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An ambrosia fungus is described from filamentous sporodochia adjacent to a wood-boring ambrosia beetle (Coleoptera: Curculionidae: Platypodinae) in mid-Cretaceous Burmese amber. Yeast-like propagules and hyphal fragments of Paleoambrosia entomophila gen. nov. et sp. nov. occur in glandular sac mycangia located inside the femur of the beetle. This is the first record of a fossil ambrosia fungus, showing that symbiotic associations between wood-boring insects and ectosymbiotic fungi date back some 100 million years ago. The present finding moves the origin of fungus-growing by insects from the Oligocene to the mid-Cretaceous and suggests a Gondwanan origin., (Published by Elsevier Ltd.)

A new species of mermithid nematode, Hexamermis popilliae n. sp. (Nematoda: Mermithidae) is described from the Japanese beetle Popillia japonica Newman in Italy, an area of new introduction for this invasive pest. The combination of the following characters separates H. popilliae from other members of the genus Hexamermis Steiner, 1924: adult head obtuse; amphidial pouches slightly posterior to lateral head papillae in female but adjacent to lateral head papillae in males; amphidial openings large, well developed; amphidial pouches elliptical in females and oblong in males; cuticular vulvar cone well developed, vulvar lips greatly reduced or lacking, vagina curved at tip where meeting uteri, without reverse bend (not S-shaped), spicules slightly curved, with a slight bend in the basal portion, approximately equal to body width at cloaca. This is the first record of a species of Hexamermis parasitizing the Japanese beetle Popillia japonica. The only previous mention of mermithid nematodes from P. japonica was an undescribed species of Psammomermis in North America. Hexamermis popilliae will be evaluated as a potential biological control agent in an integrated control program of the Japanese beetle in Italy.

Since its introduction in France 10 years ago, the yellow-legged Asian bee-hawking hornet Vespa velutina has rapidly spread to neighboring countries (Spain, Portugal, Belgium, Italy, and Germany), becoming a new threat to beekeeping activities. While introduced species often leave behind natural enemies from their original home, which benefits them in their new environment, they can also suffer local recruitment of natural enemies. Three mermithid parasitic subadults were obtained from V. velutina adults in 2012, from two French localities. However, these were the only parasitic nematodes reported up to now in Europe, in spite of the huge numbers of nests destroyed each year and the recent examination of 33,000 adult hornets. This suggests that the infection of V. velutina by these nematodes is exceptional. Morphological criteria assigned the specimens to the genus Pheromermis and molecular data (18S sequences) to the Mermithidae, due to the lack of Pheromermis spp. sequences in GenBank. The species is probably Pheromermis vesparum, a parasite of social wasps in Europe. This nematode is the second native enemy of Vespa velutina recorded in France, after a conopid fly whose larvae develop as internal parasitoids of adult wasps and bumblebees. In this paper, we provide arguments for the local origin of the nematode parasite and its limited impact on hornet colony survival. We also clarify why these parasites (mermithids and conopids) most likely could not hamper the hornet invasion nor be used in biological control programs against this invasive species.

Examination of a small portion of the viscera of an oarfish ( Regalecus russellii ) recovered from Santa Catalina Island, southern California, revealed numerous tetraphyllidean tapeworm plerocercoids, Clistobothrium cf. montaukensis; 2 juvenile nematodes, Contracaecum sp.; and a fragment of an adult acanthocephalan, family Arhythmacanthidae. This suggests that the fish was relatively heavily parasitized. The presence of larval and juvenile worms suggests that oarfish are preyed upon by deep-swimming predators such as the shortfin mako shark, Isurus oxyrinchus , known to be a definitive host for the adult tapeworm, and also by diving mammals such as sperm whales, Physeter catodon L., hosts of Contracaecum spp. nematodes.

This chapter discusses the evolutionary history of nematode parasites of invertebrates, vertebrates and plants based on fossil remains in amber, stone and coprolites dating from the Palaeozoic to the Holocene. The earliest parasitic nematode is a primitive plant parasite from the Devonian. Fossil invertebrate-parasitic nematodes first appeared in the Early Cretaceous, while the earliest fossil vertebrate-parasitic nematodes are from Upper Triassic coprolites. Specific examples of fossil nematode parasites over time are presented, along with views on the origin and evolution of nematodes and their hosts., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: The harlequin ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae) is native to central and eastern Asia and was purposely introduced into Europe to control aphids. While it proved to be a good biological control agent, its rapid spread and buildup of large populations made it a nuisance, since it overwinters in homes, emits unpleasant odors, stains fabrics, occasionally bites humans and feeds on apples, pears and grapes. Aside from the above, the ravenous appetite of H. axyridis results in their consumption of harmless native insects, including even other ladybird beetles. A study of the natural enemies of H. axyridis in Denmark revealed the presence of nematodes. The present study describes this nematode parasite and discusses aspects of its development and ecology., Methods: Adult harlequin ladybird beetles were collected from March to November from four localities in Copenhagen on different plant species. In addition, groups of last-instar larvae and pupae (n = 50) were examined for the presence of nematodes. Living and recently dead nematodes were removed from adult H. axyridis in 0.5% saline solution, the nematodes were then heat killed (at 75C), fixed in 5% formalin and transferred to glycerin on slides for further examination and measurements., Results: A new species of Allantonematidae (Tylenchida), Parasitylenchus bifurcatus n. sp., is described from adults of the harlequin ladybird, Harmonia axyridis in Denmark. The new species is characterized by a straight stylet lacking basal thickenings, a bursa and a forked tail tip in the vermiform (infective) females and juvenile males. The new species is compared with P. coccinellinae previously described from ladybird beetles in France. Parasitism resulted in depletion of the fat body and partial or complete atrophy of the reproductive organs of the beetles. Infections occurred throughout the year with rates of parasitism reaching up to 35%. The rate increased to 60% when field-collected ladybirds were incubated for 30 days in the laboratory., Conclusions: The production of subsequent generations within the host with only the fertilized females (not the males) leaving the hosts and the absence of parasitism of the larvae and pupae is an impressive developmental modification of P. bifurcatus. It is proposed that the vermiform (infective) females pass from one adult host to another when the beetles are hibernating or in assemblage groups. Rates of parasitism show that P. bifurcatus could be a significant biological control agent of H. axyridis.

The history of entomopathogenic nematology is briefly reviewed. Topic selections include early descriptions of members of Steinernema and Heterorhabditis, how only morphology was originally used to distinguish between the species; descriptions of the symbiotic bacteria and elucidating their role in the nematode- insect complex, including antibiotic properties, phase variants, and impeding host defense responses. Other topics include early solutions regarding production, storage, field applications and the first commercial sales of entomopathogenic nematodes in North America. Later studies centered on how the nematodes locate insect hosts, their effects on non-target organisms and susceptibility of the infective juveniles to soil microbes. While the goals of early workers was to increase the efficacy of entomopathogenic nematodes for pest control, the increasing use of Heterorhabditis and Photorhabdus as genetic models in molecular biology is noted.

New flea-like fossils from China provide a rare, tantalizing glimpse of bizarre insects in the Cretaceous and Jurassic. Possibly the oldest flea-like animals known, they provide a challenge to the functional morphologist to infer which animals they may have targeted., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: It is rare to find terrestrial nematode lineages parasitizing arthropods inhabiting the intertidal or littoral zone of the oceans. During an ecological study along the Oregon dunes, an allantonematid nematode (Tylenchomorpha: Allantonematidae) was discovered parasitizing the intertidal shore bug, Saldula laticollis (Reuter)(Hemiptera: Saldidae). This shore bug is adapted to an intertidal environment and can survive short periods of submergence during high tides. The present study describes the nematode parasite and discusses aspects of its development, ecology and evolution., Methods: Adults and last instar nymphs of S. laticollis (Hemiptera: Saldidae) were collected from the high intertidal zone among clumps of Juncus L. (Juncaceae) plants at Waldport, Oregon on October 3, 2011. The bugs were dissected in 1% saline solution and the nematodes killed in 1% Ringers solution and immediately fixed in 5% formalin (at 20°C). Third stage juveniles removed from infected hosts were maintained in 1% saline solution until they matured to the adult stage, molted and mated., Results: Halophilanema prolata n. gen., n. sp. (Nematoda: Allantonematidae) is described from last instar nymphs and adults of the intertidal bug, Saldula laticollis on the Oregon coast. The new genus can be distinguished from other genera in the Allantonematidae by a stylet lacking basal knobs in both sexes, an excretory pore located behind the nerve ring, ribbed spicules, a gubernaculum, the absence of a bursa and the elongate-tubular shape of the ovoviviparous parasitic females. Studies of the organogenesis of Halophilanema showed development to third stage juveniles in the uterus of parasitic females. Maturation to the free-living adults and mating occurred in the environment. The incidence of infection of S. laticollis ranged from 0% to 85% depending on the microhabitat in the intertidal zone., Conclusions: Based on the habitat and morphological characters, it is proposed that Halophilanema adapted a parasitic existence fairly recently, evolutionarily speaking. It was probably a free-living intertidal or shore nematode that fed on microorganisms, especially fungi, in the intertidal habitat and became parasitic after saldids entered the environment. Halophilanema represents the first described nematode parasite of an intertidal insect.

Background: Both sexes of bat flies in the families Nycteribiidae and Streblidae (Diptera: Hippoboscoidea) reside in the hair or on the wing membranes of bats and feed on blood. Members of the Nycteribiidae transmit bat malaria globally however extant streblids have never been implemented as vectors of bat malaria. The present study shows that during the Tertiary, streblids also were vectors of bat malaria., Results: A new haemospororidan, Vetufebrus ovatus, n. gen., n. sp., (Haemospororida: Plasmodiidae) is described from two oocysts attached to the midgut wall and sporozoites in salivary glands and ducts of a fossil bat fly (Diptera: Streblidae) in Dominican amber. The new genus is characterized by ovoid oocysts, short, stubby sporozoites with rounded ends and its occurrence in a fossil streblid. This is the first haemosporidian reported from a streblid bat fly and shows that representatives of the Hippoboscoidea were vectoring bat malaria in the New World by the mid-Tertiary., Conclusions: This report is the first evidence of an extant or extinct streblid bat fly transmitting malaria. Discovering a mid-tertiary malarial parasite in a fossil streblid that closely resembles members of a malarial genus found in nycteribiid bat flies today shows how little we know about the vector associations of streblids. While no malaria parasites have been found in extant streblids, they probably occur and it is possible that streblids were the earliest lineage of flies that transmitted bat malaria to Chiroptera.

Background: The remarkable mutualistic associations between termites and protists are in large part responsible for the evolutionary success of these eusocial insects. It is unknown when this symbiosis was first established, but the present study shows that fossil termite protists existed in the Mesozoic., Results: A new species of termite (Kalotermes burmensis n. sp.) in Early Cretaceous Burmese amber had part of its abdomen damaged, thus exposing trophic stages and cysts of diverse protists. Some protists were still attached to the gut intima while others were in the amber matrix adjacent to the damaged portion. Ten new fossil flagellate species in the Trichomonada, Hypermastigida and Oxymonadea are described in nine new genera assigned to 6 extant families. Systematic placement and names of the fossil flagellates are based on morphological similarities with extant genera associated with lower termites. The following new flagellate taxa are established: Foainites icelus n. gen. n. sp., Spiromastigites acanthodes n. gen. n. sp., Trichonymphites henis n. gen., n. sp., Teranymphites rhabdotis n. gen. n. sp., Oxymonas protus n. sp., Oxymonites gerus n. gen., n. sp., Microrhopalodites polynucleatis n. gen., n. sp., Sauromonites katatonis n. gen., n. sp., Dinenymphites spiris n. gen., n. sp., Pyrsonymphites cordylinis n. gen., n. sp. A new genus of fossil amoeba is also described as Endamoebites proterus n. gen., n. sp. Fourteen additional trophic and encystid protist stages are figured and briefly characterized., Conclusion: This represents the earliest fossil record of mutualism between microorganisms and animals and the first descriptions of protists from a fossil termite. Discovering the same orders, families and possibly genera of protists that occur today in Early Cretaceous kalotermitids shows considerable behaviour and morphological stability of both host and protists. The possible significance of protist cysts associated with the fossil termite is discussed in regards the possibility that coprophagy, as well as proctodeal trophallaxis, was a method by which some termite protozoa were transferred intrastadially and intergenerationally at this time.

Paleoophiocordyceps coccophagus, a fungal parasite of a scale insect from the Early Cretaceous (Upper Albian), is reported and described here. This fossil not only provides the oldest fossil evidence of animal parasitism by fungi but also contains morphological features similar to asexual states of Hirsutella and Hymenostilbe of the extant genus Ophiocordyceps (Ophiocordycipitaceae, Hypocreales, Sordariomycetes, Pezizomycotina, Ascomycota). Because species of Hypocreales collectively exhibit a broad range of nutritional modes and symbioses involving plants, animals and other fungi, we conducted ancestral host reconstruction coupled with phylogenetic dating analyses calibrated with P.coccophagus. These results support a plant-based ancestral nutritional mode for Hypocreales, which then diversified ecologically through a dynamic process of intra- and interkingdom host shifts involving fungal, higher plant and animal hosts. This is especially evident in the families Cordycipitaceae, Clavicipitaceae and Ophiocordycipitaceae, which are characterized by a high occurrence of insect pathogens. The ancestral ecologies of Clavicipitaceae and Ophiocordycipitaceae are inferred to be animal pathogens, a trait inherited from a common ancestor, whereas the ancestral host affiliation of Cordycipitaceae was not resolved. Phylogenetic dating supports both a Jurassic origin of fungal-animal symbioses within Hypocreales and parallel diversification of all three insect pathogenic families during the Cretaceous, concurrent with the diversification of insects and angiosperms.

Phyllopsora dominicanus sp. nov. (Bacidiaceae, Lecanorales, lichen-forming Ascomycota) is described and illustrated from Dominican amber. The diagnostic features of the lichen include a minute subfolious thallus of lacinulate, ascending squamules, a well-developed upper cortex, and a net-like pseudocortex on the lower surface. The algal symbionts are unicellular green algae, forming a distinct layer immediately below the upper cortex. The fossil demonstrates that distinguishing features of Phyllopsora have remained unchanged for tens of millions of years. The fossil also provides the first detailed views of mycobiont-photobiont contacts in Tertiary green algal lichens. The mycobiont hyphae formed apical and intercalary appressoria by pressing closely against the photobiont cells. This indicates that a conserved maintenance of structure is also seen in the fine details of the fungal-algal interface.

Allomermis solenopsi n. sp. (Mermithidae: Nematoda) is described from the fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) in Argentina. Diagnostic characters of the new species include stiff and erect processes on the surface of the mature egg, small female amphids, extension of the latero-medial rows of male genital papillae beyond the middle rows, an obliquely truncate spicule tip and a ventrally swollen male terminus. This is the first record of Allomermis Steiner, 1924 from South America and the first host record for members of this genus. Previous records of mermithids from Solenopsis spp. are summarised. The placement in Allomermis was confirmed by molecular analyses based on nuclear 18S ribosomal DNA sequences, the first such molecular framework for the Mermithidae. The possible life-cycle of the parasite is discussed, with the aim of using A. solenopsi as a biological control agent for fire ants in the United States.

An important defensive strategy among animals is the use of chemical compounds with toxic or irritating properties. In this paper, we report the discovery of an Early Cretaceous soldier beetle (Coleoptera: Cantharidae) in Burmese amber that seemingly employed a chemical defense response against a potential predator. Six pairs of cuticular vesicles with associated gland reservoirs were extruded from the insect's abdomen, and a secretion released from one of these covers a portion of the antenna of a second insect species, considered to be the perpetrator of the response. This is the earliest fossil record of a putative chemical defense response and suggests that chemical defense mechanisms in beetles have been in existence for at least 100 Ma.

Evidence of mycoparasitism and hypermycoparasitism is demonstrated in Early Cretaceous Burmese amber. The agaric, Palaeoagaracites antiquus gen. sp. nov., is parasitized by the mycoparasite, Mycetophagites atrebora gen. sp. nov., which in turn is parasitized by the hyperparasite, Entropezites patricii gen. sp. nov. This discovery shows that sophisticated patterns of fungal parasitism were well developed some 100 Myrago.

The bee fossil record is fragmentary, making it difficult to accurately estimate the antiquity of bee-mediated pollination. Here, we describe a bee fossil [Melittosphex burmensis (new species), Melittosphecidae (new family)] from Early Cretaceous Burmese amber (approximately 100 million years before the present). The fossil provides insights into the morphology of the earliest bees and provides a new minimum date for the antiquity of bees and bee-mediated pollination.

Palaeoclavaria burmitis gen. et sp. nov. (Palaeoclavariaceae fam. nov, Hymenomycetes) is described from a series of fruit bodies and hyphae in Cretaceous amber from Burma (about 100 Myr). This is the first fossil record of the Aphyllophorales and establishes certain basic morphological and ecological characters for the group.

A new record of nematode parasitism of meloid beetles is reported and all earlier records are summarised. Rates of parasitism could be influenced by the toxic compound cantharidin that these beetles possess.

Resins are produced by woody plants on a worldwide basis. We have found several distinct classes of modern diterpenoid resins based phenomenologically on the solid-state (13)C NMR spectra of the bulk material. Resin fossilizes over millions of years into a robust material sometimes called amber. We have characterized several hundred samples of fossil resin by solid-state (13)C NMR spectroscopy. We can relate one globe-spanning group of fossil resins to the modern genus Agathis, based on spectral evolution over time. A second large group has not been related with certainty to specific modern plants. Fossil resins from Europe fall into two categories, the famous Baltic ambers and another that resembles the Agathis group. Fossil resins from the Americas and Africa are closely related to the modern genus Hymenaea. Based on spectral distinctions, fossil resin found in an archaeological context sometimes can be assigned to a specific geographical origin on the basis of its (13)C NMR spectrum.

A new nematode, Elaeolenchus parthenonema n. g., n. sp., is described from the palm-pollinating weevil Elaeidobius kamerunicus Faust. The new genus is placed in the Anandranematidae n. fam., which, together with the genus Anandranema Poinar et al., 1993, is characterised by nematodes having only a single autotokous generation in the insect host. This is the first report of a member of this superfamily reproducing only parthenogenetically. The development of E. parthenonema and its effect on the weevil host is discussed, along with a phylogenetic synopsis of the families of the Sphaerularioidea Lubbock 1861. The Beddingiidae n. fam. is proposed for Beddingia Blinova & Korenchenko, 1986, comprising the original Deladenus parasites of Hymenoptera that possess both free-living and parasitic amphimictic generations in their life-cycles. This family is considered to have the most primitive type of development in the superfamily.

Entomopathogenic nematodes are excellent biological control agents. Utilization of these nematodes is developing rapidly with almost a doubling of newly described species in the past five years. Advances in molecular biology and phylogenetic reconstruction have revolutionized understanding of population structure, identification, genetic improvement, systematics, and the symbiosis between entomopathogenic nematodes and their bacteria. Population structure provides the most fundamental information for reliable identification of species and unique genetic variants. Such information could be further assessed for nematode potential as biological control agents. Phylogenetic reconstruction is an important approach for understanding multitrophic interactions among entomopathogenic nematodes, symbiotic bacteria, and their insect hosts. Phylogenetic reconstruction is also important for the development of a natural and stable type of systematics, which can provide guidelines for selecting appropriate entomopathogenic nematode species for particular biological control programs.

A survey of the major fossiliferous amber deposits is provided, including ages and various categories of life forms reported from each. The frequency of occurrence of the major groups of plants and animals in these amber deposits is also given. Thus far, DNA from four insect and one plant species has been extracted from amber fossils. In the case of the stingless bee in Dominican amber, evidence of reproducibility is provided, since two independent laboratories isolated DNA from six or more different specimens of the same insect. Amber sources for DNA studies are listed together with their advantages and disadvantages. The important points are the availability of desired pieces, the proper identification of the fossil, verification of the amber deposit, the cost involved, and the feasibility of causing damage to the specimen. The availability of several types of amber (Mexican, Dominican, Baltic, Chinese, Canadian, Siberian and Lebanese) at four major sources (academic collections, commercial dealers, private collections and amber mines) is discussed. The scientific implications of obtaining DNA from amber inclusions are presented.

We report here the isolation of DNA from abdominal tissue of four extinct stingless bees (Proplebeia dominicana) in Dominican amber, PCR amplification of a 546-bp fragment of the 16S rRNA gene from Bacillus spp., and their corresponding nucleotide sequences. These sequences were used in basic local alignment search tool searches of nonredundant nucleic acid data bases, and the highest scores were obtained with 16S rRNA sequences from Bacillus spp. Phylogenetic inference analysis by the maximum-likelihood method revealed close phylogenetic relationships of the four presumed ancient Bacillus sequences with Bacillus pumilus, B. firmus, B. subtilis, and B. circulans. These four extant Bacillus spp. are commonly isolated from abdominal tissue of stingless bees. The close phylogenetic association of the extracted DNA sequences with these bee colonizers suggests that a similar bee-Bacillus association existed in the extinct species P. dominicana.

The development and morphology of the sperm of the mermithid nematode, Gastromermis sp. appears to be different than that reported for any other nematode sperm. The mature sperm of Gastromermis are elongate with membranous organelles surrounding an apical nuclear region. The mitochondria are arranged in parallel rows and form an elongate sheath. Spermatozoa contain dense tubular structures which have not been seen in other nematodes. Spermatids lack fibrous bodies. The pseudopodia of the spermatozoa are filled with microtubules. Centrioles seen throughout sperm development are composed of 9 doublets.

DNA has been successfully isolated from both fossilized plant and animal tissues. The oldest material, dated as 25-40 million years old (Tertiary), was obtained from amber-entombed bees and termites. Tissues from both these insects yielded DNA of good quality, which could be amplified by the polymerase chain reaction (PCR) and subsequently sequenced, including the genes encoding 18S ribosomal RNA and 16S rRNA. We report here the extraction of DNA from a 120-135-million-year-old weevil (Nemonychidae, Coleoptera) found in Lebanese amber, PCR amplification of segments of the 18S rRNA gene and the internal transcribed spacer, and the corresponding nucleotide sequences of their 315- and 226-base-pair fragments, respectively. These sequences were used for preliminary phylogenetic analysis of the nemonychid's sequence with three extant coleopterans: Lecontellus pinicola (Nemonychidae), Hypera brunneipennis (Curculionidae) and the mealworm Tenebrio molitor (Tenebrionidae), and two extant dipterans: the fruitfly Drosophila melanogaster (Drosophilidae) and mosquito Aedes albopictus (Culicidae) for the purpose of ascertaining the origin of the extracted and amplified DNA. The results revealed that the PCR-amplified material is that of the extinct nemonychid weevil. This represents the oldest fossil DNA ever extracted and sequenced, extending by 80 million years the age of any previously reported DNA.

Protozoa, cyanobacteria, sheathed algae, sheathed fungi, germinating pollen or spores, and fungal spores have been found in amber 220 to 230 million years old. Many of these microorganisms can be assigned to present-day groups. This discovery of terrestrial, soft-bodied protists that can be referred to modern groups indicates that morphological evolution is very gradual in many protists and that both structural and probably functional stasis extend back at least to the Upper Triassic period.

Discovery of a female spikelet of the grass genus Pharus (Gramineae: Bambusoideae: Phareae) in association with mammalian hair in Dominican Republic amber provides the first fossil evidence of epizoochory. Hooked macrohairs on the lemma of the spikelet show that morphological modifications in grasses for dispersal by attachment to the surface of animals were present in the Late Eocene. The fossil also represents 1) the second-oldest undoubted macrofossil record of the Gramineae, 2) the earliest record of a fossil grass that can be assigned to an extant genus, 3) the earliest undoubted record of a member of the bamboo subfamily and 4) the only known fossil of Pharus.

Coprinites dominicana gen.nov., spec.nov. (Coprinaceae) found in amber from the Dominican Republic is the earliest known gilled mushroom, the first fossil fleshy agaric determinable, and the only kiiown fossil "mushroom" (Agaricales) from the tropics. This find is of significance with respect to the evolutionary development of the Basidiomycetes. Because the appearance of this fossil is quite modern, it suggests that mushrooms as a group probably arose much earlier than the early to mid-Tertiary.

Larvae, pupae, and adult blackflies (Simuliidae) are capable of harbouring several groups of nematodes. Multiple parasitism involving nematodes of the same or different species, or various developmental stages of the same nematode may also occur. Thus, blackflies can serve as paratenic, intermediate, or definitive hosts of nematodes. The present study reviews the literature pertaining to the association between nematodes and Simuliidae and provides a key to various groups of nematodes found in blackflies. Emphasis is placed on the commoner filarial and mermithid nematodes, but several other unusual and rare roundworm parasites are also discussed.

A frog of the leptodactylid genus Eleutherodactylus is reported from Eocene amber found in the Dominican Republic. It is the first described amphibian fossil in amber, and the oldest complete lissamphibian fossil from Mesoamerica (Central America and Mexico). Dating of the amber matrix indicates that by the end of the Eocene a diverse fauna was present in the Antilles, much earlier than has generally been proposed. The presence of this and other amber fossils from this same age suggests that Tertiary patterns of landmass movements were significant in determining the present distribution of species.

Examination of the ultrastructure of preserved tissue in the abdomen of a fossil fly (Mycetophilidae: Diptera) entombed in Baltic amber revealed recognizable cell organelles. Structures that corresponded to muscle fibers, nuclei, ribosomes, lipid droplets, endoplasmic reticulum, and mitochondria were identified with the transmission electron microscope. Preservation was attributed to inert dehydration as well as the presence of compounds in the original sap which functioned as natural fixatives. This evidence of cell organelles in fossilized soft tissues represent an extreme form of mummification since Baltic amber is considered to have formed about 40 million years ago.

When applied to the ears of rabbits used as hosts for tsetse flies, the bacterium Serratia marcescens produced significant mortality in populations of Glossina m. morsitans and G. pallidipes. After being ingested during the blood meal, cells of S. Marcescens multiplied in the intestine of the flies and entered the hemocoel. Using the brush method of applying the bacterium, 100% mortality of both Glossina species occurred within 10 days after application. In newly killed flies, the bacteria could be found free in the hemocoel as well as in the fat body and blood cells. The supernatant of a liquid culture of S. marcescens did not produce fly mortality when applied to rabbit ears. The results indicate that S. marcescens is able to invade the hemocoel of "normal" laboratory-reared tsetse flies.

Penetrating infective juveniles of Romanomermis culicivorax usually killed first-stage larvae of Chironomus maturus Johann., Chironomus sp., Simulium damnosum Theo., and S. venustum Say. Nematodes were melanized and died after they entered fourth stage larvae of 2 chironomid species, but no host reaction was evident after entry into fourth-stage blackfly larvae. In contrast, the nematodes initiated development in the latter hosts, which died before the nematodes completed their development.

An iridovirus was observed with the electron microscope in the tissues of a mermithid nematode parasitic in the isopods Porcellio scaber and Armadillidium vulgare. Virus particles were seen associated with virogenic areas in the cytoplasm along with viral stages suggestive of particle maturation. Extracts of portions of the same nematodes used for transmission electron microscopy appeared positive in serologically specific electron microscopy with antisera prepared against iridescent virus from the isopod hosts. These same extracts in 21 of 40 isopods produced infections when fed to P. scaber. This is the first report of a known virus replicating in a nematode and extends the host range of iridoviruses to the phylum Nematoda.

Skrjabinelazia galliardi was previously known only from a description of the morphological characteristics of the female. Additional material being available, we were able to complete the morphological description and understand better the biology of the species. The male, the third stage larva and the fourth stage larva are described. Young females lay a very small number of third stage larvae, leading in a small scale to a reproduction of the atractide-type, that is a multiplication of the parasite directly inside the host. The old females are oviparous, but eggs contain a third stage infective larva. These eggs, after being ingested by field-crickets, hatch and without further development remain as larvae in the insect. The definitive entomophagous lizard host, which, in the field, has no opportunity to ingest the eggs, is infested by eating insects. So, the life history is intermediary between the cosmocercid like cycle (with three larval stages) and the spirurid-like cycle (with development of larval stages in an invertebrate).

A gravid female Mermis nigrescens Dujardin (Mermithidae: Nematoda) was recovered from the mouth of a 1-month-old infant in Mehama, Oregon. This nematode is a parasite of grasshoppers and deposits its eggs on vegetation. The parasite was probably carried on the hair of the household dog or cat to the vicinity of the patient and was attracted to the moisture in the region of the mouth.