Phenological relationships between two insect galls and their host plants: Aspidosperma australe and A. spruceanum (Apocynaceae)

Abstract

RESUMO -(Relações fenológicas entre duas galhas induzidas por insetos e suas plantas hospedeiras: Aspidosperma australe e A. spruceanum (Apocynaceae)). Embora a diversidade de galhas na região neotropical seja grande, poucos são os estudos fenológicos comparando a fenologia das espécies hospedeiras com aquela das galhas. O desenvolvimento de galhas geralmente requer alta sincronia fenológica entre os organismos associados. A relação entre a fenologia de duas galhas foliares induzidas por um Cecidomyiidae e Aspidosperma spruceanum Benth. ex Müell. Arg. e de uma espécie de Pseudophacopteron sp. e A. australe Müell. Arg. foram investigadas. O trabalho foi realizado em dez indivíduos de cada espécie em intervalos quinzenais, levando em consideração a percentagem de folhas galhadas. Durante um ano, foram observadas três fenofases distintas para as galhas foliares e quatro fenofases para a hospedeira. A maior percentagem de folhas galhadas em A. australe (80%) ocorreu após o pico de brotação, com uma boa correlação entre a brotação e a indução de novas galhas. Em A. spruceanum, a percentagem de folhas galhadas foi sempre acima de 50%, o que pode ser relacionado à contínua produção de folhas e indução das galhas nesta espécie. Em ambas as espécies, as galhas em desenvolvimento foram observadas durante todo o ano, indicando multivoltinismo. A capacidade de induzir galhas em tecidos jovens e maduros parece ser uma boa estratégia para a sobrevivência destes galhadores. Palavras chaves: abundância de galhas, fenologia, interação inseto-planta, sincronismo ABSTRACT -(Phenological relationships between two insect galls and their host plants: Aspidosperma australe and A. spruceanum (Apocynaceae)). Although gall diversity in the Neotropical region is immense, comparative studies on the phenology of host plants and their galls are scarce. Gall systems generally require high levels of phenological synchrony between the associated organisms. The relationships between the phenology of two leaf galls induced by an unidentifi ed Cecidomyiidae in Aspidosperma spruceanum Benth. ex Müell. Arg. and by Pseudophacopteron sp. in A. australe Müell. Arg. were investigated. The investigation was performed on ten individuals per species in 15-day intervals taking into consideration the percentage of galled leaves. In a one-year study, three distinct phenophases for the leaf galls and four phenophases for host plants were observed. The maximum percentage of leaf galls (80%) on A. australe occurred just after the peak of leaf sprouting. In A. spruceanum, the percentage of leaf galls was always over 50%, which can be related to continuous leaf production and gall induction in this species. In both species, developing galls were observed over the entire year, indicating multivoltinism. The ability to induce galls at young and mature sites seems to be a good strategy for galling species survivorship.

Responses of the Host Plant Tissues to Gall Induction in <i>Aspidosperma spruceanum</i> Müell. Arg. (Apocynaceae)

“…This morphogenical redirection is directly dependent on the presence of the galling insect, and the changes cease after the senescence of the gall. All the four basic developmental stages of the Cecidomyiidae galls sensu Rohfritsch [27] occur simultaneously in A. sprucenum ( Table 2), indicating the multivoltinism of the insect, as proposed by Campos et al [13]. The induction phase seems to start with oviposition, which occurs inside the leaf tissues, indicating that the female of this species has a strong and long ovipositor, called terebra [28], able to pierce the thick cuticle, the epidermis and the parenchyma.…”

“…(Apocynaceae)-Cecidomyiidae system has been addressed in several focuses [5,12,13]. These galls can be induced in young or mature leaves, and develop in the second or third order veins, or in the internervural region where they are commonly more numerous [12].…”

The imbalance of redox homeostasis in arthropod-induced plant galls: Mechanisms of stress generation and dissipation

“…In such cases, besides producing carbohydrates [46], photosynthesis may play a secondary function by supplying new O 2 molecules to the system. The additional O 2 supply is especially important for galls with anomalous, functionally deficient stomata or in those where stomata are totally absent [15,52,70,74]. Some of these galls may have a suberized dermal system, and reduced intercellular spaces due to intense cell hypertrophy and tissue hyperplasia.…”

Building Two Houses on a Single Host Plant: Galling Insect Synchronizes Its Life Cycle With Plant Phenology

“…The gall induction concomitant with the time of leaf sprouting have also been reported in the Aspidosperma austral (Gentianales, Apocynaceae) -Pseudophacopteron sp. (Hemiptera, Phacopteronidae) system (Campos et al 2010) and in the C. langsdorffii-multiple Cecidomyiidae system . For species that strictly oviposit on young leaves, food resources are available for a limited period of the host plant life cycle (Oliveira et al 2016).…”