# The Diversity of Spoon-Winged and Thread-Winged Lacewing Larvae Today and in Deep Time—An Expanded View

## TL;DR

This paper explores the diversity of lacewing larvae, both modern and ancient, revealing insights into their evolution and convergent traits.

## Contribution

The study presents new fossil lacewing larvae from Myanmar and provides evidence for greater ancient morphological diversity and convergent evolution.

## Key findings

- New fossil lacewing larvae from 100-million-year-old Kachin amber expand the known fossil record of Nemopteridae.
- Morphological diversity in fossil larvae is greater than in modern ones, though results are less conclusive than in other lacewing groups.
- Convergent evolution played a significant role in shaping similar larval morphologies among antlion-like lacewings.

## Abstract

Most larvae of lacewings (Neuroptera) prey on other animals, such as the larvae of antlions. In the larger group of antlion-like lacewings, the larvae look similar to those of antlions but have their own certain characteristics. Larvae of the group Nemopteridae can be easily separated into two groups: the larvae of thread-winged lacewings (Crocinae), also known as long-necked antlions, have relatively slender mouthparts and long necks, as the name suggests; the larvae of spoon-winged lacewings (Nemopterinae) have stout mouthparts and bodies. We here report new lacewing larvae of the group Nemopteridae from about 100-million-year-old Kachin amber, Myanmar. With the new findings several new fossil larvae of this group are now known. We used shape analyses to compare the fossil and modern larvae. Our results support those of earlier studies, more exactly that the morphological diversity of the fossils was larger than of the modern larvae. However, the results are not as conclusive as in other lacewing groups. The comparison also indicates that independent evolution of similar morphologies played an important role in the evolution of larvae of antlion-like lacewings.

Larvae of lacewings (Neuroptera) are (mostly) ferocious predators, and the most well known are the larvae of antlions. In the larger group of antlion-like lacewings, the larvae resemble those of antlions to a certain degree but have certain peculiarities. Larvae of the group Nemopteridae can be easily separated into two groups: the larvae of Crocinae (thread-winged lacewings), also known as long-necked antlions, have relatively slender mouthparts and long necks, as the name suggests; the larvae of Nemopterinae (spoon-winged lacewings) have stout mouthparts and bodies. We here report new lacewing larvae of the group Nemopteridae from about 100-million-year-old Kachin amber, Myanmar. The new findings significantly expand the dataset of these animals in the fossil record. Quantitative analyses comparing the fossil and extant larvae support earlier indications that the morphological diversity of the fossils was in fact larger, yet the results are not as conclusive as in other ingroups of Neuroptera. The comparison also indicates that convergent evolution played an important role in the evolution of larvae of antlion-like lacewings.