FIRST EVIDENCE OF SEED PREDATION BY ARTHROPODS FROM GONDWANA AND ITS EARLY PALEOZOIC HISTORY (RIO BONITO FORMATION, PARANÁ BASIN, BRAZIL)

ABSTRACT Seeds are plant organs commonly found worldwide in late Paleozoic deposits. In Gondwana, the seeds are found in deposits from Southern Africa, Antarctica, Oceania, and South America, and are widely reported in the well-known “Glossopteris Flora”. Even with a significant record of these plant organs, little is known about plant-insect interactions with seeds during the Pennsylvanian and Permian periods. In the present paper, we recorded the first formal record of seed consumption by arthropods in Cordaicarpus and Samaropsis-like seeds for Gondwana from lower Permian (Artinskian) deposits in Southern Brazil. The material analyzed was collected from the Itanema II outcrop of Santa Catarina State and consisted of 34 seed specimens. Of these, eight specimens presented evidence for plant-insect interaction, representing 23.5% of all specimens that were attacked by seed predators. The consumption was inflicted by insects with stylate mouthparts, probably belonging to hemipteroid or paleodictyopteroid lineages. The damage is described as perforations and scale-insect marks along the seed body. We recorded one damage type as DT74 and three others as new damage types DT399, DT400, and DT401, some of which are specific to a few seed morphotypes, including one morphotype with subtending cupule still attached to the seed. The elevated frequency of seed predation indicates that seed consumption by insects was well established during the early Permian.

Plant Insect Interaction And Crop Protection: A Dynamic Analysis

Integrating supporting and regulating ecosystem functions provided by several components of biodiversity into cropping systems has been prepared as a promising way to decrease agrochemical inputs and negative environmental impacts while maximizing crop productivity and food security. The co-evolutionof plants and insects in very intriguing and plays vital role in the crop protection. Plants have developed efficient mechanisms to protect them against herbivore while insects have found diverse ways of avoiding negative effects of their host plant defense mechanism. Even though many workers have attempted to studyplant - insect interaction, still our knowledge is limited. A changing climate, growing pest have given uncertain impacts on crop protection so, the present study address the key question that Is it possible to find alternative to meet these challenges by studying the plant-insect interaction and formulating integrated pestmanagement? The study was conducted at Dharapuram, Dindugal district as this area is riched with the variety of crop cultivation. The study concludes that the biological control of insect pests with natural products by the development of new plant varieties with enhanced chemical defenses should be followed forthe better crop protection.

Natural Products Diversity in Plant-Insect Interaction between Tithonia diversifolia (Asteraceae) and Chlosyne lacinia (Nymphalidae)

The chemical ecology of plant-insect interactions has been driving our understanding of ecosystem evolution into a more comprehensive context. Chlosyne lacinia (Lepidoptera: Nymphalidae) is an olygophagous insect herbivore, which mainly uses host plants of Heliantheae tribe (Asteraceae). Herein, plant-insect interaction between Tithonia diversifolia (Heliantheae) and Chlosyne lacinia was investigated by means of untargeted LC-MS/MS based metabolomics and molecular networking, which aims to explore its inherent chemical diversity. C. lacinia larvae that were fed with T. diversifolia leaves developed until fifth instar and completed metamorphosis to the adult phase. Sesquiterpene lactones (STL), flavonoids, and lipid derivatives were putatively annotated in T. diversifolia (leaves and non-consumed abaxial surface) and C. lacinia (feces, larvae, pupae, butterflies, and eggs) samples. We found that several furanoheliangolide-type STL that were detected in T. diversifolia were ingested and excreted in their intact form by C. lacinia larvae. Hence, C. lacinia caterpillars may have, over the years, developed tolerance mechanisms for STL throughout effective barriers in their digestive canal. Flavonoid aglycones were mainly found in T. diversifolia samples, while their glycosides were mostly detected in C. lacinia feces, which indicated that the main mechanism for excreting the consumed flavonoids was through their glycosylation. Moreover, lysophospholipids were predominately found in C. lacinia samples, which suggested that they were essential metabolites during pupal and adult stages. These findings provide insights into the natural products diversity of this plant-insect interaction and contribute to uncovering its ecological roles.