Honey bees are different from other livestock for several reasons, but especially in that no other domesticated animal co-exists and routinely interbreeds with a wild population.
The implications of managed honey bee colonies interbreeding with a wild population are profound, especially where the size or density of the interacting populations are both substantial. Many people, including most beekeepers, may imagine that there are two distinct populations: 1) a feral population; and, 2) the population of bees that occupy their managed hives and the hives of their fellow beekeepers.
In biological reality, two interbreeding populations that co-exist at the same time and in the same space will ultimately converge to a single population over multiple generations. Consequently, discernable attributes or traits of the respective populations will crossover or merge in the limit of long time scales of interbreeding.
This is what has happened in Texas over the past 30 plus years. In the beginning, and for several years after the New World African (NWA) population first invaded and occupied Texas, the wild or feral population was hyperdefensive in the extreme. Because the suite of behavioral, physiological and metabolic traits that the hyperdefensive and invasive NWA population carried was conveyed by interbreeding to new generations of the managed population, there was a time when our BeeWeaver bees were noticeably more defensive than they had been prior to the arrival of the New World African (NWA) population. But even at the apex of New World African introgression and the parasitism of managed colonies by Africanized queens, our population of bees were never anything like the unadulterated NWA bees that we encountered initially. For instance, in South and SouthWest Texas, wild colony densities in the post-NWA invasion phase were very high and nearly every wild colony exhibited extreme defensive behavior. As a consequence, the influence of the wild population, and the introgression of defensive behavioral traits into isolated pockets of managed colonies in apiaries across South and SouthWest Texas was a serious challenge throughout the 1990s and into the early 2000s.
Today, colonies with NWA African behavioral phenotypes – that is mean hives with a propensity to sting en masse with minimal provocation – do pop up occasionally though with nothing like the frequency or intensity of the mid 1990s. But wild colonies with hyperdefensive behavior remain more common in the riparian corridors across the more arid regions of South and SouthWest Texas even today due in large part to the wild population having higher densities and exerting a dominant population-level genetic influence over subsequent generations.
Ignoring for the time being the phase where two behaviorally distinct populations initially interact, and the succeeding period when those populations are not thoroughly blended (we’ll talk about this very interesting phase later), let’s focus on where we are now. At this juncture – late 2021 – most wild colonies in the regions of Texas where we keep and breed honey bees (Central and SouthEast Texas) are behaviorally similar to the bees in our managed hives. Defensive behavior is and will always be discrete at the individual colony level, but individual colony phenotype reflects a range or continuum of defensive behavioral phenotypes that exist in the population in which those individual colonies are embedded. So objectionable defensive behavior can pop up unexpectedly in any population, but it will occur with higher frequency in those populations where extremely defensive bees are more common or prevalent. We only rarely encounter bjectionably defensive bees, whether managed or wild, in the regions of Central and SouthEast Texas where most of our colonies are. Consequently bees with that phenotype do not have a significant influence on subsequent generations of our population and so the incidence of objectionably defensive bees remains very low in our BeeWeaver population.
What are the ramifications of all of this today? We have extremely mellow bees under most conditions. If our colonies are undisturbed by weather or environmental insults, not facing high infestations of parasites, or predation and harassment by skunks, raccoons, bears or humans (some masquerading as beekeepers!) our bees are remarkably restrained and are not prone to sting with minimal provocation. However, our bees do retain resentment at intrusions and are more defensive than some other managed populations when confronted with threats, however those threats manifest. For instance, our virus and mite resistant bees do become more irritated than some ultra-gentle commercial stocks if they are battling a surge in Varroa infestation or other parasites or pathogens precipitated by collapse of non-resistant colonies in their vicinity that harbor high Varroa mite loads or large numbers of small hive beetles, both of which will eventually impact surviving colonies in that area.
[Varroa mites abandon collapsing hives by attaching themselves as phoretic mites to robber bees that come to recover the unguarded honey and pollen resources of colonies killed by Varroa mites and the viruses Varroa transmit. Consequently many Varroa mites from dying colonies end up in the hives from which those robber bees originated as robbing bees return to their homes with hitchhiking parasites. Similarly, small hive beetles produce hordes of beetle offspring in colonies they overwhelm, and those beetles are drawn to other honey bee colonies in their vicinity.]
So where does that leave us today? Do you have to worry about getting an objectionably defensive hive if you buy queens from BeeWeaver? The short answer is no. However, neither we or any other beekeeper can completely exclude the possibility that a rogue queen emerges from time to time, maybe in a wild colony, and then parasitizes a mating nuc, or produces drones that contribute to the paternity of the next generation. The probability of you getting an objectionably defensive colony by using our queens is extremely low, and based upon the number of hives we’ve requeened this year for being too defensive, I’d venture that the actual probability is less than one in a thousand (0.001).
Remember, the other part of the equation is that defensive behavior is a normal response to colony threats. In fact, recent research has demonstrated that extremely non-defensive colonies exhibit gene expression patterns that resemble the gene expression patterns of sick colonies. In order to achieve Varroa mite and honey bee virus resistance we selected principally for traits associated with Varroa and virus resistance and tolerated more defensive bees in the early years of our quest to develop a Varroa and virus resistant population. After achieving our principal aims, for the past 20 + years we have carefully re-emphasized gentle behavior as one of our principal selection criteria while continuing to preserve virus resistance and Varroa tolerance. Today I am not confident that we can further reduce the natural defensive posture of our population without surrendering the vitally important mite and virus resistance traits we have worked so hard to obtain and retain for future generations.