Invasive Species 4

Exam Preparations:
  - Exam scheduled for Tuesday.
  - Key Focus Areas for the Exam:
    - Knowledge of three community parameters.
    - Understanding of species interactions.
    - Exam material includes content up to the April 9 lecture.
  - Potential Exam Content:
    - Readings from Mitchell, Enders, and community studies may appear on the exam.
  - Final Exam Information:
    - Topics discussed will be featured in the final exam but not in exam 3.
Special Guest Lecture:
  - Dr. Jonathon Cammack:
    - Expert in livestock entomology.
    - Discussion centered on the New World Screw Worm (NWSW).

Invasive Species Debate:
  - Inquiry: Can a native species be deemed invasive?
    - Yes, if it poses harm to human health, economic stability, or environmental integrity.
  - Naming Clarification:
    - Called “New” as it pertains to the New World.
Species Identification:
  - Classification:
    - NWSW is not a worm but a fly, specifically a blow or bottle fly.
    - Characteristically metallic green or blue in color.
    - Most species of this family feed on decomposing organic materials.

Definition:
  - Myiasis refers to the infestation of living tissue by fly larvae.
  - Evolutionary Aspect:
    - Ancestors of these species were believed to be obligate parasites.
Forms of Myiasis:
  - Accidental Myiasis/Pseudomyiasis:
    - Not technically myiasis; larvae may be ingested.
  - Facultative Myiasis:
    - Larvae exhibit versatility; can be free-living or parasitic and primarily feed on decomposing organic matter.
    - Typically relevant in cases of wool wounds that become soiled or necrotic.
    - These flies are medically utilized to treat wounds resistant to antibiotics (intentional larval infestation).
  - Obligate Myiasis:
    - Perpetually parasitic; require a host organism to survive.

Feeding Mechanism:
- Screwworms feed head-first and possess backward-facing spines that prevent being removed from the host.
Habitat Preference:
- Many screwworm species are semi-aquatic, possessing the ability to breathe through their rear.
Scientific Discovery:
- The behavioral differences between the NW screwworm and the secondary screwworm were not recognized until 1933.
- Differentiation is based on stripe length and specific hair coloration.

Hosts of Screwworms:
- Common hosts include livestock, wildlife, pets, and humans; mammals are the primary targets, with birds also being susceptible.
Infestation Requirements:
- Infestation necessitates a location for oviposition, such as natural body openings or open wounds.
- Common infestation sites include ear tag holes and umbilical openings in young animals.
Control Measures:
- Implementation of pesticide ear tags helps mitigate infestation.

Attraction Mechanism:
- Open wounds become infected with bacteria, attracting screwworms due to odors produced in quorum sensing.
Lifecycle Stages:
  - Females lay eggs on host wounds; eggs hatch in 10-20 hours.
  - The larvae mature through three instars and display head-down feeding behavior.
  - After feeding, they burrow into the soil to pupate over 5-7 days, transitioning to adults in up to 2 weeks.
Seasonal Behavior:
- Typically observed in warmer seasons in areas like Oklahoma; thrive at temperatures between 35-50°C with 70% humidity.
Reproductive Facts:
  - Mating occurs around 3-4 days after reaching adulthood; females are autogenous, meaning they do not require a protein meal to lay their first batch of eggs.
  - Daily activities include pollination and drinking water.
  - Despite limited travel range (5-7 miles) during their lifespan, their hosts can be transported over greater distances.

Sterile Insect Technique (SIT):
- Strategy to control populations by overwhelming the native system with sterilized males; females only mate once.
Recent Outbreaks and Eradication Efforts:
  - Last major outbreak in the U.S. occurred in Florida in 2016, affecting Key deer.
  - Fighting among deer created wounds suitable for screwworm colonization.
  - A total of 188 million sterile flies were released at a cost of $3.15 million to resolve the outbreak; eradication took six months.
Economic Impact:
- Notable economic burden from a massive outbreak in Texas in 1976, costing $132.1 million in management.
Wildlife Impact:
- Screwworms also inflict damage on wildlife, such as white-tailed deer, where they oviposit on umbilical wounds.
Geographical Concerns:
- A permanent quarantine zone exists in Panama; there are ongoing issues of screwworms moving northward despite livestock checks.
- Notably, a report on July 9, 2025, indicated an animal had traveled approximately 70 miles south of the U.S., impacting livestock transport regulations with Mexico.

SIT Fly Production Locations:
- Currently, sterile flies are only produced in Panama, with efforts underway to establish a production facility in South Texas.
IPM Pyramid:
  - Describes the layered approach of Integrated Pest Management, emphasizing prevention.
  - Key components include:
    - Monitoring (correct identification of species).
    - Implementation of control measures.
    - Continuous surveillance.
    - Ongoing monitoring of pest populations.
Challenges in Monitoring and Management:
  - Historical challenge: In the 1970s, a strain of sterile flies was produced that was unable to fly.
  - Logistical drawbacks with only one production facility for SIT flies located in Panama.
  - Emerging facilities in South Texas and Mexico require time to become operational.
  - Fluctuations in livestock producers' involvement; cattle calving times are increasingly misaligned due to seasonal shifts.
  - Complications with wildlife management, particularly with feral swine.
Resources:
- Online information available at livestockbugs.okstate.edu/nws