scholarly journals Comprehensive comparative morphology and developmental staging of final instar larvae toward metamorphosis in the insect order Odonata

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Genta Okude ◽  
Takema Fukatsu ◽  
Ryo Futahashi
Keyword(s):  
Larval Development ◽  
Morphological Changes ◽  
Larval Instar ◽  
Small Variation ◽  
Comparative Morphology ◽  
Insect Order ◽  
Comprehensive Survey ◽  
Three Stages ◽  
Evo Devo ◽  
Developmental Staging

AbstractThe order Odonata (dragonflies and damselflies) is among the most ancestral groups of winged insects with drastic morphological changes upon metamorphosis, and thus important for understanding evo-devo aspects of insects. However, basic developmental descriptions of Odonata have been scarce. In an attempt to establish the foundation of developmental and experimental biology of Odonata, we present an unprecedentedly comprehensive survey of dragonflies and damselflies, in total 158 larvae representing 49 species and 14 families, wherein morphological changes of all the final and/or penultimate instar larvae were photographed and monitored everyday. Although their morphology and development were diverse, we consistently identified two visually recognizable morphogenetic events in the final larval instar, namely start of wing expansion and onset of melanization on the wing sheaths, thereby categorizing the final instar into three stages. While the duration of the first stage ranged 4–66 days across diverse Odonata species, the second or third stages exhibited relatively small variation ranging 3–22 days or 1–8 days, respectively, probably reflecting the steady and irreversible metamorphosis process after stage 2. We also described other characteristic morphological changes during the larval development, although they were observed only in some Odonata species and lineages.

Effect of methyl farnesoate and farnesoic acid during 5th zoea and megalopa metamorphosis in the mud crab Scylla paramamosain Estampador, 1950 (Decapoda, Brachyura, Portunidae)

Crustaceana ◽  
2021 ◽  
Vol 94 (7) ◽  
pp. 855-863
Author(s):  
Ming Zhao ◽  
Fengying Zhang ◽  
Wei Wang ◽  
Zhiqiang Liu ◽  
Lingbo Ma
Keyword(s):  
Larval Development ◽  
Morphological Changes ◽  
Scylla Paramamosain ◽  
Dependent Manner ◽  
Mud Crab ◽  
Methyl Farnesoate ◽  
Concentration Dependent Manner ◽  
Low Levels ◽  
Juvenile Crab ◽  
Farnesoic Acid

Abstract The mud crab Scylla paramamosain is one of the economically important aquaculture species in China. The larval development of the mud crab is characterized by two significant morphological changes, from the 5th zoea (Z5) to the megalopa (M) stage and from the M to the first juvenile crab (C1) stage. In this study, we found that methyl farnesoate (MF) could prohibit the Z5 to M metamorphosis in a concentration-dependent manner, and that a concentration of 10 μM MF could completely prohibit the Z5 metamorphosis. Farnesoic acid (FA) could also prohibit the Z5 metamorphosis, but its effects seemed to be concentration-independent. In addition, MF could delay rather than prohibit the M to C1 metamorphosis, while FA had no effect on the M to C1 metamorphosis at all. To summarize, it is hypothesized that either absence of MF and FA, or at least very low levels of these substances, might be necessary for a successful Z5 to M metamorphosis.

scholarly journals Morphological Features Of The Immune Structures Of The Thin Intestine Of Laboratory Animals With Various Characters Of Nutrition

2020 ◽  
Vol 2 (09) ◽  
pp. 72-74
Author(s):  
Khusanov Erkin ◽  
Ortikbaeva Nilufar ◽  
Korzhavov Sherali
Keyword(s):  
Small Intestine ◽  
Digestive Tract ◽  
Structural Organization ◽  
Morphological Changes ◽  
Comparative Morphology ◽  
Morphological Features ◽  
The Body ◽  
Laboratory Animals ◽  
Chemical Processing ◽  
Digestive Tube

The nutritional nature of mammals, which has developed during a long evolution, leads to adaptive - morphological changes in their digestive tract and its immune structures, although the general laws of their structural organization are identical. The literature has data on the study of the immune structures of the small intestine under normal conditions and under the influence of certain factors. In the structure of immune structures there are numerous parallelisms, however, in each class of vertebrates, complication of this organization is achieved independently. The small intestine is an important section of the digestive tube, where the final chemical processing of the chyme and the absorption of nutrients into the body take place. However, the comparative morphology of the immune structures of the small intestine in mammals with different nutrition patterns remains poorly understood.

scholarly journals Diversity of the Larval Cranial Setae in Palaearctic Notodontidae (Noctuoidea) and and their Taxonomic Distribution

2013 ◽  
Vol 47 (1) ◽  
pp. 24-34
Author(s):  
I. V. Dolinskaya
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Larval Development ◽  
Larval Instar ◽  
Far East ◽  
Far East Of Russia ◽  
Primorskii Krai ◽  
Taxonomic Distribution ◽  
Outgroup Species ◽  
Scanning Electron

Abstract Larval cranial setae of each larval instar of 66 species belonging to 35 genera of Palaeartic Notodontid moths from Ukraine and Far East of Russia (Primorskii krai) was examined with the use of a scanning electron microscope. A comparison with outgroup species - Lasiocampoidea (Lasiocampidae), Sphingoidea (Sphingidae) and Noctuoidea (Erebidae: Lymantriinae, Arctiinae; Noctuidae) is conducted. Main kinds of setae during larval development and their transformation are discussed. Possible apomorphic and plesiomorphic states of the different characters are discussed in relation to the different taxa.

scholarly journals Production of germ-free mosquitoes via transient colonisation allows stage-specific investigation of host-microbiota interactions

2019 ◽  
Author(s):  
Ottavia Romoli ◽  
Johan Claes Schönbeck ◽  
Siegfried Hapfelmeier ◽  
Mathilde Gendrin
Keyword(s):  
Larval Development ◽  
Emerging Adults ◽  
Larval Instar ◽  
Bacterial Colonisation ◽  
Germ Free ◽  
Functional Studies ◽  
The Third ◽  
Novel Approach ◽  
Folate Biosynthesis ◽  
Vector Borne

AbstractThe mosquito microbiota impacts the physiology of its host and is essential for normal larval development, thereby influencing transmission of vector-borne pathogens. Germ-free mosquitoes generated with current methods show larval stunting and developmental deficits. Therefore, functional studies of the mosquito microbiota have so far mostly been limited to antibiotic treatments of emerging adults. In this study, we developed a novel approach to produce germ-free Aedes aegypti mosquitoes. It is based on reversible colonisation with bacteria genetically modified to allow complete decolonisation at any developmental stage. We show that, unlike germ-free mosquitoes previously produced using sterile diets, reversibly colonised mosquitoes show no developmental retardation and reach the same size as control adults. This allowed us to uncouple the study of the microbiota in larvae and adults. In adults, we detected no impact of bacterial colonisation on mosquito fecundity or longevity. In larvae, we performed a transcriptome analysis and diet supplementation experiments following decolonisation during the third larval instar. Our data suggest that bacteria support larval development by contributing to folate biosynthesis and by enhancing energy storage. Our study establishes a novel tool to study the microbiota in insects and deepens our knowledge on the metabolic contribution of bacteria to mosquito development.

scholarly journals Unexpected Mechanism of Symbiont-Induced Reversal of Insect Sex: Feminizing Wolbachia Continuously Acts on the Butterfly Eurema hecabe during Larval Development

2007 ◽  
Vol 73 (13) ◽  
pp. 4332-4341 ◽  
Author(s):  
Satoko Narita ◽  
Daisuke Kageyama ◽  
Masashi Nomura ◽  
Takema Fukatsu
Keyword(s):  
Larval Development ◽  
Developmental Stages ◽  
Larval Instar ◽  
Reproductive Organs ◽  
Eurema Hecabe ◽  
Early Embryonic Stage ◽  
Different Strains ◽  
Pupal Mortality ◽  
Intermediate Traits ◽  
Insect Sex

ABSTRACT When the butterfly Eurema hecabe is infected with two different strains (wHecCI2 and wHecFem2) of the bacterial endosymbiont Wolbachia, genetic males are transformed into functional females, resulting in production of all-female broods. In an attempt to understand how and when the Wolbachia endosymbiont feminizes genetically male insects, larval insects were fed an antibiotic-containing diet beginning at different developmental stages until pupation. When the adult insects emerged, strikingly, many of them exhibited sexually intermediate traits in their wings, reproductive organs, and genitalia. The expression of intersexual phenotypes was strong in the insects treated from first instar, moderate in the insects treated from third instar, and weak in the insects treated from fourth instar. The insects treated from early larval instar grew and pupated normally but frequently failed to emerge and died in the pupal case. The dead insects in the pupal case contained lower densities of the feminizing Wolbachia endosymbiont than the successfully emerged insects, although none of them were completely cured of the symbiont infection. These results suggest the following: (i) the antibiotic treatment suppressed the population of feminizing Wolbachia endosymbionts; (ii) the suppression probably resulted in attenuated feminizing activity of the symbiont, leading to expression of intersexual host traits; (iii) many of the insects suffered pupal mortality, possibly due to either intersexual defects or Wolbachia-mediated addiction; and hence (iv) the feminizing Wolbachia endosymbiont continuously acts on the host insects during larval development for expression of female phenotypes under a male genotype. Our finding may prompt reconsideration of the notion that Wolbachia-induced reproductive manipulations are already complete before the early embryonic stage and provide insights into the mechanism underlying the symbiont-induced reversal of insect sex.

FACTORS AFFECTING LARVAL DIAPAUSE IN DENDROCTONUS RUFIPENNIS (COLEOPTERA: SCOLYTIDAE)

1977 ◽  
Vol 109 (11) ◽  
pp. 1485-1490 ◽  
Author(s):  
E.D.A. Dyer ◽  
P.M. Hall
Keyword(s):  
Life Cycle ◽  
Larval Development ◽  
Larval Instar ◽  
Fourth Instar ◽  
Dendroctonus Rufipennis ◽  
Factors Affecting ◽  
Temperature Changes ◽  
Larval Diapause ◽  
Laboratory Results ◽  
Development Threshold

AbstractThe effect of daily day-degrees C in relation to brood age was investigated to determine its influence on the induction of larval (prepupal) diapause in Dendroctonus rufipennis (Kirby). Daily day-degrees of less than about 9° above the development threshold (6.1°C) induced diapause in most of the broods while diapause was averted by daily day-degrees C of 10 or more above the threshold. Induction of diapause occurred no later than third larval instar; temperature changes during the fourth instar produced no change in aversion or induction of diapause. Laboratory results reveal that field temperatures during larval development determine whether most beetles have a 1- or 2-year life cycle.

External changes in embryonic and larval development of Odontophrynus cordobae Martino et Sinsch, 2002 (Anura: Cycloramphidae)

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Pablo Grenat ◽  
Lucio Zavala Gallo ◽  
Nancy Salas ◽  
Adolfo Martino
Keyword(s):  
Larval Development ◽  
Body Mass ◽  
Related Species ◽  
Developmental Stages ◽  
Morphological Changes ◽  
Larval Form ◽  
Larval Stages ◽  
In Captivity ◽  
Mass Increment ◽  
Embryonic And Larval Development

AbstractWe provide the first description of development for a species belonging to Odontophrynus genus by describing all external changes of embryonic and larval stages for Odontophrynus cordobae. External morphological changes through development were analyzed on specimens bred in captivity. Embryonic and larval development, from fertilization to metamorphosis, was completed in 62 days and 46 stages were defined. We split the staging series into ten developmental groups: fertilization (stages 1 and 2); segmentation (stages 3–9); gastrulation (stages 10–12); neurulation (stages 13–16); elongation (stages 17–19); external gill larva (stages 20–24); internal gill larva (stage 25); pre-metamorphosis (stages 26–41); pro-metamorphosis (stage 42); metamorphic climax (stages 43–46). Marked increases in total length were evidenced during elongation and during stage 25, when the tadpole begins to feed. Stage 25 was the longest one (8 days) and it was related to organs rearrangement, morphological progression and body mass increment typical of free life larval form. Similar studies on related species are needed to compare different developmental stages at different taxonomic levels.

scholarly journals Vruggroei van Macadamia integnfolia Maiden & Betche cv Keauhou in die Transvaalse Laeveld

1993 ◽  
Vol 12 (2) ◽  
pp. 40-43
Author(s):  
A. J. Joubert ◽  
L. C. Holtzhausen
Keyword(s):  
Seed Development ◽  
Fruit Ripening ◽  
Fruit Set ◽  
Morphological Changes ◽  
Growth Period ◽  
Growth Phases ◽  
Full Bloom ◽  
Dormant Stage ◽  
Macadamia Integrifolia ◽  
Three Stages

The morphological changes of the fruit of Macadamia integrifolia, from fruit set to fruit ripening, were studied and the growth phases of the fruit are described. The length of the fruit growth period, from full bloom to fruit ripening, was 31 weeks and the growth period is divided into three stages. During Stage I, which lasted 2 weeks, the zygote was dormant. Stage II is the seed development period, which lasted 12 weeks. Stage III is the ripening period, which occurred over 17 weeks.

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