Journal Article

Functional response and predatory interactions in conspecific and heterospecific combinations of two congeneric species (Coleoptera: Coccinellidae)

Mishra, G., University of Lucknow (India). Dept. of Zoology, Omkar, O., University of Lucknow (India). Dept. of Zoology, Kumar, B., University of Lucknow (India). Dept. of Zoology

2014

Overview

In the present study, the predatory interactions between two locally abundant large lady beetles, Coccinella septempunctata L. (C7) and Coccinella transversalis F. (Ct) provided with either an extremely scarce, scarce, sub-optimal, optimal or abundant supply of the pea aphid, Acyrthosiphon pisum (Harris) were investigated. For this, three 2-predator combinations (conspecific C7 + C7 and Ct + Ct, and heterospecific C7 + Ct) of 10-day-old unmated adult females were used. The relationships between the proportion of prey consumed by the predators in the conspecific and heterospecific combinations when provided with five different abundances of prey were similar in consisting of a decelerating (type II) functional response when provided with an extremely scarce to optimal supply of prey, followed by an accelerating (type III) functional response when provided with an optimal to abundant supply of prey. It is likely that the modified type II functional response recorded in the present study was a consequence of using a small experimental arena (Petri dish). The multiplicative risk model analysis revealed that the predators interacted antagonistically except in the C7 + C7 combination provided with an extremely scarce supply of prey where the predators had an additive effect. The predators in the heterospecific C7 + Ct combination consumed fewer aphids when provided with an extremely scarce, scarce, sub-optimal or optimal supply of prey prey than the predators in conspecific C7 + C7 combination but a similarly high number when provided with an abundant supply of prey. In addition, the efficiency of converting prey biomass into their own biomass was higher in the heterospecific C7 + Ct than in the conspecific C7 + C7 or Ct + Ct combinations at all prey densities. Although the conversion efficiency of the predators in the conspecific and heterospecific combinations provided with an extremely scarce supply of prey was the highest recorded, their growth rate was the lowest. In contrast, both the conversion efficiency and growth rate of the predators in the three combinations were highest when provided with an abundant supply of prey. It may, therefore, be concluded that when the predators in the combinations occupy similar ecological niches, they will probably consume less prey than they require when prey is both scarce and abundant because the predators interact antagonistically.

• Publisher: Institute of Entomology,Institute of Entomology, Biology Centre, Czech Academy of Science
• Subject: Acyrthosiphon pisum / ADULTE / ADULTOS / ADULTS / AGENT DE LUTTE BIOLOGIQUE / AGENTES DE CONTROL BIOLOGICO / ANIMAL DEVELOPMENTAL STAGES / APHIDIDAE / BEHAVIOUR / BIOLOGICAL CONTROL AGENTS / BIOMASA / BIOMASS / BIOMASSE / c. transversalis / COCCINELLA SEPTEMPUNCTATA / Coccinella transversalis / Coccinellidae / COLEOPTERA / COMPORTAMIENTO / COMPORTEMENT / COMPORTEMENT ALIMENTAIRE / Contests / conversion efficiency / DEPREDACION / Efficiency / ETAPAS DEL DESARROLLO ANIMAL / EVALUACION DE RIESGOS / EVALUATION DU RISQUE / EXPERIMENTACION / EXPERIMENTATION / FEEDING HABITS / FEMALES / FEMELLE / GREENHOUSES / GROWTH RATE / HABITOS ALIMENTARIOS / HEMBRA / INDICE DE CRECIMIENTO / INSECTE SUCEUR / INSECTOS CHUPADORES / Insects / INVERNADEROS / lady beetles / LARVAE / LARVAS / LARVE / MODELE / MODELOS / PESTS OF PLANTS / PLAGAS DE PLANTAS / PREDATION / PREDATOR PREY RELATIONS / Predators / predatory guilds / Prey / RAVAGEUR DES PLANTES / RELACIONES PREDADOR PRESA / RELATION PREDATEUR PROIE / RISK ASSESSMENT / SERRE / STADE DE DEVELOPPEMENT ANIMAL / Studies / SUCKING INSECTS / TAUX DE CROISSANCE / VICIA FABA