Scientists Worked For Four Years To Find A New Wasp That Barely Departs Its Home For Two Days

Parasitic gall wasps don't leave their nests very often. From eggs to larvae, pupae to adults, these tiny insects spend the most of their year encased in cocoon-like crypts on the leaves, blossoms, and stems of oak trees. There's no time to waste when spring arrives, not even for food. Before they die, the wasps have only a few days to mate and lay eggs.

The scientists that research these insects must wait for the majority of the year. Then, with magnifying glasses in hand, they must also spring into action.

More than 1,000 species of gall wasps have been found so far, and because to the animals' severe hermitism and short lifetime, they were continuously discovering new ones, including this one. It was also not a simple task to describe this new species. Despite the fact that the wasp was discovered in their backyard, it took Rice University researchers four years to describe it.

Pedro Brando-Dias initially noticed the millimeter-long wasp, Neuroterus valhalla, in the oak tree outside the university tavern Valhalla in 2018.Brando-Dias, the paper's lead author, was looking for another gall wasp species that was known to live in the same tree as N. valhalla. On closer inspection, however, it was discovered that some of the wasp's legs were slightly different colours than they should have been.

The wasp could have been a new species or an alternating generation of an existing species.Each generation of gall wasps alternates between sexual and asexual reproduction, as bizarre as it may sound.

When an asexual female wasp lays her eggs, sexual male and female offspring are produced. When those progeny reproduce, however, they only generate asexual female eggs.

The wasps are significantly more difficult to track over numerous generations because of their reproductive cycle.

Researchers needed to identify both generations of wasps with lighter coloured legs to ascertain if they were a new species or an alternating generation of a known species.The first generation of N. valhalla was discovered on the oak tree's catkins in a swelling, or gall. When the insects are just eggs, the tree forms galls to keep their voracious appetites at bay.

There are no more flowers for the adult wasps to lay their eggs on when they emerge in March. As a result, the adult beetles must tuck the next generation into a different structure on the tree. But where are you going?

Researchers seeking for gall wasps in Florida in 2019 discovered two separate species emerging from crypts near the blossoming stems of oak trees. One of these species, according to DNA analysis, was the missing generation of N. valhalla. Rice University researchers used this knowledge to remove galls from their oak tree's catkins and deposit them in a petri dish with other tree tissues in the lab.

The wasps ultimately emerged from their crypts after two or three weeks and began laying their eggs on nearby stem nodes. It took another 11 months for the second generation to emerge and deposit eggs on the catkins.

Researchers confirmed the life cycle observed in the lab by inspecting live oak trees in Austin, Texas, where they had previously observed N. valhalla but found no males.Both generations of N. valhalla have only two days to experience the outside world, and given that Texas is currently experiencing significantly cooler temperatures than normal for springtime, these species may struggle to survive in a climatic catastrophe.In our ecosystems, parasites like the gall wasp establish complex interconnected food webs that affect not only the oak tree in which they dwell, but also other parasites that devour them.A single oak tree, such as the one outside Valhalla at Rice University, can support over 100 different species. Many gall wasps, on the other hand, have only had one generation identified.