Insect hotels are very fashionable at the moment, but mainly for commercial or aesthetic reasons. In any case, building or installing a house for insects is a simple and inexpensive way to increase the biodiversity of your garden, terrace or balcony, and is within the reach of all.
Why encourage insects?
For their role as pollinators:
Insects form a very important link in ecosystems. Whilst mostly unpopular, insects play very important roles. The best known are bees, appreciated since prehistoric times, especially for the honey they produce, but also for their role as pollinators.
For some plants pollination is provided by wind (eg conifers, grasses, including cereals). However for much of the plant kingdom, pollination is provided by insects. Insect-pollinated flowers have evolved to attract different pollinators. For example, the flowers of many European orchids mimic, in form and colour, the bees or bumblebees that pollenate them, in order to attract them (eg Bee orchid (Ophrys spp,).
Insects from different taxonomic groups do not all see the same colours: blue, purple or pink flowers attract butterflies; yellow flowers attract flies and other Diptera. There are flowers that have patterns only visible under ultra-violet light because some insects can see this part of the spectrum of light. These patterns guide the insects to the nectar and sexual organs of the plant to ensure pollination. Other plants are pollinated mainly by different species of Diptera and Coleoptera (eg Arum species, including the enormous Titan Arum (Amorphophallus titanum) for which the inflorescence can reach 3 m in height). The flowers of plants pollinated by insects have colours and often very special perfumes, sometimes extremely nauseating.
For their role in the biological control of « undesirable » species:
Other insects are useful to humans for their control of other insect species, eg. Ladybirds in aphid control.
For their role in the food chain of the ecosystem:
For the vast majority of insects, their roles in ecosystems are not well known. Many, however, serve as food for many animals such as swallows, dippers, shrews, tits, honey buzzards, badgers … to name just a few European species.
– For their usefulness to us:
If we eliminate insects, or destroy a good part of them with our pesticides, the repercussions on the food chain of the ecosystems can be catastrophic, even for man. If we destroy the pollinators, we will no longer have fruit and vegetables for our food, except for varieties that self-pollinate, or are genetically-modified organisms …
What can you do ?
Farmers can convert to organic farming, or at least reasoned, at the same time reducing their own exposure to these poisons, but they will need our support when making our choices during our shopping.
We can all do something to slow down the reduction of insect populations:
- stop gardening with pesticides which kill all insects without discrimination, including bees and ladybirds.
- leave a corner of the garden uncultivated to diversify species and constitute a pantry for butterflies, for example Peacock (Inachis io) and Vulcan (Vanessa atalanta) on nettles (Urtica dioïca),
- install an insect hotel now !