Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Genetic differences in termite castes may lead to better control


Termite colonies, such as this one collected on the Purdue campus, are helping researchers like Michael Scharf develop ways to control the pest. Scharf is an entomology research professor and director of the Purdue Industrial Affiliates Program in the Center for Urban and Industrial Pest Management. (Purdue Agricultural Communications photo/Tom Campbell)

Learning the molecular processes that cause termite larvae to grow into workers, soldiers or reproductive adults may lead to new methods to decimate colonies of the wood-eaters, according to Purdue University researchers.

The scientists identified 25 genes that provide some of the first information concerning the differentiation of the insects based on the role they play within a colony. The study, published in this month’s issue of the journal Genome Biology (, shows that the level at which some of the newly discovered genes are expressed differs depending on which adult form the termite becomes.

"Many of the genes we found are involved in muscle function," said Michael Scharf, entomology research professor and lead author of the study. "Most of these muscle proteins are expressed in the soldiers and not the workers. The soldiers have big heads and jaws, so they require more muscle in the head to drive those jaws.

"But soldiers don’t have wings, so they don’t have flight muscles as are found in the developing nymphs, which become winged reproductive adults."

Though possibly hundreds of termite species exist around the world that are different sizes and live in different types of colonies, they all have similarities. They all eat wood or woody plants high in cellulose. They are very social and form monogamous relationships in which a new king and queen fly away from the original colony to form a new one. Termite larvae can become a member of any of three castes – soldiers, workers and the nymphs that develop into alates, or reproductively mature males and females.

The soldiers guard the colony but can’t reproduce, fly or feed themselves. Workers feed the other termites, tend the larvae and young insects, and dig tunnels. The alates can fly and reproduce.

"Termites have a hormone, called juvenile hormone, that is very important to insects during their development," said Scharf, also director of the Purdue Industrial Affiliates Program in the Center for Urban and Industrial Pest Management. "When they are immature they have this hormone, but when it’s gone they molt for a final time and become adults. In termites, the adults are the reproductive individuals that replenish the colony with new members."

Scharf and his team found that if they treated worker termites with juvenile hormone, they became soldiers. They also found that in normal colonies some nymphs begin to develop eyes, wings and reproductive anatomy, but also can regress into workers by molting backwards and losing their eyes, wing pads and their reproductive characteristics.

"If we could modify proteins in termites to change workers into helpless soldiers, then we could make 75 percent of the colony soldiers," he said. "That would be pretty lethal to the termites but have minimal environmental impact."

Since the alates and the soldiers can’t feed themselves or dig tunnels, and the workers and soldiers can’t reproduce, the termites would die off fairly quickly, Scharf said.

The researchers found that workers have high levels of four genes that produce enzymes for breaking down cellulose into digestible sugars. Cellulose is the substance that makes up the structure of plants; the enzymes that break down the cellulose are called cellulases. Two of these four genes produce cellulases in the termites. The other two are from microbes in the termites’ digestive system. These bacteria aid in metabolizing the food.

The Purdue scientists also found a number of termite genes related to ones found in the common research insect, Drosophila. Some of these genes also may be similar, or homologous, to development genes in other animals.

Mutation of one of these related genes causes Drosophila, or fruit flies, to have two lower halves and no head. The related gene in termites is found at higher levels in the soldiers, Scharf said. This mutation, fatal in fruit flies, may explain why soldier termites’ heads and bodies are almost the same size.

"Our research is teaching us about termite biology and development – how they diverge into their different forms, create a colony and exploit their environment, which quite often could be somebody’s house," Scharf said. "What we have learned so far is just the tip of the iceberg."

Termites found in many areas of the United States are Reticulitermes flavipes, a species of lower termites. Lower termites are subterranean, meaning they live below ground and in wood. These are about the size of a ballpoint pen tip. Higher termites, which aren’t found in the continental United States, are much bigger and build large mounds above the ground.

Termites are often mistaken for ants, however, there are some easy ways to tell the difference. Termites have straight antenna and an oval or oblong body, and those with wings have two pairs of equal length. Ants have antenna that bend at a 90-degree angle, a pinched-in abdomen and those with wings have front wings that are much longer than the back pair.

According to experts, the first known termites evolved about 100 million years ago when dinosaurs existed. They came from the same ancestors as wood-dwelling cockroaches.

The other researchers involved with this study were research scientist Dancia Wu-Scharf, assistant professor Barry Pittendrigh and professor Gary Bennett, all of the Purdue Department of Entomology.

The Center for Urban and Industrial Pest Management Industrial Affiliates Program and the Office of the Vice President of Agricultural Research provided funding for this study.

Writer: Susan A. Steeves, (765) 496-7481,

Source: Michael Scharf, (765) 494-6314,

Susan A. Steeves | Purdue News
Further information:

More articles from Life Sciences:

nachricht Biologists unravel another mystery of what makes DNA go 'loopy'
16.03.2018 | Emory Health Sciences

nachricht Scientists map the portal to the cell's nucleus
16.03.2018 | Rockefeller 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: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>