'Western honey bee' (Apis mellifera) on Asclepias tuberosa.
Many people don't like insects, bees sting, ants bite, bugs stink, gnats drink our blood and wasps even claim a part from our sweet cake. :) I, however, admire these little creatures for their skills to defend themselves and be able to survive whatever the environmental conditions are.
Because of the limited amount of available time and the huge amount of interesting data I decided to write part I now and add part II as soon as time allows. Enjoy reading now! :)
At least nowadays more and more people are getting aware about how useful many insects are as pollinators of our fruit trees and as honey producers ('useful' in a sense to benefit our survival on the planet; considered from a less egocentric point of view every creature has its value, independent from its utility for us humans).
In addition in my opinion insects will be a precious food source of the future because of their huge biomass, their high protein content and proliferation rate and their low required space when farming them.
Obviously insects are associated with many different attributes ... but being intelligent is normally not one of them ...
I will show you by means of a few examples why I think that some insects are actually amazingly 'intelligent'. Of course I am aware that many of their behavioral patterns (even if fascinating) are innate and proceed instinctive, but there exist hints that insects actually show kind of conscious thinking and are even aware of themselves as single individuals. You don't believe me? This 
Remark: I will restrict myself on examples of insects belonging to the order Hymenoptera[1] (which contains for example ants, bees, bumblebees and wasps), because they are well known and also has been objects of many studies.
Osmia spec. and 'large earth bumblebee' (Bombus terrestris) on Cirsium spec..
As Jon Lieff describes within a beehive with the aid of pheromones the queen influences the choice of bees to either feed the larvae or work as foragers or scouts.[3] The rather small group of scouts is busy with seeking new food resources (nectar, pollen, water). In case they found something they return to their hive and inform the other bees by using a 'dance language', the 'waggle dance', about the good news.
During this dance a bee walks on a straight line while waggling its abdomen (the waggle phase). At the end of the line it turns to the right and makes a semicircle back to the starting point (the return phase). Then comes a waggle phase again after which the bee turns to the left to circle back to the starting point. This can happen up to more than 100 times, whereby after every waggle phase the scout alternating turns to the right and then the left side again to begin its semicircles.[4] Watched at it from above it looks like the figure eight.
Deciding for having any impact on the behavior of the other bees is that the dancers are emitting signals in the form of impulses of frequencies between 240 to 260 Hz. Beside these impulses, which are transmitted by the molecules of the air, also vibrations of the same frequencies are forwarded by the wax of the honeycombs.[5]
This symbolic language contains the following information:
Amazingly one can observe that scouts which stay in the nest for a longer timescale have the ability to adjust the angles of their dances according to the changing position of the sun.
Most of the time this waggle dance is used if any flowers are further than 100 meters away from the hive, otherwise the more simple 'round dance' is the means of choice.
The waggle dance is also used when bees are seeking new nest-site locations (which is even supposed to be the origin of this behavior).
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I hope that the drawing below may lead to a better understanding of how the waggle dance works:
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As fascinating the waggle dance is, one cannot really speak of intelligent behavior here. It is about an innate instinctive activity, but you need to know about it to understand the following examples.
I recommend German speaking Steemians to read the very detailed description of the waggle dance by the famous bee researcher Prof. Dr. Randolf Menzel: "Was denken Bienen, wenn sie tanzen?"[6]
Two solitary bees on Cirsium spec..
Bee brains belong to the biggest ones within the class of insects. 'Big' means that their volume amounts to roughly 1 mm3 (approximately the size of a sesame seed) containing about 960000 neurons (ant brains show similar sizes).[7]
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One reason for the amazing cognitive performances of bees and other hymenoptera (I will deal with some examples in part II) can be found in a special
brain structure called mushroom bodies (MBs) which contains nearly 200000 parallel neurons, the Kenyon cells.[13] They are segmented into several modules which allow multi-sensory input (olfactory, visual, mechanosensory, gustatory). These different informations are allocated on and processed parallel by many different neurons within the mushroom bodies, but finally converge in a small number of output neurons. This system of divergence and then multi-modal convergence helps the insects to integrate different kinds of information, interlink them and even draw logical conclusions (as we will see next time).[13], [11] |
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Some other interesting aspects I would like to mention:
Learning of bees seems to be coupled with emotions, similar like in our own case. Researches of Clint Perry and colleagues of the Queen Mary University of London showed that due to dopamine-dependent positive emotions bumblebees which received pretest sucrose were more motivated and 'optimistic' to check the edibility of the unknown content of a cylinder and also recovered faster from negative environmental cues like a simulated predator attack.[14]
Because of the comparable low number of neurons, single nerve cells can have a much higher impact on the behavior of the animal. In an interview Randolf Menzel goes so far to label certain neurons as 'individuals' respectively 'individual neurons' which by getting active all alone have the power to regulate a certain behavioral pattern, for example to make a bee remember a certain scent.[15]
The plasticity of the bee brain is amazing. Some time ago scientists assumed that organisms with such a low number of nerve cells should be 'hardwired' - once connected, neurons would stay like that, unable to react on environmental changes and learning new things. However, neuroplastic changes have been observed for specific dendritic spine activity in the mushroom bodies during learning.[3]
Finally also acetylation of histones, and methylation of DNA are used in learning and memory consolidation like mammals do (same source).
Two 'western honey bees' (Apis mellifera) on Asclepias tuberosa.
Photos are own work where not otherwise stated.
