Houston’s gall wasp has a new species that spends 11 months in protected crypts. It’s been named for a pub.

Neuroterus valhalla — which is just a millimetre long — honours ‘Valhalla’, the Rice University graduate student pub outside of which it was found in a live oak tree.

‘It would have been a missed opportunity to not call it something related to Rice or Valhalla,’ said biologist Pedro Brandão-Dias, who first collected the wasp in 2018.

According to the researchers N. valhalla is the first insect species to be described alongside the publication of its fully sequenced genome.

A new species of gall wasp (pictured) discovered in Houston whose lifecycle involves spending 11 months of the year locked up in protective 'crypts' has been named after a pub

Houston’s gall wasp found a new species. It spends its entire life in protective crypts. The species has been named for a pub.


Family: Cynipidae (all wasps) 

First discovered: 2018

Formally described 2021 

Size: 1 millimetre long

Range:Mexico and the Southern US 

The study was led from the lab of Rice University evolutionary biologist Scott Egan — who, over the course of eight years, have discovered just as many new species of either gall wasps like N. valhalla or their predators.

Professor Egan explained that Rice emphasizes learning by doing.

“In my laboratory, both undergraduate and graduate students participate in experiential learning by studying the biologically diverse ecosystems of the live oaks outside our front doors. 

The possibilities are endless if one has patience and is equipped with a magnifying device.

According to the researchers, there are more than 1,000 different species of gall wasps — all of which have a lifecycle that involves tricking their host tree into feeding and sheltering their young.

The tree forms a crypt around their egg when it lays its eggs.

“Once they have emerged, they live only three to four days. They don’t eat. Their only purpose is to mate and lay eggs,’ Mr Brandão-Dias said of the tiny wasps. 

Galls take various forms, with some forming on the underside of leaves, some inside branches and others on the flowers of trees — with latter of which is where the biology student first collected specimens of N. valhalla back in the spring of 2018.

Mr Brandão-Dias and his colleagues had been collecting oak catkins while looking for an entirely different species of gall wasp known to make the flowers home — but DNA analysis revealed that they had managed to catch more than expected.

‘They lay their eggs into the catkins that are developing,’ Mr Brandão-Dias said. 

“They grow from the galls that are on the flowers. Then they rise. That happens in March. The flowers only bloom once a year and then they disappear. 

“So they must lay eggs on another tissue.”

In fact, many ‘gallers’ lay their eggs biannually and not necessarily in the same kind of places each time — which is why it took almost four years for the researchers to feel comfortable publishing their description of N. valhalla as a new species.

As Professor Egan explained, it is not unprecedented for alternating generations of gallers to be confused for entirely different species — making genetic testing of the specimens across the different parts of their lifecycle essential.

This was not all. The team needed to find out where N. valhalla had laid its eggs, if it wasn’t in the flowers.

In 2019, Kelly Weinersmith of University of Iowa, along with her associates discovered N. Valhalla’s missing generation during a Florida trip. They found it in galls in branch junctions of Florida species of live oak. 

Neuroterus valhalla ¿ which is just a millimetre long ¿ honours 'Valhalla', the Rice University graduate student pub outside of which it was found in a live oak tree. Pictured: researchers Pedro Branda¿o-Dias (left) and Camila Vinson (right) in front of Valhalla

Neuroterus valhalla — which is just a millimetre long — honours ‘Valhalla’, the Rice University graduate student pub outside of which it was found in a live oak tree. Pictured: researchers Pedro Brandão-Dias (left) and Camila Vinson (right) in front of Valhalla

‘To confirm where they were going after they left the flowers, I performed an experiment where we offered the wasps a bunch of different tissues from the tree and observed them,’ Mr Brandão-Dias explained.

This experiment, undertaken in a petri dish, allowed the researchers to see where N. valhalla went after emerging from the catkin galls at Rice — and catch them in the act of laying their eggs elsewhere.

However, the coronavirus epidemic made it more complicated. 

“We’d go together to collect catkin galls, tissues and other materials for behavioral tests in petri dish. [undergraduate student Camila Vinson, who lived on the Rice campus] had to go everyday to the lab to see if any bugs had emerged,’ Mr Brandão-Dias said. 

Based on Dr Weinersmith’s observations and the lab tests, the researchers were able to go back to the live oak trees on the Rice campus where they had found the first generation of the wasps — to find the missing galls from the other generation.

According to Mr Brandão-Dias, the N. valhalla generation that hatches in live oak catkins matures from being eggs to fully-formed adults in around 2–3 weeks — but their successors spend 11 months growing inside the branches.

“They must be out exactly at the time that the tree is blooming.” The biologist said that if they arrive at an incontinentally time and there are no flowers, then they won’t be able to lay eggs, which would cause them to die.

Pictured: the life cycle of N. valhalla. Females of one generation (A) lay their eggs in live oak flowers (or 'catkins', B) ¿ inducing the formation of galls (or 'crypts', C1/2), from which a second generation hatches (D2) within 2¿3 weeks. After maturation, these adults lay they eggs at the junctions of tree branches (E), also forming galls (F1/2) that hatch after 11 months, in time for the flowering season. The team have yet to discover a male wasp (D1)

The life cycle of N. Valhalla. Females of one generation (A) lay their eggs in live oak flowers (or ‘catkins’, B) — inducing the formation of galls (or ‘crypts’, C1/2), from which a second generation hatches (D2) within 2–3 weeks. These adults hatch at 11 months after maturation and lay their eggs near the intersections of tree branch branches (E). A male wasp has not yet been discovered by the team (D1).

It is unclear at present exactly how N. valhalla manages to coordinate their emergence with the flowering of the trees, which can vary from year-to-year.

At present, the researchers are waiting with baited breath to see how last year’s winter storm in February — which caused record cold temperatures across Houston and delayed the flowering of live oak trees — might have affected the insects.

Pedro said that the freeze had occurred on January 1, 2008. He asked Pedro: “Is this going be a problem when they get out, or their ability even to reproduce?”Ms Vinson said that she remembered.

The biologist is tackling this question as part of her senior thesis, which is exploring more widely how climate change might be affecting such specialized insects.

‘Our gall wasps live on live oaks from the southern United States all the way down through Mexico — environments [that]They are not used the temperature we experienced in February,’ noted Ms Vinson.

“These types of freezes will probably happen more often with climate change.” The big question is — are these populations going to be in danger, or can they quickly adapt?’

Systematic Entomology has published all of the findings.


Experts believe that nature is facing greater danger than ever before. Over one million species are at risk of extinction.

That’s the key finding of the United Nations’ (UN) first comprehensive report on biodiversity – the variety of plant and animal life in the world or in a particular habitat.

According to the report published by May 6th 2019, species are losing at an unprecedented rate. 

According to the report, many of the worst consequences can be stopped by changing how food is grown, produced, and disposed of.

Summary of the 39-page report highlighted five methods that humans are decreasing biodiversity.

– Transforming forests and grasslands into cities, farms and other development. Habitat loss can make animals and plants homeless. The report stated that three quarters of Earth’s surface, two thirds of Earth’s oceans, and 85% of Earth’s crucial wetlands were severely altered, or gone, which makes it more difficult for species to live.

– The overfishing of the oceans. Overfishing accounts for a third of all fish stocks in the world.

– Allowing climate change caused by fossil fuel burning to cause it to be too hot, dry or wet to support some species. Global warming has already affected nearly half the land mammals and almost a quarter the bird species.

– Land and water pollution. The world waters are contaminated with 300 million to 400 millions tons of solvents, heavy metals, and toxic waste every year.

– Allowing invading species to outnumber native animals and plants. Since 1970, the number of countries with invasive species has increased by 70%. One species of bacteria threatens nearly 400 amphibian species.