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.

THE IMMATURE STAGES OF PTYCHOPTERA LENIS LENIS (DIPTERA: PTYCHOPTERIDAE) WITH NOTES ON THEIR BIOLOGY

1973 ◽  
Vol 105 (8) ◽  
pp. 1091-1099 ◽  
Author(s):  
I. D. Hodkinson
Keyword(s):  
Life Cycle ◽  
Water Depth ◽  
Adult Stage ◽  
Atmospheric Oxygen ◽  
Adult Emergence ◽  
Fourth Instar ◽  
Immature Stages ◽  
Experimental Conditions ◽  
Marginal Areas ◽  
Pharate Adult

AbstractThe four larval instars and the pupa of Ptychoptera lenis lenis Osten Sacken are described. Instars 2 to 4 are very similar morphologically but instar 1 is markedly different. Both a pharate pupal and a pharate adult stage were observed. Larvae are found in stagnant marginal areas of ponds where water depth does not exceed 4 cm and where benthic deposits of plant detritus exceed 8 cm. Fourth instar larvae, under experimental conditions, survived up to 45 days without contact with atmospheric oxygen but development was arrested. P. lenis has a 1 year life cycle with an extended adult emergence season from late May to the end of July.

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 Factors Affecting Gastropod Larval Development and Performance: A Systematic Review

2018 ◽  
Vol 37 (4) ◽  
pp. 851-867
Author(s):  
Dianna K. Padilla ◽  
David Charifson ◽  
Alyssa Liguori ◽  
Mica McCarty-Glenn ◽  
Maria Rosa ◽  
...  
Keyword(s):  
Systematic Review ◽  
Larval Development ◽  
Factors Affecting ◽  
And Performance

Demographic studies of Oomyzus incertus (Hymenoptera: Eulophidae), a larval parasitoid of Hypera postica (Coleoptera: Curculionidae), treated with four organophosphorous insecticides

2005 ◽  
Vol 137 (4) ◽  
pp. 488-491
Author(s):  
Qodrat Sabahi ◽  
Khalil Talebi
Keyword(s):  
Life Cycle ◽  
Medicago Sativa ◽  
Fourth Instar ◽  
Northern Iran ◽  
Alfalfa Weevil ◽  
Hypera Postica ◽  
Larval Parasitoid ◽  
Organophosphorous Insecticides

The alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), can severely damage the first cutting of alfalfa, Medicago sativa L. (Fabaceae), in much of Iran. The pest has been parasitized by several parasitoids including Oomyzus incertus (Ratzeburg) (Hymenoptera: Eulophidae), a gregarious larval endoparasitoid. This wasp can parasitize up to 30% of weevil larvae in alfalfa fields in northern Iran. It produces three to four generations per year, and the female prefers the fourth instar of the host for oviposition. Each female lays 2 to 22 eggs per host, which hatch within 47–60 h. The life cycle is completed in about 2 weeks, upon pupation inside the host. This species is predominantly present during the summer months in alfalfa fields (Streams and Fuester 1967).

scholarly journals The efficiency of Paecilomyce farinosus as biocontrol to larve stage on second ad sixith instar larve of Trogoderma granarium (Everts)

2013 ◽  
Vol 10 (4) ◽  
pp. 1096-1101
Author(s):  
Baghdad Science Journal
Keyword(s):  
Larval Instar ◽  
The Other ◽  
Biocontrol Agents ◽  
Larval Instars ◽  
Paecilomyces Farinosus ◽  
Trogoderma Granarium ◽  
Laboratory Conditions ◽  
Other Hand ◽  
Laboratory Results ◽  
Treatment Concentration

The present study was conducted to determine the pathogenicity of Paecilomyces farinosus as biocontrol agents against Tragoderma granarium (khapra) under laboratory conditions with three concentrations ( 2.8 x 108 , 2.8 x 106 ,2.8 x104 spores/ ml). The laboratory results revealed that fungi showed it's higher pathogencity to larve stage on 2nd instar and 6th instar , although their capability differs according to the fungi concentrations this fungi caused higher mortality of 2nd larval instar 70% and 60% ,55% when it was used at concentrations 2 .8 x 106 ,2.8 x104 spores/ ml respectively. On the other hand on 6th larval instars 55% , 35% , 30% at concentrations ( 2.8 x 108 , 2.8 x 106 ,2.8 x104 spores/ ml) respectively, and the highest rate of distortions in the adult insects from the 2nd instar treatment than the adult insects from the 6th instar treatment concentration of this fungi.

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 Biologi Stenocranus pacificus Kirkaldy (Hemiptera: Delphacidae) pada tanaman jagung (Zea mays L.) di rumah kasa

2020 ◽  
Vol 17 (2) ◽  
pp. 104
Author(s):  
Dosma Ulina Simbolon ◽  
Maryani Cyccu Tobing ◽  
Darma Bakti
Keyword(s):  
Zea Mays ◽  
Life Cycle ◽  
Sex Ratio ◽  
Zea Mays L ◽  
Instar Nymph ◽  
Fourth Instar ◽  
The Third ◽  
First Instar ◽  
Corn Plants ◽  
North Sumatra

<p><em>Stenocranus pacificus </em>Kirkaldy (Hemiptera: Delphacidae) is destructive pest on corn plants in South Lampung and it has been reported to cause corn damages in North Sumatra. The  objective of this research was to study some aspects biology of <em>S. pacificus</em> on corn plants in screenhouse. The research was conducted by observing the biology of <em>S. pacificus</em> that was reared on corn plants in screenhouse.<em> </em>The results showed that life cycle of <em>S. pacificus </em>was 38–47 (41,60 ± 3,19) days: egg was 9–11 (10,20 ± 0,79) days, the first instar nymph was 3–4 (3,70 ± 0,48) days, the second instar nymph was 3–4 (3,90 ± 0,32) days, the third instar nymph was 3–4 (3,70 ± 0,48) days, the fourth instar nymph was 3–4 (3,80 ± 0,42) days, and the fifth instar nymph was 3–4 (3,60 ± 0,52) days. Age of female was 13–17 (15,30 ± 1,34) days. It was longer than age of male which was 8–12 (10,10 ± 1,20) days. Female could produce 181–214 (197,60 ± 11,64) eggs during its life. The sex ratio was 1:1,98.</p>

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