Thursday, May 3, 2018

[PaleoEntomology • 2018] Phyllochrysa huangi • Liverwort Mimesis in a Cretaceous Lacewing Larva

Phyllochrysa huangi 
Liu, Shi, Xia, Lu, Wang & Engel, 2018

• A new lacewing species is described from the Cretaceous based on larvae
• Distinctive foliate lobes are present on the thorax and abdomen of these larvae
• Such morphological modifications grossly match coeval liverworts
• The new larvae are the first example of direct mimicry in lacewing larvae

Camouflage and mimicry are staples among predator-prey interactions, and evolutionary novelties in behavior, anatomy, and physiology that permit such mimesis are rife throughout the biological world. These specializations allow for prey to better evade capture or permit predators to more easily approach their prey, or in some cases, the mimesis can serve both purposes. Despite the importance of mimesis and camouflage in predator-avoidance or hunting strategies, the long-term history of these traits is often obscured by an insufficient fossil record. Here, we report the discovery of Upper Cretaceous (approximately 100 million years old) green lacewing larvae (Chrysopoidea), preserved in amber from northern Myanmar, anatomically modified to mimic coeval liverworts. Chrysopidae are a diverse lineage of lacewings whose larvae usually camouflage themselves with a uniquely constructed packet of exogenous debris, conveying greater stealth upon them as they hunt prey such as aphids as well as evade their own predators. However, no lacewing larvae today mimic their surroundings. While the anatomy of Phyllochrysa huangi gen. et sp. nov. allowed it to avoid detection, the lack of setae or other anatomical elements for entangling debris as camouflage means its sole defense was its mimicry, and it could have been a stealthy hunter like living and other fossil Chrysopoidea or been an ambush predator aided by its disguise. The present fossils demonstrate a hitherto unknown life-history strategy among these “wolf in sheep’s clothing” predators, one that apparently evolved from a camouflaging ancestor but did not persist within the lineage.

Keywords: Neuroptera, Chrysopidae, Mesozoic, Burmese amber, mimicry, liverwort

Figure 1. New Green Lacewing Larva Phyllochrysa huangi gen. et sp. nov. in Upper Cretaceous (earliest Cenomanian) Amber from Northern Myanmar (Holotype NIGP167955)
(A) Dorsal habitus. (B) Ventral habitus.

Figure 2. Phyllochrysa huangi gen. et sp. nov. and Potential Model Plants from Upper Cretaceous Amber from Northern Myanmar
(A, D, and F) An unnamed liverwort (PB22713) and its leaves.
 (B, E, and G) Phyllochrysa huangi gen. et sp. nov. (LPAM BA17003) and its lateral plates.
(C) An unnamed leaf liverwort (PB22712).
Scale bars, 1.0 mm ([A]–[C]), 0.1 mm ([D]–[G]).

Systematic Paleontology 
Order Neuroptera Linnaeus, 1758. 
Superfamily Chrysopoidea Schneider, 1851. 

Phyllochrysa huangi gen. et sp. nov.

Etymology The genus-group name is a combination of phyllon (Greek, meaning, ‘‘leaf’’) and chrysos (Greek, meaning, ‘‘gold’’ and a common suffix for chrysopoid genera). The specific epithet honors Yiren Huang, who kindly donated the holotype for our study.


Figure 3. Ecological Reconstruction of Phyllochrysa huangi gen. et sp. nov.
Two larvae are shown at rest on liverworts.
Illustration: Dinghua YANG

 Xingyue Liu, Gongle Shi, Fangyuan Xia, Xiumei Lu, BoWang and Michael S. Engel. 2018. Liverwort Mimesis in a Cretaceous Lacewing Larva. Current Biology. In Press.  DOI: 10.1016/j.cub.2018.03.060

100-million-year-old liverwort mimicry in insects  @physorg_com