The life history of Philocasca alba (Trichoptera: Limnephilidae) in a Rocky Mountain stream

1984 ◽  
Vol 62 (7) ◽  
pp. 1282-1288 ◽  
Author(s):  
R. A. Mutch ◽  
G. Pritchard

The life cycle of Philocasca alba Nimmo spans 3 years in a cold, second order, subalpine stream in the Rocky Mountains of Alberta. The flight period was from mid-May to late July. Larval instar 1 was found only in August–September; all other four instars were present in samples throughout most of the year. In their third autumn in the stream larvae in the final instar burrowed into gravel, pupated, and overwintered. Growth was confined to the ice-free period, June to November, when larval densities were greatest among deposits of conifer needles, cones, and woody material in pools. Larvae from these detrital accumulations had mainly fragments of conifer needles in their guts, although laboratory experiments showed that larvae could feed and grow on conifer needles only if they were highly conditioned. The later instars, particularly instar V, constituted a much greater than expected proportion of total larvae among submerged bank vegetation in spring and summer and deciduous leaves in autumn. Larvae in these two microhabitats mainly had fragments of moss and fragments of leaves, respectively, in their guts. The importance of moss was confirmed by a field experiment which showed that fifth instar larvae had significantly faster growth rates when fed on detritus supplemented with bank moss than detritus alone or detritus supplemented with deciduous leaves during the autumn.

1984 ◽  
Vol 62 (7) ◽  
pp. 1273-1281 ◽  
Author(s):  
R. A. Mutch ◽  
G. Pritchard

The life cycle of Zapada columbiana (Claassen) is basically 3 years in a subalpine stream in the Rocky Mountains of Alberta, although some individuals may complete their life cycle in 2 years. Adults emerged from mid-April to early June and did not disperse far from the stream. Emerging adults and ovipositing females showed no tendency to move upstream. The eggs hatched prior to winter of the same year and growth of larvae was confined to the ice-free period of June to November. It was estimated that at any time during the growth season at least 50% of the population in the stream was in moss covering boulders and cobbles in riffles. Moss was the predominant component in guts of larvae taken from moss, and detritus predominated in guts of larvae from other habitats. During the winter, detritus (from conifer needles) was the major component of the gut contents. Experiments demonstrated that larvae grew faster on moss than on conditioned Salix glauca leaves. Larvae grew on conifer needles only when the latter were highly conditioned and fragmented. This study has indicated that Zapada columbiana, an abundant shredder in many Rocky Mountain subalpine creeks, is as dependent on the autochthonous production of moss as it is on allochthonous detritus.


1952 ◽  
Vol 84 (10) ◽  
pp. 316-321 ◽  
Author(s):  
R. W. Stark

General.—The purpose of this paper is to analyse a sampling method devised to assess larval populations in an outbreak of the lodgepole needle miner, Recurvaria milleri Busck (Busck 1914, Hopping 1945).The problem of developing an adequate sampling method is intimately concerned with the life-history of the insect, the region of the outbreak and the nature of the forest stand in which the outbreak occurs. In sampling most defoliator populations the problem is made more difficult by external feeding and wandering habits, hence it is usually done in some relatively inactive stage at a fixed time. de Gryse (1934) describes the problems inherent in sampling these insects. The needle miner, however, is fixed in its location for most of its life-cycle and is therefore readily obtainable for study. The problem here is reduced to a statistical one, that of obtaining an acceptable sample i.e. within suitable error limits with due regard for existing variables.


1987 ◽  
Vol 65 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Olga Kukal ◽  
Peter G. Kevan

The life history of Gynaephora groenlandica was studied in the high arctic at Alexandra Fiord, Ellesmere Island. Life history events (larval development, pupation, adult emergence, mating, oviposition, hatching, and moulting to the second larval instar) occurred only in the 3–4 weeks before mid-July. Larvae fed mainly on Salix arctica. They stopped feeding by the end of June, hid, and spun hibernacula. Nineteen percent of third- and fourth-instar larvae were parasitized by the wasp Hyposoter pectinatus (Ichenumonidae); 52% of fifth- and sixth-instar larvae and pupae were parasitized by the fly Exorista sp. (Tachinidae). We estimated that G. groenlandica has a life cycle lasting 14 years. Parasitism caused 56% of overall mortality, whereas cumulative winter mortality was calculated as 13% of a cohort passing through a 14-year life cycle. Peak of activity of adult parasitoids coincided with inactivity of Gynaephora larvae during July. Selective pressure of parasitism may restrict development of G. groenlandica to a short period before adult parasitoids are most active. The importance of parasitoids in the life history of G. groenlandica suggests that parasitism is as significant as climate in population regulation of insects living in the high arctic.


1954 ◽  
Vol 86 (1) ◽  
pp. 1-12 ◽  
Author(s):  
R. W. Stark

General. The life history of the lodgepole needle miner in Yosemite National Park, California, has been described (24). The Canadian outbreak was discovered in 1942 but intensive investigations were not commenced until 1948. Many differences have been noted between the Canadian and Californian life histories since the discovery of the outbreak.It is the purpose of this paper to bring together all information collected by the author and staff of the Laboratory of Forest Zoology at Calgary, Alberta, concerning the life history of the lodgepole needle miner in the Canadian Rocky mountains.


1983 ◽  
Vol 61 (3) ◽  
pp. 586-596 ◽  
Author(s):  
Vytenis Gotceitas ◽  
Hugh F. Clifford

Dicosmoecus atripes (Hagen) has a 2-year life cycle in Dyson Creek, Alberta, a second order foothills stream of the eastern Canadian Rockies. Emergence and oviposition occur from August to mid-October. The first winter is spent as first instar larvae, the second as inactive fifth (final) instars in a form of diapause. No growth was observed in overwintering first instar larvae, and a significant (P < 0.05) weight loss was recorded in overwintering fifth instar larvae. Temperature seems to be the most important factor responsible for the 2-year life cycle. Annual production was estimated at 91.4 mg∙m−2∙year−1, with an annual production and biomass turnover (P/B) ratio of 4.97. Larval diet and microhabitat changed between instars. The proportion of diatoms in the diet of early instar larvae was significantly (P < 0.001) greater than that of third and later instars. Early instar larvae inhabit stream margins, while larvae of third and later instars were mainly found in midstream reaches. Larvae of all instars preferred pools to riffles. Abiotic factors important in microhabitat selection seemed to differ between larval instars.


Author(s):  
J. B. Brown-Gilpin

The wide variety of reproductive patterns and behaviour in the many species of Nereidae already studied clearly justifies further research. But the life history of Nereis fucata (Savigny) is not only of interest from the comparative point of view. Its commensal habit (it occurs within shells occupied by hermit crabs) immediately gives it a special importance. This alone warrants a detailed study, particularly as no commensal polychaete has yet been reared through to metamorphosis and settlement on its host (Davenport, 1955; Davenport & Hickok, 1957). The numerous interesting problems which arise, and the experimental methods needed to study them, are, however, beyond the range of a paper on nereid development. It is therefore proposed to confine the present account to the reproduction and development up to the time when the larvae settle on the bottom. The complete life cycle, the mechanism of host-adoption, and related topics, will be reported in later papers.


1953 ◽  
Vol 31 (4) ◽  
pp. 351-373 ◽  
Author(s):  
Liang-Yu Wu

A cause of swimmer's itch in the lower Ottawa River is Trichobilharzia cameroni sp. nov. Its life cycle has been completed experimentally in laboratory-bred snails and in canaries and ducks, and the various stages are described. The eggs are spindle-shaped. The sporocysts are colorless and tubular. Mother sporocysts become mature in about a week. The younger daughter sporocyst is provided with spines on the anterior end and becomes mature in about three weeks. The development in the snail requires from 28 to 35 days. A few cercariae were found to live for up to 14 days at 50 °C., although their life at 16° to 18 °C. was about four days. Cercariae kept at room temperature for 60 to 72 hr. were found infective. The adults become mature in canaries and pass eggs in about 12 to 14 days. Physa gyrina is the species of snail naturally infected. It was found in one case giving off cercariae for five months after being kept in the laboratory. Domestic ducks were found to become infected until they were at least four months old, with the parasites developing to maturity in due course; no experiments were made with older ducks. Furthermore, miracidia were still recovered from the faeces four months after the duck had been experimentally infected, and it is suggested that migratory birds are the source of the local infection.


2013 ◽  
Vol 88 (2) ◽  
pp. 230-236 ◽  
Author(s):  
R. Brinesh ◽  
K.P. Janardanan

AbstractThe life-cycle stages of Pleurogenoides malampuzhensis sp. nov. infecting the Indian bullfrog Hoplobatrachus tigerinus (Daudin) and the skipper frog Euphlyctiscyanophlyctis (Schneider) occurring in irrigation canals and paddy fields in Malampuzha, which forms part of the district of Palakkad, Kerala, are described. The species is described, its systematic position discussed and compared with the related species, P. gastroporus (Luhe, 1901) and P. orientalis (Srivastava, 1934). The life-cycle stages, from cercaria to egg-producing adult, were successfully established in the laboratory. Virgulate xiphidiocercariae emerged from the snail Digoniostoma pulchella (Benson). Metacercariae are found in muscle tissues of dragonfly nymphs and become infective to the frogs within 22 days. The pre-patent period is 20 days. Growth and development of both metacercariae and adults are described.


1957 ◽  
Vol 35 (6) ◽  
pp. 641-689 ◽  
Author(s):  
Gordon K. Sweatman

Chorioptic mange mites have been reared in vitro on epidermal debris. The life history of the mite has been observed, and each stage in the cycle described. Mites from the cow, horse, goat, sheep, and llama have been shown to be identical biologically and morphologically, and the specific names of equi, caprae, and ovis have been synonymized with C. bovis. The in vitro life cycle has been completed on epidermal debris from a variety of wild Cervidae, Bovidae, and Equidae, as well as on material from several breeds of domestic cattle, horses, sheep, and goats. From these and other data, three additional species or subspecies of Chorioptes were synonymized also with C. bovis. Only one other species, namely C. texanus, remains in the genus.


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