Roberta Poinar

Paleoleishmania proterus n. gen., n. sp., (Trypanosomatidae: Kinetoplastida) from Cretaceous Burmese amber.

A trypanosomatid (Trypanosomatidae: Kinetoplastida) associated with a blood-filled female sand fly in Cretaceous Burmese amber, is described in the new genus and species, Paleoleishmania proterus. The genus Paleoleishmania is established as a collective genus for digenetic fossil trypanosomes associated with sand flies. Amastigotes, promastigotes and paramastigotes are described. Paleoleishmania proterus is the first fossil kinetoplastid and provides a minimum age for the digenetic Trypanosomatidae. Its discovery indicates that vector-borne pathogens had been established by the Early Cretaceous.

Description and development of Gastromermis anisotis sp. n. (Nematoda: Mermithidae), a parasite in a quadritrophic system involving a cyanobacterium, midge and virus

This paper reports the results of a 25 year study on an obligate quadritrophic system involving a midge, Cricotopus nostocicola (Diptera: Chironomidae), its cyanobacterial food source, Nostoc parmeliodes (Nostocales), a new species of nematode parasite of the midge, Gastromermis anisotis sp. n. (Mermithidae), and a virus infecting the nematode. Occurring in a mountain stream in California, the components of this system are adapted for survival at temperatures just above freezing (4-8°C). Developmental studies of the nematode include mating, oviposition, egg hatch, host penetration, parasitic development, free-living habits, spermatogenesis, platelet structure, and virus infection. Rates of parasitism varied between 5-42% over the 25 year period. The nematode was considered to be the most significant biological control agent of Cricotopus populations in the stream.

Ancient hastisetae of Cretaceous carrion beetles (Coleoptera: Dermestidae) in Myanmar amber

Hastisetae are extremely elaborate and intricate insect setae that occur solely on dermestid larvae (Coleoptera: Dermestidae). The present work characterizes hastisetae found in mid-Cretaceous amber from Myanmar and compares them to hastisetae found on extant dermestid larvae. The presence of hastisetae in Myanmar amber shows that lineages of dermestid beetles had already developed hastisetae by the mid-Cretaceous and their presence allows us to follow the evolutionary development of this particular arthropod structure over the past 100 million years. Hastisetae attached to a parasitic wasp in the same piece of amber indicates that ancient dermestid beetles used their hastisetae for defense, similar to their function today.