The Life-History and Morphology of Chironomus hyperboreus

1936 ◽  
Vol 2 (2) ◽  
pp. 209-221 ◽  
Author(s):  
J. G. Rempel
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Late Summer ◽  
Soft Bottom ◽  
Lake Surface ◽  
Larval Instars ◽  
Surface Sink

In lakes of Saskatchewan adults emerge in late May and early June. Eggs, deposited over lake surface, sink to bottom. Larvae in soft bottom ooze (10–20 m. depth) grow rapidly in late summer, but little during rest of year. Four larval instars and two-year life-cycle. Larva and pupa described and additions made to Staeger's description of adult.

BIOLOGY AND LIFE HISTORY OF EPURAEA OBLIQUUS HATCH (COLEOPTERA: NITIDULIDAE) ON WESTERN GALL RUST

1996 ◽  
Vol 128 (2) ◽  
pp. 177-186 ◽  
Author(s):  
Cameron R. Currie ◽  
John R. Spence ◽  
W. Jan A. Volney
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Late Summer ◽  
Natural Control ◽  
Larval Instars ◽  
Endocronartium Harknessii ◽  
History Of ◽  
The Impact

AbstractThe life cycle, phenology, and abundance of Epuraea obliquus Hatch was studied near Hinton, Alberta. Most of the life cycle occurs on galls of Endocronartium harknessii (J.P. Moore) Y. Hiratsuka (western gall rust) infecting lodgepole pine (Pinus contorta Dougl. var latifolia Engelm.). Both adults and larvae feed on the spores of the fungus. Individuals of this beetle were found on most galls sampled. Adults overwinter in the soil. They emerge in the spring to seek out and colonize galls. Eggs are laid on the surface of galls, mainly under the periderm, and larvae feed on the fungus, developing through three larval instars. Larvae in the last instar drop from galls to pupate in the soil. Adults leave the soil in late summer and return to feed on inactive galls before overwintering in the soil. The phenology of E. obliquus is closely synchronized with the timing of rust sporulation and the impact of beetle feeding may be an important natural control of western gall rust.

LIFE CYCLE AND MORTALITY OF PISSODES TERMINALIS (COLEOPTERA: CURCULIONIDAE) IN LODGEPOLE PINE

1998 ◽  
Vol 130 (4) ◽  
pp. 387-397 ◽  
Author(s):  
David W. Langor ◽  
Daryl J.M. Williams
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Late Spring ◽  
Cold Temperatures ◽  
Larval Instars ◽  
Complete Development ◽  
Early Fall ◽  
New Generation

AbstractThe seasonal life history and mortality of the lodgepole terminal weevil, Pissodes terminalis Hopping (Coleoptera: Curculionidae), were investigated in young lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann (Pinaceae), at three sites in west-central Alberta. Flight was monitored with traps. Development and mortality of all stages were investigated by dissecting infested leaders biweekly from late spring to early fall. Two years were required for P. terminalis to complete its life cycle, and generations overlapped. Overwintered adults emerged from the duff and commenced flight in late May, with a peak in mid-June. Eggs were present from mid-June to late July. There were four larval instars. The first two instars fed only in the phloem. Third and fourth larval instars eventually entered the pith to continue feeding, overwinter, and complete development the following spring. The new generation of adults emerged between mid-July and early August, fed on new shoots for several weeks, and overwintered in the duff. Adults have an obligatory diapause and did not reproduce until after winter. Fourth larval instars suffered the highest mortality. The major attributable cause of mortality was resinosis among eggs and young larvae and cold temperatures during the winter among mature larvae. Pathogens caused little mortality. Six species of parasitoids were collected.

Characteristics of Attack of Coastal Timbers by Pselactus spadix (Herbst) (Col.: Curc.: Cossoninae) and an Investigation of its Life History

Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 335-359 ◽  
Author(s):  
P. Oevering ◽  
A.J. Pitman
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Wood Surface ◽  
Development Time ◽  
Adult Emergence ◽  
Head Capsule ◽  
Adult Longevity ◽  
Larval Instars

Summary Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%

THE LIFE-HISTORY AND HABITS OF THE LARCH BARK BEETLE, IPS CEMBRAE (COLEOPTERA: SCOLYTIDAE), IN THE NORTH-EAST OF SCOTLAND

1970 ◽  
Vol 102 (2) ◽  
pp. 226-239 ◽  
Author(s):  
R. A. Balogun
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Bark Beetle ◽  
Egg Laying ◽  
Larval Instars ◽  
North East ◽  
The North ◽  
Host Trees ◽  
Ips Cembrae

AbstractAn investigation of the life-history and habits of Ips cembrae (Heer) has been made at the Ord wood, Cawdor Estate in Nairnshire. The species is polygamous and has a 1-year life cycle with two broods a year. The first broods result from eggs laid in May and June, producing teneral adults in August and September, and the second arise from egg-laying in late September and early October; these second broods generally overwinter under bark in the larval and pupal stages, and the adults emerge the following spring. There are three larval instars before pupation. Maturation feeding of the young beetles and regeneration feeding of the old ones take place either under the bark where broods have developed, or by attacking fresh host trees.

The Life History and Seasonal Regulation of Aeshna viridis Eversm. in Southern Sweden (Odonata)

1971 ◽  
Vol 2 (3) ◽  
pp. 170-190 ◽  
Author(s):  
Ulf Norling
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Late Summer ◽  
Early Spring ◽  
Southern Sweden ◽  
Regular Sampling ◽  
History Of ◽  
Rapid Transition ◽  
Seasonal Regulation

AbstractThe life-history of Aeshna viridis Eversm. has been studied at a peat-pit in southern Sweden by means of regular sampling. Larvae from some samples from late summer to early spring have been experimentally subjected to constant artificial day-lengths of I3, I4.5, I6 and I9.5 hours at a temperature of 20°C. The results of experiments suggest that the rapid transition of photoperiod in autumn and spring is most important in the regulation of the life-cycle, which in the population studied had a duration of 2-3 years. A comparison is made between the seasonal regulation in Aeshna viridis and that in some other species. The causes of the phenological differences between certain types of spring and summer species and the differences in life-history of Aeshna species at different latitudes are discussed.

scholarly journals Life History Phenology and Sediment Size Association of the Dragonfly Cordulegaster dorsalis (Odonata: Cordulegastridae) in an Ephemeral Habitat in Southwestern British Columbia

2006 ◽  
Vol 120 (3) ◽  
pp. 347 ◽  
Author(s):  
Laurie B. Marczak ◽  
John S. Richardson ◽  
Marie-Claire Classen
Keyword(s):  
British Columbia ◽  
Life History ◽  
Life Cycle ◽  
Systematic Sampling ◽  
Limited Evidence ◽  
Larval Instars ◽  
Sediment Size ◽  
Ephemeral Habitat ◽  
Organic Sediments ◽  
One Year

The life cycle of the dragonfly Cordulegaster dorsalis was studied over one year by systematic sampling of larvae in three intermittent headwater streams in southwestern British Columbia. We determined that larvae normally take three years to reach maturity, emerging throughout July and August. There is limited evidence suggesting a split cohort development, with early emergence after two years. Additionally, we tested whether larval instars were distributed randomly or if they occupied different sediment microhabitats. Smaller animals tend to be associated with smaller grained organic sediments, although there was high variation between the streams.

Life History and Some Habits of the Pine Gall Weevil, Podapion gallicola Riley, in Michigan

1965 ◽  
Vol 97 (9) ◽  
pp. 962-969
Author(s):  
Louis F. Wilson
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Adult Emergence ◽  
Pinus Resinosa ◽  
Head Capsule ◽  
Red Pine ◽  
Larval Instars ◽  
The Third ◽  
Second Year

AbstractThe pine gall weevil has a 3-year life cycle on red pine (Pinus resinosa Ait.) in Michigan. Adults oviposit from June to August, depositing 1 to 10 eggs in a niche chewed in the bark of a branch internode. Larvae first emerge in August, feed as a group toward the cambium, and then radiate out along the xylem. Head capsule measurements from 1585 larvae indicate that there are three larval instars. Gall development begins in June of the second year, shortly after the larvae begin the second instar. The third instar commences in June of the third year. Pupation occurs in May of the fourth season; adult emergence follows in June. Overwintering occurs in the egg stage or in the three larval instars. Adults do not overwinter, and apparently three distinct broods occur in Michigan.

Preliminary investigations into the life cycle of Ventruia inaequalis (Cooke) WINT. in South Australia.

1953 ◽  
Vol 4 (4) ◽  
pp. 415 ◽  
Author(s):  
MW Jeffery
Keyword(s):  
Life Cycle ◽  
Primary Infection ◽  
South Australia ◽  
Late Summer ◽  
Relative Importance ◽  
New Information ◽  
One Year

Investigation into the possible sources of primary infection by the fungus Ventruia inaequalis (Cooke) Wint. in spring has been carried out. The results present new information on the life cycle of the pathogen under South Australian conditions. Sources of primary infection, such 'as lesions on one-year-old wood or overwintering superficial conidia on the trees, do not appear important. Bud-scale infection of dormant buds has been shown, and its relative importance is discussed. Ascospores are the most important source of primary infection. Their period of discharge extends to a later date than previously reported for South Australia and is considered in relation to leader shoot and late summer spot infection.

LIFE HISTORY AND HABITS OF A LEAF TIER, AROGA ARGUTIOLA (LEPIDOPTERA: GELECHIIDAE), ON SWEET FERN IN MICHIGAN

1974 ◽  
Vol 106 (9) ◽  
pp. 991-994 ◽  
Author(s):  
Louis F. Wilson
Keyword(s):  
Life History ◽  
Larval Instars

AbstractAroga argutiola is univoltine in Michigan. The adult emerges in late May and oviposits on sweet fern (Myrica aspleniifolia L.). There are six larval instars. The larva constructs a nest by tying leaves together, and then feeding on the leaves in and adjacent to the nest. The last instar overwinters on the ground in a cocoon. The pupa appears in May.

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.

Sign in / Sign up

Export Citation Format

Share Document