Fossils reveal diverse Mesozoic pollinating lacewings

September 17, 2018, Chinese Academy of Sciences
a, Jurassic kalligrammatids in the Daohugou forest. b, Cretaceous kalligrammatids in the Burmese amber forest Credit: YANG Dinghua

Insect pollination played an important role in the evolution of angiosperms. Little is known, however, about ancient pollination insects and their niche diversity during the pre-angiosperm period due to the rarity of fossil evidence of plant-pollinator interactions.

Recently, a research group led by Prof. Wang Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has provided new insight into the niche , chemical communication, and defense mechanisms of Mesozoic pollinating insects. Its findings were published in Nature Communications on September 17.

One of the most intensely investigated examples of pollination niches is the morphological match between insect proboscis and floral tube length, which Darwin described in a publication in 1877. Kalligrammatid lacewings are among the largest and most conspicuous Mesozoic insects with siphoning mouthparts.

The NIGPAS researchers reported 27 well-preserved kalligrammatids from late Cretaceous Burmese amber (99 Ma) and Chinese Early Cretaceous (125 Ma) and Middle Jurassic (165 Ma) compression rocks.

Kalligrammatid proboscides vary greatly in length, from 0.6 to 3.2 mm in amber inclusions and about 5 to 18 mm in compression fossils. The high diversity of kalligrammatids and large variation in proboscis length strongly suggest diverse plant hosts with different floral tube lengths. Therefore, pollination niche partitioning may have been present among some Mesozoic insects.

Jurassic and Cretaceous kalligrammatids from China. Credit: NIGPAS

If pollination niches were partitioned, as in extant ecosystems, this likely increased pollination effectiveness and reduced the cost of pollination mutualism, thus contributing to the high diversity of pollinating insects and the success of pollinator-dependent plants during the Cretaceous period.

Kalligrammatid species diversification was potentially promoted by coevolution between pollinating kalligrammatids and their host plants under highly partitioned niches.

Traits such as wing eyespots, which likely functioned as a defense in large-sized species, and sexually dimorphic antennae, which were likely used for pre-mating chemical communication, elucidate how kalligrammatids survived in the Mesozoic terrestrial ecosystem under intense competition.

Kalligrammatids in Burmese amber. Credit: NIGPAS

However, such elaborate associations between kalligrammatids and their host plants (mostly confined to gymnosperms) could have been a key factor contributing to the extinction of kalligrammatids, which likely occurred during the late Cretaceous with the decline in gymnosperm diversity.

Explore further: 99-million-year-old beetle trapped in amber served as pollinator to evergreen cycads

More information: Qing Liu et al, High niche diversity in Mesozoic pollinating lacewings, Nature Communications (2018). DOI: 10.1038/s41467-018-06120-5

Related Stories

Chinese fossils reveal middle-late Triassic insect radiation

September 5, 2018

Recently, scientists from China and the UK reported two Middle-Late Triassic entomofaunas, providing not only the earliest records of several modern insect elements, but also new insights into the early evolution of freshwater ...

Flies that pollinized Cretaceous plants 105 million years ago

July 10, 2015

When we think about pollination, the image that comes first to mind is a bee or a butterfly covered by pollen. However, in the Cretaceous —about 105 million years ago— bees and butterflies did not exist, and most terrestrial ...

Amber unveils evolution of ancient antlions

August 22, 2018

Myrmeleontiformia, consisting of antlions and their relatives, are an ancient group of lacewing insects characterized by predatory larvae with unusual morphologies and behaviors. An international team led by Prof. WANG Bo ...

Recommended for you

Galactic center visualization delivers star power

March 21, 2019

Want to take a trip to the center of the Milky Way? Check out a new immersive, ultra-high-definition visualization. This 360-movie offers an unparalleled opportunity to look around the center of the galaxy, from the vantage ...

Ultra-sharp images make old stars look absolutely marvelous

March 21, 2019

Using high-resolution adaptive optics imaging from the Gemini Observatory, astronomers have uncovered one of the oldest star clusters in the Milky Way Galaxy. The remarkably sharp image looks back into the early history of ...

When more women make decisions, the environment wins

March 21, 2019

When more women are involved in group decisions about land management, the group conserves more—particularly when offered financial incentives to do so, according to a new University of Colorado Boulder study published ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

TeeSquared
3 / 5 (2) Sep 17, 2018
Those lacewings sure looked fully formed. Pretty well looks like the fully formed insects of today.

What did they look like before the fossilized specimens?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.