Despite their name, stingless bees or meliponines are equipped with powerful mandibles to bite intruders alongside injecting a painful formic acid. Stingless bees will also use a sticky resin to actively stick intruders to the floor with some species forming a soldier caste solely to dispatch intruders.
Unlike honeybees, stingless bees have vestigial (atrophied) stingers that cannot be used to sting any attackers.
Despite their name, this fascinating taxonomy of bees is fully equipped to deter and dispatch predators and intruders.
Let’s take a closer look at how these bees go about defending their nest from unwanted visitors.
Stingless bee defence methods
Stingless bees have a myriad of strategies for defending their nest from predation. Each strategy has advantages and disadvantages and some of the methods listed here are only available to certain taxonomies.
Biting and formic acid
All stingless bees are equipped with a pair of powerful mandibles that they can use to bite any predators or opportunists trying to steal honey.
Stingless bees can inject formic acid at the site of the bite adding to the discomfort for any potential predators.
During foraging trips collecting nectar and pollen, stingless bees collect a sticky resin that attaches to the lower part of their legs.
This sticky resin may seem like an annoyance but it plays a crucial role in protecting the entrance to the nest and helping with hygiene.
The sticky resin gets laid at the entrance of the hive in a similar fashion to a doormat. Antibacterial properties of the resin work to remove any potential parasites or diseases from the feet of bees entering the nest.
It also acts as a trap for any unwanted visitors. They get stuck to the resin placed on the floor allowing guard or soldier bees to dispatch them quickly with their powerful mandibles.
A soldier caste within the nest
Some forms of stingless bees have evolved to develop a soldier caste within their colonies. Scientists observed a form of stingless bee called the Jatai bee found in Brazil that had developed soldiers within the colony’s ranks, prior to this there had been no recordings or mention of soldier castes amongst any stingless bee species.
Since this discovery, four other species of stingless bee have been observed producing soldier bees with the sole intention of defence rather than foraging for nectar and pollen.
These bees are tasked with fortifying and defending the colony and dispatching any insects trapped by the sticky resin situated at the entrance to the nest.
These soldier bees have been observed to be 10-30% larger than their worker bee counterparts.
Interestingly this morphological evolution has occurred mainly due to another species of opportunistic stingless bee that specialises in stealing honey from other nests.
Robber bees constitute any nearby nest that opts to steal honey stores from neighbouring bees rather than go out foraging. This will predominantly occur when you have a much more dominant colony within close range of a much weaker colony.
Bees are all about survival and if it’s easier to simply steal honey from nearby nests they will.
Before the creation of this special caste within the colony, the division of labour was decided purely on age. Younger bees are tasked with caring for the young and maintaining the hygiene of the nest. As bees age they begin to take on a foraging role, leaving for daily flights to collect nectar and pollen.
This simple division has been in place for thousands if not millions of years and only now we are starting to see a fascinating change.
Bees within the soldier caste are identified by a different morphology due to their much larger size, a truly incredible evolutionary development in an insect that has remained unchanged for such a long period of time.
A study undertaken by researchers at the University of Sussex found that some species of stingless bees go as far as to sacrifice themselves in defence of the hive.
The researchers used small black felt flags which they waved near the entrance of the hive to simulate an attack of robber bees.
This test was conducted on a range of species but in particular bees for the family T.hylinata reacted in a fascinating manner. The attack was instant and vicious, so much so that some of the attacking bees separated their heads from their abdomen in an effort to clamp onto the perceived attackers.
Interestingly it was found that colonies with higher populations reacted more aggressively to any perceived attackers.
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