bluuebunny/crossref_metadata_2025 huggingface dataset:
The innervation of the thorax of the adult milkweed bug Oncopeltus fasciatus (Dallas). III. The metathorax
Authors: Govind C. K. , Dandy J. W. T.
Published: August 2008

The peripheral distribution of the seven paired nerves of the metathorax of the milkweed bug Oncopeltus fasciatus (Dallas) is described. Reference is also made to the first abdominal nerve serving the metathorax. The pattern of innervation in the pro-, meso-, and meta-thorax is briefly summarized.
A study of the hatching process in aquatic invertebrates. XXV. Hatching in the blackfly, Simulium (probably venustum) (Diptera, Simuliidae)
Authors: Davis Charles C.
Published: August 2008

Hatching from the egg was studied in Simulium (probably venustum). In early stages of development the embryo completely fills the space enclosed by the chorion, but in later stages there are sizable fluid-filled spaces between the prolarva and the shell. Initiation of hatching involves the beginning of swallowing and absorption of the intrachorionic fluid. As a result of this the prolarva swells until it not only completely fills the egg again, but also exerts considerable pressure from within against the shell. This process brings the cephalic egg burster into strong contact with the chorion. Eventually the burster penetrates the shell and thus initiates the rupture which permits the first instar larva to escape from the egg, always head first.
Geographic and morphological variation in the presence and absence of the pelvic skeleton in the brook stickleback, Culaea inconstans (Kirtland), in Alberta and Saskatchewan
Authors: Nelson Joseph S. , Atton F. Mervyn
Published: August 2008

Brook sticklebacks, Culaea inconstans (Kirtland), are known from 20 locations in Alberta and Saskatchewan in which a high proportion of the individuals lack all or part of the pelvic skeleton. These locations are interspersed and surrounded by other locations containing individuals with a normal pelvic skeleton. Individuals which lack the skeleton are of both sexes and are fertile in at least one of the lakes.Considerable variation exists between locations in the proportion of individuals with and without the pelvic skeleton. Morphological intermediates are known from most of the 20 locations and virtually all degrees of pelvic skeleton formation exist between its absence and its full development. Little or no gradation exists, however, in pelvic spine length between their absence and presence. Although the pelvic spines are the first part of the pelvic skeleton to appear during ontogeny, they are present only in intermediates with a virtually complete skeleton base. In addition, many intermediates are highly asymmetrical in their pelvic skeleton while development during the ontogeny of normal individuals is symmetrical.There is a greater tendency for individuals in which the pelvic skeleton is deficient to occur in lakes which lack an outlet rather than to occur in lakes with a permanent outlet. An unusually high proportion of the lakes with these aberrant individuals have been subject to fishery management activities (fish introduction and poisoning), but these disturbances are not causing the loss of the pelvic skeleton.
La radiothyroïdectomie et son effet sur la consommation d'oxygène chez les cichlidés Aequidens latifrons
Authors: Ruhland M.-L.
Published: August 2008

The thyroidectomy produced after radioiodide immersion of the cichlid fish Aequidens latifrons during 5 months was characterized by progressive alterations of the thyroid tissue from the disappearance of colloid, the degeneration of thyroid cells until an intensive proliferation of fibrous tissue, which replaced the thyroid follicles of the gland. Autoradiographic examinations revealed a few microfollicles, which presented a small activity.The consequential effects on the respiratory exchanges are significant decreases of the oxygen consumption which are progressive and more important than the decreases obtained after thiourea treatment. The decreases reach a third of the normal rate of oxygen consumption, 32% after a long treatment period (150 days). This proves the relationship between the thyroid gland and the oxygen consumption of fishes.
Life history and biology of the riffle bug Rhagovelia obesa Uhler (Heteroptera: Veliidae) in Southern Ontario
Authors: Cheng Lanna , Fernando C. H.
Published: August 2008

The life history of Rhagovelia obesa (Heteroptera: Veliidae) was investigated using field collected and laboratory reared material. The nymphal instars and adults are described and figured. This is the first life-history study of Rhagovelia or its related genera Tetraripis and Trochopus. These genera together have almost a worldwide distribution and are characterized by a unique swimming plume beating underwater. Four nymphal instars occur instead of the usual five. The overwintering stage is the egg, another unusual feature for aquatic Hemiptera. The site(s) of egg laying have not been located. For the first time Rhagovelia has been raised in the laboratory from first instar to adult.
Helminth parasites of alcids in the northwestern North Atlantic
Authors: Threlfall William
Published: August 2008

One thousand and one alcids of six species (Alca torda, Uria aalge, Uria lomvia, Plautus alle, Cepphus grylle, Fratercula arctica) were collected in the northwestern North Atlantic, during the period June, 1966 – September, 1969, and examined for parasites. Helminths belonging to 12 genera were recovered, the common murre (U. aalge) containing the greatest number of species. Statistically significant annual variations (P < 005) in the parasite burden of this species were noted. No differences in intensity of infection in male and female birds and in chicks and adults were detected. Twelve new host records are noted.
Neoechinorhynchus pungitius n. sp. (Acanthocephala: Neoechinorhynchidae) from ninespine stickleback of Lake Huron
Authors: Dechtiar Alex O.
Published: August 2008

Neoechinorhynchus pungitius n. sp. is described on the basis of more than 100 specimens collected from the ninespine stickleback, Pungitius pungitius (Linnaeus), from South Bay, Lake Huron. Several additional specimens were collected from brook sticklebacks, Eucalia inconstans (Kirtland), and from yellow perch, Perca flavescens (Mitchill).
Helminths of the Rocky Mountain bighorn sheep in Western Canada
Authors: Uhazy Leslie S. , Holmes John C.
Published: August 2008

Thirty-six Rocky Mountain bighorn sheep (Ovis c. canadensis), 33 from four areas in Alberta and 3 from Kootenay National Park, British Columbia, were examined for helminths. Data from these examinations were supplemented by examination of 462 fecal samples from the same areas.Seventeen species of helminths were recovered: 3 cestodes, Moniezia expansa and Wyominia tetoni and the cysticerci of Taenia hydatigena; and 14 nematodes, Capillaria sp., Marshallagia marshalli, Nematodirus archari, N. davtiani, N. maculosus, N. oiratianus, N. spathiger, Ostertagia circumcincta, O. occidentalis, Protostrongylus rushi, P. stilesi, Skrjabinema ovis, Teladorsagia davtiani, and Trichuris ovis. The records of Capillaria sp., Nematodirus maculosus, and Teladorsagia davtiani are apparently the first from bighorn sheep. Nine other records are new for bighorn sheep in Canada.Total numbers of helminths (excluding lungworms) per bighorn ranged from 36 to 8345. There was little variation in the prevalence or the relative abundance of the different species in the areas sampled.
The anatomy, histology, and physiology of the reproductive systems of Lytta nuttalli Say (Coleoptera: Meloidae). I. The internal genitalia
Authors: Gerber G. H. , Church N. S. , Rempel J. G.
Published: August 2008

The anatomy and histology of the male and female internal genitalia of Lytta nuttalli Say and the functions of the various organs during copulation and oviposition are described. In addition to the ovaries, lateral and common oviducts, and vagina, the female system includes a spermatophoral receptacle, accessory gland, and spermatheca. The most distinctive feature is the voluminous spermatophoral receptacle, which seems to be homologous with the bursa copulatrix of other Coleoptera, but serves to store and digest old spermatophores. The accessory gland is not a colleterial gland, but instead produces materials that probably are involved in the transfer of the spermatozoa into the spermatheca. The epithelia of the calyces and oviducts secrete the frothy, mucilaginous material that coats the eggs at oviposition. In the absence of a separate spermathecal gland, the epithelium of the spermatheca apparently has taken over its functions. The ovaries contain several hundred ovarioles of the telotrophic type. The chief structures of the male system are three pairs of accessory glands plus the testes, vasa deferentia, and ejaculatory duct. Each vas deferens consists of an enlarged portion that serves as an additional accessory gland and a narrow part, which is the seminal vesicle. Materials produced in the three pairs of accessory glands and the glandular portions of the vasa deferentia are used in spermatophore formation. The testes contain several hundred short sperm tubes similar to those of other insects. The arrangement, form, and functions of the internal reproductive organs of L. nuttalli are compared with those of other insects. Observations made on the reproductive systems of four species of Epicauta are also discussed in this context.
Blackfly wing surface
Authors: Hannay C. L. , Bond E. F.
Published: August 2008

The wings from both sexes of seven species of Simuliidae were measured then the surface replicated in carbon. It was confirmed that the wings were covered with small raised cylindrical buttons in hexagonal arrays. The dimensions of these buttons were about 80–100 nm in height and diameter and the center to center spacing in the different species only varied between 150 and 180 nm. It was calculated that the raised buttons increased the wing surface area by over 80%. In addition the wings are covered with microtrichia. Preliminary measurements indicate that microtrichia length may be of greater value taxonomically than either wing size or button spacing.In ultrathin sections it has been found that from each and every raised button on the wing surface a wax filament extends through the cuticle. The number of buttons and wax filaments on both surfaces of one wing of S. vittatum amounted to ca. 3.28 × 108.When the adult fly emerges from its underwater pupal case it does so with a lifebelt of gas between head and thorax. The wings and their surfaces play no part in this episode for they remain tightly folded against the body until the fly has passed through the water–air interface.
An electrophysiological study of the giant fiber system of the locust Schistocerca gregaria
Authors: Seabrook W. D.
Published: August 2008

Electrophysiological studies have indicated that there are three giant fibers activated in the ipsilateral connective and two in the contralateral connective when the cercus is mechanically stimulated. Conduction speeds in these fibers and synaptic delays to the cereal giant synapse have been measured. A second-order interneurone is postulated between the cereal afferent fibers and the contralateral giant fibers. There is a considerable reduction in velocity as the potentials pass through the abdominal ganglia and may be related to a reduction in sheath thickness within the ganglion.Afferent neurones of the lateral branch of the ninth sternal nerve have been shown to synapse with the giant fibers.Though the giant fibers respond to cereal and ninth sternal stimulation there is no evasion response in Schistocerca. This lack of response is correlated with the absence of functional synapses between the giant fibers and the efferent neurones of the metathoracic leg nerve. The giant fibers activated by cereal stimulation terminate within the metathoracic ganglion.
In vitro cultivation of exoerythrocytic stages of Leucocytozoon simondi
Authors: Yang Y. J.
Published: August 2008

Spleen cells of ducklings infected with exoerythrocytic stages of L. simondi were grown in vitro for 5 days. Parasites of variable size and appearance developed in macrophages; some were closely associated with the nucleus of the cell, others were in the cytoplasm. The infected cells possess enlarged, and densely stained nuclei. The cultured parasites were infective to ducks and gave rise to elongate as well as round gametocytes. Parasites lived in cultures of hepatic tissues for at least 10 days, but hepatic schizonts were not seen.
Studies on two populations of Ixodes kingi Bishopp (Ixodidae)
Authors: Gregson J. D.
Published: August 2008

Studies on tick size, distribution, and hosts are made of two populations of Ixodes kingi Bishopp, the individuals of which appear to differ only in size. In Canada large specimens were collected only in Alberta and mainly from carnivores and ground squirrels, while small specimens were found only in British Columbia and mostly on pocket gophers and mice but occasionally on weasels. A study of available United States material revealed a similar pattern, the two populations being separated by the Rocky Mountains and the Wasatch Range, but each containing a scattered few specimens of intermediate size. It was shown that individuals of the two populations will interbreed and yield viable F2 larvae. It is suggested that the species is in a state of evolutionary divergence northwards.
Effects of feeding coho salmon and other Great Lakes fish on mink reproduction
Authors: Aulerich R. J. , Ringer R. K. , Seagran H. L. , Youatt W. G.
Published: August 2008

Feeding experiments were conducted to investigate reproductive problems attributed to the feeding of Great Lakes coho salmon to mink. Several other species of fish were fed for comparison. Whole, raw, sexually mature coho salmon taken from tributaries of Lake Michigan were ground, mixed into a diet at a 30% level, and fed to mink before breeding and during gestation. This diet caused reproductive failure and (or) very early kit mortality. Feeding canning by-products of coho salmon from the same source and at the same level to adult mink for 3 months resulted in mortality. Reduced reproductive performance and (or) excessive kit mortality were observed in mink which were fed diets that contained Lake Michigan bloater chub, Lake Michigan yellow perch, and mature coho from the Lake Erie system. Mink rations which contained West Coast coho salmon and Lake Erie yellow perch did not impair reproduction nor result in excessive mortality.No correlation was found between the degree of oxidative rancidity or mercury contamination of the fish and the reproductive performance of the mink. The levels of pesticide residues in the fish (and the complete diets) and the degree of reproductive decline and (or) kit mortality observed in the mink appeared related.The study demonstrated that coho salmon per se does not cause the reproduction and mortality problems. Further, the disorder is also associated with other species of Great Lakes fish and appears to be dependent upon the species of fish and its environment.
Seasonal changes in glycerol content and supercooling points of Megachile rotundata (F.) and M. relativa Cress.
Authors: Krunic M. D. , Salt R. W.
Published: August 2008

Supercooling points of prepupae of the exotic species Megachile rotundata during storage at 5 °C are not closely related to glycerol content and are not sufficiently low to avoid freezing outdoors in southern Alberta. In contrast, supercooling points of prepupae of the indigenous species M. relativa are inversely related to glycerol concentrations, which are double those of M. rotundata and are low enough for successful overwintering. Neither species is frost-tolerant.Older feeding larvae of M. rotundata also synthesize glycerol in the fall, probably in response to cold night temperatures.
The ultrastructure of the lachrymal 'salt' gland and the Harderain gland in the euryhaline Malaclemys and some closely related stenohaline emydines
Authors: Cowan F. Brian M.
Published: August 2008

The ultrastructure of the Harderian gland from the euryhaline species Malaclemys terrapin is nearly identical with that of the Harderian gland from several freshwater and stenohaline emydines. The abundant rough-surfaced endoplasmic reticulum, and the prominence of the secretory droplets throughout most of the cytoplasm, indicate that this gland is primarily involved in the secretion of organic materials, and has no role related to the salinity of the environment in which the animals are kept. However, the ultrastructure of the lachrymal gland in Malaclemys differs markedly from that of the remaining emydines studied. In the freshwater emydines the lachrymal gland appears to be involved in the secretion of organic material; the tubules contain both mucous and serous cells. In the lachrymal gland from Malaclemys secretory droplets, Golgi apparatus, and endoplasmic reticulum were insignificant features, while mitochondria, glycogen, and microvilli on the serosal surfaces of the cells were very prominent. These and other features cause a strong resemblance between the lachrymal gland in Malaclemys and other tissues noted for active transport. The above morphological evidence suggests that if either of the orbital glands is involved in osmoregulation the most probable choice is the lachrymal gland.
The genus Amblyseius (Acarina: Phytoseiidae) in Canada and Alaska
Authors: Chant D. A. , Hansell R. I. C.
Published: August 2008

Three genera in the subfamily Phytoseiinae (Acarina: Phytoseiidae) are known to occur in Canada and Alaska: Phytoseius Ribaga, Amblyseius Berlese, and Typhlodromus Scheuten. Chant (1965b) reviewed the genus Phytoseius in Canada. The present paper, based on examination of more than 5000 specimens, describes, keys, and figures the 48 species of Amblyseius known to occur in Canada and Alaska, and includes full collection records. Thirty-two new species are described. Chant's (1965a) generic diagnosis is followed.
Cycle vital et croissance de Bithynia tentaculata L. (Mollusca, Gastropoda, Prosobranchia) du Lac St-Louis près de Montréal
Authors: Pinel-Alloul Bernadette , Magnin Etienne
Published: August 2008

A total of 13468 specimens of Bithynia tentaculata were collected at four sampling sites on Lake St-Louis from May 1968 to July 1969. To obtain a representative sample of the populations, various collecting methods were used. The life history and the growth at each station were compared and correlated with the physical and chemical features of the habitat. Comparisons with Lilly's (1953) observations in Britain are also included.
Mating of the alfalfa leafcutter bee, Megachile rotundaia (F.), in the laboratory
Authors: Krunic M. D.
Published: August 2008

Females of M. rotundata will mate in the laboratory and evidently mate only once. Under the conditions of this study about 35% of the females in cages were inseminated.
Nosema thomsoni n. sp., a microsporidian from Choristoneura conflictana (Lepidoptera: Tortricidae)
Authors: Wilson G. G. , Burke J. M.
Published: August 2008

A microsporidian pathogen of Choristoneura conflictana is described. The pathogen appears to attack primarily the gut, silk glands, and malpighian tubules. Spores of the pathogen were observed in the progeny of infected adults. The name Nosema thomsoni n. sp. is proposed for the microsporidian protozoa.
Some cytological changes in the fat body and testes of male spruce budworm (Choristoneura fumiferana Clem.) pupae after treatment with tepa
Authors: Addy Norton D.
Published: August 2008

A histological study was conducted to determine the effects of tepa, an aziridine-alkylating agent, on male spruce budworm pupae. The results indicated an increase in protein concentration in the fat body and testes of the tepa-treated insects. The profound changes in protein metabolism in the tepa-treated insects are similar to known protein patterns in fat bodies that are mediated by increases in ecdysone titer during the pupal period. These changes are further evident in the eye and testes pigment production and in the differentiating sperm that result in sterile gametes which all depend on ecdysone titer for their normal development. From this it seems evident that tepa may have an effect on the cell's ability to regulate hormone levels, protein metabolism, or both. And these effects result in the critical changes in mature sperm that lead to the dominant lethal mutation occurring in resulting zygotes.
Surface specializations of the hindgut cuticle of lepidopterous larvae
Authors: Byers J. R. , Bond E. F.
Published: August 2008

The cuticular intima lining the pyloric region of the hindgut of lepidopterous larvae bears numerous spines, comprising four distinct types, which are arranged in regular discrete patterns. On the basis of location, form, and other criteria three of the four types of spines have clearly attributable roles in alimentary function. One of these roles is the shredding of the peritrophic membrane as it passes through the pylorus. Although the spines are arranged in a basic pattern characteristic of lepidopterous larvae, there is within this basic pattern considerable diversity among species.The intima of both the colon and anterior rectum, although devoid of spines, is pitted with numerous small depressions. The presence of these small depressions is probably indicative of the reabsorptive abilities of the underlying epithelium.
Notes on the African long-eared bats of the genus Laephotis (family Vespertilionidae)
Authors: Peterson R. L.
Published: August 2008

The third known specimen of Laephotis wintoni is compared with the other two known examples, and morphological details are analyzed and compared with examples of Laephotis angolensis. Details of the face and ear of L. wintoni are illustrated, and photographs of the skulls of both species are provided for the first time.
Neurosecretory cells and their axon pathways in Culiseta inornata (Williston) (Diptera: Culicidae)
Authors: Burgess L.
Published: August 2008

Paired medial, intermediate, and anterior groups of neurosecretory cells are present in the protocerebrum of Culiseta inornata (Williston). The medial and intermediate cells seem to persist through larval, pupal, and adult stages; the anterior cells become inconspicuous about the time of adult emergence. Axons of the intermediate neurosecretory cells could not be traced for an appreciable distance, but axons of the medial cells could be traced to a neurohaemal organ on the aorta, and they appear to constitute the NCC I. Branches of the anterior-cell axons seem to constitute the NCC II, and other branches of these axons in fourth-instar larvae and young pupae can be traced into the ventral nerve chain. From the neurohaemal organ some neurosecretory axons pass into the oesophageal nerves, and the expanded posterior portion of each oesophageal nerve in adults may be a storage and release organ of neurosecretory material. A neurosecretory pathway can be traced from the neurohaemal organ to the corpora allata in adults; it is probably present also in larvae. Conspicuous neurosecretory axons of uncertain origin, which are distinct from the anterior-cell axons, can be traced from the protocerebrum through the circumoesophageal connectives and along the whole length of the ventral nerve chain in fourth-instar larvae; these axons are present, probably in a similar form, also in younger larvae, in pupae, and in newly emerged adults.
The Leuctridae of Eastern Canada (Insecta; Plecoptera)
Authors: Harper P. P. , Hynes H. B. N.
Published: August 2008

After a short discussion of the taxonomy of the adult Leuctridae of Eastern Canada, the nymphs of the eight most common species are described and a key for their identification is proposed.
The Capniidae of Eastern Canada (Insecta; Plecoptera)
Authors: Harper P. P. , Hynes H. B. N.
Published: August 2008

A key to the adults of the 18 species of Capniidae of Eastern Canada is presented together with drawings of the main taxonomic characters. Descriptions of the nymphs of the 15 common species and a preliminary key for their identification is also given.
A note on the nest-raiding behavior of male sticklebacks
Authors: Wootton R. J.
Published: August 2008

The circumstances in which nest-raiding behavior was shown by male sticklebacks are described. These observations refer to natural situations rather than laboratory situations. It is hypothesized that nest raiding is normally a response to a shortage of food or material for building nests.
Blood cell destruction in the opisthonephric kidney of the sea lamprey, Petromyzon marinus L.
Authors: Youson John H.
Published: August 2008

Electron microscopic observations reveal that blood cells are engulfed by macrophages within interstitial sinusoids of the opisthonephric kidneys of larval and adult Petromyzon marinus. Therefore the kidneys represent one site where blood cell destruction may occur in this animal.
Variations in the foliar amino acid composition of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) in relation to outbreaks of the spruce budworm (Choristoneura fumiferana (Clem))
Authors: Kimmins J. P.
Published: August 2008

The amino acids of new and old foliage of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) were investigated using two-dimensional descending paper chromatography. The data were analyzed for variation associated with age of foliage, age of tree, and flowering condition. The concentration of foliar amino acids was greater in balsam fir than in white spruce, and greater in new foliage than old foliage.The difference in concentration between foliage of flowering and non-flowering trees was smaller. However, the new foliage of flowering fir had higher levels of most of the amino acids examined than any other foliage category. This appears to reflect the known suitability of these foliage categories for spruce budworm larvae. While the data presented do not quantify the ecological significance of this apparent correlation, they do support the theory that variations in the nutritional quality of host plants play a very important role in the dynamics of herbivore populations.
The distribution of Microtus pennsylvanicus within grassland habitat
Authors: Grant P. R. , Morris Ralph D.
Published: August 2008

A 4-year live-trapping study in southern Quebec demonstrated that Microtus pennsylvanicus was distributed randomly in three half acres of enclosed grassland habitat. It was not possible to establish, by correlation analysis, a strong association between number of captures at each position and environmental (mainly plant species) variables. The random distributions are attributed more to the operation of population factors than to the operation of habitat factors in these areas. A simple model is presented which shows how, at different densities, animal distribution varies in relation to the distribution of habitat structure. Specifically, it predicts that (a) as animal density increases the distribution tends toward uniformity, and (b) at a given density, animal distribution in a patchy habitat is more aggregated than in a uniform habitat.The model is tested with data from the Quebec enclosures and from an enclosure in Saskatchewan which contained 1.4 ac of grassland. First it is established that the grassland is spatially more varied (patchy), in terms of plant species composition and presumed structure, in the Saskatchewan enclosure than in any of the three Quebec enclosures. In conformance with predictions of the model, Microtus distribution was aggregated in the Saskatchewan grassland. Also in conformance with the model the distributions became less aggregated as density increased, in both Saskatchewan and Quebec enclosures, but at a given density the animals were more aggregated in the patchy Saskatchewan grassland than in the uniform Quebec grassland.
A presumed strigeid metacercaria in the skeleton of a Triturus newt
Authors: Simmons David J. , Wolfgang Robert W. , Cummins Helen , McWhinnie Dolores J.
Published: August 2008

A trematode metacercaria was observed histologically in the marrow cavity of a metatarsal bone from a Triturus newt. The general morphology of the larva and the lack of oral suckers and an acetabulum make it probable that it is a strigeid. In situ growth of the encysted parasite was detected by labeling the host with 3HTdr.
Ultrastructure of a chordotonal and a sinusoidal peg organ in the antenna of larval Aedes aegypti (L.)
Authors: Zacharuk R. Y. , Blue Sharon G.
Published: August 2008

Two specialized sensilla in the antenna of fourth-instar larvae of Aedes aegypti are described and their probable functions are speculated. One has an external peg innervated to the tip by a dendrite from a single neuron. The central portion of the dendrite is broken up into numerous fine branches within a large sinus formed by the trichogen cell around this region. The suggested function is osmo-reception. The second sensillum is of a simple chordotonal type. It is suspended within the antennal cavity and is attached within the antennal cone. Suggestions are that it functions either as a stretch receptor or as a monitor for low-frequency vibrations in the adjacent aquatic environment.
Food preferences of the dusky grasshopper, Encoptolophus sordidus costalis (Scudder) (Orthoptera: Acrididae)
Authors: Bailey C. G. , Riegert P. W.
Published: August 2008

Crop analyses of 578 grasshoppers showed that the dusky grasshopper, Encoptolophus sordidus costalis, is primarily a grass-feeding species. All grasses are not selected randomly. About 80% of the diet consisted of Agropyron smithii, A. dasystachyum, and Carex eleocharis. The latter was eaten at a rate that was more than twice as great as that expected if feeding were proportional to the relative abundance of plant species on the study site. Therefore, this sedge is a specific preferred food plant, especially for the three early instars. Forbs were ingested very sparingly in nature (1% of diet) but 11 out of 22 species were fed upon when offered singly to starved adult grasshoppers. Non-adherence to a strictly grass diet under stress conditions is indicative of great flexibility and explains the widespread distribution of this species throughout central North America.
Incorporation of Na-1-14C-acetate into the fatty acids of two insect parasites (Hymenoptera) reared on different hosts
Authors: Barlow J. S. , Bracken G. K.
Published: August 2008

Sodium-1-14C-acetate was injected into larvae of the parasite, Exeristes comstockii, reared on Galleria mellonella or on Lucilia sericata. The concentration and specific activities of the fatty acids in the larvae were measured 24 h later. The concentration of palmitoleic acid was 10 times greater in C. comstockii when it grew on L. sericata but the specific activity of this fatty acid was the same on either host. It is concluded that the level of palmitoleic acid and probably other fatty acids in the parasite is controlled predominantly by changes in metabolic rates which are regulated by the concentration of the fatty acid in the parasite's diet, that is, host tissue. Direct deposition of dietary fat would not accomplish this result.Another parasite, Itoplectus conquisitor, reared on G. mellonella was also examined.
Attempts at chemotherapy of Echinococcus multilocularis infections in rodents. II. A study of some parasiticides and cytostatic agents
Authors: Lubinsky G. , Lee Ch.-F. , Baron R. W.
Published: August 2008

Seven parasiticides were studied for their ability to inhibit the growth of Echinococcus cysts, but none was found to be active. Of the six cytostatic agents examined, demecolcine and dactinomycin inhibited the growth of cysts, but only when used in toxic doses.
In vitro cultivation of hemocytes of Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae)
Authors: Sohi S. S.
Published: August 2008

Prolonged culturing of the hemocytes of Malacosoma disstria has been accomplished using Grace's insect tissue culture medium supplemented with fetal bovine serum (5%) and Bombyx mori hemolymph (3%). The cultures started to grow after 3–6 months. These cells have now been in vitro for over 16 months, and have been subcultured 35 times. Three types of cells were present in primary cultures, but only one type, prohemocytes, persisted and grew after subculturing. The M. disstria larvae that were used as the original source of hemocytes were naturally infected with the microsporidian Glugea disstriae. The microsporidian also grew in [he cell cultures, and the cells are still infected.
Neurosecretion and water balance in Cenocorixa bifida (Hung.) (Hemiptera, Corixidae)
Authors: Jarial M. S. , Scudder G. G. E.
Published: August 2008

The type A neurosecretory cells of the pars intercerebralis in C. bifida have axons that pass direct to the region of the dorsal aorta. When insects are in their normal hyposmotic medium, these protocerebral NSC have moderate amounts of neurosecretory material. In isosmotic or hyperosmotic media there is a considerable reduction in stainable material, whereas when they are in distilled water, the protocerebral NSC stain deeply, the cells being loaded with neurosecretory material. The depletion of neurosecretory material under potential dehydration conditions strongly suggest that water balance in C. bifida is under neuroendocrine control. Comparison with the described conditions in other insects suggests that the protocerebral NSC in C. bifida produce an antidiuretic principle.
Blood parasites of geese of the McConnell River, N.W.T.
Authors: Bennett Gordon F. , MacInnes Charles D.
Published: August 2008

Of 736 blue, snow, and Canada geese from the McConnell River, N.W.T. which were examined for blood parasites only 21 birds (2.9%) were found to be infected. Of these, 15 infections were with Leucocytozoon simondi (2.0%) and 2 each with Parahaemoproteus nettionis, Plasmodium species, and microfilaria. Both adults and young of the year were infected. We suggest that the low incidence is an indirect result of adaptations of the simuliid vectors to tundra conditions. It is possible that increased incidence of L. simondi in the boreal forest is a factor contributing to the restriction of five of the six North American goose species to the tundra nesting habit.
Meristic comparisons of populations of mummichog Fundulus heteroclitus (L.) from Sable Island and mainland Nova Scotia
Authors: Tay Kok Leng , Garside E. T.
Published: August 2008

Mean counts were recorded for gillrakers, fin rays, and vertebrae in samples of mummichog Fundulus heteroclitus (L.) collected from a freshwater pond (0.05‰ salinity (S)), a brackish pond (16‰ S), Sable Island, 290 km east of Halifax, Nova Scotia, and a sample collected along the coast near Halifax (26‰ S). Virtually all differences were statistically significant. Mean counts for gillrakers and rays of all fins were lowest in the sample from the brackish pond. Counts of trunk vertebrae were relatively stable but counts of caudal and total vertebrae decreased along the gradient of increasing salinity. The frequency of mummichog with anomalous vertebrae, principally in the caudal peduncle, was also least in the sample from the brackish pond and highest in the freshwater sample. Although the effects of temperature and other important variables cannot be removed from these observations, the consistent trend of structures such as fin rays and gillrakers which are differentiated relatively late in the embryonal phase suggests that osmotic stress, which should be minimal near 16‰ S, is also involved in the regulation of differentiation.
Studies on the ecology of cuterebrid parasitism in deermice
Authors: Hunter D. M. , Sadleir R. M. F. S. , Webster J. M.
Published: August 2008

This study of Cuterebra parasitic on the deermouse (Peromyscus maniculatus) refutes some previous hypotheses of why infested Peromyscus appear to survive longer than healthy mice. This phenomenon is solely the result of mice that remain on the plot longer having a longer exposure to the infestation and hence a greater incidence of attack. This contention is supported by the incidence of infestation per month being the same in transients and residents even though residents had a greater overall degree of infestation. The similar incidence of infestation per month also indicates that the fly lays its eggs in such a way that neither transients nor residents are favored to contact the infestation, a result that is compatible with the observations of several workers on botfly oviposition habits.
Reproduction in female reindeer and caribou
Authors: McEwan E. H. , Whitehead P. E.
Published: August 2008

Reindeer and caribou which are polyestrous, undergo estrous cycles of two lengths, a short cycle of 10 to 12 days, and a long cycle of 24 days. The duration of pregnancy in free-roaming animals was found to be considerably longer than in animals reared in captivity, which may be due to prenatal undernourishment. The estimated digestible energy consumed during the late pregnancy of penned animals amounted to about 6000 kcal/day.
Interspecificity of lipid-regulating factors from insect corpus cardiacum
Authors: Downer R. G. H.
Published: August 2008

Aqueous extracts of corpus cardiacum from Periplaneta americana L. elicit the characteristic locust response of hyperlipemia when injected into adult male Locusta migratoria migratoides R. and F. Conversely, gland extracts of L. m. migratoides cause the typical cockroach response of hypolipemia when injected into adult male P. americana.It is proposed that similar factors are present in both species with specificity being determined at the site of action.
Hibernation of eastern chipmunks (Tamias striatus) maintained under controlled conditions
Authors: Scott Grace Workman , Fisher Kenneth C.
Published: August 2008

The hibernation pattern of captive eastern chipmunks maintained under controlled conditions of light and temperature was examined. It was consistent with the view that hibernation results from an endogenous rhythm with a periodicity of about a year, probably temperature independent.Continuous recording from nest bottom temperature sensors was tested for the first time with this species and found to be more accurate than the sawdust technique for detecting arousals. It also provided useful information about trends in body temperature.The hypothesis that a shift in the temperature at which heat-producing responses are mobilized occurs during hibernation and that it is responsible for the pattern of periodic arousals, is discussed in relation to the observations made.
Responses of miracidia of Schistosomatium douthitti (Cort 1914) to monochromatic light
Authors: Wright D. G. S. , Lavigne D. M. , Ronald K.
Published: August 2008

When exposed to an equal energy spectrum (irradiance = 0.225 W/m2) from 450–650 nm miracidia of Schistosomatium douthitti exhibited a significant directed response to monochromatic light at 500 and 525 nm.
The life history of Scaphiostomum pancreaticum McIntosh, 1934 (Trematoda: Brachylaemidae)
Authors: Jensen Doris N.
Published: August 2008

The life cycle of the brachylaemid trematode Scaphiostomum pancreaticum McIntosh, 1934, was completed experimentally in the laboratory. Eggs were obtained from trematodes removed from naturally infected Tamias striatus. Eggs are mature when laid and hatch naturally only after ingestion by a snail. In vitro hatching and subsequent examination of the miracidium was accomplished in snail gastric juice. Sporocysts developed in Anguispira alternata and cercarial emergence began 129 days after infection. Metacercariae developed in the kidney of A. alternata, Triodopsis albolabris, and Haplotrema concavum and were infective to the chipmunk after 5 months, and ovigerous adults were obtained in 30 days. This is the first description of the life cycle of a member of this genus.
Etude morphologique comparée de l'estomac de deux rongeurs Ondatra zibethicus et Marmota monax (Mammalia : Rodentia)
Authors: Garon Olivier , Piérard Jean
Published: August 2008

A macroscopic description of the stomach of both Ondatra zibethicus and Marmota monax is given. The structure of this organ is related to the ecology of these species. Both capacity and weight of the stomach of Marmota are relatively superior to those of Ondatra. The cardia of Ondatra is prolonged on the lesser curvature of the stomach through a grooved surface. In Ondatra the fundic area is partly separated from the body and the organ's wall is highly extensible. In the same species, the glandular area is concentrated in a well-circumscribed and well-vascularized part of the stomach body.
Histogenesis of the islets of Langerhans in insulin-treated chick embryos
Authors: Kalliecharan R. , Gibson M. A.
Published: August 2008

Chick embryos were exposed to a teratogenic dose of insulin at the 6-day incubation stage and the effect of this treatment on the histogenesis of the islets of Langerhans was studied throughout the incubation period. The exogenous insulin caused an initial delay in the differentiation of the beta islets and in the elaboration of the endogenous insulin. During the final prehatching stages, the endogenous insulin appeared to be elaborated more rapidly than in the control tissues. The insulin treatment caused an increased activity of the alpha cells and an increased production of glucagon. Histochemically, the ribonucleic acid content of both alpha and beta cells was reduced, especially during the early stages of development. Also, there was an initial increase in glycogen storage and alkaline phosphatase activity within the alpha cells. The beta islets in the insulin-treated tissues, except for the initial delay in their development, showed no significant differences in the glycogen and alkaline phosphatase patterns from the control.
A stabilizing interaction between the founder effect and interdeme mixing in competing populations of Drosophila melanogaster and Drosophila simulans
Authors: Gibo David L.
Published: August 2008

Population cages with Drosophila melanogaster and D. simulans in competition were maintained under high predation pressure. The cages were established under three different conditions. One group of cages was started with a large population (150 adults) of each species. In these cages D. melanogaster was quickly depressed to low levels by D. simulans. A second group of cages was established with a small population (15 adults) of each species. These cages showed a great deal of diversity of both population size and dominant species. The third group of cages was established by mixing the populations of the cages of the second group and redistributing this mixed population among separate cages. In this last group of cages, the D. simulans population resembled those observed in the cages started with large populations, but the D. melanogaster populations had changed. Instead of being depressed to extinction, D. melanogaster was observed to maintain an apparently stable population. Interspecific competition between the two species appeared to have been reduced. The relationship of these results to the founder effect, interdeme mixing, and rapid changes in competitive relationships is discussed.
Strain-specific and organ-specific factors influencing development of ectopically transplanted mouse blastocysts
Authors: James D. A.
Published: August 2008

Mouse blastocysts were transplanted to syngeneic and allogeneic kidney and testis. Organ-specific factors markedly affected the course of development of the blastocyst. Strain-specific factors alone showed a lesser effect. From these findings it was concluded that blastocyst differentiation can be influenced by the environment and that organ-specific characteristics have a more appreciable effect than strain-specific characteristics.
Activity response to chlorine in the brook trout, Salvelinus fontinalis (Mitchill)
Authors: Dandy J. W. T.
Published: August 2008

Exposure of brook trout to chlorine evoked changes in activity, ventilation, the "coughing" reflex, and at lethal levels a heavy secretion of mucus. Locomotory activity increased initially and was subsequently depressed. Both responses were seen at 0.35 and 0.08 ppm, but the initial increase was not seen at 0.04 or 0.005 ppm. The initial increase lasted 2 h, whilst the depressant response was still continuing after 7 days at the sublethal level of 0.005 ppm.The results are discussed in relation to the different selection responses to different chlorine concentrations shown in rainbow trout by Sprague and Drury (1969).
A new species of Dendronotus from the northeastern Pacific with notes on Dendronotus nanus and Dendronotus robustus (Mollusca: Opisthobranchia)
Authors: Robilliard Gordon A.
Published: August 2008

A new species of Dendronotus, discovered in the San Juan Islands, Washington, is described. The description is based on color, external morphology, structure of the jaws, number and shape of radula teeth, and structure of the reproductive system. In the laboratory, this species copulated and spawned in February. It showed a swimming escape response to the asteroid, Pycnopodia helianthoides, a potential predator in natural situations. The prey of this new species of Dendronotus is probably one or more species of hydroids.Dendronotus nanus is provisionally accepted as a valid species distinct from D. iris. However, the similarities between the two species are discussed and it is suggested that further studies will show that the two species are the same with the name D. iris taking precedence.Some features of the radula, jaw, and digestive system of D. robustus are discussed briefly. The reproductive system is described in detail and figured for the first time. Some aspects of ecology, especially feeding, are discussed. Although most specimens examined had eaten hydroids, some had ingested whole one or more sabellid polychaetes.
Further records of Polychaeta new to British Columbia with comments on some others
Authors: Berkeley C.
Published: August 2008

Thirteen species of Polychaeta distributed between 10 families are dealt with. Of these, one is new to science, one new to North America, and two new to British Columbia. The remaining discussions are of species already recorded from British Columbia, but the records of which call for further comment.
The fine structure of the ookinete of Parahaemoproteus velans (= Haemoproteus velans Coatney and Roudabush) (Haemosporidia: Haemoproteidae)
Authors: Desser Sherwin S.
Published: August 2008

The ookinete of Parahaemoproteus velans is bounded externally by a trilaminar membrane, beneath which lies a fibrillar zone. Below this zone and forming the inner surface of the pellicle is a second, dense, membranelike layer. The specialized apical region of the ookinete is modified into a thickened "caplike" structure. The inner layer of the pellicle in this region is thickened and wavy in appearance. In a sub-pellicular space in the cap region lie about 27 elongate cylindrical structures, and beneath these about 50 microtubules ring the cytoplasm. Numerous dense spherical bodies are located in the anterior cytoplasm of the parasite. A large, more or less central nucleus, often containing microtubular elements, lies in a cytoplasm richly endowed with granular endoplasmic reticulum. Two or more areas containing a "crystalloid" material lie anterior and posterior to the nucleus.
Gill irrigation in Rana catesbeiana. Part I. On the anatomical basis
Authors: Gradwell Norman
Published: August 2008

The gross and histological anatomy of the gill irrigation apparatus are discussed. Two histologically different types of muscle fiber are identified in certain muscles by virtue of the difference in the proportion of fibrillar to sarcoplasmic material in the muscle fibers. An accessory jaw tendon, the valve of the first gill cleft, and several ligaments are described for the first time in an anuran tadpole. An opercular muscle and a fascia lateralis are also described for the first time in a ranid tadpole. The rugulose lining of the pharynx is well vascularized; attention is also drawn to epithelial cells whose points project into the lumen of the pharynx. Several discrepancies in the literature on tadpole anatomy are discussed. To facilitate functional studies, an alphanumeric terminology is proposed for the branchiomeric muscles.