An owlfly larva preserved in Mexican amber and the Miocene record of lacewing larvae

Abstract

Neuroptera (lacewings) is today a rather small lineage of Holometabola. These representatives of Insecta have mostly predatory larvae with prominent venom-injecting stylets formed by upper and lower jaws. These impressive larvae can be found not only in the modern fauna, but sometimes also as fossils, predominantly preserved in amber. Here we report a new specimen of a lacewing larva from Miocene Mexican amber, most likely a larva of an owlfly (Ascalaphidae) with large prominent stylets, each with three teeth. These stylets arise from a more or less square-shaped head (in dorsal view) that has distinct eye hills with at least three simple eyes (stemmata) each. The trunk is rather short. Trunk segments possess finger-like protrusions carrying numerous setae, which could have been used to attach camouflaging debris to it. Remarkably, the specimen represents only the second report of a lacewing from Miocene Mexican amber, and the first larva. Additionally, we review the Miocene record of lacewing larvae. It includes otherwise only fossils preserved in Dominican amber and remains rather scarce, with only eight specimens in the literature so far. While there seem to be additional specimens in private collections, the overall number is astonishingly low compared to the numbers in Eocene and Cretaceous ambers. Ecological and taphonomic factors possibly explaining the rarity of lacewing larvae in Miocene amber are discussed here.

The Morphological Diversity of Antlion Larvae and Their Closest Relatives over 100 Million Years

“…It is an interesting detail that there are significantly more larvae in Miocene ambers than in Eocene ones. This ratio is quite different for other lacewing groups (e.g., [ 62 ]), as the Eocene amber, especially Baltic amber, is known for a much larger number of amber pieces than Miocene amber. Despite the larger sample size of the Miocene specimens, the sub-sample size of the Miocene and Eocene is still quite small, and a most reliable comparison is to be expected from the Cretaceous versus the extant fauna.…”

“…The impression of a more diverse lacewing fauna in the past is provided by numerous fossils, especially from the Mesozoic (e.g., [46][47][48][49][50][51][52][53][54][55][56]), but also from the Cenozoic era (e.g., [57][58][59][60][61][62]). These fossils include numerous different types of lacewing larvae (e.g., [26,47,50,52,), among them being also larvae that have been interpreted as representatives of the combined group including Myrmeleontidae and Ascalaphidae [47,50,52,57,62,86]. Some of these larvae have more precisely been interpreted as offshoots of the direct evolutionary lineage towards the combined group [50].…”

“…The impression of a more diverse lacewing fauna in the past is provided by numerous fossils, especially from the Mesozoic (e.g., [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]), but also from the Cenozoic era (e.g., [ 57 , 58 , 59 , 60 , 61 , 62 ]). These fossils include numerous different types of lacewing larvae (e.g., [ 26 , 47 , 50 , 52 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 ]), among them being also larvae that have been interpreted as representatives of the combined group including Myrmeleontidae and Ascalaphidae [ 47 , 50 , 52 , 57 , 62 , 86...…”

The first adult mantis lacewing from Baltic amber, with an evaluation of the post-Cretaceous loss of morphological diversity of raptorial appendages in Mantispidae

“…There are over a dozen adults of Mantispidae known from Cretaceous ambers (Poinar and Buckley 2011, Pérez-de la Fuente and Peñalver 2019, Lu et al 2020, Shi et al 2020a, and three records from Miocene ambers (Poinar 2006, Engel andGrimaldi 2007). In many instances, Baltic amber has yielded significantly more specimens than are known from Miocene ambers (e.g., Haug et al 2020aHaug et al , 2021b. The lower number of specimens of Mantispidae in Baltic amber compared to that of Cretaceous ambers could be explained by the overall decline of Neuroptera during at least the last 100 million years (e.g., Aspöck and Aspöck 2007).…”

The First Fossil Record of a Mantis Lacewing Pupa, and a Review of Pupae in Mantispidae and Their Evolutionary Significance

“…Engel & Grimaldi 2007;Menon & Makarkin 2008;Jepson 2015;Winterton et al 2019), but also for larvae (e.g. Pérez-de la Fuente et al 2020;Haug et al 2021a), while fossil pupae are an absolute rarity (see discussion).…”