Slug season

SANDY LONG

Posted 6/27/18

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Slug season

TRR photos by Sandy Long

I chanced upon this encounter between an earthworm, at left, and a slug while walking on a dirt road. Both species exhibited considerable interest in the other. Some slugs consume earthworms. Both are hermaphrodites, meaning that each individual carries male and female reproductive organs. Neither is harmful to humans.

This slug created an artful pattern as it consumed algae on a propane tank. Slugs have a flexible band of microscopic teeth called a radula, with which they scrape up food particles.

Slugs have two pairs of retractable tentacles on their heads. The upper pair senses light and has eyespots at the ends; the lower pair provides a sense of smell. Atop and behind a slug’s head is the mantle, and behind that, the tail. The flat bottom of a slug is called the “foot,” which enables it to move via rhythmic waves of muscular contractions. Some slugs have a structure around the edge of the foot called a “foot fringe,” as can be seen in the photo with the earthworm.

Posted Wednesday, June 27, 2018 9:45 am

SANDY LONG

Summer officially arrived on June 21, heralding the return of some critters we might prefer not to share our lives and regional landscape with. In addition to ticks and mosquitos, slugs are suddenly sliming around our yards and gardens, silently and slowly consuming all sorts of stuff we’d rather not relinquish—like garden lettuce and home-grown strawberries.

Slugs (and snails) are gastropods and belong to a large division of invertebrates known as mollusks. Unlike snails, slugs typically have no shell, which puts their soft tissues at risk of dessication and requires them to generate protective mucus to survive.

The mucus trails they produce help to keep the slug from sliding down vertical surfaces, while the “slime trail” some slugs leave behind can be recognized by other slugs of the same species in pursuit of a potential mate. Such trails can also lead to a slug’s demise when followed by a carnivorous slug.

While slugs are often viewed as destructive garden pests, they in turn play an important role by consuming decaying plant material, fungi and sometimes carrion. In turn, they are preyed upon by reptiles, birds, amphibians and mammals, making them a valuable food source in our regional ecosystems.