Fatty Acids of the Boll Weevil

Lambremont, Edward N.; Blum, M. S.

doi:10.1093/aesa/56.5.612

Cited by 31 publications

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“…Diapause larvae of the pink bollworm are heavier and possess 30% more fat than non-diapausing larvae (Adkisson et al 1963). A large build-up of lipids during the transition into adult diapause in the boll weevil Anthonornus grmdis Boheman is also reported by Lamberemont and Blum (1963). The relationship between various sugars, unsaturated fatty acids, sorbitol, and glycerol and cold-hardiness (Salt 1961 ; S@mme 1967) suggests that these predormancy stages have adequate safeguard against likely cold spells during late summer.…”

Section: Preparatory Phasementioning

confidence: 96%

Physiological Classification of Dormancies in Insects

1971

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A new classification of dormancy in insects is proposed on the basis of the evolutionary nature of dormancy, its synchronization with the aetiology of the species for their phenological advantage, the nature of ecological adversity, and the consequent physiological and biochemical adjustments. The roles of the above factors in the induction and termination of dormancies are discussed. The inadequacies of all the previous systems of describing various conditions of dormancy are pointed out.All instances of dormancy are divided into three major groups: hibernation, aestivation, and athermopause. Each of these classes is further subdivided into three categories representing a sequence of evolutionary adaptations: quiescence, oligopause, and diapause, in that order of evolutionary development. Depending upon the physiological condition of diapausing individuals or populations, two diapause states are recognized: teleodiapause and ateleodiapause. Each term is defined and discussed with examples.

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Section: Preparatory Phasementioning

confidence: 96%

Physiological Classification of Dormancies in Insects

1971

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“…The range and pattern of energy content in C. cornutus are similar to values reported for other insects (e.g., Wiegert 1965, Schaefer and Washinko 1970, Lawton 1971a, McNeill 1971, Bailey and Riegert 1972. These ontogenetic changes in energy content of insects associated with the development of the larvae, metamorphosis and vitellogenesis are produced by changes in lipid content (Laughlin 1956, Lambremont and Blum 1963, Strong 1963, Gilby 1965.…”

Section: Individual Energy Budgetmentioning

confidence: 99%

Life History and Population Energetics of the Dobson Fly, Corydalus Cornutus

Brown¹,

Fitzpatrick²

1978

Ecology

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. Ecological Society of America is collaborating with JSTOR to digitize, preserve and extend access to Ecology.Abstract. Rates and energies of consumption (C), egestion (F), assimilation (A), respiration (R), growth (Pg), production of exuviae (P,,), and production of egg masses (Pr) with associated efficiencies, and effects of seasonal temperature, weight and life-history stage upon them were examined for a typical individual and cohort of Corydalus cornutus (L.) from a stream in north-central Texas. Dobson flies are univoltine with 11 larval instars. Emergence, oviposition, and hatching occurred from late May into August. The typical dobson fly hatched in mid-June, grew rapidly until November, and again in March, reaching adult size prior to pupation in early June. Adult females fed to provide energy to yolk eggs, produce egg cases and for maintenance during their week of reproductive activities.Metabolic compensation enabled larval dobson flies to maintain fairly constant rates of R during winter (6.07 J g-~ h-', 5-15°C) and summer (16.15 J g-~ h-1, 20-30°C); with a seasonal acclimatization threshold occurring between 15-20°C. Metabolic constancy is adaptive and probably contributed to high ratios of P/R (1.94) and P/A (66%) for individual larvae. Rates of C, F, A and R, but not assimilation efficiency (AE = A/C x 100), were influenced by temperature and size.The energy budget for a typical dobson fly during the 47 wk as a larva was: C = 17,435, A 14,401, F = 3,033, Pg = 8,682. P,v = 828 and R = 4,892 J. Embryos respired 0.45 J/wk, prepupae 1,494 J/wk, male pupae 2,130 J/wk, female pupae 1,900 J/wk, male adults 2,615 J/wk and female adults 3,075 J/wk. Prepupal and pupal exuviae were 602 J and 502 J respectively. The average adult female's minimal reproductive effort was 2,791 J for eggs and 774 J for egg cases, 54 and 100% of her A and P respectively, and 17% of her life-history A. Annual energetics of the larval population were; C = 165,343, A = 136,574, F = 28,769, Pg 54,610, P,(V = 15,096, Pr = 1,502-1,711 and R = 66,869 J m-2.data indicate a 1-yr cycle in north-central Texas. Typically, final-instar larvae leave the stream to pupate in the soil, under rocks or in rotting logs several metres from the stream. The first pupal stage (prepupa) retains the appearance of the larva, but soon molts to a cream-colored, exarate pupa. After a week or so, depending upon latitude, the nocturnal adult emerges. Mating occurs almost immediately and females deposit egg masses within several days on objects hanging directly over streams near suitable riffle habitats. Eggs normally hatch within 2 wk and the first-instar larvae fall into the stream. The study area Population estimates were taken...

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“…The microvillar membranes of Coleoptera are predominantly phospholipids (Jordao et al, 1995). POPC and POPE were chosen because they are the predominant lipids present in A. grandis (Lambremont & Blum, 1963;Lambremont et al, 1964Lambremont et al, , 1965Stanley-Samuelson et al, 1988).…”

mentioning

confidence: 99%

Investigation of Membrane Disruption in the Reaction Catalyzed by Cholesterol Oxidase

1997

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Dye leakage experiments were undertaken to investigate the membrane disruption properties of cholesterol oxidase. Inspection of the X-ray crystal structures of cholesterol oxidase suggested that an active-site "lid" opens in order to bind substrate [Li, J., Vrielink, A., Brick, P., & Blow, D. M. (1993) Biochemistry 32, 11507-11515]. We tested whether the interaction of the putative active-site lid with the membrane was sufficiently disruptive of the membrane structure to cause leakage or lysis of the cell membrane. Vesicles (100 nm) composed of egg phosphatidylcholine, 2-palmitoyl-3-oleoyl-1-sn-phosphatidylethanolamine, and 2-palmitoyl-3-oleoyl-1-sn-phosphatidylcholine were used in this study to mimic biomembranes. To separate the effects of membrane binding from conversion of cholesterol to cholest-4-en-3-one, the active-site mutant E361Q was utilized. In the reaction catalyzed by E361Q, isomerization of the cholest-5-en-3-one intermediate is suppressed and cholest-5-en-3-one is the major product isolated. Furthermore, E361Q produces cholest-5-en-3-one 20-fold more slowly than wild type produces cholest-4-en-3-one from cholesterol. Wild-type and E361Q cholesterol oxidases bind to vesicles with an apparent K(D) of approximately 25 microM, as measured by quenching of intrinsic tryptophan fluorescence, irrespective of headgroup size and cholesterol content. Membrane disruption was measured by leakage of the encapsulated marker carboxyfluorescein. Leakage was observed with cholesterol-containing vesicles and wild-type enzyme only; the rate of leakage was dependent on the rate of cholest-4-en-3-one production. E361Q did not induce membrane disruption, regardless of vesicle type tested. Thus, binding of cholesterol oxidase to the membrane and partitioning of cholesterol into the active site does not sufficiently perturb the bilayer to cause leakage of vesicle contents. Formation of the product cholest-4-en-3-one, however, does increase membrane permeability. Expansion of the lipid bilayer upon conversion of cholesterol to cholest-4-en-3-one is the likely cause of this increased permeability.

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Fatty Acids of the Boll Weevil

Cited by 31 publications

References 0 publications

Physiological Classification of Dormancies in Insects

Physiological Classification of Dormancies in Insects

Life History and Population Energetics of the Dobson Fly, Corydalus Cornutus

Investigation of Membrane Disruption in the Reaction Catalyzed by Cholesterol Oxidase

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