LIFE HISTORIES OF COEXISTING SPECIES OF CERACLEA CADDISFLIES (TRICHOPTERA: LEPTOCERIDAE): THE OPERATION OF INDEPENDENT FUNCTIONAL UNITS IN A STREAM ECOSYSTEM

1976 ◽  
Vol 108 (12) ◽  
pp. 1303-1318 ◽  
Author(s):  
Vincent H. Resh
Keyword(s):  
Life Histories ◽  
Mass Matrix ◽  
Adult Emergence ◽  
Life Cycles ◽  
Adult Survival ◽  
Egg Mass ◽  
Emergence Period ◽  
Larval Instars ◽  
Feeding Cycle ◽  
Coexisting Species

AbstractBionomics of the stream caddisflies, Ceraclea transversa (Hagen) (= Athripsodes angustus Banks) and Ceraclea ancylus (Vorhies) (= Athripsodes ancylus (Vorhies)) were compared with generalized trichopteran life cycles. The univoltine detritus-feeding C. ancylus has five larval instars and a brief adult emergence period. C. transversa has five larval instars but two distinct cohorts, in which larvae of the first cohort feed entirely on freshwater sponge, overwinter as inactive prepupae, pupate, and emerge the following spring. The second larval cohort feeds on sponge until the onset of gemmulation in autumn, then the larvae must overwinter as active third- or fourth-instar detritus-feeders, pupating and emerging later in the summer than the first cohort. The detritus-feeding C. ancylus larvae have a diurnal feeding cycle. The sand case of C. ancylus and the silk-secreted case of C. transversa differ in shape and composition, although both species initiate case construction using egg mass matrix, silk, and detritus. Emergence, flight activity, sex ratios, and adult survival depart from reported generalizations of caddisfly biology. Neither the validity of generalizing typical life cycles in benthic studies, nor the rationale that congeneric species operate as a functional unit in stream dynamics, is substantiated.

scholarly journals Community structure, life histories and secondary production of stoneflies in two small mountain streams with different degree of forest cover

2015 ◽  
Author(s):  
Pavel Beracko ◽  
Andrea Kušnírová ◽  
Michaela Partlová ◽  
Jana Ciceková
Keyword(s):  
Community Structure ◽  
Secondary Production ◽  
Life Histories ◽  
Forest Cover ◽  
Adult Emergence ◽  
Life Cycles ◽  
Mountain Streams ◽  
Annual Life Cycle ◽  
Forested Stream ◽  
The Difference

<p>Our study examines community structure and nymphal biology (life cycles and secondary production) of stoneflies in two adjacent mountain streams with different degree of forest cover in the Prosiečanka River Basin (Chočské Vrchy Mts., West Carpathians). One of the streams has non-forested catchment, converted to meadows and pastures, while the other one has catchment with 60% covered by spruce forest. Differences in forest cover and in thermal regime of the streams were reflected by the difference of stonefly communities at their structural and functional level. Species <em>Nemoura cinerea and Leuctra aurita </em>created stonefly assemblage in non-forested stream, whereas <em>Nemoura cinerea</em> also occurred in naturally forested stream together with species <em>Leuctra armata, Leuctra nigra, Leuctra prima, Siphonoperla neglecta</em> and <em>Arcynopteryx dichroa</em>. All examined species had maximally annual life cycle and in eudominant species <em>Nemoura cinerea</em> one month shift was found in nymphal hatching and adult emergence between streams. Total secondary production of stoneflies in undisturbed stream (126.46 mg DW m<sup>-2</sup> y<sup>-1</sup>) was more than two times higher than the production in non-forested stream (47.39 mg DW m<sup>-2</sup> y<sup>-1</sup>). </p>

Life histories of six species of Leptoceridae (Insecta: Trichoptera) in Victoria

1993 ◽  
Vol 44 (2) ◽  
pp. 363 ◽  
Author(s):  
RM St.Clair
Keyword(s):  
Life History ◽  
Larval Development ◽  
Life Histories ◽  
Adult Emergence ◽  
Severe Drought ◽  
Emergence Period ◽  
University Life ◽  
History Of ◽  
Study Sites ◽  
Temporary River

Life history studies were carried out for populations of six species of Leptoceridae. Study sites were a permanent river (Acheron), a temporary river (Lerderderg) and a permanent lake (Monash University). Life histories varied in degree of synchrony of larval development, in length of adult emergence period, and from bi- to semivoltine. Oviposition requirements of adults were found to be the major factor influencing synchrony of the life history of one species. Life history features did not ameliorate the effects of the severe drought of 1982-83, nor did drought result in large changes in life histories.

LIFE HISTORY AND BIOLOGY OF EINFELDIA SYNCHRONA (DIPTERA: CHIRONOMIDAE)

1971 ◽  
Vol 103 (11) ◽  
pp. 1597-1606 ◽  
Author(s):  
H. V. Danks
Keyword(s):  
Life History ◽  
Adult Emergence ◽  
Population Level ◽  
Bottom Fauna ◽  
Egg Mass ◽  
Larval Population ◽  
Larval Instars ◽  
Biological Features ◽  
First Instar

AbstractEinfeldia synchrona Oliver is univoltine in a small, shallow, highly eutrophic pond near Ottawa (45°N.). Adult emergence is synchronized with slight protandry in May, and from this small pond exceeded 145,000 individuals in 1970. Emergence is inhibited experimentally at short photoperiods. More than one egg mass is produced, during a period of several days following emergence. First instar larvae, which lack ventral tubules, are at first pelagic but build cases before moulting. The remaining three larval instars possess 1 pair of ventral tubules. Larvae show a preference for central areas of the pond over 40 cm deep, and show some mobility in response to seasonal depth changes. There are arrests in the development of larvae both in winter and during summer, with cessation of feeding, penetration into the mud, and construction in winter of special sealed cocoons. Marked year to year differences in the stage reached by winter, and in the larval population level, were detected. Many of these biological features are probably widespread in Chironomini and hence of some importance in the interpretation of studies of the bottom fauna.

scholarly journals Biology and development of Sitophilus oryzae L. feeding on split pulses

2018 ◽  
Author(s):  
S Vijay ◽  
K. Bhuvaneswari
Keyword(s):  
Room Temperature ◽  
Sitophilus Oryzae ◽  
Reproductive Potential ◽  
Adult Emergence ◽  
Oviposition Rate ◽  
Adult Survival ◽  
Adult Longevity ◽  
Emergence Period ◽  
Survival Percentage ◽  
Female Longevity

An experiment was carried out at the Entomology Laboratory, Horticultural College and Research Institute for Women, Trichy in November- December 2013 to study the biology and development of Sitophilus oryzae L. under laboratory conditions. Observations were made on oviposition rate, total number of eggs, adult emergence per 100 grains, egg to adult survival percentage, adult longevity, adult emergence period and reproductive potential. The oviposition rate per female (9.43 nos), total number of eggs (94.30 nos), adult emergence per 100 grains (38.50 nos), reproductive potential (35.50 nos), egg to adult survival percentage (41.85), adult female longevity (12.88 weeks) and adult male longevity (8.33 weeks) were higher in redgram under room temperature condition feeding by the respective population as compared to controlled condition. In case of sorghum, all the above parameters were superior to redgram feeding by the respective population under room and controlled temperature condition. The larval (26.13 days), pupal (7.63 days) and adult emergence period (33.75 days) was maximum in lentil under room temperature as compared to controlled condition. In case of sorghum, larval, pupal and adult emergence period was minimum when compared to split pulses feeding by the respective population irrespective of temperature and humidity.

Life histories of some Benthic invetebrates form streams of the Northern Jarrah Forest, Western Australia

1988 ◽  
Vol 39 (6) ◽  
pp. 785 ◽  
Author(s):  
SE Bunn
Keyword(s):  
Life History ◽  
Life Histories ◽  
Adult Emergence ◽  
Adaptive Strategy ◽  
Life Cycles ◽  
Jarrah Forest ◽  
Stream Insects ◽  
Long Period ◽  
Life History Pattern ◽  
High Degree

Life history patterns of thirteen species of invertebrates from streams of the northern jarrah forest were examined over a 1-year period. Five species had univoltine cycles with a single cohort and demonstrated a high degree of synchrony of larval development and a restricted period of adult emergence. Two species of Leptophlebiidae also had univoltine cycles but showed the more typical pattern of Australian mayflies, with extended recruitment, multiple overlapping cohorts and a long period of adult emergence. Uroctena sp., a small gammarid, had a generation time of 1 year but showed considerable spatial variation in the degree of synchrony of development. This appeared to be a result of differences in the constancy of stream discharge and was not attributable to differences in the temperature regime of the streams. At least three species demonstrated cohort splitting which resulted in an apparently bivoltine cycle. A life-history pattern of alternating long and short development times is described which, on average, would produce two generations every 3 years. This is considered to be a highly adaptive strategy for Australian stream insects with slow life cycles and can explain the extended periods of recruitment and adult emergence so often observed. Streams of the northern jarrah forest are depauperate compared with other Australian streams, despite predictable temperature and discharge regimes. The insular nature of the south-west Bassian region and its long period of isolation may be the principle cause of this reduced diversity. The invertebrate community of these streams is simple in structure and has a high degree of seasonality that is atypical of the temperate streams of Australia and New Zealand.

Life histories of some Australian Siphlonurid and Oligoneuriid mayflies (Insecta : Ephemeroptera)

1986 ◽  
Vol 37 (2) ◽  
pp. 261 ◽  
Author(s):  
IC Campbell
Keyword(s):  
Life Histories ◽  
Adult Emergence ◽  
Single Population ◽  
Emergence Period ◽  
Normal Distributions ◽  
Wide Range ◽  
Early Instar ◽  
Life History Patterns ◽  
Time Required ◽  
Classificatory System

The life histories of nine populations of mayflies were investigated through monthly field collections over a 3-year period. Seven species were studied, one each from the genera Tasmanophlebia, Ameletoides and Mirawara (Siphlonuridae) and four from Coloburiscoides (Oligoneuriidae). Nymphs were sorted and measured and life histories inferred from size frequency diagrams, and cohorts were separated using a technique for distinguishing multiple overlapping normal distributions. The life histories were all relatively poorly synchronized with adult emergence extended over 5 months or more in every case. A wide size range of nymphs was present in most populations for most of the year and these often formed multiple overlapping cohorts. The time required for development by different cohorts of a single population was quite varied. Marked differences in the length and timing of the adult emergence period, and of the importance of particular cohorts, were apparent in different years. It was concluded that more than a single year's data from one site was necessary to interpret the life histories of Australian mayflies adequately. The four Coloburiscoides species investigated displayed a wide range of development times and patterns, the shortest being displayed by C. haleuticus. This species had some cohorts that seemed to complete their development in about 6 months, whereas C. giganteus had some cohorts that required up to 3 years and also appeared to have a nymphal or early-instar diapause of between 9 and 11 months. The life-history patterns found in this study did not readily fit into the classification schemes proposed by Northern Hemisphere workers. The general asynchrony found in this and previous Australian studies makes it doubtful that a useful classificatory system for Australian mayfly life histories can be developed.

SEASONAL EMERGENCE OF SOME HIGH ARCTIC CHIRONOMIDAE (DIPTERA)

1972 ◽  
Vol 104 (5) ◽  
pp. 661-686 ◽  
Author(s):  
H. V. Danks ◽  
D. R. Oliver
Keyword(s):  
Adult Emergence ◽  
High Arctic ◽  
Life Cycles ◽  
The Arctic ◽  
Emergence Period ◽  
Arctic Species ◽  
Chironomid Species ◽  
Annual Total ◽  
Shallow Ponds ◽  
Deep Site

AbstractThe annual emergence of 11 chironomid species from more or less shallow ponds in the area of Hazen Camp (81°49′ N., 71°18′ W.) is considered. Features of emergence are very similar in all these arctic species, although different species emerge at slightly different times in the same habitat.In the deeper habitats, emergence from a deep site is slightly later than that from a shallower one in the same pond. There are very marked differences in times of emergence from pond to pond: emergence of 50% of the annual total for a given species may be reached in different ponds up to 3 weeks apart. These differences from habitat to habitat mean that adults are present over the general Hazen area throughout the arctic summer.The time at which emergence begins in a given pond (or given site within a deeper pond) is primarily dictated by the temperature required for pre-emergence development, but also by other features of individual ponds. Pond temperatures near 4° or 5 °C are most important in this respect. The time of first emergence differs between years in the same pond according to year-to-year temperature differences.Emergence of a given species is basically highly synchronized within a pond, but the emergence period may be prolonged by lowered temperatures acting as a threshold for adult emergence at about 7 °C. The emergence pattern is less regular in shallow ponds in which the temperature fluctuates greatly, and it is more regular with lower peaks in deeper ponds.Males of a number of species generally emerge slightly before the females.Emergence of given species within given ponds is synchronized because only larvae which are ready to pupate without further feeding in spring emerge in any year. There must therefore be control of a ’diapause’ type.Aquatic insect species are characterized as ’absolute spring species’ if all potential émergents overwinter as mature larvae (i.e. larvae in which no further growth is necessary before emergence) and also ’diapause’ is present at this stage. To this category all of these high arctic species belong. They are apparently derived from ’absolute spring species’ farther south, the life-cycles of which are pre-adapted to the shortness of the arctic season. Despite the potential for highly synchronized emergence which such species possess, this potential is not fully realized in the arctic because the irregular fluctuations of temperature there operate near values which may directly inhibit development and emergence.

scholarly journals Evaluation of indigenous the nucleopolyhedrovirus (NPV) of Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) in combination with chlorantraniliprole against Spodoptera species

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ghulam Sarwar ◽  
Naeem Arshad Maan ◽  
Muhammad Ahsin Ayub ◽  
Muhammad Rafiq Shahid ◽  
Mubasher Ahmad Malik ◽  
...  
Keyword(s):  
Larval Mortality ◽  
Adult Emergence ◽  
Lethal Concentration ◽  
Pest Species ◽  
Vegetable Crops ◽  
Chemical Insecticide ◽  
Larval Instars ◽  
Novel Method ◽  
High Larval Mortality ◽  
Lepidoptera Noctuidae

Abstract Background The armyworms, Spodoptera exigua (Hübner), and S. litura (Fabricius) (Lepidoptera: Noctuidae) are polyphagous pests of many cash crops. Heavy crop losses have been reported for the fruit and vegetable crops each year owing to the diverse impact on global economies. The present study was aimed to sort out a novel method of pest control using the insect’s own nucleopolyhedrosis virus (NPV) alone and in combination with a new chemistry insecticide chlorantraniliprole. Results In the study, the effect of indigenous isolated nucleopolyhedrovirus (NPV) and the chemical insecticide (chlorantraniliprole) formulations against the 2nd and 4th larval instars of S. litura and S. exigua, collected from the different geographical region of Punjab (Pakistan) province, was evaluated. Three concentrations of the NPV isolate, sub-lethal (1 × 104, 6 × 104 POB ml−1), lethal (3 × 105 POB ml−1), and chlorantraniliprole 0.01 μl l−1, were applied alone and in combination against the 2nd and 4th larval instars of both pest species. The lethal concentration of NPV + chlorantraniliprole exhibited synergistic interaction and caused high larval mortality against both instars, while in all other combinations, additive effect was observed. Moreover, NPV + chlorantraniliprole at lethal concentration exhibited decreased pupation, adult emergence, and egg eclosion. Conclusion The implications of using NPV alone and in combination with an insecticide are discussed briefly in this study.

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.

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.

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