Bugs are capable of complex and amazing communication with each other, with other animals and with plants. These communications evolved to enable bugs to avoid threats, secure resources, and breed. However the threats to bugs from humans far exceed the communication ability of bugs which is why Buglife is here to speak out, educate and persuade on their behalf.
Last Saturday was the Environment Trust for Richmond annual lecture. This year the theme was communication in the natural world and the speakers were David Attenborough, who gave an inspiring talk with amazing examples of the complexity of animal communication, Joe Pecorelli of ZSL who opened up the aquatic communication world of fish and me, explaining why and how bugs communicate. Here are some highlights and thoughts arising from the lectures.
Communication depends on an organism emitting a signal and another organism receiving the signal, there are several mediums that can carry this information. Humans perceive the world primarily through ‘audible’ sound and ‘visible’ light, with important added information from touch, smell and taste.
We struggle to even conceive perception outside these parameters, but many organisms build up their ‘picture’ of the world in a way that is alien to humans. For instance:-
- • Moths see in colour (not black and white) even on the darkest night
- • Many insects see ultraviolet light that is invisible to us
- • Mosquitoes ‘see’ in infrared – they detect heat
- • Bats, cats, crickets and many other animals hear ultrasound, sounds above our hearing range
- • Senses of smell and taste vary widely depending on the animal’s specific chemical detectors
- • Some fish and insects perceive a world of electrical fields
- • Bees, birds and other animals sense magnetic fields
It is not clear that all of these are used for communication, for instance it has not been shown that animals are able to deliberately produce magnetic fields or heat based signals, but as we would not be able to perceive this communication then perhaps we are overlooking it?
Some signals are emitted on a common medium and are very widely understood. The highly contrasting and bright black and yellow stripes of a wasp are understood by almost all animals as a warning – “I am dangerous – leave me alone”.
When the audience is not so wide, communication often happens in a much narrower and more discrete medium. Males of many insects are fine-tuned with large antennae to enable them to detect the pheromone signals of their females, quite a feat considering the thousands and thousands of messages being sent as chemicals on the breeze. The Roesel’s bush cricket calls to females at a frequency that many of us can’t hear.
Indeed mating communications are perhaps the most amazing and detailed of communication activities. The peacock spiders are great exponents of mating communication. These little jumping spiders live in hot arid places and the male has a fabulous dance. He erects a stunning red and blue disk over his head and dances, waving his black and white stripy legs in the air and swaying his ‘tail’ from side to side to impress a potential mate. Each species has a different pattern on its disk and a unique dance. In at least one species the female peacock spider responds by ‘twerking’ her abdomen – evidence that twerking has been on the planet for millions of years before the birth of Miley Cyrus.
Sexual reproduction evolved 1200 million years ago and it is probable that some basic “I’m here!” communication followed soon afterwards. Bugs and plants have evolved together for 400 million years and complex communications between them have been around for at least 125 million years.
The most obvious complex communication is around pollination – a partnership between species that is essential for the reproduction of most wild flowers and provides humans with much of the food we eat. Flowers create chemical attractants – the fantastic scents that are often beautiful and beguiling to us, as well as to bees; flowers are also colourful, including in ultraviolet for the benefit of the insects. In addition recent research at the University of Bristol has shown that flowers are able to create electrical fields that the insects can detect, and the plant can even switch these on and off to direct insects to the flowers with the most resources and in the greatest need of pollination.
Social insects often have particularly sophisticated communication, the waggle dance of the Honeybee in which the returning worker tells her fellow workers where they can find flowers, being one of the best known. However the communication skills of the Honeybee are outstripped by the Honey badger that sprays the hive with a fluid from its anal glands that appears to subdue the bees and inhibit them from attacking the Honey badger.
Bugs may be sophisticated communicators, but their communication skills are failing to protect them from Humans. A Glow worm is unable to tell the Local Authority to turn off the streetlamps that mean it can no longer see the dim glow of the female; a bumblebee is ill-equipped to complain that car exhaust fumes are making it much harder for her to find flowers; and 1,000 species of parasitic wasps cannot explain to the Government that plans to plant new GM crops, that would flood the countryside with plant alarm pheromones, may make it very hard for them to find aphids and other herbivores in which to lay their precious eggs.
The inability of bugs to alert us to potentially devastating changes we are making to the environment is why it is so important that Buglife exists and provides an essential service as the professional advocate for invertebrates and their conservation. Buglife speaks out on behalf of 40,000 species in the UK alone and influences the public, policy makers and land managers so that one species (us) can make better decisions for bugs and can manage the planet more sustainably.