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 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.

Selective feeding behaviour of Gambusia affinis

Oecologia ◽  
1972 ◽  
Vol 11 (1) ◽  
pp. 79-81 ◽  
Author(s):  
P. T. Rajasekharan ◽  
B. N. Chowdaiah
Keyword(s):  
Feeding Behaviour ◽  
Gambusia Affinis ◽  
Selective Feeding

scholarly journals A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti)

2017 ◽  
Author(s):  
Robert Boessenecker ◽  
Danielle Fraser ◽  
Morgan Churchill ◽  
Jonathan Geisler
Keyword(s):  
Phylogenetic Analysis ◽  
South Carolina ◽  
Feeding Behaviour ◽  
Stabilizing Selection ◽  
Suction Feeding ◽  
Feeding Mode ◽  
Milk Teeth ◽  
Feeding Morphology ◽  
Tooth Count

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones - all adaptations for suction feeding upon fish and squid. We report a new fossil odontocete from the Oligocene (~30 Ma) of South Carolina (Inermorostrum xenops, gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour amongst modern Odontoceti.

Sign in / Sign up

Export Citation Format

Share Document