Insects demonstrate color preferences

Dec 05, 2013

(Phys.org) —Insects prefer to eat green leaves rather than red ones, research from Victoria University has shown.

Ignatius Menzies, who will be awarded a PhD in Ecology and Biodiversity next week, tested a long-standing hypothesis that use red foliage as a visual warning to deter approaching .

"The possibility that plants use a visual warning system as a defence has been discussed in the literature for over 10 years," he says, "but there hasn't been a lot of data collected in this area."

Ignatius was part of an international team of researchers from Victoria University of Wellington, the Plant Extracts Research Unit (Plant & Food Research) in Otago and the University of Freiberg in Germany, which carried out the study using horopito, the New Zealand native pepper tree.

"It's an ideal species to test," says Ignatius, "because of its vibrant colour."

Earlier work on the topic had shown that redder leaves contain higher levels of an unpalatable defence compound—"the redder the leaf, the more peppery the taste," says Ignatius.

His research involved spending a lot of time in the hills of Lower Hutt's Belmont Regional Park, an area with a rich population of horopito. He studied 30 pairs of plants that were identical except for one being coloured red and one green.

Ignatius checked every leaf for caterpillars, quantified leaf damage and counted the fruit produced by the plant.

Back in the laboratory, he examined levels of pigment and the defence compound, assessed whether the leaves had nutrient deficiency and carried out choice tests with typical eaters including leaf-roller caterpillars, stick insects and weta.

"The redder plants had 20 percent fewer caterpillars—it was clear the caterpillars much preferred to eat the ," he says.

His research concluded that although redder-leaved bushes can defend themselves better against insect attacks, contrary to expectations, they do not produce more fruit or seeds than the green bushes.

"We found that the redder plants photosynthesise less than the ," says Ignatius, "so, there seems to be cost to the plant. Red plants are eaten less, but the plants have more energy to put into the formation of new leaves."

Professor Kevin Gould, who supervised Ignatius's research, says: "This work makes a significant contribution to our knowledge of how plants can defend themselves from the incessant onslaught from insect herbivores.

"Simply by changing the colour of their leaves, plants can better protect themselves from hungry caterpillars."

Explore further: Female moths use olfactory signals to choose the best egg-laying sites

add to favorites email to friend print save as pdf

Related Stories

Caterpillars attracted to plant SOS

Jul 01, 2013

Plants that emit an airborne distress signal in response to herbivory may actually attract more enemies, according to a new study published in the open-access journal Frontiers in Plant Science .

Insects use plant like a telephone

Apr 23, 2008

Dutch ecologist Roxina Soler and her colleagues have discovered that subterranean and aboveground herbivorous insects can communicate with each other by using plants as telephones. Subterranean insects issue chemical warning ...

A tale of two fungi

Mar 05, 2013

(Phys.org) —In the February issue of New Phytologist, Tulane University biologists examine why leaf-cutting ants target some plants and avoid others, concluding that high levels of friendly fungi in the ...

Honeybees as plant 'bodyguards'

Dec 22, 2008

Honeybees are important to plants for reasons that go beyond pollination, according to a new study published in the December 23rd issue of Current Biology, a Cell Press publication. The insects' buzz also d ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

Apr 18, 2014

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...