MORPHOLOGICAL CHARACTERISTICS FOR DIFFERENTIATING LARVAL INSTARS OF LEATHERJACKETS, TIPULA PALUDOSA (DIPTERA: TIPULIDAE)

1972 ◽  
Vol 104 (6) ◽  
pp. 899-902 ◽  
Author(s):  
A. B. Q. Lam ◽  
J. M. Webster
Keyword(s):  
Morphological Characteristics ◽  
Head Capsule ◽  
Larval Instars ◽  
Shape And Size

AbstractMeasurements of head capsule lengths and widths show that Tipula paludosa Meig. larvae have four instars. The shape and size of the mandibles and labia are good characters for differentiating the instars.

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.

scholarly journals Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae)

2009 ◽  
Vol 43 (1) ◽  
pp. e-15-e-24
Author(s):  
I. Dolinskaya
Keyword(s):  
Pattern Formation ◽  
Larval Instar ◽  
Head Capsule ◽  
Diagnostic Character ◽  
Key To Species ◽  
Larval Instars ◽  
Diagnostic Characters ◽  
Ontogenetic Stages ◽  
First Time ◽  
Taxonomic Relations

Formation of Pattern and Diagnostic Instar Features of the Head in Caterpillars from Genus Peridea (Lepidoptera, Notodontidae) Pattern and colouration of caterpillar head of all larval instar of 7 species from genus Peridea Stephens, 1828 are studied. Formation of caterpillar head pattern in ontogenesis is discussed. Diagnostic characters, both specific and larval instars, are recorded for the first time. Key to species according to larval instars is given. Evidently, only larvae of the 1st instar demonstrate different directions in the pattern formation. This characteristic can be used for clearing of taxonomic relations in the genera and on the earliest ontogenetic stages (1st larval instar) only. In the following (2nd-5th) instars, the pattern became more or less of the same type. It depends on stripes shape or colouration only and can serve as good specific diagnostic character. To determine larval instar, both width of the head capsule and head pattern should be taken into account.

scholarly journals Descriptions of immature stages of Octodonta nipae (Maulik) (Coleoptera, Chrysomelidae, Cassidinae, Cryptonychini)

ZooKeys ◽  
2018 ◽  
Vol 764 ◽  
pp. 91-109 ◽  
Author(s):  
Ling-fei Peng ◽  
Jin-lei Li ◽  
You-ming Hou ◽  
Xiang Zhang
Keyword(s):  
Invasive Species ◽  
Electron Micrographs ◽  
Head Capsule ◽  
Scanning Electron Micrographs ◽  
Immature Stages ◽  
Larval Instars ◽  
Palm Trees ◽  
Scanning Electron

Octodontanipae(Maulik, 1921), a hispid that damages several species of palm trees, was introduced accidently into China in 2001. The egg, larva, prepupa and pupa ofO.nipaeare illustrated and described in detail and compared with another invasive species,Brontispalongissima(Gestro, 1885); the scanning electron micrographs of the head capsule, antenna, maxilla, labium and lateral scoli are provided, as well as photos of body of all larval instars and pupa. It is the second description of immature stages in the genusOctodontaChapuis.

scholarly journals Morphological Characteristics of Dimples of Ductile Fracture of VT23M Titanium Alloy and Identification of Dimples on Fractograms of Different Scale

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2051 ◽  
Author(s):  
Ihor Konovalenko ◽  
Pavlo Maruschak ◽  
Janette Brezinová ◽  
Jozef Brezina
Keyword(s):  
Titanium Alloy ◽  
Ductile Fracture ◽  
Digital Images ◽  
Morphological Characteristics ◽  
Automated Detection ◽  
Fracture Mechanisms ◽  
Test Results ◽  
High Quality ◽  
Quality Requirements ◽  
Shape And Size

The authors developed a method for the automated detection and calculation of quantitative parameters of dimples of ductile fracture on the digital images of fracture surfaces obtained at different scales. The processing algorithm of fractographic images was proposed, which allowed high quality recognition of the shape and size of dimples to be achieved, taking into account the morphological features of their digital images. The developed method for identifying dimples of various physical and morphological characteristics was tested on the VT23M alloy. The test results showed that the method meets the quality requirements for the automated diagnostics of fracture mechanisms of titanium alloys.

scholarly journals A Probabilistic Statistical Method for the Determination of Void Morphology with CFD-DEM Approach

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4041
Author(s):  
Yuanxiang Lu ◽  
Sihan Liu ◽  
Xinru Zhang ◽  
Zeyi Jiang ◽  
Dianyu E
Keyword(s):  
Probabilistic Method ◽  
Gas Injection ◽  
Morphological Characteristics ◽  
Packed Bed ◽  
Two Dimensional ◽  
Two Phase ◽  
Binary Images ◽  
Void Shape ◽  
Shape And Size

Voids that are formed by gas injection in a packed bed play an important role in metallurgical and chemical furnaces. Herein, two-phase gas–solid flow in a two-dimensional packed bed during blast injection was simulated numerically. The results indicate that the void stability was dynamic, and the void shape and size fluctuated within a certain range. To determine the void morphology quantitatively, a probabilistic method was proposed. By statistically analyzing the white probability of each pixel in binary images at multiple times, the void boundaries that correspond to different probability ranges were obtained. The boundary that was most appropriate with the simulation result was selected and defined as the well-matched void boundary. Based on this method, the morphologies of voids that formed at different gas velocities were simulated and compared. The method can help us to express the morphological characteristics of the dynamically stable voids in a numerical simulation.

Re-description of larvae of Chostonectes nebulosus (Macleay, 1871) (Coleoptera: Dytiscidae, Hydroporinae, Hydroporini, Sternopriscina) with an identification key to the known larvae of Chostonectes Sharp, 1882

Zootaxa ◽  
2020 ◽  
Vol 4718 (3) ◽  
pp. 436-446
Author(s):  
EDWARD TSYRLIN ◽  
MELISSA CAREW ◽  
YVES ALARIE
Keyword(s):  
Abdominal Segment ◽  
Head Capsule ◽  
Identification Key ◽  
Molecular Approach ◽  
Larval Instars ◽  
First Time

The second and third larval instars of the Australian endemic dytiscid Chostonectes nebulosus (Macleay, 1871) are described and illustrated for the first time including a detailed chaetotaxic analysis of head capsule and appendages, legs, last abdominal segment and urogomphi. Collected larvae were successfully associated with adults using rearing and a molecular approach. The identification key and COI barcodes for C. nebulosus, C. gigas (Boheman, 1858) and C. johnsonii (Clark, 1862) are provided. 

LIFE HISTORY AND HABITS OF THE WILLOW BEAKED GALL MIDGE, MAYETIOLA RIGIDAE (DIPTERA: CECIDOMYIIDAE), IN MICHIGAN

1968 ◽  
Vol 100 (2) ◽  
pp. 202-206 ◽  
Author(s):  
Louis F. Wilson
Keyword(s):  
Life History ◽  
Gall Midge ◽  
Head Capsule ◽  
Instar Larva ◽  
Larval Instars ◽  
The Third ◽  
First Instar ◽  
Salix Discolor

AbstractThe willow beaked gall midge, Mayetiola rigidae (Osten Sacken), is univoltine in Michigan. Adults emerge from bud galls on Salix discolor Mühl. and other willows on mornings of warm days in early April. Eggs are laid singly on or near the buds of the host. Head capsule measurements indicate three larval instars. The last two instars each possess a spatula. The first-instar larva emerges in late April and penetrates the soft bud tissues. The gall begins to develop at the beginning of the second instar in mid-May. The third instar appears in early July and continues to enlarge the gall until fall. Prior to overwintering, the larva lines the inner chamber of the gall with silk and constructs one to seven silken septa across the passageway. Pupation occurs in mid-March. The gall deforms the stem and occasionally a galled branch dies or breaks off.

Simulium vittatum (Simuliidae: Diptera), a black fly with a variable instar number

1989 ◽  
Vol 67 (7) ◽  
pp. 1730-1732 ◽  
Author(s):  
M. H. Colbo
Keyword(s):  
Head Capsule ◽  
Size Increase ◽  
Black Fly ◽  
Larval Instars ◽  
Simulium Vittatum

Simulium vittatum is a black fly that normally has 7 larval instars but may undergo several more, with a maximum of 11 instars being recorded in this study. The size increase was relatively constant between individuals for any one instar under similar conditions, but the increase in the first two molts was much greater than observed between late instars. There was little relationship between the relative sizes of certain head capsule measurements in the final instar, indicating the difficulty in determining stable characters for taxonomic separation of closely related simuliid species.

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