COMMENT ON CASTES QUESTION
I read with intrigue, your answer to the question about castes. I probably would have answered the same way, but we both would be wrong. Darwin, in his book “Origin of the Species” refers to castes to distinguish between the different types of workers, not the different sexes. Diana Wheeler, writing in 1986, also states: “Among social Hymenoptera, only ants have evolved morphologically complex worker castes.” By this definition, honey bees cannot be divided into castes at all.
However, later in the paper, she says this about honey bees: “The developmental pathways of the two female castes diverge at this point, allowing expression of the dozens of morphological characters that distinguish them. The nutritional switch represents the point in development at which the developmental paths of the two castes diverge.”
More recently, she and Jay Evans wrote:
Many insects show polyphenisms, or alternative morphologies, which are based on differential gene expression rather than genetic polymorphism. Queens and workers are alternative forms of the adult female honey bee and represent one of the best known examples of insect polyphenism. Hormonal regulation of caste determination in honey bees has been studied in detail, but little is known about the proximate molecular mechanisms underlying this process, or any other such polyphenism. We report the success of a molecular-genetic approach for studying queen- and worker-specific gene expression in the development of the honey bee (Apis mellifera). Numerous genes appear to be differentially expressed between the two castes.
Peter Borst
New York
Sources:
Wheeler, D. E. (1986). Developmental and physiological determinants of caste in social Hymenoptera: evolutionary implications. The American Naturalist, 128(1), 13-34.
Evans, J. D., & Wheeler, D. E. (1999). Differential gene expression between developing queens and workers in the honey bee, Apis mellifera. Proceedings of the National Academy of Sciences, 96(10), 5575-5580.
Reply from Jerry
Thank you Peter. There are different definitions and that was just the one I used. And as you say, we both could very well be wrong or not.☺ Science moves on.
Q King Bee?
A swarm departed from a hive in my apiary on May 2nd. It settled in a pear tree about fifty feet away. I hived the swarm in two deeps. The lower box
had all drawn out combs. The upper box had some drawn out combs and some frames with only foundation. As an attractant, I placed two cotton balls with lemongrass oil in the lower box. I also provided a top feeder with 1:1 sugar water and Honey-B-Healthy. When I checked the feeder five days later, it was empty, so I refilled it.
On May 20th, I inspected the hive. The top box was teeming with bees. There were frames with pollen, nectar, and capped “honey” (most likely sugar water). One frame had many capped drone brood cells and some drone larvae. No worker brood was present. I reversed the two deeps. I was unsure if the queen was a drone layer, or if I had unknowingly killed the queen when hiving the swarm and laying workers were present. I was unable to purchase a queen locally at the time, so I decided to let nature take its course and see what would happen.
On June 17th, my daughter and I thoroughly inspected the colony. It was still teeming with bees, which surprised me. They remained calm during the entire inspection. Many frames had lots of capped drone brood and drone larvae. We found no worker brood whatsoever. The bees had extended the worker size cells to accommodate drone brood. There was also capped “honey”, nectar, and pollen on nearly all drawn out combs that I had provided. We saw two bees with their corbiculae full of pollen, and we only noticed a couple of drones. The drones were smaller than normal (I assume because they were raised in worker size cells).
During the inspection, we discovered five queen cells. One was located at the very top of a frame, one at the very bottom, and the other three were toward the center of their frames. The queen cell located at the very bottom of its frame appeared to have a larva floating in royal jelly. We then noticed two workers apparently feeding the larva. Worker bees construct queen cells to prepare for swarming, emergency queen cells to replace a missing queen, or supersedure queen cells to replace a failing queen. Since the hive strongly appears to contain only drone brood, would workers construct queen cells for drones?
Thank you very much for your help in solving this mystery!
Ross Englehart
Dayton, MDT
A
Learning about anything is experimentation. Equally if not more so when you are introduced and submerge yourself in the insect world of honey bees. The short story is workers (sexually undeveloped females) result from fertilized eggs, egg+sperm. Strangely enough drones result from unfertilized eggs, egg+0, having only half of the chromosomes which is called “haploid”. They develop from unfertilized eggs in a biological process called “parthenogenesis”.
All this to set the stage for stating that there has to be a fertilized egg to be chosen to develop into a sexually developed female called a queen. And a fertilized egg has to come from another queen in the colony somewhere, someplace who has eggs and a few sperm left. She may be flawed and imperfect and not able to lay many fertilized eggs and more unfertilized eggs (drones) than any other kind, but she is there someplace.
Unfertilized eggs cannot result in queen cells, regardless if they come from laying workers or a queen on her last reproductive legs if no sperm is provided, normally.
All that to say that as the last reproductive survival gasp of this colony it is trying to requeen itself with whatever emerges from those cells. If it is a failure, you may be wise to combine this colony with a functioning queen-right colony and take your loss early as colonies prepare for winter.
Comment from Ross
Thank you for answering my question so quickly. I am cognizant of the information you provided concerning “haploid” and of course diploid processes. You state that “Unfertilized eggs cannot result in queen cells, regardless if they …
