The Third Trophic Level as an Agent of Selection

2012 ◽  
Vol 26 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Noah K. Whiteman

Ecology ◽  
2012 ◽  
Author(s):  
Lee A. Dyer

Trophic levels are determined by feeding relationships, with basal levels consisting of primary producers or detritus and upper levels based on consumption of these basal levels. Organisms on the second trophic level are referred to as primary consumers, which are in turn consumed by secondary consumers, and so on up a theoretical trophic chain. Primary consumers consist of herbivores and detritivores, while the third trophic level and those above include predators and parasites. Energy and matter move up trophic chains, and some compounds, including various toxins, may bioaccumulate at upper trophic levels. The concept of trophic level has generated a sizeable literature yielding useful ecological models, such as trophic cascades, and debates about top-down versus bottom-up regulation of herbivores. This article focuses on the contributions of the trophic-level concept to ecological theory, evolutionary biology, and the applied fields of agricultural and global change biology.


Oikos ◽  
1996 ◽  
Vol 75 (2) ◽  
pp. 330 ◽  
Author(s):  
Robert J. Marquis ◽  
Christopher Whelan

2015 ◽  
Vol 8 (3) ◽  
pp. 196-200
Author(s):  
Marina Robles Angelini ◽  
Arlindo Leal Boiça Júnior

Resumo. Estudou-se o efeito da alimentação com lagartas de Dione juno juno (Cramer) (Lepidoptera: Nymphalidae), criadas em diferentes genótipos de maracujazeiro: Passiflora edulis Sims., Passiflora edulis f. flavicarpa Deg. (Seleção de Jaboticabal), P. edulis f. flavicarpa (cv. Sul Brasil) e P. edulis f. flavicarpa (cv. Maguary FB-100), Passiflora alata Dryand, Passiflora serrato-digitata Linn. e Passiflora foetida Linn. sobre imaturos e adultos de Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae). O experimento foi conduzido sob condições controladas (temperatura: 26 ± 1°C, UR de 60 ± 10% e fotofase de 14 horas). Grupos de cinco ninfas de P. nigrispinus de 2º ínstar foram mantidos em recipientes plásticos (4,5 cm de altura e 7,5 cm de diâmetro), contendo as presas no seu interior. Diariamente, cinco lagartas de D. juno juno de 10 dias de idade (cerca de 2,0 cm de comprimento), criadas em folhas dos diferentes genótipos de maracujazeiro foram oferecidas aos predadores. O experimento constou de 10 repetições, totalizando 50 ninfas por tratamento. Foram avaliadas, diariamente, as durações e sobrevivência de cada instar; peso de ninfas (24 horas após a ecdise) e de adultos. Os resultados mostram a influência de genótipos de maracujazeiro sobre o terceiro nível trófico, onde lagartas criadas no genótipo P. edulis f. flavicarpa Sel. Jaboticabal mostraram-se mais adequadas ao desenvolvimento do predador. Os resultados obtidos nesse trabalho mostram a influência de genótipos de maracujazeiro sobre o terceiro nível trófico. O genótipo P. edulis f. flavicarpa cv. Sul Brasil mostra-se menos adequado ao predador, sugerindo de forma negativa a associação entre a resistência de plantas e o uso do controle biológico. Já os genótipos P. edulis e P. edulis f. flavicarpa Seleção de Jaboticabal podem ser utilizados juntamente com o predador, pois essas cultivares não afetaram o terceiro nível trófico. P. edulis f. flavicarpa cv. Maguary FB-100, considerado pouco adequado ao desenvolvimento de lagartas de D. juno juno, afetou o predador, resultando em associação negativa entre esse genótipo e o controle biológico.Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) Fed with Dione juno juno (Cramer) (Lepidoptera: Nymphalidae) Caterpillars, Raised in Different Passion fruit Genotypes, Adults and Immatures BiologyAbstract. The development of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) nymphs fed with Dione juno juno (Cramer) (Lepidoptera: Nymphalidae) larvae reared on leaves of the passion fruit genotypes Passiflora edulis Sims., Passiflora edulis f. flavicarpa Deg. (Seleção de Jaboticabal), P. edulis f. flavicarpa (cv. Sul Brasil) and P. edulis f. flavicarpa (cv. Maguary FB-100), P. alata, P. serrato-digitata and P. foetida. The experiment was conducted under controlled conditions (temperature: 26 ± 1°C, RH = 60 ± 10% and photophase of 14 hours). Second instar nymphs of the predator were kept in plastic cups (4.5 cm high and 7.5 cm wide) groups of five. Ten-day-old (approx. 2 cm) D. juno juno larvae reared on leaves of different passion fruit genotypes were provided daily to P. nigrispinus. The experiment was carried out with 10 replications, totalizing 50 nymphs per treatment. Daily evaluations were performed to measure the duration and viability of each instar, the body mass of nymphs (24 hours after each ecdysis) and adults, and the duration and viability of the nymph phase and adult longevity under starvation. Results show the influence of passion fruit genotypes at the third trophic level, since larvae reared with P. edulis f. flavicarpa (Seleção de Jaboticabal) have shown to be more adequate for predator development. The results of this experiment show the influence of passion fruit genotypes on the third trophic level. The genotype P. edulis f. flavicarpa cv. Sul Brasil has a less appropriate to the predator, suggesting a negative way the association between host plant resistance and use of biological control. Already P. edulis and genotypes P. edulis f. flavicarpa Jaboticabal Selection can be used along with the predator because these cultivars did not affect the third trophic level. P. edulis f. flavicarpa cv. Maguary FB-100, considered ill-suited to the development of larvae of D. juno juno, affected the predator, resulting in a negative association between this genotype and biological control.


2019 ◽  
Vol 167 (4) ◽  
pp. 306-312 ◽  
Author(s):  
Anderson Mathias Holtz ◽  
Jeanne Scardini Marinho‐Prado ◽  
Angelo Pallini ◽  
André Assis Pires ◽  
Tatiane Pereira Cofler ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document