The influence of parasitism on the life history of a high arctic insect, Gynaephora groenlandica (Wöcke) (Lepidoptera: Lymantriidae)

1987 ◽  
Vol 65 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Olga Kukal ◽  
Peter G. Kevan
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Larval Instar ◽  
Adult Emergence ◽  
High Arctic ◽  
Winter Mortality ◽  
Short Period ◽  
History Of ◽  
Gynaephora Groenlandica ◽  
Overall Mortality

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.

Revision of the life history of the High Arctic moth Gynaephora groenlandica (Wocke) (Lepidoptera: Lymantriidae)

1998 ◽  
Vol 76 (7) ◽  
pp. 1371-1381 ◽  
Author(s):  
W Dean Morewood ◽  
Richard A Ring
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Head Capsule ◽  
High Arctic ◽  
The Arctic ◽  
Base Line ◽  
Laboratory Rearing ◽  
History Information ◽  
History Of ◽  
Gynaephora Groenlandica

Many studies have explored the adaptations of arctic and alpine Gynaephora species (Lepidoptera: Lymantriidae) to their environment, and base-line life-history information is important for the interpretation of such studies. Data and observations on G. groenlandica (Wocke) collected in recent years at Alexandra Fiord, Ellesmere Island, Canada, contradict some of the life-history information previously published for this species from the same site. Detailed analysis of larval head capsule widths and consideration of growth ratios indicate that there are seven rather than six larval instars and that the pattern of development does not deviate significantly from that defined by the Brooks-Dyar rule. Field-rearing of larvae indicates that first-instar larvae overwinter, while field- and laboratory-rearing both indicate that larvae moult once per year, every year. These data and observations greatly shorten and simplify the life history from that previously published and suggest a life cycle of 7 rather than 14 years. This revised life cycle is not presented as an absolute, in recognition of the potential for individual variation, but rather as typical of the developmental pattern of most of the population. As such, it should provide a useful base line for further studies, especially those addressing the influence of predicted climate change in the Arctic.

Life history and larval density of Cheumatopsyche digitata Mosely (Trichoptera: Hydropsychidae) in Opa Reservoir spillway, Ile-Ife, southwestern Nigeria

Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 401-407
Author(s):  
SYLVESTER OGBOGU ◽  
WILLIAMS ADU
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Larval Instar ◽  
Larval Density ◽  
Adult Emergence ◽  
Head Capsule ◽  
Southwestern Nigeria ◽  
Growth Ratio ◽  
Head Capsule Width ◽  
Site Density

The life history and density of Cheumatopsyche digitata Mosely (Trichoptera: Hydropsychidae) were examined below Opa Reservoir in Ile-Ife, southwestern Nigeria. This caddisfly is the only species that occurs immediately below the impoundment auxiliary spillway where it closely associates with an aquatic bryophyte, Fontinalis sp. We collected larvae every month between July 2004 and June 2005 as long as larvae were available in the study site. The instar growth ratio was fairly constant and ranged from 1.198 to 1.402 (mean ± standard error = 1.285 ± 0.073) but mean head capsule width increased with larval development. The frequency distribution of head capsule width of larvae clustered into 5 size classes, suggesting 5 larval instars for C. digitata in the study site. Density of larvae ranged from 1,100 to 11,150 inds.m-2 (mean ± SE = 6739  inds.m-2 ± 3904.70), the highest densities occurring in October 2004 during the bloom of Fontinalis. The first larval instar appeared in July 2004. Adult emergence occurred mainly in December 2004 through January 2005 at the onset of reservoir draw-down and death of Fontinalis. These patterns indicate that C. digitata tended to show a univoltine life cycle in the study site.

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
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Rocky Mountains ◽  
Laboratory Experiments ◽  
Larval Instar ◽  
Rocky Mountain ◽  
Mountain Stream ◽  
Flight Period ◽  
Conifer Needles ◽  
History Of

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.

BIOLOGY OF TACHINAEPHAGUS ZEALANDICUS (HYMENOPTERA: ENCYRTIDAE), PARASITOID OF SYNANTHROPIC DIPTERA

1974 ◽  
Vol 106 (8) ◽  
pp. 785-800 ◽  
Author(s):  
G. S. Olton ◽  
E. F. Legner
Keyword(s):  
Life History ◽  
Developmental Stages ◽  
Average Length ◽  
Host Density ◽  
Adult Emergence ◽  
Reproductive Period ◽  
Laboratory Studies ◽  
Pupal Parasitoid ◽  
History Of ◽  
Parasitoid Development

AbstractThe synonymy, distribution, host range, and life history of the gregarious larval–pupal parasitoid Tachinaephagus zealandicus Ashmead, is discussed. Laboratory studies of its biology were conducted at 25° ± 2 °C using Musca domestica L. as host. Its developmental stages are described. Under laboratory conditions its life cycle lasted 23–27 days. Parasitoid development accelerated with higher average densities per host. Single standardized hosts produced 3–18 adult parasitoids. Mated females provided with hosts lived 50.4–67.2 h. The average length of the reproductive period and number of hosts parasitized were independent of host density; however, the average number of eggs deposited per host increased at lower host densities. Adult emergence displayed circadian rhythmicity independent of photoperiod over 3+ days.

scholarly journals Breaking the rule: Five larval instars in the podonomine midge Trichotanypus alaskensis Brundin from Barrow, Alaska

2018 ◽  
Author(s):  
Alec R. Lackmann ◽  
Malcolm G. Butler
Keyword(s):  
Life Cycle ◽  
Larval Instar ◽  
Adult Emergence ◽  
Head Capsule ◽  
The Arctic ◽  
Larval Instars ◽  
Daily Monitoring ◽  
Field Samples ◽  
Standard Life ◽  
Capsule Size

Except for one unconfirmed case, chironomid larvae have been reported to pass through four larval instars between egg and pupal stages. We have observed a fifth larval instar to be a standard life-cycle feature of the podonomine Trichotanypus alaskensis Brundin 1966 in tundra ponds on the Arctic Coastal Plain near Barrow, Alaska. T. alaskensis has a one-year life cycle in these arctic ponds. Adults emerge in June ~2-3 weeks after pond thaw, then mate and oviposit; most newly-hatched larvae reach instar IV by October when pond sediments freeze. Overwintering larvae complete instar IV within a few days of thaw, then molt again to a fifth larval instar. Imaginal discs, normally seen only during instar IV in Chironomidae, develop across both instars IV & V prior to pupation and adult emergence. While monitoring larval development post-thaw in 2014, we noticed freshly-molted T. alaskensis larval exuviae a week or more prior to any pupation by that species. In 2015-16 we reared overwintering instar IV larvae from single pond sources, individually with daily monitoring, through molts to instar V, pupa, and adult. Some overwintering instar II and III larvae were reared as well, but were few in number. During 2016 we also reared T. alaskensis progeny (from eggs) through instar II, thus documenting head capsule size ranges for all five instars in a single pond’s population. Without individual rearings, the fifth larval instar was not readily apparent for two reasons: 1) The molt itself occurs immediately after thaw and is so synchronous it is difficult to discern in daily field samples. 2) The head capsule size increment between instars IV-V is much lower than the ratio predicted by the Brooks-Dyar Rule. Up through instar IV, the Brooks-Dyar ratio for T. alaskensis ranged 1.30-1.61, but during the IV-V molt head capsule dimensions (sexes pooled) increased by a ratio of 1.09 – comparable to the magnitude of sexual dimorphism in head capsule size within each of the final two larval instars. Individual rearings coupled with 2014-2016 field surveys in nine other ponds suggest that five larval instars is an obligatory trait of this species at this location. As this is the first confirmed case of five larval instars in a chironomid, the phylogenetic uniqueness of this trait needs further investigation.

The reproduction and larval development of Nereis fucata (Savigny)

1959 ◽  
Vol 38 (1) ◽  
pp. 65-80 ◽  
Author(s):  
J. B. Brown-Gilpin
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Experimental Methods ◽  
Point Of View ◽  
Hermit Crabs ◽  
Special Importance ◽  
Reproductive Patterns ◽  
Complete Life Cycle ◽  
History Of ◽  
The Many

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.

scholarly journals A STUDY OF THE LIFE HISTORY OF TRICHOBILHARZIA CAMERONI SP. NOV. (FAMILY SCHISTOSOMATIDAE)

1953 ◽  
Vol 31 (4) ◽  
pp. 351-373 ◽  
Author(s):  
Liang-Yu Wu
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Room Temperature ◽  
Migratory Birds ◽  
Local Infection ◽  
Domestic Ducks ◽  
Ottawa River ◽  
Daughter Sporocyst ◽  
Physa Gyrina ◽  
History Of

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.

The life history of Pleurogenoides malampuzhensis sp. nov. (Digenea: Pleurogenidae) from amphibious and aquatic hosts in Kerala, India

2013 ◽  
Vol 88 (2) ◽  
pp. 230-236 ◽  
Author(s):  
R. Brinesh ◽  
K.P. Janardanan
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Related Species ◽  
Growth And Development ◽  
Systematic Position ◽  
Patent Period ◽  
Hoplobatrachus Tigerinus ◽  
Life Cycle Stages ◽  
Muscle Tissues ◽  
History Of

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.

Nesting biology and life history of the dung beetle Onthophagus lecontei (Coleoptera: Scarabaeinae)

2017 ◽  
Vol 67 (1) ◽  
pp. 41-52 ◽  
Author(s):  
L. Arellano ◽  
C. Castillo-Guevara ◽  
C. Huerta ◽  
A. Germán-García ◽  
C. Lara
Keyword(s):  
Life History ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Dung Beetle ◽  
Reproductive Behaviour ◽  
Nesting Behavior ◽  
Nesting Biology ◽  
Preimaginal Development ◽  
History Of ◽  
Capra Aegagrus

Obtaining knowledge about a species’ life history and reproductive behaviour is fundamental for understanding its biology, ecology, and potential role in ecosystem services. Here, we focused on the dung beetle species Onthophagus lecontei. Adults were collected in the field and then confined to terrariums, where they were supplied with semi-fresh domestic goat dung (Capra aegagrus Erxleben, 1777). After being paired (26 pairs), the nesting behavior of beetles was observed under laboratory conditions and the preimaginal development of individuals obtained from mating (from the deposition of the egg until the emergence of the adult) was described. Their nesting behavior was found to be characteristic of what is known as pattern I, which comprises building of brood masses, oviposition of a single egg in each brood mass, development of three larval instars, construction of a pupation chamber, pupal stage and adult emergence. Both sexes were involved in the handling of dung, tunnel construction, and mass nest elaboration. Pairs built from one to seven brood masses. The pre-nesting period (feeding) lasted 16 days; the egg stage two days, the larval period 22 days; the pupal period 11 days and the imagoes four days, after which the adults emerged. Our results are discussed and compared with other species in the genus. However, our knowledge of this dung beetle is still limited, and further studies are required in all areas of its biology.

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