Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Leaf chewing links insect diversity in modern and ancient forests


Observations of insects and their feeding marks on leaves in modern forests confirm indications from fossil leaf deposits that the diversity of chewing damage relates directly to diversity of the insect population that created it, according to an international team of researchers.

"The direct link between richness of leaf-chewing insects and their feeding damage across host plants in two tropical forests validates the underlying assumptions of many paleobiological studies that rely on damage-type richness as a means to infer changes in relative herbivore richness through time," the researchers report in today's (May 2) issue of a.

A scarab beetle (Coleoptera: Scarabaeidae) observed inducing margin feeding on leaves from Tapirira guianensis Aubl. tree during feeding experiments.

Credit: Wilf, Penn State

A katydid observed inducing margin feeding on leaves from Guatteria dumetorum tree during feeding experiments.

Credit: Wilf, Penn State

Studies of leaf chewing include observation of the leaves, but rarely include all the insects that actually made the marks. Mónica R. Carvalho, graduate student, Cornell University and Peter Wilf, professor of geosciences, Penn State, and colleagues looked at leaf predation in two tropical forests in Panama to test for a relationship between the richness of leaf-chewing insects and the leaf damage that the same insects induce.

Using Smithsonian Tropical Research Institute canopy-access cranes and working in the dark at almost 200 feet high in the treetops at new moon during two summers the researchers collected a total of 276 adult and immature leaf-chewing insects of 156 species. While the largest category of insect was beetles, leaf chewers among grasshoppers, stick insects and caterpillars, as well as a few ants, were also collected.

The team also collected fresh leaves of the insects' host plants and placed the insects in feeding experiment bags with these leaves. They allowed adult insects to feed for two to three days and immature stages to feed until full maturity when possible. The researchers then classified the damage to the leaves into categories, in the same way they catalog fossil leaf- chewing damage.

"This is the first attempt to compare leaf-chewing damage inflicted by many kinds of living insects on many kinds of plants throughout a large forest area, both to the culprit insects and to the leaf damage we see in the fossil record," said Carvalho. "We mounted 276 of the insects with their damaged leaves and deposited them in the STRI Insect Collection."

This collection is the only known vouchered collection of diverse, identified insects and their feeding damage on leaves of identified plant hosts.

The number of collected insect species correlated strongly with the number of damage types recorded in canopy leaves of 24 tree and liana species observed in the feeding experiments. This suggests that the number of types of damage seen in the fossil record is also related to the actual diversity of damage-making insects.

The researchers also compared the modern leaf data to fossil data from Colombia, Argentina, the Great Plains and the Rocky Mountains. They found that the distribution of chewing marks was the same across both modern and ancient settings, showing a striking consistency in how insects have divided up their leaf resources since at least the end of the age of dinosaurs.

"In the fossil record we frequently find a decrease in damage-type richness during cooling events and after extinctions and an increase in damage-type richness during warming events and post-extinction recovery," said Wilf. "Usually, insect body-fossils from these critical time intervals are absent or very rare, so we rely on the insect-damaged leaves to tell the story. These fossil studies have been considered tremendously important for understanding how ecosystems have responded, and will respond, to climate change and disturbance. We now have direct observational evidence that the fossil data represent changes in actual insect richness and no longer need to infer this through deduction alone."

"This work also unlocks the potential to use insect damage as a new way to assess living insect richness, as in the fossil record, in the context of climate change," said Carvalho. "We used fossils to frame a hypothesis about how the world works, today and through time, and discovered in the living tropical rainforest that the hypothesis is correct. More kinds of chewing marks means more kinds of insects."


Other researchers on this project were Héctor Barrios, Programa de Maestría en Entomología, Universidad de Panamá; Donald M. Windsor and Carlos A. Jaramillo, Smithsonian Tropical Research Institute, Panamá; Ellen Currano, assistant professor of geology and environmental earth science, Miami University of Ohio; Conrad C. Labandeira, department of paleobiology, Smithsonian Institution and department of entomology, University of Maryland.

The David and Lucile Packard Foundation and the National Science Foundation supported this research.

A'ndrea Elyse Messer | Eurek Alert!

Further reports about: Carvalho damage diversity forests immature insect leaves species tropical tropical forests

More articles from Life Sciences:

nachricht New supercomputer simulations enhance understanding of protein motion and function
24.11.2015 | DOE/Oak Ridge National Laboratory

nachricht Sensor sees nerve action as it happens
24.11.2015 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Lactate for Brain Energy

Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.

In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...

Im Focus: Laser process simulation available as app for first time

In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.

Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...

Im Focus: Quantum Simulation: A Better Understanding of Magnetism

Heidelberg physicists use ultracold atoms to imitate the behaviour of electrons in a solid

Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...

Im Focus: Climate Change: Warm water is mixing up life in the Arctic

AWI researchers’ unique 15-year observation series reveals how sensitive marine ecosystems in polar regions are to change

The warming of arctic waters in the wake of climate change is likely to produce radical changes in the marine habitats of the High North. This is indicated by...

Im Focus: Nanocarriers may carry new hope for brain cancer therapy

Berkeley Lab researchers develop nanoparticles that can carry therapeutics across the brain blood barrier

Glioblastoma multiforme, a cancer of the brain also known as "octopus tumors" because of the manner in which the cancer cells extend their tendrils into...

All Focus news of the innovation-report >>>



Event News

Gluten oder nicht Gluten? Überempfindlichkeit auf Weizen kann unterschiedliche Ursachen haben

17.11.2015 | Event News

Art Collection Deutsche Börse zeigt Ausstellung „Traces of Disorder“

21.10.2015 | Event News

Siemens Healthcare introduces the Cios family of mobile C-arms

20.10.2015 | Event News

Latest News

Siemens offers concrete solution portfolio for Industrie 4.0 with Digital Enterprise

24.11.2015 | Trade Fair News

Compact, rugged, three-phase power supplies for worldwide use

24.11.2015 | Trade Fair News

Sensor sees nerve action as it happens

24.11.2015 | Life Sciences

More VideoLinks >>>