Nav: Home

Effort clarifies major branch of insect tree of life

November 26, 2018

CHAMPAIGN, Ill. -- The insects known as Hemiptera are not a particularly glamorous bunch. This group includes stink bugs, bed bugs, litter bugs, scale insects and aphids. Their closest relatives are thrips, bark lice and parasitic lice. But with a massive number of species, two-thirds of which are still unknown to science, these insects together make up one of the twiggiest branches of the tree of life.

A new study published in the Proceedings of the National Academy of Sciences collected a vast amount of molecular data on these insects and used the information to help tease out their family relationships and evolutionary history. The findings - and the data, which are now publicly available - will aid future research into some of the most abundant and economically important insects on the planet, the researchers said.

"There are 120,000 known species in this group, which is maybe a third of what's actually out there," said Illinois Natural History Survey entomologist Christopher Dietrich, who led the study with INHS ornithologist Kevin Johnson. "To put that in perspective, that's more than all the vertebrates combined. It's a massively diverse group. They cover the planet. They're in every habitat."

Many of these insects feed on plants and animals and can be seen as pests, Dietrich said. But they also provide food for birds, insectivorous mammals, reptiles, amphibians and other predacious insects.

"Many of them form the first link of the food chain, converting plant material into protein that can be used by other animals," he said.

Among this group are many, like aphids and planthoppers, that afflict crops; others, such as body lice and certain assassin bugs, transmit disease, Dietrich said.

To sort out these insects' family relationships and history, the researchers analyzed nearly 2,400 protein-coding genes, their expression in the form of messenger RNA and the resulting amino-acid sequences. It was a massive effort involving collaborators in China, Europe, Japan and across the United States.

"We wanted to use newer sequencing technologies to address how all these major groups of hemipteroid insects related to each other," Johnson said. "This is probably one of the largest data sets in existence for insects."

The effort yielded several key findings. The most interesting of these had to do with the development of special mouthparts in some members of this group, the researchers said.

"The earliest, most primitive insects just had a pair of mandibles to chew, like ants do," Dietrich said. "But some groups went off in a different direction."

For those, the mandibles gradually evolved into sturdy narrow tubes that could pierce things and suck out the juices. "It was a major shift in feeding strategy," Dietrich said. "All the insects to this point had just been chomping on things."

The team's molecular divergence estimate revealed that the evolution of piercing and sucking mouthparts likely occurred more than 350 million years ago. Similar mouthparts evolved independently in parasitic lice and other insects with the trait, such as mosquitoes.

"According to the fossil record, this group became the dominant group of insects on Earth in the Permian, 300 million years ago to 250 million years ago," Dietrich said. "But at the end of the Permian they underwent a mass extinction, which was worse than the one that killed off the dinosaurs a couple hundred million years later."

Eventually, the Hemiptera, along with the orders representing thrips and lice, were eclipsed by another group of insects, the Holometabola, which undergo complete metamorphosis and are even more diverse. Holometabola include butterflies, moths, ants, bees, flies and beetles.

Though more robust than other genetic studies of this group of insects, the new analysis has not fully resolved the relationship between the order that includes bark lice and parasitic lice, and the hemiptera and thrips, which likely belong to the same superorder, the researchers said. But the study sets the stage for future work, and an improved understanding of how some of the less charismatic, but ecologically essential, insects evolved.
-end-
The INHS is a division of the Prairie Research Institute at the University of Illinois at Urbana-Champaign.

The U.S. National Science Foundation supported this research.

Editor's notes:

To reach Kevin Johnson, call 217-244-9267; email kpjohnso@illinois.edu.

To reach Christopher Dietrich, call 217-244-7408; email chdietri@illinois.edu.

The paper "Phylogenomics and the evolution of hemipteroid insects" is available from the U. of I. News Bureau via diya@illinois.edu.

University of Illinois at Urbana-Champaign

Related Bed Bugs Articles:

People who go to bed late have less control over OCD symptoms
A late bedtime is associated with lower perceived control of obsessive thoughts, according to new research from Binghamton University, State University of New York.
Bed bug awareness poor among US travelers, but reactions are strong
Most US travelers can't identify a bed bug, and yet the pest evokes a stronger response than any other potential hotel-room deficiency -- putting the hospitality industry in a difficult spot.
Bed partners may unintentionally contribute to the perpetuation of insomnia
Preliminary results from a new study show that partners of people who have insomnia may try to be supportive by engaging in a range of behaviors that unintentionally contradict treatment recommendations.
Bed bugs: Proactive pest management critical in multi-unit housing
Amid the persistent threat of bed bug infestations in multi-unit housing, the best advice for property owners, managers, and tenants looking to avoid the pests is the same advice that applies to many other afflictions: an ounce of prevention is worth a pound of cure.
Some bed bugs show early signs of resistance to 2 common insecticides
Pest management professionals battling the ongoing resurgence of bed bugs are wise to employ a well-rounded set of measures that reduces reliance on chemical control, as new research shows the early signs of resistance developing among bed bugs to two commonly used insecticides, chlorfenapyr and bifenthrin.
Some bed bugs are better climbers than others
Not all bed bugs are created equal, and some of the leading bed bug traps used by pest management professionals are ineffective against species with better climbing abilities than others.
Corralling stink bugs could lead to better wine
To wine makers, stink bugs are more than a nuisance.
Cycling in bed is safe for ICU patients: Hamilton study
Researchers at McMaster University and St. Joseph's Healthcare Hamilton have demonstrated that physiotherapists can safely start in-bed cycling sessions with critically ill, mechanically ventilated patients early on in their ICU stay.
Can you bounce water balloons off a bed of nails? Yes, says new study
A group of first year students at Roskilde University, supervised by Dr.
Nurses' scrubs often contaminated with bad bugs
ICU nurses' scrubs often are contaminated by bad bugs spread from the patient or surfaces in the room, finds an IDWeek 2016 study.

Related Bed Bugs Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Jumpstarting Creativity
Our greatest breakthroughs and triumphs have one thing in common: creativity. But how do you ignite it? And how do you rekindle it? This hour, TED speakers explore ideas on jumpstarting creativity. Guests include economist Tim Harford, producer Helen Marriage, artificial intelligence researcher Steve Engels, and behavioral scientist Marily Oppezzo.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".