Produção de formas aladas em colônias de Brevicoryne brassicae (L.) (Hemiptera: Aphididae) por indução do parasitóide Diaeretiella rapae (McIntosh) (Hymenoptera: Aphidiidae) e alguns aspectos comportamentais da interação destas espécies

Abstract

Production of Winged Morphs in Colonies of Brevicoryne brassicae (L.) (Hemiptera: Aphididae) Induced by the Parasitoid Diaeretiella rapae (McIntosh) (Hymenoptera: Aphidiidae) and Some Behavioral Aspects of the Interaction Between These Species ABSTRACT-The objective of this study was to verify whether winged morphs are induced in colonies of Brevicoryne brassicae (L.) by exposure to Diaeretiella rapae (McIntosh). Behavioral aspects of the interaction between these species were also described. Aphid colonies were initiated by transferring ten adults to each cabbage plant, kept inside transparent recipients. In the treatment, a parasitoid couple was released inside each recipient-test, and the female was allowed to oviposit freely for 3h; no parasitoids were released in the control recipient. Winged morphs were produced in both conditions, but in the presence of the parasites, their number was significantly higher and they were produced earlier. No significant correlation was obtained between the number of winged individuals and the number of mummies. Parasitoids' longevity was 2.3 ± 0.19 days and the parasitoidism percentage was 20.6 ± 5.21. The increased production of winged morphs in B. brassicae clones in response to the presence of the parasitoid D. rapae can be considered a defense mechanism, because aphids could strategically maintain the clone survivorship, escaping by flight to form a new colony in other plants. Two other types of defense behavior were described: vigorous body shaking and escaping from the parasitoids. During 26h of observation, 20 types of D. rapae behavior were recorded and divided into five categories: self-cleaning, feeding, exploitation, copulation, and oviposition. Direct interactions between these species occur not only during oviposition, but also when the wasp touches the aphids with their antennae and ovipositor.

Ocorrência de formas aladas de pulgões e sua relação com fatores meteorológicos e plantas hospedeiras

“…Lipaphis erysimi, apesar de ocorrer em brassicáceas (Blande et al, 2004), é também encontrada em outras espécies de plantas como o agrião (Blackman & Eastop, 2000), a batata (Carrera & Cermeli, 2001) e o tomate (Nasreen et al, 2004). Brevicoryne brassicae difere das duas espécies anteriores, por ser considerada especialista quanto ao hábito alimentar, com plantas hospedeiras que são quase exclusivamente da família Brassicaceae (Pontoppidan et al, 2003).…”

“…No entanto, vários outros fatores são reconhecidos como infl uentes no aparecimento de formas aladas nas populações de pulgões, em que se destacam: a temperatura, o fotoperíodo, as mudanças na qualidade nutricional da planta hospedeira (Hodgson et al, 2005;Aheer et al, 2008;Mirmohammadi et al, 2009) e a presença de inimigos naturais (Pereira & Lomônaco, 2003). Com relação à temperatura, Bale et al (2007) Pesq.…”

Predator biodiversity strengthens herbivore suppression

“…Collard ( Brassica oleracea L.) plants are attacked by a diverse group of herbivores, including two phloem‐feeding aphid species, the green peach aphid, Myzus persicae (Sulzer), and the cabbage aphid Brevicoryne brassicae (L.). Cabbage aphids aggregate in tight clusters, with aphid groups exhibiting a group‐twitching defensive behaviour when disturbed (Pereira & Lomonaco 2003) and also producing a waxy secretion as a physical defence (Metcalf & Flint 1963). In contrast, green peach aphids feed primarily on the undersides of collard leaves without aggregating (G. Snyder, personal observation), and this species exhibits no obvious defensive behaviour beyond occasional dropping (Hodgson 1991).…”

Computer simulation applied to the biological control of the insect Aphis gossypii for the parasitoid Lysiphlebus testaceipes

“…Weisser et al (1999) verified that the presence of a predator enhanced the proportion of winged morphs among the offspring produced by the aphid Acyrthosiphon pisum (Harris). Pereira and Lomônaco (2003) verified that alate morphs of Brevicoryne brassicae (L.) were produced in the presence or absence of the parasitoid Diaeretiella rapae (McIntosh). However, in the presence of parasitoids, their number was significantly higher and they were produced earlier.…”

“…Alate morphs can disperse over great distances to colonize new plants. However, this generates an energy cost that generally is revealed by a fall in the fecundity or increase in the period of development (Pereira and Lomônaco, 2003). In such a way, the probability of reproduction of alate females is considered smaller than for apterous females.…”