2024 FIELD REPORT: HELICONIA HERBIVORY SURVEY (pdf)
5E Lesson Plan: Coming Soon
Date: July 14-20, 2024
Location: Explorama’s Napo-Sucusari Biological Reserve, Loreto Peru
Study Site: The Amazon Conservatory for Tropical Studies (ACTS); Quebrada Grande Trail
Lead Researcher: Dr. Rob Naczi*
Team Members: *Piero Mazzei, Jeannine H. Richards, Andrea Camilo, Alli Yen, Michael McAloon, Josías Tello, Cinda Murray, Matthew Naczi, Kirsten A. Franklin, Roldán Hidalgo, Nancy Trautmann, Garly Aliaga, César Sevillano, Jordan Wolf, Percy Reyna. (*= authors of this report)
Abstract
Heliconia is a genus of perennial plants found in Neotropical ecosystems that remains under-studied in the Amazon rainforests in Loreto, Peru. This study focuses on Heliconia juruana populations in the Napo-Sucusari Biological Reserve near the ACTS Field Station, examining flowering patterns and herbivory by leaf beetles of the Chrysomelidae family. We mapped Heliconia occurrences, recorded flowering stages, and determined correlations between patch size and beetle abundance and diversity. Our findings suggest asynchronous flowering within H. juruana colonies and a positive correlation between patch size and beetle abundance, though not statistically significant due to small sample sizes. Continued research with expanded sampling will enhance understanding of leaf beetle interactions with Heliconia in Amazonian ecosystems.
Lay/Marketing Summary
We examined the relationship between Heliconia plants and leaf beetles in the Napo-Sucusari Biological Reserve, in the Peruvian Amazon. We found that larger Heliconia patches tend to support more beetles, and that Heliconia flowering patterns vary across colonies. These insights add to our understanding of tropical plant-animal interactions and demonstrate the ecological role of Heliconia as a host species of diverse insects in this ecosystem.
Introduction
Heliconia L. is a genus of perennial, rhizomatous herb that is poorly documented in the Loreto region of Peru. Herbivory of these plants by various genera of leaf beetles from the Chrysomelidae family likewise remains understudied. These leaf beetles typically develop within the young, furled leaves (buds) of Heliconia sp. Since 2022, this ongoing research project has focused on evaluating populations of several Heliconia species across various locations in the Amazon rainforest of Loreto, Peru.
The objectives of this project include mapping and documenting the occurrences of Heliconia in the Napo-Sucusari Biological Reserve, specifically near the Amazon Conservatory for Tropical Studies (ACTS) Field Station, examining flowering patterns, and assessing Heliconia herbivory by leaf beetles in this region.
Specifically, we test the following hypotheses:
H0: There is no correlation between the frequency of adult herbivorous beetles and the area of Heliconia juruana colonies.
HA: There is a correlation between the frequency of adult herbivorous beetles and the area of Heliconia juruana colonies.
H0: There is no correlation between the diversity of adult herbivorous beetles and the area of Heliconia juruana colonies.
HA: There is a correlation between the diversity of adult herbivorous beetles and the area of Heliconia juruana colonies.
H0: Heliconia juruana colonies do not flower.
HA1: Heliconia juruana colonies flower synchronously.
HA2: Heliconia juruana colonies flower asynchronously.
This research on Heliconia will contribute to a fundamental understanding of the biology of these keystone species, which play a crucial role in many Neotropical rainforests. Additionally, our study aims to establish baseline data on plant-herbivore interactions between Heliconia and leaf beetles, forming a foundation for future ecological studies.
Materials and Methods
We conducted our study on patches of Heliconia near the ACTS Field Station along the River Trail. We first identified several larger patches where multiple individual plants could be studied and documented. At each Heliconia patch, our fieldwork focused on three primary activities: (1) assessing the habitat conditions of Heliconia, (2) documenting leaf phenology and flowering, and (3) collecting leaf beetle specimens found within the leaf furls.
To document leaf phenology and flowering, we recorded the location of each patch using a hand-held GPS unit (Garmin GPSmap 78s). We then measured the length and width of each Heliconia patch to estimate its area. For the largest leaf in each occurrence, we recorded the length, width, petiole length, leaf color, presence or absence of leaf beetle herbivory, and the morphology of the inflorescence.
For beetle collection within the leaf furls, we selected furls that were approximately half unfurled. These were cut from the plant, and we carefully unfurled each leaf to ensure all specimens were collected. Leaf beetle adults were placed in a labeled plastic bag, with location and time noted for future processing.
Results
We located three colonies (L2, L3, and L4) of Heliconia juruana along the River Trail in the Napo-Sucusari Biological Reserve, in addition to a single individual plant at location L1 (Table 1, Map 1). The colonies varied in size and floral stage, with L2 being vegetative, L3 in pre-anthesis, and L4 exhibiting a senescent inflorescence. The individual plant at L1 had an inflorescence with most flowers in bud. The presence of multiple flowering stages suggests asynchronous flowering among Heliconia juruana individuals.
In addition to Heliconia juruana, we located two other Heliconia species along the River Trail: Heliconia stricta and Heliconia velutina. Due to time constraints, these species were not included in detailed studies but were briefly noted.
A total of 99 beetle specimens were collected from H. juruana colonies L2, L3, and L4, comprising four different beetle species (Table 2).
Patch Area vs. Beetle Specimen Abundance: The analysis of patch area and the number of beetle specimens collected per colony (Figure 1) yielded a Pearson correlation coefficient of 0.964 and a p-value of 0.086. Although this suggests a strong positive correlation, indicating that larger H. juruana colonies tend to host more beetles, the p-value indicates the correlation is not statistically significant (p > 0.05), likely due to the small sample size (n=3).
Patch Area vs. Beetle Species Richness: The correlation between patch area and beetle species richness (Figure 2) produced a Pearson coefficient of -0.4 and a p-value of 0.4. These values indicate a moderate negative correlation; however, the result is also not statistically significant, likely due to low sample size and variability in beetle species richness among patches.
Discussion
The observed variation in flowering stages (vegetative, pre-anthesis, and senescent) within the H. juruana colonies suggests asynchronous flowering. Asynchronous flowering may have ecological implications, potentially influencing patterns of herbivory and interactions with pollinators. Further studies should examine whether these patterns persist across larger populations and whether environmental factors influence flowering synchronicity.
The positive correlation observed between patch area and beetle abundance suggests that larger H. juruana patches may support more individual herbivores, although this relationship was not statistically significant. Increased sampling could provide the statistical power needed to confirm this trend and clarify how patch size may influence herbivore community structure.
Conversely, the lack of a significant correlation between patch area and beetle species richness suggests that factors other than patch size may be influencing beetle diversity. This might include microhabitat conditions, specific plant traits, or interactions among beetle species. Expanding the study to more locations and incorporating additional ecological variables could provide more insights.
This project provides a good foundation for continued research on Heliconia and its insect herbivores in the Loreto region. Future work will benefit from sampling additional patches of H. juruana to further explore patterns of herbivory and beetle diversity. Expanding the study to other Heliconia species along the river trail could provide comparative insights into plant-herbivore relationships and flowering dynamics across taxa. In addition, examining flowering synchronicity in these additional Heliconia species could show potential variations in reproductive timing and pollinator interactions. Finally, a more complete survey around the ACTS Field Station to map Heliconia distribution and habitat conditions would allow for a broader ecological understanding of this genus and facilitate future long-term studies on its ecological roles and interactions.
References:
Jalinsky, J. R., Wertenberger, R. A., Radocy, T. A., & Chaboo, C. S. (2014). Insects inhabiting two host plants, Heliconia stricta Huber (Heliconiaceae) and Calathea lutea Schult (Marantaceae), in southeastern Peru. Journal of the Kansas Entomological Society, 87(4), 299-311.
Previous Field Reports
For additional information or questions about this field report, please contact Dr. Lindsey Swierk (lindseyns@gmail.com), Director of Scientific Research for The Morpho Institute and Associate Director of Research for the Amazon Conservatory for Tropical Studies.
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