order to extract the desired organs, the honey bee's legs are first fixed using paraffin, and then the specimen is placed under the stereoscopic microscope and the organs are extracted using tweezers, scalpel and scissors (Raes et al, 1985;Caláburia et al, 2010;Jackson et al, 2011;Carreck et al, 2013). This process is time consuming, especially in identifying organs, unless an operator is welltrained and experienced.…”