Laboratory of Entomology, Science and Animal Science Graduate Programs, University of Franca (UNIFRAN), Avenida Dr Armando Sales de Oliveira, 201, Parque Universitário, Franca, São Paulo, 14404-600, Brazil.
Department of Entomology, Luiz de Queiroz College of Agriculture/University of Sao Paulo (ESALQ/USP), Avenida Pádua Dias 11, Piracicaba, São Paulo, 13418-900, Brazil.
J Insect Sci. 2021 Sep 1;21(5). doi: 10.1093/jisesa/ieab055.
Native to the neotropics, the avocado seed moth Stenoma catenifer Walsingham (Lepidoptera: Elachistidae) is a specialist pest of the family Lauraceae and considered one of the most important pests of avocados worldwide. However, little is known regarding its spatial distribution within a single tree. Therefore, we designed a study to evaluate the effects of canopy height and aspect (i.e., side of the tree) on fruit infestation by S. catenifer larvae in avocados. The study was conducted in three commercial organic avocado orchards located in São Paulo, Brazil. At each orchard, 40 fruit from 30 random trees were sampled weekly from October 2017 through February 2018, evaluating the number of fruits infested by S. catenifer larvae at three tree heights (bottom, middle, and top). In addition, fruits on the ground were also sampled. We also evaluated the effect of the side of the tree where the fruits were collected, i.e., whether they were on the side facing the east (sunrise) or the west (sunset). Within the avocado canopy, the level of fruit infestation by S. catenifer larvae was significantly higher at the top of the trees than in the middle and bottom. Fruit on the ground had lower levels of infestation than those on the tree canopy. The level of fruit infestation was also higher on the side of avocado trees facing the east (sunrise). Understanding the within-tree distribution of S. catenifer will help to better target monitoring and control activities against this pest in avocados.
原产于新热带地区的鳄梨种子蛾 Stenoma catenifer Walsingham（鳞翅目：Elachistidae）是樟科植物的专业害虫，被认为是世界范围内最重要的鳄梨害虫之一。然而，关于其在单棵树内的空间分布知之甚少。因此，我们设计了一项研究来评估树冠高度和朝向（即树的一侧）对鳄梨中 S. catenifer 幼虫果实感染的影响。该研究在巴西圣保罗的三个商业有机鳄梨园进行。在每个果园中，从 2017 年 10 月到 2018 年 2 月，每周从 30 棵随机树中抽取 40 个果实，评估 3 个树高处（底部、中部和顶部）受 S. catenifer 幼虫感染的果实数量。此外，还对地面上的果实进行了采样。我们还评估了收集果实的树一侧的影响，即它们是在面向东方（日出）还是西方（日落）的一侧。在鳄梨树冠内，S. catenifer 幼虫对果实的感染程度在树顶明显高于中部和底部。地面上的果实感染程度低于树冠上的果实。在面向东方（日出）的鳄梨树一侧，果实的感染程度也更高。了解 S. catenifer 的树内分布将有助于更好地针对鳄梨中的这种害虫进行监测和控制活动。
