Hemiparasitism effect on Baccharis dracunculifolia DC. and consequences to its major galling herbivore

Acta Botanica Brasilica

Thaise De Oliveira Bahia¹  Irene Gélvez Zúñiga¹  Matheus Lopes Souza¹  Etiene Silva Coutinho¹  Mauricio Quesada¹  G. Wilson Fernandes¹ 

关键词: Baccharopelma dracunculifoliae;    insect galls;    mistletoe;    rupestrian grasslands;    Struthanthus flexicaulis;   

DOI  :  10.1590/0102-33062014abb0008

来源: SciELO

【 摘 要 】

ABSTRACTMistletoes obtain nutrients and water from their hosts, with varying effects among those hosts. We assessed the factors that influence the colonization of the mistletoe Struthanthus flexicaulis on Baccharis dracunculifolia and the subsequent effects on host performance. We evaluated the incidence of S. flexicaulis according to size (height classes) and architecture of the host as well as its effects on various physiological parameters of the host. Furthermore, we assessed the occurrence of insect galls induced by Baccharopelma dracunculifoliae(Psyllidae), including the number of leaves infected, and the mortality of infected and non-infected branches. Taller hosts had a higher abundance of mistletoes (60%, p> 0.05). Physiological parameters of hosts were not affected by parasitism, although galling occurred more often (p <0.05) and leaf loss increased (p>0.05) on infected branches. Taller individuals are more colonized by mistletoes and more architecturally complex hosts support a greater number of mistletoes. Mistletoe causes a top-down effect on host-associated organisms on parasitized branches. Mistletoes had a strong top-downeffect on B. dracunculifolia due to a reduction in the number of leaves on parasitized branches and the replacement of the bush crown, as well as an increased incidence of insect galls. Furthermore, the occurrence of a heavy parasite load increased the mortality rate of the host branches.

【 授权许可】

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