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.

Life history patterns of Hydropsyche bronta and H. morosa (Trichoptera: Hydropsychidae) in summer-warm rivers of southern Ontario

1984 ◽  
Vol 62 (2) ◽  
pp. 271-275 ◽  
Author(s):  
Rosemary J. Mackay
Keyword(s):  
Life History ◽  
Second Order ◽  
Southern Ontario ◽  
Larval Instars ◽  
Life History Patterns

Life history patterns are described for Hydropsyche bronta and Hydropsyche morosa in the Credit and Humber rivers of southern Ontario. In the lower reaches (stream orders 4 and 5) of these rivers, summer water temperatures exceed 24 °C for 3 months and reach maxima of 27–30 °C. Here H. morosa appeared to be bivoltine while at least half of the H. bronta population at each of four sites was trivoltine. At a fifth site below an impoundment on a second-order tributary to the Humber, H. bronta was bivoltine; H. morosa was extremely rare at this site and in upper reaches in general. Hydropsyche bronta is smaller than H. morosa and tends to overwinter in slightly older larval instars than H. morosa. Both these characteristics, and the fact that H. bronta is probably living in the optimal part of its habitat range in the Credit and Humber, may explain its ability to be trivoltine.

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.

Causes of variation in body size and consequences for the life history of Sitodiplosis mosellana

2004 ◽  
Vol 136 (6) ◽  
pp. 839-850 ◽  
Author(s):  
M.A.H. Smith ◽  
R.J. Lamb
Keyword(s):  
Life History ◽  
Body Size ◽  
Larval Instar ◽  
Larval Density ◽  
Egg Parasitoid ◽  
The Body ◽  
Adult Size ◽  
Larval Size ◽  
Sitodiplosis Mosellana ◽  
Developing Seed

AbstractThe body sizes of mature larvae and adults from field and laboratory populations of the wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were measured to determine possible causes of variation in size and consequences of such variation through the life history. Mature larvae varied eightfold in mass. Female larvae were 80% heavier than males, on average. Variation in mass was associated with both the position of larvae on a wheat spike and the number feeding together on a developing seed. Larvae were 9% smaller when they developed on smaller, later developing seeds and 15%–18% smaller when they competed with five other larvae on an average-sized seed. Fewer small larvae survived winter. Larval density per infested seed increased with number of larvae per spike, suggesting that larval size may have density-dependent population effects. Small larvae produced few adults of Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae), an egg parasitoid that overwinters as a larva in the third larval instar of S. mosellana. These effects were probably due to size, but sex may also have been a factor. The size of adults, measured by wing and abdomen length, was also variable, although less so than the size of larvae. Adult size was not associated with time of emergence and both large and small females dispersed, but female fecundity (4–105 mature eggs per individual) increased with body size.

Ontogenies of some Ordovician Telephinidae from Argentina, and larval patterns in the Proetida (Trilobita)

1999 ◽  
Vol 73 (2) ◽  
pp. 219-239 ◽  
Author(s):  
Brian D. E. Chatterton ◽  
Gregory D. Edgecombe ◽  
Norberto E. Vaccari ◽  
Beatriz G. Waisfeld
Keyword(s):  
Life History ◽  
New Species ◽  
Life Cycles ◽  
Larval Stages ◽  
The Third ◽  
Larval Type ◽  
New Findings ◽  
Argentine Precordillera ◽  
Life History Patterns ◽  
Three New Species

The ontogenies of three new species of Telephinidae, Telephina calandria, Telephina chingolo, and Telephina problematica are described from Arenig-Caradoc strata in the Argentine Precordillera, and compared with the larval stages of some other Proetida, including other telephinids.New findings reveal 1) a radical metamorphosis in the ontogenies of these Telephina species late in the meraspid period, not previously described among Trilobita; and 2) distinctive hypostomes of Telephinidae containing long, thin anterolaterally and dorsally splayed anterior wings. Early ontogenies of different species currently assigned to the genus Telephina fall into at least two distinct morphological and life history groups, and hypostomes (if correctly assigned in previous works) vary significantly. The three new species strengthen the hypothesis of a phylogenetic connection between Oopsites and Telephina.Three morphological types of protaspid instars are described for proetide trilobites. Two are anaprotaspides, and the third is a metaprotaspis. They always occur in the same sequence in the ontogeny, but no cases are known of all three types in the same species. These larval types are important for understanding the systematics and life cycles of the Proetida. Benthic/pelagic transitions identify four life history patterns among the the Proetida. The best larval synapomorphy for the Proetida is the distinctive metaprotaspid larval type, which is absent in very few proetides (some Telephinidae), perhaps as a result of heterochronic displacement of this stage into the meraspid period.

Recognition of larvae of the Tetrabothriidae (Eucestoda): implications for the origin of tapeworms in marine homeotherms

1987 ◽  
Vol 65 (4) ◽  
pp. 997-1000 ◽  
Author(s):  
Eric P. Hoberg
Keyword(s):  
Life History ◽  
Phylogenetic Relationships ◽  
Host Switching ◽  
Larval Morphology ◽  
Dominant Group ◽  
Marine Birds ◽  
Marine Communities ◽  
Definitive Evidence ◽  
Life History Patterns ◽  
Ecological Associations

The Tetrabothriidae represent the dominant group of cestodes, previously known only as adult parasites, in marine birds and mammals. Recognition of their unique plerocercoid larvae provides the first definitive evidence for life history patterns and phylogenetic relationships with other cestodes. Affinities of the Tetrabothriidae and Tetraphyllidea, cestodes of elasmobranchs, are indicated by larval morphology and ontogeny. However, patterns of sequential heterochrony in the ontogeny of the adult scolex of Tetrabothrius sp. appear to be unique among the Eucestoda. Tetrabothriids constitute a fauna that originated by host switching from elasmobranchs to homeotherms, via ecological associations, following invasion of marine communities by birds and mammals in the Tertiary.

Life-history and systematic position of the European Alomya species (Hymenoptera: Ichneumonidae)

1983 ◽  
Vol 14 (4) ◽  
pp. 462-466 ◽  
Author(s):  
Rolf Hinz ◽  
John Short
Keyword(s):  
Life History ◽  
Larval Instar ◽  
Systematic Position ◽  
European Species ◽  
Host Parasite

AbstractAlomya is a genus of uncertain systematic position. Rearing out of Alomya semiflava Stephens from caterpillars of Hepiallls lupulinus L. is described, and the host-parasite associations of all European species of Alomya are discussed. The final larval instar of A. semiflava is described and on the basis of this the systematic position of Alomya is discussed.

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