Riqueza e abundância de herbívoros em flores de Vellozia nivea (Velloziaceae)

Abstract

RESUMO -(Riqueza e abundância de herbívoros em flores de Vellozia Ilivea (Velloziaceae). Vellozia Ilivea (Velloziaceae) é planta de porte herbáceo que ocorre em solos rochosos, nos campos rupestres da Serra do Cipó, MG . Suas flores hermafroditas são extremamente macias, representando fonte tenra de alimento para os insetos que predam suas tépalas e estruturas reprodutivas. Este trabalho teve como objetivo observar a influência da altura e do número de flores da planta hospedeira na abundância e riqueza de insetos herbívoros. Foram encontradas o total de 21 morfoespécies de insetos (nove fanulias e três ordens) associadas às flores de V. Ilivea. A altura e o número de flores da planta não apresentaram correlações significativas com a riqueza de herbívoros por planta (r 2 = 0,17; P > 0,05). Entretanto, estes dois fatores juntos explicaram 39% da variação observada na abundância dos insetos herbívoros por planta (P < 0,05). Portanto, o número de flores e a altura das plantas hospedeiras influenciaram apenas a abundância dos herbívoros.Palavras-chave -herbivoria, interação inseto-planta, Serra do Cipó, Vellozia Ilivea ABSTRACT -(Richness and abundance ofherbivores on Vellozia Ilivea (Velloziaceae) flowers). Vellozia Ilivea (Velloziaceae) is a herbaceous plant that occurs on rocky soils in the rupestrian fields of the "Serra do Cipó", Minas Gerais State, Brazil. Its hermaphrodite flowers are extremely soft, representing a source of tender food for the insects that prey on its tepals and reproductive structures. The aim of this study was to observe the effect of the height and number of flowers of the host plant on the abundance and richness of herbivorous insects. We found 21 morphospecies of insects (nine farnilies and three orders) associated to flowers of V. lZivea. No significant correlation between the number of flowers and plant height and the variety of herbivorous insects per plant was observed (r 2 = 0.17, P> 0.05). However, these two factors together explained 39% of the variation of insect abundance (P < 0.05). Thus, only the abundance of herbivorous insects was influenced by the number of flowers and the height of host plant.

Massive post-fire flowering events in a tropical mountain region of Brazil: high episodic supply of floral resources

“…During the field sampling, many insects were observed seeking pollen and nectar in the flowers, as is the case for other species of Vellozia (Ayensu 1973;Landau et al 1998). In addition to bees, which apparently represented legitimate pollinators, other insect species obtained nectar by chewing holes in the corolla tube and hypanthium, and many flowers showed evidence of herbivore damage (Fig.…”

Pollination of two species of Vellozia (Velloziaceae) from high-altitude quartzitic grasslands, Brazil

“…In contrast with the great taxonomic interest in the family (Mello-Silva 2005), there are very few works focusing on the ecology or pollination biology of Velloziaceae from the Espinhaço Range (Sazima & Sazima 1990;Landau et al 1998). Our objectives were to study the breeding system and pollinator behaviour of two sympatric species of Vellozia, V. leptopetala Goeth.…”

Physiological ecology of photosynthesis of five sympatric species of Velloziaceae in the rupestrian fields of Serra do Cipó, Minas Gerais, Brazil

“…In spite of the enormous ecological relevance of the Velloziaceae in the high-altitude lands (e.g., Owoseye and Sanford, 1972;Sazima and Sazima, 1990;Oliveira et al, 1991;Alves, 1994;Ibisch et al, 1995;Landau et al, 1999;Werneck and Espirito-Santo, 2002), studies on natural history and ecology of the species are still poorly developed. Many Velloziaceae are desiccation tolerant resurrection plants, e.g.…”

“…Casual observations indicate that species are not evenly distributed in the altitudinal gradient of 800-1700 m of the Serra do Cipo´, and that soil quality and humidity, topography, wind, and pollinator distribution are strong ecological factors that influence species distribution and patterns of co-occurrence (Landau et al, 1999). A total of 57 species have been found in the rupestrian fields of the Serra do Cipo´ (Menezes and Mello-Silva, 1987).…”

“…Smith (Smith and Ayensu, 1976), and the recently described species of V. gigantea with a highly restricted distribution (MelloSilva and Menezes, 1999). Flowering is limited to short phenological periods (e.g., Landau et al, 1999), which, however, are mostly asynchronous throughout the year. Therefore, one Vellozia species will always be flowering in these rupestrian fields, irrespective of season or time in the year.…”