scholarly journals Effects of leaf herbivory on the bromeliad Aechmea blanchetiana: a study of selective feeding by the scraper Acentroptera pulchella

2012 ◽  
Vol 26 (4) ◽  
pp. 944-952 ◽  
Author(s):  
Noa Magalhães ◽  
Lucas Bevilaqua Ferreira ◽  
Gilda Leitão ◽  
André Mantovani
Keyword(s):  
Feeding Pattern ◽  
Total Phenol Content ◽  
Apical Region ◽  
Selective Feeding ◽  
Potential Influence ◽  
Nitrogen Levels ◽  
Defensive Strategies ◽  
Young Leaves ◽  
Nutritional Benefits ◽  
Leaf Herbivory

The scraper Acentroptera pulchella (Chrysomelidae, Hispinae) feeds on the leaves of Aechmea blanchetiana (Bromeliaceae), but not indiscriminately. This insect apparently concentrates its attack on the apical region of the intermediate leaves from the bromeliad tank. To characterise the potential influence of leaf defensive strategies on the intraspecific feeding pattern of A. pulchella on the leaves of the bromeliad A. blanchetiana, we quantified the apparent intraspecific preference of this feeding pattern; compared distinct leaves and portions in relation to morpho-physiological, mechanical, nutritional and chemical anti-herbivore strategies; and investigated whether some or all these defensive strategies help explain the observed feeding pattern. A. pulchella preferentially attacked the mid-upper portions of mature and adult leaves of A. blanchetiana, but not the mid-lower portions of the same leaves, which are more resistant to punch, are thicker and present less nitrogen content than the upper portions. However, soft young leaves were not attacked. Attacked portions also presented higher total phenol content than did non-attacked portions, indicating that phenols do not act defensively. Other morpho-physiological and chemical anti-herbivore strategies evaluated did not differ between portions and leaves. This herbivore feeds preferentially on leaf portions that have higher nitrogen levels, avoiding others that present increased punch resistance. The scraper A. pulchella exhibits a clearly selective feeding pattern that is driven by nutritional benefits rather than strictly mechanical or chemical anti-herbivore strategies.

scholarly journals Cytokinin-mediated leaf manipulation by a leafminer caterpillar

2007 ◽  
Vol 3 (3) ◽  
pp. 340-343 ◽  
Author(s):  
David Giron ◽  
Wilfried Kaiser ◽  
Nadine Imbault ◽  
Jérôme Casas
Keyword(s):  
Plant Physiology ◽  
Feeding Behaviour ◽  
Adaptive Significance ◽  
Plant Defences ◽  
Selective Feeding ◽  
Feeding Mode ◽  
Leaf Mining ◽  
Galling Insects ◽  
Nutritional Benefits

A large number of hypotheses have been proposed to explain the adaptive significance and evolution of the endophagous-feeding mode, nutritional benefits being considered to be one of the main advantages. Leaf-mining insects should feed on most nutritional tissues and avoid tissues with high structural and/or biochemical plant defences. This selective feeding behaviour could furthermore be reinforced by manipulating the plant physiology, as suggested by the autumnal formation of ‘green islands’ around mining caterpillars in yellow leaves. The question we address here is how such metabolic manipulation occurs and what the nutritional consequences for the insect are. We report a large accumulation of cytokinins in the mined tissues which is responsible for the preservation of functional nutrient-rich green tissues at a time when leaves are otherwise turning yellow. The analogy with other plant manipulating organisms, in particular galling insects, is striking.

scholarly journals Antioxidant Activity of Ketapang Leaf Tea (Terminalia catappa)

2021 ◽  
Vol 4 (2) ◽  
pp. 220-227
Author(s):  
Retno Widyastuti ◽  
Agustina Intan Niken Tari ◽  
Novian Wely Asmoro
Keyword(s):  
Antioxidant Activity ◽  
Water Content ◽  
Leaf Age ◽  
Black Tea ◽  
Total Phenol ◽  
Total Phenol Content ◽  
Phenol Content ◽  
Terminalia Catappa ◽  
Young Leaves

The purpose of this study was to determine the antioxidant activity of fermented tea (black tea) with Ketapang leaves (Terminalia catappa) using two variations of leaf age, namely leaflets 1-3 and 4-5. The parameters observed were water content, pH, antioxidant activity (IC 50) and total phenol content of tea. Results showed that the antioxidant activity of young leaves (shoots 1-3) significantly higher than old leaves (shoots 4-5) but had lower total phenol and pH. In general, the character of Ketapang leaf tea products at shoots 1-5 has water content ranging from 5.55-5.58%, total phenol content of 22.63-28.97 mg / g EAG, and antioxidant activity (IC 50) of 6.27-6 .71 µg/ml and the pH of steeping water from 5.9 to 6.1. 

Observations on the Lower Carboniferous Lycopod Oxroadia gracilis Alvin

1986 ◽  
Vol 77 (2) ◽  
pp. 127-142 ◽  
Author(s):  
Albert G. Long
Keyword(s):  
Cross Sections ◽  
Oil Shale ◽  
Secondary Xylem ◽  
Apical Region ◽  
Lower Carboniferous ◽  
Stem Base ◽  
Tap Root ◽  
Young Leaves ◽  
Aerial Stem ◽  
Deep Cavities

ABSTRACTA stem-base of Oxroadia gracilis is described showing 12 distal rhizophores and 72 roots. The rhizophores branch in a manner interpreted as dichotomy in successive planes at right angles. Each has a siphonostele which may possess medullary tracheids. Root-traces are monarch and wedge-shaped in section and their departure leaves ramular gaps in the siphonostele. The largest root may have functioned as a tap-root formed earlier than the rhizophores and exogenous. Only two out of ten known rooting specimens show rhizophores.An aerial stem with leaves shows secondary xylem up to the level of the probable second dichotomies.Leaves have slightly decurrent clasping bases forming low cushions and are recurved. Ligules (when preserved) occur in deep cavities of leaf-bases. In the apical region young leaves are small, recurved, and grooved distally below, giving a pseudo-forked appearance in cross sections of the stem.Only incomplete strobili are known.Comparisons are made with ‘Lepidodendron’ saalfeldense Solms-Laubach, and Trabicaulis ftabellilignis Meyer-Berthaud; these are considered co-generic.Oxroadia is recorded from the Oil-Shale Group (late Viséan or Asbian) near Kinghorn, Fife, Scotland; and from the Cementstone Group (late Tournaisian or Courceyan) East Lothian, Scotland; Berwickshire, Scotland; and Northumberland, northern England.

Dynamics of herbivory in Belizean mangal

1993 ◽  
Vol 9 (4) ◽  
pp. 435-453 ◽  
Author(s):  
Elizabeth J. Farnsworth ◽  
Aaron M. Ellison
Keyword(s):  
Leaf Age ◽  
Rhizophora Mangle ◽  
Avicennia Germinans ◽  
Age Classes ◽  
Tidal Zone ◽  
Younger Age ◽  
Young Leaves ◽  
Damage Types ◽  
Leaf Herbivory

ABSTRACTWe report long-term observations on leaf herbivory in the mangroves Rhizophora mangle and Avicennia germinans, on the Placencia Peninsula of Belize. We labelled and traced leaves and recorded the amount of damage appearing over a period of 310 days. Herbivores had damaged 1–4% of total mean leaf area within the first 10 days, but damage rates levelled off thereafter, to a final total of 4–10% damage. Herbivores did not concentrate on leaves of younger age classes. Rhizophora mangle growing in the high tidal zone (HHW) exhibited the highest initial and total attack rates at all but the final sampling dates. We also documented the dynamics of injury expansion and necrosis following artificial injury to seedling and tree leaves. Artificial holes in leaves were associated with higher subsequent rates of herbivory that varied among leaf age classes, and particular damage types were more prevalent in previously injured leaves. Artificial holes expanded significantly more in young leaves of both species. Holes in young leaves of both species expanded by up to 45.1% in area over 50 days, consistent with a similar study in Australia. Substantial necrotic areas developed around the injury site; a secondary effect of damage not often considered in herbivory studies. We discuss the implications of hole expansion and necrosis in estimating error in herbivory measurements. Temporally dynamic studies of herbivory are especially needed in tropical systems that show non-deciduous phenologies and long-lived leaves.

scholarly journals Rates of calcium, yield and quality of snap bean

2007 ◽  
Vol 64 (6) ◽  
pp. 616-620 ◽  
Author(s):  
Simone Palma Favaro ◽  
José Antônio Braga Neto ◽  
Hideaki Wilson Takahashi ◽  
Édison Miglioranza ◽  
Elza Iouko Ida
Keyword(s):  
Nutrient Solution ◽  
Calcium Concentration ◽  
Fruits And Vegetables ◽  
Negative Relationship ◽  
Dry Weight ◽  
Apical Region ◽  
Snap Bean ◽  
Bean Cultivar ◽  
Snap Beans ◽  
Young Leaves

Calcium ions (Ca) play an important role in many biochemical processes, delaying senescence and controlling physiological disorders in fruits and vegetables. The objective of this experiment was to analyze the effect of increasing calcium concentrations in snap beans. Snap bean cultivar UEL 1 was sown in sand containing 80 mg L-1 of calcium supplemented with nutrient solution, plus calcium at different contents: 0, 75, 150 and 300 mg L-1. Ca was mainly recovered in the shoots, followed by roots and pods. Calcium concentrations in the pods were 130, 259, 349 and 515 mg 100 g-1dry matter on a dry weight basis, in relation to the enhancement of calcium contents in the nutrient solution, respectively. A negative relationship between nitrogen content in the pods and calcium concentration in the nutrient solution was observed. Pods from plants grown in a solution without Ca presented necrosis in their apical region. Dieback of roots, shoots and young leaves also occurred under low calcium supply. Dry matter of pods, roots and shoots, number of pods per plant, pod weight and pod length increased proportionally to calcium concentration in solution. Increasing rates of calcium improved biomass production in snap bean cultivar UEL 1.

DIVERGENT DEFENSIVE STRATEGIES OF YOUNG LEAVES IN TWO SPECIES OF INGA

Ecology ◽  
2005 ◽  
Vol 86 (10) ◽  
pp. 2633-2643 ◽  
Author(s):  
Phyllis D. Coley ◽  
John Lokvam ◽  
Kathleen Rudolph ◽  
Keryn Bromberg ◽  
Tara E. Sackett ◽  
...  
Keyword(s):  
Defensive Strategies ◽  
Young Leaves

scholarly journals A syndrome of mutualism reinforces the lifestyle of a sloth

2014 ◽  
Vol 281 (1778) ◽  
pp. 20133006 ◽  
Author(s):  
Jonathan N. Pauli ◽  
Jorge E. Mendoza ◽  
Shawn A. Steffan ◽  
Cayelan C. Carey ◽  
Paul J. Weimer ◽  
...  
Keyword(s):  
Algal Biomass ◽  
Forest Canopy ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Algal Growth ◽  
Nitrogen Levels ◽  
Nutritional Benefits ◽  
Oviposition Sites ◽  
Limited Diet

Arboreal herbivory is rare among mammals. The few species with this lifestyle possess unique adaptions to overcome size-related constraints on nutritional energetics. Sloths are folivores that spend most of their time resting or eating in the forest canopy. A three-toed sloth will, however, descend its tree weekly to defecate, which is risky, energetically costly and, until now, inexplicable. We hypothesized that this behaviour sustains an ecosystem in the fur of sloths, which confers cryptic nutritional benefits to sloths. We found that the more specialized three-toed sloths harboured more phoretic moths, greater concentrations of inorganic nitrogen and higher algal biomass than the generalist two-toed sloths. Moth density was positively related to inorganic nitrogen concentration and algal biomass in the fur. We discovered that sloths consumed algae from their fur, which was highly digestible and lipid-rich. By descending a tree to defecate, sloths transport moths to their oviposition sites in sloth dung, which facilitates moth colonization of sloth fur. Moths are portals for nutrients, increasing nitrogen levels in sloth fur, which fuels algal growth. Sloths consume these algae-gardens, presumably to augment their limited diet. These linked mutualisms between moths, sloths and algae appear to aid the sloth in overcoming a highly constrained lifestyle.

scholarly journals Levels of leaf Herbivory in Amazonian trees from different stages In forest regeneration

1999 ◽  
Vol 29 (4) ◽  
pp. 615-623 ◽  
Author(s):  
Heraldo L. VASCONCELOS
Keyword(s):  
Leaf Age ◽  
Secondary Forests ◽  
Leaf Production ◽  
Canopy Trees ◽  
Significant Difference ◽  
Young Leaves ◽  
Leaf Cutting ◽  
Leaf Herbivory ◽  
Amazonian Trees

Leaves from 120 canopy trees and 60 understory tree saplings growing in primary and secondary forests near Manaus, Brazil, were collected for determination of standing levels of herbivory (percent leaf area lost). Overall, levels of herbivory on leaves of central Amazonian trees were low. About one quarter of the leaves examined (n = 855) had no damage at all. In most other Neotropical sites studied the mean percentage of herbivory was found to vary between 5.7 and 13.1%, whereas in Manaus it was only 3.1%. The data presented here support the contention that levels of herbivore damage are positively related to soil fertility. No significant difference was found in herbivory levels between canopy trees and understory saplings. Also, there was no difference in damage between leaves from pioneer and late successional trees. Field assays of preference, however, revealed that leaves from pioneer trees are more palatable to leaf-cutting ants (Atta laevigata). This effect was dependent upon leaf age, being observed in mature leaves, but not in young leaves. The greater rate of leaf production in secondary forests may be a factor accounting for the greater abundance of leaf-cutting ants in secondary compared to primary forests.

scholarly journals Fertility Affects Susceptibility of Chrysanthemum to Cotton Aphids: Influence on Plant Growth, Photosynthesis, Ethylene Evolution, and Herbivore Abundance

2004 ◽  
Vol 129 (3) ◽  
pp. 344-353 ◽  
Author(s):  
Fred T. Davies ◽  
Chunajiu He ◽  
Amanda Chau ◽  
Kevin M. Heinz ◽  
Andrew D. Cartmill
Keyword(s):  
Plant Growth ◽  
Leaf Area ◽  
Aphis Gossypii ◽  
Leaf Nitrogen ◽  
Low Fertility ◽  
High Fertility ◽  
Ethylene Evolution ◽  
Nitrogen Levels ◽  
Young Leaves ◽  
Leaf N

This research details the influence of fertility on plant growth, photosynthesis, ethylene evolution and herbivore abundance of chrysanthemum (Dendranthema grandiflora Tzvelev `Charm') inoculated with cotton aphids (Aphis gossypii Glover). We tested five fertility levels that consisted of 0%, 5%, 10%, 20%, and 100% (375 ppm N) of recommended nitrogen levels. Aphid abundance was greatest at high fertility. Fertility affected the vertical distribution of aphids. A higher population of aphids were observed in physiologically mature and older leaves at low fertility, whereas at high fertility young leaves had 33% more aphids than older, basal leaves. Aphids depressed plant vegetative and reproductive growth, and altered carbohydrate partitioning at high fertility. Aphid-inoculated (AI) plants at high fertility had increased specific leaf area [(SLA), i.e., thinner leaves] and greater leaf area than aphid-free (NonAI) plants. Aphids caused greater ethylene production in reproductive buds and young leaves of high fertility plants, but had no effect on ethylene evolution in physiologically mature or older, basal leaves. Plant growth, leaf nitrogen (N), phosphorus (P), iron (Fe) and manganese (Mn) increased at higher fertility, as did chlorophyll and photosynthetic rates. Leaf N was highest in young and physiologically mature leaves compared to basal leaves. Aphids decreased leaf N and P. Aphids reduced photosynthesis in young leaves of high fertility plants, whereas physiologically mature and older leaves were unaffected.

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