L'ami des châtaigners

Il se promenait tranquillement sur une feuille de menthe au bord du sentier. C’est un téléphore fauve (Rhagonycha fulva) qui se reconnaît par rapport aux autres espèces de coléoptères cantharidae par sa couleur rousse avec des antennes, des yeux, le bout des élytres et les tarses noir.

Rhagas signifie « fente » et onux, « griffe » : « avec des griffes fendues » ; fulva signifie « fauve ».

Dans son nom commun « téléphore », têle provient de « loin » et phorein de « porter » : « répandu partout ».

Les imagos (forme adulte) se nourrissent surtout de pollen. C’est notamment un important pollinisateur du Châtaignier dont nous avons parlé recemment, et ce loin devant l'Abeille mellifère car ces dernières ne visitent pas les fleurs femelles. Ils sont également à l’occasion prédateurs d'autres espèces floricoles, surtout quand le pollen vient à manquer, s’avèrant même un auxiliaire des cultures de pomme de terre en s’attaquant au doryphore.

La femelle pond ses œufs à la surface du sol. Les larves se nourrissent d'escargots et de petits insectes. Elles hivernent à terre, sous les pierres ou les feuilles mortes.

Avant de s'envoler il a fait tout aussi tranquillement un petit numéro d'équilibriste sur une tige de graminée.

Monsieur muscle

Elle était posée sur la porte et brillait au soleil. C’est une oedémère noble (Oedemera nobilis), un coléoptère dont les élytres sont de couleur vert métallique, souples et ne ouvrent pas tout l’abdomen.

C’est une femelle car les mâles des espèces d’œdémères possèdent des fémurs postérieurs enflés. Comme ci-dessous le mâle d’une autre espèce d’oedémère (Oedemera pthysica), On en ignore la raison car ce ne sont pas des insectes sauteurs. Par contre ils volent très bien.

 

Ils vivent au bord des forêts et dans les prairies fleuries. Les adultes se nourrissent de fleurs et de pollen jouant ainsi un rôle actif dans la pollinisation des fleurs. Mais les larves sont xylophages.

Comme le crache-sang et le méloé, ces insectes produisent aussi des gouttelettes toxiques pour dissuader les prédateurs.

This bright green coleoptera is a female of Oedemera nobilis. The elytra are strongly narrowed towards the apexes, not hiding the membranous hind wings.

The male of Oedemera species, possesses the hind femora very swollen, like this Oedemera pthysica, whereas in female the femora are thin. However, these insects are not jumping, they fly.

Oedemera nobilis is abundant in spring on several flower species. It feeds on pollen and nectar. Larvae are eating wood or shrubs.

Like bloody beetle and meloe, they can exude droplets of poison as a defensive behaviour.

Under the fallen leaves

Thanks to my two border collie that like digging holes in the forest I found this Carabus nemoralis (commonly called the "Bronze Carabid"). This beetle is mainly nocturnal, most active from March - December, and especially in late summer. When resting it is found under stones and logs.

It can run fast and is a beneficial voracious predator as it eats the agricultural pest like snails, slugs, in its young stage and also its eggs and many other invertebrates. Use of Carabus nemoralis as a biocontrol agent for multiple pests in large scale farming operations have been tested in recent years.

It is a ground beetle common in central and northern Europe, as well as Iceland. While native to Europe, it has been introduced to and is expanding its range throughout North America.

There are over 25,000 species of Carabids (ground beetles) world wide of which 2,600 species in Europe. The color of the elytra (wing cases) of Carabus nemoralis, here green, can also be dark, brown or with a copper sheen and always contains irregular ridges and three lines of pores down each elytron. The one pictured here is a male because its forelegs show larger tarsal parts than in females’ forelegs.

Six dangerous legs

Strange insect on the path: at first it seemed dead but as for the bloody beetle we already met, it is a trick.

This is Meloe violaceus, the violet oil beetle, part of the blister beetle genus Meloe commonly referred to as oil beetles because they release oily droplets of hemolymph (name of the blood of insects) from their joints when disturbed; this contains cantharidin, a poisonous chemical causing blistering of the skin and painful swelling. Members of this genus are typically flightless, without functional wings, and shortened elytra.

Indeed after a few minutes, the insect moved and went on its way.

The body is 10–30 millimeters long, females are somewhat larger than the males.

As in other members of the family, they are hypermethamorphic, going through several larval stages, the first of which is typically a mobile triungulin that finds and attaches to a host in order to gain access to the host's offspring. In this genus, the host is a bee, and each species of Meloe may attack only a single species or genus of bees; while sometimes considered parasitoids, it appears that in general, the Meloe larva consumes the bee larva along with its provisions, and can often survive on the provisions alone.

The birds, the bees … and the bugs too!

On the trail two bugs are preparing next generations…

Bloody beetle

When having a walk in the forest, the favourite hobby of the dogs is digging holes. Doing that, they opened the tunnel of an amazing beetle which is going out mainly at night: a bloody-nosed beetle (Timarcha tenebricosa), also called blood spewer or blood spewing beetle.

As defensive behavior, to deter potential bird predators from eating them, they exude droplets of their bright red-orange hemolymph by breaking thin membranes in their mouth which is foul-tasting to predators. This phenomenon of "bleeding" exists in some other insects, such as ladybugs.

After a while, it went on slowly, as this beetle never flies.

Timarcha tenebricosa is monophagous, the larva feed exclusively on bedstraws, especially species with tender leaves (Galium verum, Galium mollugo). Eggs are laid in spring on bedstraws. Larvae are quite large, blue-black in color.

The beetle can be found in southern and central Europe, and is common in Ireland and in Britain, but becomes rare in the north.

Colourful beetle on the trail

We have plenty Carabus here, from black ones to more colourful. I like very much the Carabus hispanus pictured above.

Carabus hispanus is a species of beetle in family Carabidae native to southwestern France, with the Massif Central as the northern boundary of its distribution range. These carabus likes beeches, oaks and chestnut trees forests like around here. Their meal is made of worms, slugs and snails.

More carabus here: http://www.insectes-net.fr/carabus/carabus7.htm