Episode 349 – Yam Hawkmoth: Yam Bam

“…and today we’re talking about a bug with a very funny name. But more on that now.”

In the dead of night, amidst the hum of crickets and the flutter of wings, there’s one creature that buzzes around like a stealthy, flying ninja with a twist. It glides from flower to flower like a hummingbird on caffeine, its wings an iridescent blur. But the Yam Hawkmoth isn’t just another garden-variety moth—no, this one has a unique defense mechanism tucked away in an…ahem…unconventional spot. So, if you think all moths are just dusty butterflies, think again. There’s more to this little guy than meets the eye here in Life, Death, and Taxonomy.

Description of the Yam Hawkmoth

The yam hawkmoth (Theretra nessus) has a distinctive appearance:

  • Coloration: The head and thorax are olive-green with a ferruginous (rusty) tinge. There is a gray lateral stripe running from the palpus (mouthpart) to the end of the thorax.
  • Abdomen: Features a green stripe down the center and golden yellow sides1.
  • Forewings: Olive brown with a black and white patch at the base on the inner margin. A black dot is present at the end of the cell.
  • Labial Palps: The second segment is more triangular compared to other Theretra species, with some long scales protruding.

Measure Up

Welcome to the beloved Measure Up segment. The official listener’s favorite part of the show! The part of the show when we present the animal’s size and dimension in relatable terms through a quiz that’s fun for the whole family. It’s also the part of the show that’s introduced by you when you send in audio of yourself saying, singing, or chittering the words Measure Up into ldtaxonomy at gmail dot com. We don’t have a new Measure Up intro! 

Mothim

Wingspan

Ranges from 90 to 130 mm (5.1 inches)

  1. 4 wingspans go into a the height of a common household blender
  2. 1 toothpick
  3. 458 go into the wingspan of a 747

Caterpillar length

11 centimeters (4.3 inches)

  1. 1 chicken wing drumstick
  2. 5,032 go into the height of a rural cell tower
  3. 28 go into a blue tick healer dog

Fast Facts about Yam Hawkmoth

  1. Habitat: These moths are commonly found in tropical and subtropical regions, particularly in Asia and Africa.
  2. Diet: The larvae (caterpillars) primarily feed on the leaves of yam plants, hence the name. Adult moths feed on nectar from various flowers.
  3. Behavior: Yam hawkmoths are known for their strong and fast flight. They are also nocturnal, being most active during the night.
  4. Life Cycle: Like other moths, they undergo complete metamorphosis, transitioning from egg to larva (caterpillar), then pupa, and finally to an adult moth.
  5. Pollination: As adults, they play a role in pollinating flowers while feeding on nectar.

Major Fact

  • Yam hawkmoths produce ultrasonic blasts from their genitals to confuse and deter predators, especially bats.
  • These blasts are high-pitched and disorienting to echolocation-dependent creatures.
  • This ability is primarily used to escape mid-flight bat attacks.
  • The ultrasound is emitted through a specialized organ near the abdomen.
  • These moths produce sounds in short bursts, making it difficult for bats to “see” them.
  • The sound is not loud enough for humans to hear but is effective against predators.
  • It’s believed that the ultrasound mimics the frequencies of other bat species, adding to the confusion.
  • The moth’s defense mechanism activates only when a predator gets too close.
  • This adaptation reduces the chances of being eaten by sonar-guided hunters.

Ending: So prep your sonic blaster, disorient your predators with your…uh… anatomy, and take back the night like the yam moth here in LDT.