Life cycles, microdistribution, and food of two species of caddisflies (Trichoptera) in a wooded stream in Southern Ontario

1984 ◽  
Vol 62 (12) ◽  
pp. 2582-2588 ◽  
Author(s):  
M. P. Singh ◽  
S. M. Smith ◽  
A. D. Harrison
Keyword(s):  
Plant Material ◽  
Life Histories ◽  
Larval Instar ◽  
Life Cycles ◽  
The Other ◽  
Plant Food ◽  
Filter Feeder ◽  
Southern Ontario ◽  
Physical Conditions ◽  
First Instar

Accounts of life histories, microdistributions, and food of Rhyacophila minor and Wormaldia moesta (Trichoptera) inhabiting a headwater stream in Ontario are presented. Rhyacophila minor is a caseless predator and W. moesta is a net-spinning filter feeder. First-instar larvae of W. moesta inhabited the stream longer than those of R. minor. The other instars of W. moesta grew rapidly and those of R. minor grew slowly. Pupae of both species showed a tendency to aggregate on bare stones. Both species were univoltine and water temperature is hypothesized to be an important factor regulating growth and voltinism. Wormaldia moesta was patchily and R. minor more uniformaly distributed in the stream. Rhyacophila minor preferred moss-covered stones whereas W. moesta preferred bare stones; however, these preferences changed with season and larval instar and are attributed partially to changing physical conditions in the stream. Although R. minor is primarily carnivorous, the early instars fed extensively on plant material; this behavior is attributed partly to their inability to prey and partly to the abundance of plant-food resources. Wormaldia moesta fed primarily on detritus; it may supplement the diet by grazing on diatoms when the seston is in low supply.

EARLY STAGES OF SOME HESPERIINAE

1939 ◽  
Vol 71 (5) ◽  
pp. 117-118
Author(s):  
V. G. Dethier
Keyword(s):  
Larval Stage ◽  
Life Histories ◽  
Larval Instar ◽  
Full Account ◽  
The Third ◽  
Early Stages ◽  
First Instar ◽  
Previous Communication

Observations on the life histories of Polites verna Edw., Hesperia leonardus Harr., and Ancyloxypha numitor Fabr. are reported here. Previous work on the rare P. verna included a vague description by Scudder of a drawing of the egg and a full account of the last larval instar. Concerning H. leonardus only the egg and first instar were known. A drawing of the second instar was also described (Scudder, 1889). In a previous communication (Dethier, 1938) it was pointed out that the third brood of A. nomitor probably passed the winter in the larval stage. This is confirmed and further details presented.

POST EMBRYOLOGICAL DEVELOPMENT OF EPHEMEROPTERA (MAYFLIES). EXTERNAL CHARACTERS ONLY

1935 ◽  
Vol 12 (4) ◽  
pp. 433-478 ◽  
Author(s):  
F. P. Ide
Keyword(s):  
Life History ◽  
Structural Change ◽  
Life Histories ◽  
External Genitalia ◽  
The Other ◽  
Embryological Development ◽  
First Instar ◽  
Definite Case ◽  
History Of ◽  
Number Of Segments

The development of external structures is followed from hatching to maturity. The life histories of two species Stenonema canadense Wlk. and Ephemera simulans Wlk. are described in detail and less complete accounts given of nine others.Each moult results in a change in the number of segments in the caudal filaments and on this basis it has been possible to determine the number of instars. In Stenonema canadense the number was found to be between 40 and 45, and in Ephemera simulans about 30. Segments are added to the caudal filaments of the former at each moult in the following way: one in each of the first two moults, two in each of the next three, three in the next and four at each subsequent nymphal moult. In the change from nymph to subimago distal segments are dropped in Ephemera and probably in Stenonema also.Mouth parts are very different in the newly hatched than in the full grown nymph as described for Stenonema canadense.A definite case of a hypermetamorphosis of the tarsus and its claws appears in the life history of Epeorus humeralis and Iron pleuralis.Gills are absent in the first instar in all the species studied. In some species they appear simultaneously on all the gill bearing segments at the first moult. In others they appear on segments five and six only at this moult, those of the other segments appearing only after several moults. The internal or secondary ramus of the gills appears much later in the nymphal life. The ultimate shape of the gill is influenced in some cases by the fact that the gills of segments five and six are segmented or unsegmented.In S. canadense the wing pads make their appearance in about the fifteenth from the last instar and the claspers and external genitalia of the male are apparent in about the eighth from the last instar.At each moult there is some structural change in the nymph adapting it to the environment. The environmental relation is being constantly changed by increase in size of the organism, thus necessitating these adaptations to preserve an equilibrium.

Life history patterns of some species of Hydropsyche (Trichoptera: Hydropsychidae) in southern Ontario

1979 ◽  
Vol 57 (5) ◽  
pp. 963-975 ◽  
Author(s):  
Rosemary J. Mackay
Keyword(s):  
Life History ◽  
Food Quality ◽  
Larval Instar ◽  
Life Cycles ◽  
Larval Size ◽  
Southern Ontario ◽  
Ecological Segregation ◽  
Summer Generation ◽  
Life History Patterns ◽  
Slow Growing

Life history patterns are described for five species of Hydropsyche in the Credit and Humber rivers. Larvae of univoltine species matured in May or June. Bivoltine species had a fast-growing summer generation of larvae maturing in July or August and a slow-growing winter generation of larvae maturing in April or May. Hydropsyche betteni, H. dicantha, H. slossonae, and H. sparna were bivoltine at some sampling stations, univoltine at others. Hydropsyche scalaris was exclusively univoltine. Most species were represented by many instars concurrently during summer. Overwintering occurred in a smaller number of instars. Species that overwintered in the final or penultimate larval instar were more likely to mature early and to be bivoltine than species overwintering in younger instars. High summer water temperatures and (or) food quality increased growth rates and the probability that a summer generation could mature before fall. Smaller species were more likely to be multivoltine than larger species.Differences among the life cycles of the five species did not suggest effective ecological segregation in summer in terms of larval size. Different overwintering stages among the species may prove to be important factors controlling the number of generations per year.

The life histories of some Plecoptera and Ephemeroptera in a southern Ontario stream

1970 ◽  
Vol 48 (6) ◽  
pp. 1333-1339 ◽  
Author(s):  
M. J. Coleman ◽  
H. B. N. Hynes
Keyword(s):  
Life Cycle ◽  
Life Histories ◽  
Life Cycles ◽  
Southern Ontario ◽  
Stream Insects ◽  
Flight Season

The life cycles of 4 species of stonefly and 11 of mayfly are described, based upon the flight season of the adults and measurements of nymphs collected at all seasons from the Speed River. It is shown that they fit into all but one of the categories of life cycle that have been described for stream insects in Europe, and that where more than one species of the same genus coexist there is usually a marked difference in the timing of their life histories.

State of Fashion: Searching for the New Luxury

APRIA Journal ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 11-16
Author(s):  
José Teunissen
Keyword(s):  
Twentieth Century ◽  
Daily Life ◽  
Life Cycles ◽  
The Other ◽  
Century Model ◽  
Cocktail Party ◽  
The Public ◽  
Other Hand ◽  
The One

In the last few years, it has often been said that the current fashion system is outdated, still operating by a twentieth-century model that celebrates the individualism of the 'star designer'. In I- D, Sarah Mower recently stated that for the last twenty years, fashion has been at a cocktail party and has completely lost any connection with the public and daily life. On the one hand, designers and big brands experience the enormous pressure to produce new collections at an ever higher pace, leaving less room for reflection, contemplation, and innovation. On the other hand, there is the continuous race to produce at even lower costs and implement more rapid life cycles, resulting in disastrous consequences for society and the environment.

scholarly journals Robustness of life histories to environmental variability in complex versus simple life cycles

2021 ◽  
Author(s):  
Annie Jonsson
Keyword(s):  
Growth Rate ◽  
Life Histories ◽  
Environmental Variability ◽  
Life Cycles ◽  
Relative Advantage ◽  
Complex Life Cycle ◽  
Life Stages ◽  
Vital Rates ◽  
Habitat Separation ◽  
Simple Life

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

DNA Barcode Identification of Black Cohosh Herbal Dietary Supplements

2012 ◽  
Vol 95 (4) ◽  
pp. 1023-1034 ◽  
Author(s):  
David A Baker ◽  
Dennis Wm Stevenson ◽  
Damon P LittLe
Keyword(s):  
Adverse Events ◽  
Dietary Supplements ◽  
Related Species ◽  
Plant Material ◽  
Dna Barcode ◽  
The Other ◽  
Black Cohosh ◽  
Test Plant ◽  
Actaea Racemosa ◽  
Validation Set

Abstract Black cohosh (Actaea racemosa) herbal dietary supplements are commonly consumed to treat menopausal symptoms, but there are reports of adverse events and toxicities associated with their use. Accidental misidentification and/or deliberate adulteration results in harvesting other related species that are then marketed as black cohosh. Some of these species are known to be toxic to humans. We have identified two matK nucleotides that consistently distinguish black cohosh from related species. Using these nucleotides, an assay was able to correctly identify all of the black cohosh samples in the validation set. None of the other Actaea species in the validation set were falsely identified as black cohosh. Of 36 dietary supplements sequenced, 27 (75%) had a sequence that exactly matched black cohosh. The remaining nine samples (25%) had a sequence identical to that of three Asian Actaea species (A. cimicifuga, A. dahurica, and A. simplex). Manufacturers should routinely test plant material using a reliable assay to ensure accurate labeling.

Speciation of cestoda. Evidence for two sibling species in the complex Bothrimonus nylandicus (Schneider 1902) (Cestoda: Cyathocephalidea)

Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 139-147 ◽  
Author(s):  
F. Renaud ◽  
C. Gabrion
Keyword(s):  
Sibling Species ◽  
Definitive Host ◽  
Parasite Species ◽  
Adult Stage ◽  
Life Cycles ◽  
The Other ◽  
Congeneric Species ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
Biological Differences

SUMMARYUsing biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.

The Influence of Ephestia Kuehniella on the Development of its Parasite Nemeritis Canescens

1968 ◽  
Vol 48 (2) ◽  
pp. 291-304
Author(s):  
SARAH A. CORBET
Keyword(s):  
Protein Concentration ◽  
Freezing Point ◽  
Larval Instar ◽  
Behavioural Response ◽  
Freezing Point Depression ◽  
Rate Of Development ◽  
First Instar ◽  
Rapid Changes ◽  
Fast Development ◽  
Insect Parasites

1. The first larval instar of Nemeritis lasts longer in young caterpillars of Ephestia than it does in older caterpillars. First-instar Nemeritis larvae in young hosts feed and grow very slowly, but they remain capable of fast growth if transferred to older host caterpillars. 2. Measurements of the protein concentration, the amino acid concentration and the freezing-point depression show rapid changes in the composition of the haemolymph of Ephestia caterpillars at that stage of larval development at which they first become capable of supporting the fast development of first-instar larvae of Nemeritis. 3. It is suggested that the rate of development of Nemeritis larvae depends on their rate of feeding, and that their rate of feeding is determined by a behavioural response to the composition of their food, the host's haemolymph; they feed slowly in young host caterpillars because the concentration of solutes (notably amino acids) in their food is so high. 4. A similar situation may hold when the development of insect parasites is delayed in diapausing hosts.

scholarly journals Influence of cutting type and size on rooting of Lavandula dentata L

2012 ◽  
Vol 14 (1) ◽  
pp. 8-11 ◽  
Author(s):  
C.M. Bona ◽  
I.R. Biasetto ◽  
M. Masetto ◽  
C. Deschamps ◽  
L.A. Biasi
Keyword(s):  
Essential Oil ◽  
Vegetative Propagation ◽  
Plant Material ◽  
The Other ◽  
Root Weight ◽  
Root Number ◽  
Polystyrene Foam ◽  
High Quality ◽  
Cutting Propagation ◽  
Superior Clones

Even though the Lavandula species may be propagated by seeds, it should not be the preferred propagation method because it causes a great lack of uniformity. On the other hand, asexually propagated lavender crops would provide more homogeneous crops, and clones from high quality plant material would increase the odds for obtaining a higher quality essential oil. However, problems such as poor rooting and restrict market availability for superior clones have been a problem in vegetative propagation of the Lavandula species. The objective of this work was to define which type and size of cutting is more adequate for cutting propagation of L. dentata, a very productive Lavandula species. Cuttings with 5, 8, 10 or 13 cm and from the apical or basal parts of stems cut from L. dentata stock plants were placed in Plantmax HT® filled polystyrene foam trays and kept under intermittent mist system for two months. Averages of root number, length of the longest root, fresh and dry root weight, and percentage of rooting were evaluated. Apical cuttings combined 97.9% rooting with an average of 13.2 roots per cutting and basal cuttings 93.7% rooting with 2.98 roots per cutting. Apical cuttings with at least 10 cm in length were considered the most adequate for cutting propagation of L. dentata.

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