Like humans, insects communicate with each other by “telephone” and can even leave messages, according to Dutch researchers.

No special electronics are needed because the bugs literally use green technology – plants – to communicate.

According to the new study from the Netherlands Institute of Ecology and Wageningen University, insects which live in and above the ground use a plant as a telephone by eating its roots. That changes the chemical composition of its leaves, which in turn causes the plant to release alarm signals into the air.

These signals tell other insects not to eat that plant and move along, in order to avoid any competition between insects. The signals also warn others of possibly-dangerous chemical compounds in the plant.

If a bug isn’t around to immediately receive the message, the study shows another insect can leave a ‘voicemail’ message in the soil itself, through various soil fungi, by leaving specific remains in the soil after eating from the plant.

In the Netherlands Institute of Ecology greenhouse, plants and plant-feeding insects are put together to assess their ability to store 'voicemail messages' in the soil. (Photo: Olga Kostenko/NIOO-KNAW)

Unlike our own ‘voicemail’ messages which disappear at a push of a button, these warning messages live on to serve future generations of insects.  Any new plants that happen to grow on the same spot, according to the research, can grab these same signals from the soil and again communicate the message to other insects.

The messages left in the soil can be rather specific . The new plant could warn bugs that its predecessor suffered from conditions that could be harmful to insects.

In their experiments, the researchers grew ragwort plants in a greenhouse and then left the plants open to threatening insects, such as leaf-eating caterpillars or root-feeding beetle larvae.  They later replaced those plants by growing new ones in the same soil and again the plants were left open to the hungry insects.

“What we discovered is that the composition of fungi in the soil changed greatly and depended on whether the insect had been feeding on roots or leaves,” explains researcher and study author, Olga Kostenko. “These changes in fungal community, in turn, affected the growth and chemistry of the next batch of plants and therefore the insects on those plants.”

The researchers are working to find an answer to how long the warning messages remain in the soil and just how widespread this occurrence is throughout nature.

December 1972 - Apollo 17 Astronaut Eugene 'Gene' Cernan was the last human on the Moon (Photo: NASA)

A team of European scientists wants to send people back to the moon, ending the 40-year break from human lunar exploration.

The group not only wants to see a resumption of lunar exploration, but it recommends those efforts be dramatically stepped-up.

In a report to be published in “Planetary and Space Science,” the authors argue sending humans back to the moon, placing new scientific instruments on, and returning additional samples from the surface of the moon, will help us better understand the history of the Solar System, the origin and evolution of the Earth-Moon system, the geological evolution of rocky planets, and the near-Earth cosmic environment throughout Solar System.

The last time a human walked on the moon was during the Apollo 17 mission in December 1972.

The USSR's Luna 24 unmanned lunar explorer was the last to go and return from the moon in August 1976 (Image: NASA)

The scientists believe a renewed emphasis on exploration of the moon would also provide a number of research opportunities in astronomy, astrobiology, fundamental physics, life sciences, human physiology and medicine.

Over the past decade, there’s been something of a renaissance in lunar exploration. A number of unmanned spacecraft – from the European Space Agency (ESA), Japan, China, India and the U.S. – have orbited the moon, but none have performed a controlled landing on its surface.  The last spacecraft to touch down on the moon and return to Earth was Russia’s Luna 24 robotic mission in August 1976.

However, a portion of the US Lunar Crater Observation and Sensing Satellite (LCROSS) and India’s Chandrayaan-1 Moon Impact Probe (MIP) were deliberately crashed into the moon’s surface in order to perform experiments required by their missions.

Although some of their objectives can still be achieved robotically,  the European science team says lunar exploration would benefit significantly from renewed human operations on the moon.

Artist Concept of the unmanned Lunar Reconnaissance Orbiter currently orbiting and mapping the moon at 50 kilometers from lunar surface. (Image: NASA)

They recommend current and future non-manned lunar exploration missions be developed in the context of future human exploration, similar to what’s outlined in 2007’s Global Exploration road map which recommends an expansion of human presence throughout the Solar System and human exploration missions to the surface of Mars.

Following the framework of a 1992 study by the European Space Agency, the paper’s authors propose their lunar science objectives can logically be divided into three categories:

• Science of the moon (study of the moon itself)
• Science on the moon (studies that use the moon’s surface as a platform for experiments, not related to the moon itself.
• Science from the moon (using the lunar surface as a base to conduct astronomical observations).