Abstract
Galling sap-feeding insects are presumed to cause only minor changes in host plant tissues, because they usually do not require development of nutritive tissues for their own use. This premise was examined through comparison of the histometry, cytometry and anatomical development of non-galled leaves and galls of Calophya duvauae (Scott) (Hemiptera: Calophyidae) on Schinus polygamus (Cav.) Cabrera (Anacardiaceae). Cell fates changed from non-galled leaves to galls during the course of tissue differentiation. C. duvauae caused changes in dermal, ground, and vascular systems of the leaves of S. polygamus. Its feeding activity induced the homogenization of the parenchyma, and the neoformation of vascular bundles and trichomes. The histometric and cytometric data revealed compensatory effects of hyperplasia and cell hypertrophy in the epidermis, with hyperplasia predominating in the adaxial epidermis. There was a balance between these processes in the other tissues. Thus, we found major differences between the developmental pathways of non-galled leaves and galls. These changes were associated with phenotypic alterations related to shelter and appropriate microenvironmental conditions for the gall inducer. The nondifferentiation of a typical nutritive tissue in this case was compared to other non-phylogenetically related arthropod gall systems, and is suggested to result from convergence associated with the piercing feeding apparatus of the corresponding gall-inducer.
Highlights
Related lineages of gall-inducing insects tend to influence their host plant tissues (Rohfritsch 1992), because of the similarities in their feeding habits
We examined this question further by comparing through histometry, cytometry and anatomy the development of non-galled leaves of Schinus polygamus (Cav.) Cabrera (Anacardiaceae) with the leaf galls induced by a parenchyma sapfeeder, Calophya duvauae (Scott) (Hemiptera: Calophyidae)
Our data clearly showed that there are pronounced anatomical changes caused by the presence and feeding habit of the gall inducer
Summary
Related lineages of gall-inducing insects tend to influence their host plant tissues (Rohfritsch 1992), because of the similarities in their feeding habits. Assuming that the peculiarities of the galls are related to the gall-inducer’s feeding behavior, it is expected that the processes of differentiation and redifferentiation (sensu Lev-Yadun 2003) that occur from hosts to galls induced by sap-feeding insects are similar to those induced by other sucking arthropods. We examined this question further by comparing through histometry, cytometry and anatomy the development of non-galled leaves of Schinus polygamus (Cav.) Cabrera (Anacardiaceae) with the leaf galls induced by a parenchyma sapfeeder, Calophya duvauae (Scott) (Hemiptera: Calophyidae). Additional goals of the current study were: (1) to describe the developmental pattern of the host leaf tissues that are not influenced by the attack of C. duvauae; (2) to describe the anatomical development of the gall during the life cycle of C. duvauae; and (3) to quantify the reactions of cell hypertrophy or hyperplasia from non-galled tissues to mature galls, and their relationship to the alterations in S. polygamus cell fates
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have