Psocoptera

Background

The California Coastal Prairie has the highest biodiversity of North America's grasslands, but also has the highest percentage of urbanization.  The most urbanized part of the California Coastal Prairie is its southernmost area, in Los Angeles County.  This southernmost region, known as the Los Angeles Coastal Prairie, was historically dotted with vernal pools, and has a unique biodiverse composition.  More than 99.5% of its estimated original 95 km (23,475 acres), as well as almost all its vernal pool complexes, have been lost to urbanization.

The Madrona Marsh Preserve, in Torrance, California, safeguards approximately 18 hectares (44 acres) of Los Angeles Coastal Prairie and includes a complex of vernal pools.  Its aquatic biodiversity had been studied, predominantly to genus level, but its terrestrial macro-invertebrates were virtually unknown, aside from butterfly, dragonfly, and damselfly observations.

Results

In order to better understand the biodiversity at the Madrona Marsh Preserve, a minimally-invasive macro-invertebrate inventory was conducted. The results of this inventory, with 689 invertebrate organisms recorded, covering eight phyla, 13 classes, 39 orders, and 222 families, are presented in this document.

Six new species of Elaphopsocus Roesler from Brazil and Colombia are described and illustrated. Revised generic diagnoses are provided for Elaphopsocoides and Elaphopsocus; based on the structure of the male hypandrium and phallosome three species groups are recognized in Elaphopsocus.

Two new species of Elaphopsocoides n. gen. from Valle del Cauca, Colombia, are here described and illustrated. The new genus is related to Elaphopsocus Roesler, but differs from it mostly in the hypandrial projections and in phallosome structure. The female subgenital plate has a distinct, median, posterior projection. The types are deposited in the Entomology Museum, Universidad del Valle (MUSENUV), Santiago de Cali, Colombia.

Mesophthirus engeli (Mesophthiridae incerti ordinis), described as a feather-feeding parasite of dinosaurs, has recently been reinterpreted as the early instar nymph (crawler) of a primitive scale insect. Mesophthirus has no specific similarities to bird lice, although life on feathers should modify parasites in a similar way. Based on re-examination of photographs of the type specimens of M. engeli, the subfamily Mesophthirinae stat. nov. is assigned to the archaic extant family Xylococcidae s.l. (recorded since Hauterivian), next to the extant subfamilies Xylococcinae and Stigmacoccinae. Xylococcid honeydew is an important food resource for birds and other arboreal vertebrates. Like their modern relatives, Mesophthirinae lived under the bark of trees and produced copious honeydew. Early birds and their precursors, small feathered dinosaurs, may well have fed on honeydew and the mesophthirines themselves. Scale crawlers are adapted to the wind transport and phoresy on insects and vertebrates, so finding Mesophthirus on feathers is natural.
View the paper at https://rdcu.be/cPAGq