A century of slumber: NHM insect researcher rediscovers a neuroptera species after 100 years
07. March 2024
The brightly coloured green lacewing is likely a common sight to anyone who frequently spends time in the
garden or the great outdoors. Their larvae are aphids’ greatest nemesis. Less well known is the graceful antlion lacewing,
a member of the neuroptera insect group whose larvae are called simply antlions. When hunting they build sand traps where
they hide and wait to throw sand at prey when it approaches. There are around 5,500 of these species worldwide and around
120 in Central Europe.
However, there are also lesser-known members of the neuropteran order. These include, for
example, the Nevrorthidae family including the species Nevrorthus apatelios. Dr. Susanne Randolf, insect researcher
at the Natural History Museum Vienna, is particularly fascinated by these inconspicuous, light brown creatures.
In 1929, the then curator of the Natural History Museum Vienna, Dr. Hans Zerny, was able to collect a single adult male N. apatelios on his trip to Bosnia-Herzegovina, Montenegro and Dalmatia. There have been no documented sightings since.
In 2022, several scientists from the NHM Vienna (including Michaela Brojer, Dr. Elisabeth Haring and Dr. Michael Duda) took part in the Neretva Science Week as part of the “Save the Blue Heart of Europe” campaign. The week is organised every year by Riverwatch, EuroNatur, Center for Environment and the ACT Foundation (both in Bosnia and Herzegovina) as well as the Manfred-Hermsen-Stiftung foundation.
A diverse team of 48 researchers from seven countries gathered in the small town of Ulog (Bosnia and Herzegovina) with the goal of preserving the Neretva River. The river is 230 km long and flows through Bosnia and Herzegovina before emptying into the Adriatic Sea on the Croatian coast.
The scientists collected data aimed at classifying this pristine and highly threatened river ecosystem. They focused on describing biodiversity aspects associated with the river by combining their expertise on different aquatic and terrestrial plant and animal groups. They also investigated the environmental conditions that promote this biodiversity, along with a range of ecosystem functions.
Susanne Randolf has now been able to identify two N. apatelios larvae from the material collected at the NHM Vienna and publish her findings. “They confirm the presence of the species in Bosnia and Herzegovina for the first time in almost 100 years,” says Dr. Randolf, a neuroptera expert and first author of the article.
The life cycle of the species is amphibious, taking place both on land and in the water. Adult insects are found near bodies of water on overhanging branches of deciduous trees and in bushes. There they search for aphid excretions, so-called honeydew, for their prey. They are rarely caught and are difficult to find even when you are specifically searching for them.
As larvae, they are predators living in the water and equipped with venom-filled sucking pincers. They are very long and slender, have long bristles and wriggle forwards and backwards at lightning speed through the gaps between gravel and coarse sand in search of prey. They can live in a large spectrum of water temperatures, but only thrive in clean, oxygen-rich waters and are therefore a good indicator of particularly high level of water quality.
The habitat in which the Nevrorthidae larvae live is dependent on year-round, non-drying watercourses with gravel riverbeds, large boulders and coarse sand in areas with intact natural vegetation.
These kinds of rivers, flowing through nearly pristine landscapes, still exist on the Balkan peninsula. These ecosystems have survived the last decades of human incursions into the natural environment, which has severely affected the rivers on most of the European continent and beyond. However, the rivers in the Balkans are also in danger today, with more than 3,500 hydropower plants currently being planned there. Constructing them would entail major changes and habitat losses for riparian animal species. The discovery of the rare N. apatelios larvae underscores the importance of preserving this precious natural heritage for the future.
Additional links:
https://journals.uni-lj.si/NaturaSloveniae/article/view/17222/15294
https://balkanrivers.net/de/neretva-wissenschaftswoche
https://balkanrivers.net/de/news/vorlaufiger-bericht-der-neretva-wissenschaftswoche
For scientific enquiries:
Dr. Susanne Randolf
Zoological Department 2, NHM Vienna
https://www.nhm-wien.ac.at/susanne_randolf
In 1929, the then curator of the Natural History Museum Vienna, Dr. Hans Zerny, was able to collect a single adult male N. apatelios on his trip to Bosnia-Herzegovina, Montenegro and Dalmatia. There have been no documented sightings since.
In 2022, several scientists from the NHM Vienna (including Michaela Brojer, Dr. Elisabeth Haring and Dr. Michael Duda) took part in the Neretva Science Week as part of the “Save the Blue Heart of Europe” campaign. The week is organised every year by Riverwatch, EuroNatur, Center for Environment and the ACT Foundation (both in Bosnia and Herzegovina) as well as the Manfred-Hermsen-Stiftung foundation.
A diverse team of 48 researchers from seven countries gathered in the small town of Ulog (Bosnia and Herzegovina) with the goal of preserving the Neretva River. The river is 230 km long and flows through Bosnia and Herzegovina before emptying into the Adriatic Sea on the Croatian coast.
The scientists collected data aimed at classifying this pristine and highly threatened river ecosystem. They focused on describing biodiversity aspects associated with the river by combining their expertise on different aquatic and terrestrial plant and animal groups. They also investigated the environmental conditions that promote this biodiversity, along with a range of ecosystem functions.
Susanne Randolf has now been able to identify two N. apatelios larvae from the material collected at the NHM Vienna and publish her findings. “They confirm the presence of the species in Bosnia and Herzegovina for the first time in almost 100 years,” says Dr. Randolf, a neuroptera expert and first author of the article.
The life cycle of the species is amphibious, taking place both on land and in the water. Adult insects are found near bodies of water on overhanging branches of deciduous trees and in bushes. There they search for aphid excretions, so-called honeydew, for their prey. They are rarely caught and are difficult to find even when you are specifically searching for them.
As larvae, they are predators living in the water and equipped with venom-filled sucking pincers. They are very long and slender, have long bristles and wriggle forwards and backwards at lightning speed through the gaps between gravel and coarse sand in search of prey. They can live in a large spectrum of water temperatures, but only thrive in clean, oxygen-rich waters and are therefore a good indicator of particularly high level of water quality.
The habitat in which the Nevrorthidae larvae live is dependent on year-round, non-drying watercourses with gravel riverbeds, large boulders and coarse sand in areas with intact natural vegetation.
These kinds of rivers, flowing through nearly pristine landscapes, still exist on the Balkan peninsula. These ecosystems have survived the last decades of human incursions into the natural environment, which has severely affected the rivers on most of the European continent and beyond. However, the rivers in the Balkans are also in danger today, with more than 3,500 hydropower plants currently being planned there. Constructing them would entail major changes and habitat losses for riparian animal species. The discovery of the rare N. apatelios larvae underscores the importance of preserving this precious natural heritage for the future.
Additional links:
https://journals.uni-lj.si/NaturaSloveniae/article/view/17222/15294
https://balkanrivers.net/de/neretva-wissenschaftswoche
https://balkanrivers.net/de/news/vorlaufiger-bericht-der-neretva-wissenschaftswoche
For scientific enquiries:
Dr. Susanne Randolf
Zoological Department 2, NHM Vienna
https://www.nhm-wien.ac.at/susanne_randolf
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