Morais Helena C, Cabral Bérites C, Mangabeira Jacimary A, Diniz Ivone R
Depto Ecologia, Instituto de Ciências Biológicas, Univ de Brasília, Brasília, DF, Brazil.
Neotrop Entomol. 2007 Nov-Dec;36(6):843-7. doi: 10.1590/s1519-566x2007000600004.
The caterpillars of Stenoma cathosiota Meyrick feed on Roupala montana Aubl. (Proteaceae) in the cerrado of the Distrito Federal, Brazil. They construct shelters by joining leaves of the plant where they feed and pupate. The caterpillars are parasitized by a wasp (Hymenoptera: Brachonidae), which emerges from the pupae. Caterpillar abundance and parasitism frequency were associated in an area of frequently burned cerrado (biennial fire) and in another area that burns sporadically (1987 and 1994). For S. cathosiota, the variation among years in a single area, with sporadic fires, was greater than the variation among areas with different fire regimes. Caterpillar abundance among years was significantly different in the area that burns sporadically (chi2 = 24.06; df. = 1; P = 0.000). However, there were no significant differences on caterpillar abundance between areas for the same period (chi2 = 3.45; df. = 1; P = 0.063). Parasitism frequency was high, reaching 29% of the collected caterpillars, and did not differ among areas. The great temporal variation in abundance of lepidopteran caterpillars in the cerrado makes it difficult to determine the effects that fire exerts over this fauna.
巴西联邦区塞拉多地区的卡氏窄翅蛾(Stenoma cathosiota Meyrick)幼虫以山地鲁帕拉木(Roupala montana Aubl.,山龙眼科)为食。它们通过将取食和化蛹所在植株的叶片连接起来建造庇护所。这些幼虫会被一种黄蜂(膜翅目:茧蜂科)寄生,黄蜂从蛹中羽化而出。在一个经常被火烧的塞拉多地区(两年一次火烧)和另一个偶尔火烧的地区(1987年和1994年),幼虫数量和寄生频率存在关联。对于卡氏窄翅蛾来说,在一个偶尔发生火灾的单一区域内,年份间的变化大于不同火灾模式区域间的变化。在偶尔发生火灾的地区,各年份间的幼虫数量存在显著差异(卡方 = 24.06;自由度 = 1;P = 0.000)。然而,同一时期不同区域间的幼虫数量没有显著差异(卡方 = 3.45;自由度 = 1;P = 0.063)。寄生频率很高,达到所收集幼虫的29%,且不同区域间没有差异。塞拉多地区鳞翅目幼虫数量的巨大时间变化使得难以确定火灾对该动物群产生的影响。