10:25 a.m., February 27, 2022
Insects spontaneously arouse less sympathy than pandas, dolphins or elephants. However, the massive decline of these little beasts, widely documented by the scientific literature over the past three years, is very bad news. For the first time, a « red list » orthopteroids from Île-de-France – locusts, crickets, grasshoppers, mantis and stick insects – has just been drawn up by the regional biodiversity agency (ARB), a department of the Paris Region Institute, and the Office for insects and their environment (Opie). It will be published on Monday, the JDD presents it in preview.
This catalog of vulnerable or threatened species, drawn up according to the standardized methodology of the International Union for Conservation of Nature (IUCN), will be of particular interest to ecologists. Because this « grass people » is considered valuable « bio-indicator of the state of health of our ecosystems, in this case meadows, lawns, wasteland, moors, clearings », explains the naturalist Hemminki Johan, co-author of the study. Especially since the results are worrying. The ARB has already launched five red lists in the Paris region, devoted to vascular plants, birds, bats, dragonflies and butterflies. All worrying.
There are 28,500 species of Orthoptera on the planet and 220 in France. In Île-de-France, this group of insects is divided into 71 species: 20 grasshoppers, 11 crickets, 38 locusts, 1 mantis (the nun) and 1 stick insect (called Gallic). “For this unprecedented census exercise, we have compiled more than 38,000 consolidated observation data collected by 350 contributors over the past ten years, says Xavier Houard, coordinator of this red list. Few Regions have this level of knowledge, Normandy, Burgundy, New Aquitaine and us. » The Ile-de-France study has a particularity: it also describes the dangers and proposes solutions.
We haven’t seen the dectic of the brandes again
“The findings are alarming, warns Xavier Houard. A quarter of Ile-de-France species are threatened with extinction in the very short term. » Among the 71 species in Ile-de-France, around ten have recently arrived in Ile-de-France, coming from the south because of climate change (another cause for concern). Of the remaining 61, 5 fall into the category « critically endangered »4 » in danger « 5 « vulnerable »7 « near threatened ». “And 4 species have been found to have disappeared from the Ile-de-France region, that’s a lot! sighs the naturalist. Unfortunately, this work illustrates the serious biodiversity crisis. » To sum up, 6% of these insects have disappeared, 22% are threatened and 11% are almost threatened in Île-de-France.
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Thus, the red oedipodium has not been seen since 1964, the heather dectic since 1922. The red-tailed locust and the calcicole tetrix are on the verge of extinction. The heather decticella, the vine ephippiger or the marsh cricket have to worry about their offspring. Some might not be moved by this announced extinction; they would be wrong. Some Orthoptera are predators, they devour aphids and mites, thus protecting crops. Others, herbivores, contribute to the diversity of grasses. And all of them are an indispensable reservoir of food for other animals. « Without them, the birds will desert the Ile-de-France countryside »summarizes Hemminki Johan.
« Let’s not forget either that we owe them the little music of the summer, the soundtrack of our holidays“, adds Sophie Deschiens, regional councilor (LR) and president of the ARB. However, it is not easy to make the general public aware of their fate. This is the ambition of the House of Insects, within the departmental park of the People of the Grass, in Carrières-sous-Poissy (78). Teams of Opie teachers also crisscross the schools. “Awareness of the usefulness of pollinators, especially bees, is now established, rejoices Xavier Houard. For locusts, it is more complicated: they are associated with one of the ten plagues of Egypt; we have to fight over two thousand years of ancestral fears in the collective unconscious. Fortunately, there is Jiminy Cricket! »
Drastically limit the use of pesticides
To halt the decline of « grassland insects » it is first necessary to drastically limit the massive use, in Ile-de-France agriculture, of pesticides, “which spare no insect”,note the naturalists. Then, it is necessary to stop the artificialization of the grounds, to support meadows and meadows, green, blue or brown wefts (open ground).
ARB specialists recommend« Avoid concrete or gravelling gardens and building courtyards » of “let the grass grow, let it wither, turn yellow”… Their red list counted 14 species of orthoptera on green roofs, including at 20 or 30 meters high: the Bordeaux cricket at the top of the musical Seine in Boulogne-Billancourt (92), for example, or the variegated decticella on the Mozinor building in Montreuil (93).
» The president [Valérie Pécresse] decided to create a new agency, called Natura, which she entrusted to me in charge, says Sophie Deschiens. It must play the role of conservatory of natural spaces in the Ile-de-France region, protect biodiversity, clean up wasteland, renature our towns and villages. » Owners of small areas can apply for a “labeling”eligible for technical assistance from the ARB. The 1,400 mayors of the Region received a questionnaire to “identify the brakes” . “Our elected officials are often tempted to favor an English lawn over a meadow”, continues the president of the agency. The Region is also working on revising its master plan, renamed Sdrif-E, to “environmental”: the notion of “zero net land take” will be set in stone there.
Environmental protection is also a competence of the metropolis of Greater Paris (MGP). « We have just voted the metropolitan territorial coherence scheme, which provides for the objective of 30% of full land », welcomes Antoinette Guhl, vice-president of the MGP in charge of nature, biodiversity and agriculture. The elected EELV has also just launched the second edition of the Nature 2050 call for projects, which finances municipalities committing to maintaining a meadow until 2050. And it will present a metropolitan biodiversity plan, in April, which will include a quarantine “action sheets”.In the meantime, the threat weighs more than ever.