Wilfried Wichard

A New Alderfly in Baltic Amber (Megaloptera: Sialidae)

Abstract A new species of alderfly (Megaloptera: Sialidae) is described and figured from a rare adult specimen preserved in middle Eocene (Lutetian) Baltic amber. Sialis (Protosialis) voigti, new species, is distinguished from the two other species of Protosialis recorded from Baltic amber. The Megaloptera documented from Baltic amber are briefly overviewed and the geological history of Sialidae summarized.

Fossil scales illuminate the early evolution of lepidopterans and structural colors

Mesozoic lepidopteran wing scales shed light on the early evolution of moths and structural colors. Lepidopteran scales exhibit remarkably complex ultrastructures, many of which produce structural colors that are the basis for diverse communication strategies. Little is known, however, about the early evolution of lepidopteran scales and their photonic structures. We report scale architectures from Jurassic Lepidoptera from the United Kingdom, Germany, Kazakhstan, and China and from Tarachoptera (a stem group of Amphiesmenoptera) from mid-Cretaceous Burmese amber. The Jurassic lepidopterans exhibit a type 1 bilayer scale vestiture: an upper layer of large fused cover scales and a lower layer of small fused ground scales. This scale arrangement, plus preserved herringbone ornamentation on the cover scale surface, is almost identical to those of some extant Micropterigidae. Critically, the fossil scale ultrastructures have periodicities measuring from 140 to 2000 nm and are therefore capable of scattering visible light, providing the earliest evidence of structural colors in the insect fossil record. Optical modeling confirms that diffraction-related scattering mechanisms dominate the photonic properties of the fossil cover scales, which would have displayed broadband metallic hues as in numerous extant Micropterigidae. The fossil tarachopteran scales exhibit a unique suite of characteristics, including small size, elongate-spatulate shape, ridged ornamentation, and irregular arrangement, providing novel insight into the early evolution of lepidopteran scales. Combined, our results provide the earliest evidence for structural coloration in fossil lepidopterans and support the hypothesis that fused wing scales and the type 1 bilayer covering are groundplan features of the group. Wing scales likely had deep origins in earlier amphiesmenopteran lineages before the appearance of the Lepidoptera.

On the systematic position of a highly derived amphiesmenopteran insect from Burmese amber (Insecta, Amphiesmenoptera)

A small fossil insect with scales on the wings and body was identified as a representative of Aphiesmenoptera from Burmese amber. The species is introduced here as Tarachocelis microlepidopterella (†). The insect is described in detail, and photos and line drawings are provided for wing venation, head, mouthparts, scales, legs and abdomen. All characters shared with primitive Lepidoptera and Trichoptera are symplesiomorphies or groundplan traits of Amphiesmenoptera. In addition, the Burmese fossil has a number of remarkable autapomorphies, giving it an appearance that deviates clearly from known families of Lepidoptera and Trichoptera. The species, representing a family of its own, Tarachocelidae, is considered a separate and unique taxon in the stem-group of Amphiesmenoptera and is provisionally placed as Amphiesmenoptera incertae sedis.* *NB: See Note Added in Proof (Section 4).

The psychomyiid genus Palerasnitsynus (Insecta, Trichoptera) in mid-Cretaceous Burmese amber

Abstract The extinct caddisfly genus Palerasnitsynus (Psychomyiidae) is revised, based on nine new species embedded in mid-Cretaceous Burmese amber. They can be distinguished from all other extinct and extant psychomyiid genera by the absence of fork III in their fore- and hindwings and by the presence of latero-apical dark sporns at the 3rd maxillary palp segment. These species belong to the smallest Trichoptera hitherto known, with forewing lengths of 1.8–2.6 mm. Moreover, the micro-caddisflies of the genus Palerasnitsynus are very common and comprise almost 60 % of all caddisflies in Burmese amber. Some amber pieces contain aggregations of specimens which indicates swarming activities of the adults.

New long-horned caddisflies in Eocene Baltic amber (Insecta, Trichoptera)

We describe two new extinct caddisflies, Electroadicella kuenowi sp. nov. and Triaenodes simoni sp. nov., embedded in Baltic amber. Both species belong to the tribe Triaenodini and enlarge the family Leptoceridae to a remarkable number of 18 extinct Eocene species from Baltic amber. The extinct Electroadicella and the extant Triaenodes are possibly closely related, by a distinct synapomorphy, a recurved process from the basal plate of the inferior appendages of the ninth abdominal segment in the male genitalia.KurzfassungAus dem Baltischen Bernstein werden zwei neue fossile Köcherfliegen beschrieben: Electroadicella kuenowi sp. nov. und Triaenodes simoni sp. nov. Die beiden fossilen Arten gehören zur Gattungsgruppe Triaenodini der Familie Leptoceridae, die mit 18 Arten auffallend artenreich im eozänen Baltischen Bernstein vorkommt. Die beiden Gattungen Electroadicella und Triaenodes sind offensichtlich eng miteinander verwandt; sie unterscheiden sich von allen anderen Leptoceriden im männlichen Genital durch einen synapomorphen Fortsatz an der basalen Platte der unteren Anhänge des 9. abdominalen Segments.