Ocorrência de insetos fitófagos em Adenium obesum (Forssk.) Roem. & Schult no estado de Goiás

Abstract

Resumo: A rosa do deserto, Adenium obesum (Forssk.) Roem. & Schult, é uma planta ornamental da família Apocynaceae, de elevado valor comercial, que é empregada na ornamentação de jardins, praças e áreas públicas. A rápida expansão dessa espécie propiciou um ambiente favorável para sua colonização por diversas espécies de insetos e ácaros em novas regiões de introdução. Dessa forma, objetivou-se com este estudo relatar a ocorrência e injúrias ocasionadas por insetos fitófagos em A. obesum. Assim, foram realizadas observações entre o período de agosto e outubro de 2012, em plantas de rosa do deserto, empregadas no paisagismo da Universidade Federal de Goiás. A coleta foi realizada aleatoriamente, sendo os insetos armazenados em recipientes de vidro contendo etanol 70%, seguindo para identificação por taxonomistas da área. Foram identificadas duas espécies de cochonilhas: Hemiberlesia rapax Comstock (Hemiptera: Diaspididae), Parasaissetia nigra (Nietner) (Hemiptera: Coccoidea: Pseudococcidae) e o pulgão Aphis nerii Boyer (Hemiptera: Aphididae), ocasionando injúrias nas folhas, flores e no caule da rosa do deserto. Durante as observações, verificou-se a presença de inimigos naturais de A. nerii, como parasitoides, em razão da presença de múmias (indivíduos parasitados), e também de predadores como crisopídeos, coccinelídeos e sirfídeos. Este é o primeiro relato de ocorrência de H. rapax em A. obesum. Palavras-chave -Injúria. Insetos sugadores. Planta ornamental. Abstract:The desert rose, Adenium obesum (Forssk.) Roem. & Schult, is an ornamental plant of the Apocynaceae family with high commercial value, that is used in the ornamentation of gardens, squares and public areas. The rapid expansion of the species has provided a favourable environment for its colonisation by several species of insects and mites in the new regions where it was introduced. The aim of this study was to report the occurrence of, and injuries caused by, phytophagous insects in A. obesum. Observations were made from August to October 2012 in plants of the desert rose used in landscaping at the Federal University of Goias. The samples were collected randomly, and the insects stored in glass containers containing 70% ethanol and forwarded for identification by taxonomists in the area. Two species of cochineals were identified: Hemiberlesia rapax Comstock (Hemiptera: Diaspididae) and Parasaissetia nigra (Nietner) (Hemiptera: Coccoidea: Pseudococcidae), and the oleander aphid Aphis nerii Boyer (Hemiptera: Aphididae), which were damaging the leaves, flowers and stem of the desert rose. During the observations, natural enemies of A. nerii, such as parasitoids, were found due to the presence of mummies (parasitised individuals), as well as predators, such as chrysopidae, coccinellidae and Syrphidae. This is the first report of H. rapax occurring in A. obesum.

Use of substrates and hydrogel to produce desert rose seedlings

“…Associated to that, the local meteorological conditions, already recorded at the experiment location (Monteiro Neto et al, 2018), favor more evapotranspiration chiefly due to high temperatures (Shimada et al, 2017), which must have increased water restriction to plants, which, according to Taiz and Zeiger (2013), affect all their development phases, limiting the growth of important physical characters like size, number of leaves, stem and branches, and may, therefore, make the plant more susceptible to attack by several phytophagous insects (Tiago Neto et al, 2017). With regard to the isolated effect of substrates, the compound containing OrganoAmazon ® and PuroHumus ® (S1) was the one that promoted most the development of desert rose seedlings, and was superior in all variables analyzed, including quality indices (Table 6).…”

Adenium obesum as a new potted flower: growth management

“…For this specie, some insects as cochineals, aphids, caterpillar and thrips are the main pests. Neto et al (2017) reported and described some of these organisms found in 2012 when investigating A. obesum used in landscaping in Goias-Brazil. These authors identified two species of cochineals, Hemiberlesia rapax Comstock (Hemiptera: Diaspididae) and Parasaissetia nigra Nietner (Hemiptera: Coccoidea); and one oleander aphid Aphis nerii Boyer (Hemiptera: Aphididae), damaging the leaves, flowers and stem of A. obesum.…”