Course Information
Course Code: Entom 2010/2011
Title: Alien Empire: The Bizarre Biology of Bugs (Spring, 2026)
Entom 2010: Lecture M/W 12:20 - 1:10 (2 credits)
Entom 2011: Lecture W/W 12:20 - 1:10 + Friday discussion 11:15-12:05 or 12:20 - 1:10 (3 credits)
Textbook: Grimaldi (2023). The Complete Insect. Princeton University Press
Prerequisites: None
Instructors:
Melissa Guzman (Email: lmg343@cornell.edu)
Beatriz Willink (Email: bw566@cornell.edu)
Course Description: Learn how your life is inextricably linked to that of insects, their diversity, and fascinating biology. Open to all majors.
Lecture Overview
Focus on Honeybee Populations
Major Theme: The declining populations of honeybees and their significance within American agribusiness and the food chain.
Key Figure: John Miller, America’s foremost migratory beekeeper.
Author: Hannah Nordhaus examines critical issues surrounding honeybee health and offers insights into the vital role of honeybees.
Learning Objectives (By the End of This Lecture Series: Nov 3, Nov 5)
Describe the Evidence for Decline in honeybee and wild bee populations.
List the 5 Main Bee Stressors:
Invasive species, pests, and pathogens
Climate change
Habitat change (loss and fragmentation)
Management practices
Agrochemicals, especially pesticides (including insecticides, fungicides, herbicides)
Articulate How Each Stressor Affects Populations:
Interactions between the stressors that affect bee populations.
Recognize Pesticide Exposure: Bees exposed to dozens of pesticides.
Compare Lethal vs Sublethal Effects: Understand the implications of pesticide exposure.
Explain Neonicotinoids: How these differ from other insecticides.
Synergistic Effects of Pesticides: Importance for bee health.
Evidence for Decline in Bee Populations
Global Statistics on Honey Bee Colonies
Managed Honey Bee Colonies: Statistics from FAO (2020) suggest fluctuations from 1961 to 2018, indicating trends by geographical region.
Colony Health Data
Overwinter Mortality Rates: Show high yea rly mortality rates of 30-56% for U.S. honey bee colonies since 2011.
Colony Collapse Disorder (CCD): First identified in the U.S. impacting bee health.
Key Statistics
The managed honey bee colonies in the U.S. are either steady or increasing, amidst significant mortality rates.
30-56% of colonies die each year since 2011 (Giacabino et al., 2025).
Managed Honey Bee Statistics (New York State):
412 managed hives
24% in decline
15% not recorded since 2000.
Main Bee Stressors
Invasive Species, Pests & Pathogens:
Novel pests and pathogens negatively affect bee health.
Climate Change:
Affects range distribution of bee populations and synchronization with flowering plants.
Habitat Change:
Loss and fragmentation of habitats lead to low diversity of bee resources and nesting sites.
Management Practices:
Stressful transport and poor management by beekeepers leading to decreased bee health.
Agrochemicals:
Use of insecticides, fungicides, and herbicides affecting both managed and wild bee populations.
Interactions Between Stressors
Stressors are interconnected. For example:
Low diversity in foraging may increase pesticide exposure.
Poor diets can compromise immunity.
Specific fungicides increase toxicity levels among pesticides, affecting bee health.
Pest and pathogen exposure impacts bees' disease tolerance and susceptibility.
Habitat Change Details
Loss of Plant Diversity: Reduced availability of native habitats leading to monocultures negatively impacts bee species.
Forestation & Fragmentation Effects: Non-intuitive impacts are observed where forest areas provide critical resources for bees.
Management Practices' Impact
Honey Bee Practices: Poor management practices contribute to unhealthy colonies by:
Taking too much honey from bees and substituting with sugar water.
Failing to track pests or pathogens leading to population increases.
Keeping hives closely packed together.
Insufficient protection in winter months.
Pesticides and their Effects
Types of Pesticides
**Categories:
Insecticides
Fungicides
Herbicides
Acaricides/Miticides**
Example: Neonicotinoids used in varnishing crops lead to environmental leaching.
Exposure Mechanisms for Bees
Sprays and Seed Dressing:
Systemic insecticides can become incorporated in the nectar and pollen of flowers, exposing bees.
In-Hive Exposure:
Miticides control Varroa mites, while fungicides target other pathogens.
Sublethal Effects of Pesticides
Sublethal Effects:
These effects often unmeasured include:
Impaired motor function resulting from organophosphate exposure.
Reduced feeding due to insecticide presence (e.g., imidacloprid).
Adverse effects on learning and homing behaviors.
Key Terms Regarding Toxicology
LD50:
The dose at which 50% of individuals will die from exposure to a toxic agent.
NOAEL (No Observed Adverse Effect Level) and LOAEL (Lowest Observed Adverse Effect Level) are critical for determining pesticide impacts.
Neonicotinoid Specifics
Definition: A subclass of synthetic insecticides resembling nicotine. Includes:
Imidacloprid: Disrupts nicotine acetylcholine receptors.
Persistence and Environmental Leaching: Often contaminates groundwater leading to broad ecological impacts.
Toxicity Assessment: Neonicotinoids are significantly toxic to bees, with effects documented across various studies.
Recent EU Developments
2013 Ban: Initial restriction on selected neonicotinoids on flowering crops.
2018 Extension: Banning all outdoor uses of specified neonicotinoids due to environmental concerns.
Emergency Use Loopholes: Subsequent closing of loopholes allowing continued pesticide use under emergencies.
Course Administration and Logistics
Quizzes/Exams:
Post-lecture online quiz deadline updates.
Upcoming exam on Wednesday for 3-credit students with additional availability for question clarifications.
Engagement with Teaching Team: Opportunity for interaction after lectures for support.