scholarly journals Field application of the geometric framework reveals a multistep strategy of nutrient regulation in a leaf-miner

2019 ◽  
Author(s):  
Mélanie J.A. Body ◽  
Spencer T. Behmer ◽  
Pierre-François Pelisson ◽  
Jérôme Casas ◽  
David Giron
Keyword(s):  
Close Association ◽  
Sugar Content ◽  
Field Application ◽  
Leaf Miner ◽  
Compensatory Mechanisms ◽  
Geometric Framework ◽  
Feeding Mode ◽  
Body Protein ◽  
Symbiotic Associations ◽  
Single Leaf

AbstractAnimals have evolved a vast array of behavioral and physiological strategies that allow them to achieve a nutritionally balanced diet. Plants as food for herbivores are often considered suboptimal, but phytophagous insects can employ pre- and post-ingestive mechanisms and/or symbiotic associations to help overcome food nutritional imbalances. This is particularly crucial for permanent multivoltine leaf-miner insects such as the caterpillar Phyllonorycter blancardella which completes development within a restricted area of a single leaf and use deciduous leaves to fuel growth and reproduction even under senescing autumnal conditions. Using the geometric framework for nutrition under natural field conditions, we show that this insect has multiple strategies to deal with inadequate food supply from the plant. First, larvae manipulate the protein-sugar content of both normal, photosynthetically active, and senescing, photosynthetically inactive, leaf tissues. Control of nutritional homeostasis of mined tissues is however higher for late instars, which differ from younger larval instars in their feeding mode (fluid-vs. tissue-feeder). Second, slight differences in the protein-sugar environment remain between mined tissues on green and yellow leaves despite this manipulation of the leaf physiology. This insect uses post-ingestive mechanisms to achieve similar body protein, sugar and lipid composition. This study demonstrates, for the first time under natural conditions, the ability of an insect herbivore to practice a combination of pre- and post-ingestive compensatory mechanisms to attain similar growth and metabolic outcomes in fundamentally different nutritional environments. Additionally, a comparison of larval nutritional requirements of 117 species from various insect groups further reinforces the hypothesis of a close association between P. blancardella and endosymbiotic bacteria for nutritional purposes.

scholarly journals A remarkable leaf mine induced by Tachygonus sp.n. (Coleoptera: Curculionidae: Curculioninae: Rhamphini) on Erythroxylum subsessile (Erythroxylaceae) with a description of the new species

2012 ◽  
Vol 72 (4) ◽  
pp. 949-953
Author(s):  
RF. Monteiro ◽  
MS. Nascimento ◽  
RM. Silva ◽  
HA. Hespenheide
Keyword(s):  
New Species ◽  
High Frequency ◽  
National Park ◽  
Host Plants ◽  
Close Association ◽  
Larval Instar ◽  
Original Data ◽  
Leaf Miner ◽  
Parasitoid Species ◽  
Great Abundance

In this study, we describe and present original data on the bionomics and ecology of Tachygonus erythroxyli Hespenheide, New Species, on Erythroxylum subsessile (Mart.). Thirty individuals of E. subsessile were analysed every two months, from October, 2006 to October, 2007 at the National Park of Restinga de Jurubatiba (PNRJ) Carapebus, Rio de Janeiro, Brazil. Females of T. erythroxyli lay their eggs singly on the upper surface of the host's leaves. The mine of T. erythroxyli is expanded with three bubbles, each one representing one larval instar. These mines occur throughout the year in at least half of the host plants and are markedly more abundant in summer. We obtained three parasitoid species, making a total of 53% of the rate of parasitism. Cirrospilus sp. (Eulophidae) was the most prevalent and represented 88% of the parasitoids. The great abundance of Tachygonus mines, their high frequency in their host plant, and local monophagy of this leaf miner weevil suggest a close association between T. erythroxyli and Erythroxylum subsessile.

The effect of leaf removal and canopy height on whole-vine gas exchange and fruit development of Vitis vinifera L. Sauvignon Blanc

2003 ◽  
Vol 30 (6) ◽  
pp. 711 ◽  
Author(s):  
Paul R. Petrie ◽  
Michael C. T. Trought ◽  
G. Stanley Howell ◽  
Graeme D. Buchan
Keyword(s):  
Leaf Area ◽  
Management Practices ◽  
Disease Incidence ◽  
Sugar Content ◽  
Canopy Height ◽  
Lag Phase ◽  
Vitis Vinifera L ◽  
Leaf Removal ◽  
Single Leaf ◽  
The Impact

Canopy topping and leaf removal are management practices commonly used in New Zealand vineyards to increase light and pesticide penetration to the fruit zone, thus, reducing disease incidence. Previous research has suggested that an increase in photosynthesis occurs when leaves are removed, and this may compensate for the reduced leaf area. However, it is difficult to extrapolate single-leaf photosynthesis measurements to a whole-plant scale. Therefore the extent of the compensation is unknown. To evaluate the impact of leaf removal and canopy height on whole-vine photosynthesis, treatments were imposed during the lag phase of berry growth. Leaves were removed from the lower quarter of the canopy, or vines were topped to three quarters of the height of control plants, in a two-by-two-factorial design. Both topping and leaf removal caused a decrease in whole-vine photosynthesis immediately after the treatments were imposed. Leaf removal, but not topping height, reduced photosynthesis on a per unit leaf area basis. This suggests that the lower portion of the canopy contributes more than the upper portion of the canopy to whole-vine photosynthesis. When measurements were made again approximately two months later, tall vines without leaf removal had a higher photosynthesis rate than the other treatments. Fruit yield, sugar content, vine carbohydrate reserves and pruning weights followed trends similar to those observed for photosynthesis, suggesting that although some photosynthetic compensation occurred, the defoliation treatments had a negative effect on vine growth.

scholarly journals Fungi Associated with Horse-Chestnut Leaf Miner Moth Cameraria ohridella Mortality

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 58
Author(s):  
Irena Nedveckytė ◽  
Dalė Pečiulytė ◽  
Vincas Būda
Keyword(s):  
Adult Stage ◽  
Total Mortality ◽  
Pupal Stage ◽  
Wiener Index ◽  
Mortality Rates ◽  
Field Application ◽  
Leaf Miner ◽  
Horse Chestnut ◽  
Environment Friendly ◽  
Chestnut Leaf

The total mortality of the leaf-miner horse-chestnut pest, Cameraria ohridella, collected in nature, and the mortality associated with mycoses were assessed under laboratory conditions in stages: for eggs mortality rates of 9.78% and 61.97% were found, respectively; for caterpillars, 45.25% and 5.59%, respectively; and for pupae 21.22% and 100%, respectively. At the egg stage, Cladosporus cladosporioides caused mycosis most often (27% of all mycoses); at the caterpillar stage there was no pronounced predominant fungus species; at the pupal stage both Cordyceps fumosorosea and Beauveria bassiana (32% and 31%, respectively) were most dominant; whereas at the adult stage Lecanicillum aphanocladii (43%) were most dominant. C. ohridella moths remained the most vulnerable during the pupal and caterpillar stages. Maximum diversity of fungi associated with the leaf-miner moth was reached during the period of development inside the chestnut leaf (Shannon–Wiener index—H′ = 2.608 at the caterpillar stage, H′ = 2.619 at the pupal stage), while the minimum was reached in the adult stage (H′ = 1.757). In the caterpillar and pupa stages, saprophytic fungi were most often recorded. Comparative laboratory tests revealed novel properties of the fungus L. aphanocladii, its effectiveness as the leaf-miner moth‘s entomopathogen and its suitability for field application trials while developing environment-friendly methods for horse-chestnut pest control.

scholarly journals Narrow safety margin in the phyllosphere during thermal extremes

2019 ◽  
Vol 116 (12) ◽  
pp. 5588-5596 ◽  
Author(s):  
Sylvain Pincebourde ◽  
Jérôme Casas
Keyword(s):  
Heat Waves ◽  
Safety Margin ◽  
Thermal Limit ◽  
Apparent Paradox ◽  
Feeding Mode ◽  
Thermal Limits ◽  
Single Leaf ◽  
Arthropod Species ◽  
Species Vulnerability ◽  
Leaf Transpiration

The thermal limit of ectotherms provides an estimate of vulnerability to climate change. It differs between contrasting microhabitats, consistent with thermal ecology predictions that a species’ temperature sensitivity matches the microclimate it experiences. However, observed thermal limits may differ between ectotherms from the same environment, challenging this theory. We resolved this apparent paradox by showing that ectotherm activity generates microclimatic deviations large enough to account for differences in thermal limits between species from the same microhabitat. We studied upper lethal temperature, effect of feeding mode on plant gas exchange, and temperature of attacked leaves in a community of six arthropod species feeding on apple leaves. Thermal limits differed by up to 8 °C among the species. Species that caused an increase in leaf transpiration (+182%), thus cooling the leaf, had a lower thermal limit than those that decreased leaf transpiration (−75%), causing the leaf to warm up. Therefore, cryptic microclimatic variations at the scale of a single leaf determine the thermal limit in this community of herbivores. We investigated the consequences of these changes in plant transpiration induced by plant–insect feedbacks for species vulnerability to thermal extremes. Warming tolerance was similar between species, at ±2 °C, providing little margin for resisting increasingly frequent and intense heat waves. The thermal safety margin (the difference between thermal limit and temperature) was greatly overestimated when air temperature or intact leaf temperature was erroneously used. We conclude that feedback processes define the vulnerability of species in the phyllosphere, and beyond, to thermal extremes.

Investigations into glyphosate-resistant horseweed (Conyza canadensis): retention, uptake, translocation, and metabolism

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 498-505 ◽  
Author(s):  
Paul C. C. Feng ◽  
Minhtien Tran ◽  
Tommy Chiu ◽  
R. Douglas Sammons ◽  
Gregory R. Heck ◽  
...  
Keyword(s):  
Glyphosate Resistance ◽  
Phloem Loading ◽  
The United States ◽  
Field Application ◽  
Sublethal Dose ◽  
Conyza Canadensis ◽  
Spray Application ◽  
Single Leaf ◽  
Treated Leaf ◽  
Foliar Retention

The mechanism of glyphosate resistance in horseweed was investigated. Eleven biotypes of putative sensitive (S) and resistant (R) horseweed were obtained from regions across the United States and examined for foliar retention, absorption, translocation, and metabolism of glyphosate. Initial studies used spray application of14C-glyphosate to simulate field application. When S and R biotypes were compared in the absence of toxicity at a sublethal dose, we observed comparable retention and absorption but reduced root translocation in the R biotypes. S and R biotypes from Delaware were further examined at field use rates and results confirmed similar retention and absorption but reduced root translocation in the R biotypes. Application of14C-glyphosate to a single leaf demonstrated reduced export out of the treated leaf and lower glyphosate import into other leaves, the roots, and the crown in R relative to S biotypes. Examination of the treated leaf by autoradiography showed that glyphosate loading into the apoplast and phloem was delayed and reduced in the R biotype. Our results consistently showed a strong correlation between impaired glyphosate translocation and resistance. Tissues from both S and R biotypes showed elevated levels of shikimate suggesting that 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) remained sensitive to glyphosate. Analysis of tissue shikimate levels demonstrated reduced efficiency in EPSPS inhibition in the R biotypes. Our results suggest that resistance is likely due to altered cellular distribution that impaired phloem loading and plastidic import of glyphosate resulting in reduced overall translocation as well as inhibition of EPSPS.

scholarly journals Acetic Acid Bacteria, Newly Emerging Symbionts of Insects

2010 ◽  
Vol 76 (21) ◽  
pp. 6963-6970 ◽  
Author(s):  
Elena Crotti ◽  
Aurora Rizzi ◽  
Bessem Chouaia ◽  
Irene Ricci ◽  
Guido Favia ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Close Association ◽  
Horizontal Transmission ◽  
Acetic Acid Bacteria ◽  
Reproductive Organs ◽  
Malpighian Tubules ◽  
Symbiotic Associations ◽  
Symbiotic Relationships ◽  
Modes Of Transmission ◽  
Scaphoideus Titanus

ABSTRACT Recent research in microbe-insect symbiosis has shown that acetic acid bacteria (AAB) establish symbiotic relationships with several insects of the orders Diptera, Hymenoptera, Hemiptera, and Homoptera, all relying on sugar-based diets, such as nectars, fruit sugars, or phloem sap. To date, the fruit flies Drosophila melanogaster and Bactrocera oleae, mosquitoes of the genera Anopheles and Aedes, the honey bee Apis mellifera, the leafhopper Scaphoideus titanus, and the mealybug Saccharicoccus sacchari have been found to be associated with the bacterial genera Acetobacter, Gluconacetobacter, Gluconobacter, Asaia, and Saccharibacter and the novel genus Commensalibacter. AAB establish symbiotic associations with the insect midgut, a niche characterized by the availability of diet-derived carbohydrates and oxygen and by an acidic pH, selective factors that support AAB growth. AAB have been shown to actively colonize different insect tissues and organs, such as the epithelia of male and female reproductive organs, the Malpighian tubules, and the salivary glands. This complex topology of the symbiosis indicates that AAB possess the keys for passing through body barriers, allowing them to migrate to different organs of the host. Recently, AAB involvement in the regulation of innate immune system homeostasis of Drosophila has been shown, indicating a functional role in host survival. All of these lines of evidence indicate that AAB can play different roles in insect biology, not being restricted to the feeding habit of the host. The close association of AAB and their insect hosts has been confirmed by the demonstration of multiple modes of transmission between individuals and to their progeny that include vertical and horizontal transmission routes, comprising a venereal one. Taken together, the data indicate that AAB represent novel secondary symbionts of insects.

scholarly journals Studies on the Effect of Different Insecticidal Applications on Quality, Nutritional Parameters and Total Antioxidant Capacity of Brinjal (Solanum melongena L.)

2018 ◽  
Vol 69 ◽  
pp. 34-42
Author(s):  
Moumit Roy Goswami ◽  
Ujjal Kumar Pati ◽  
Puja Maity ◽  
Aniruddha Mukhopadhyay
Keyword(s):  
Antioxidant Capacity ◽  
Fruit Quality ◽  
Total Antioxidant Capacity ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Field Application ◽  
Synthetic Pyrethroids ◽  
Nutritional Parameters ◽  
Fruit Samples ◽  
Total Antioxidant

Brinjal (SolanummelongenaL.) suffers from the attack of various pests throughout its cropping season. Different insecticides are used to control these pest infestations. The application of these insecticides on brinjal plants may have an effect on its quality and nutritional parameters of fruit samples. In the present study effect of three different insecticides viz. Triazophos 40% E.C Carbaryl 50% W.D.P, Cypermethrin 10% E.C, and Azadiractin 10000 ppm formulation belonging to different groups namely Organophosphate, Carbamate, Synthetic pyrethroids and Botanical insecticide on brinjal fruit quality, nutritional parameters and Total antioxidant capacity (TAC) were assessed in field conditions. The results showed that different insecticide at field application dose showed minute insignificant variation in fruit nutritional and total antioxidant activity parameters in comparison to the control samples. The fruit quality parameters also showed minute variation in comparison to the control except in the case of Triazophos treated samples which showed significant variation (p<0.05) in titrable acidity, total soluble sugar content and crude protein.

Immunocytochemical Localization of Amyloid Protein AA in the “Dense Fibrillar Inclusions” of the Reticuloendothelical Cells

1977 ◽  
Vol 35 ◽  
pp. 438-439
Author(s):  
T. Shirahama ◽  
M. Skinner ◽  
A.S. Cohen
Keyword(s):  
Amyloid Fibril ◽  
Close Association ◽  
Gel Filtration ◽  
Fibril Formation ◽  
Amyloid Protein ◽  
Electron Microscopic ◽  
Amyloid Deposits ◽  
Amyloid Fibril Formation ◽  
Electron Microscopic Technique ◽  
Lysosomal System

A1thought the mechanisms of amyloidogenesis have not been entirely clarified, proteolysis of the parent proteins may be one of the important steps in the amyloid fibril formation. Recently, we reported that "dense fibrillar inclusions" (DFI), which had the characteristics of lysosomes and contained organized fibrillar profiles as well, were observed in the reticuloendothelial cells in close association with the foci of new amyloid deposits. We considered the findings as evidence for the involvement of lysosomal system in amyloid fibril formation (l). In the present study, we attempted to determine the identity of the contents of the DFI by the use of antisera against the amyloid protein (AA) and an immuno-electron microscopic technique.Amyloidosis was induced in CBA/J mice by daily injections of casein (l). AA was isolated from amyloid-laden spleens by gel filtration and antibody to it was produced in rabbits (2). For immunocytochemistry, the unlabeled antibody enzyme method (3) was employed.

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