Key to Slugs and Snails

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Key to Common and Potential Slug and Snail Pests of Flowers and Foliage Plants

1. With external shell (Fig.127) .......Snails, 2

1.' Without external shell (Fig. 128) .......... Slugs, 5

2. Shell an elongate spire that is often broken off (Fig. 129); These snails mainly feed on other snails; they are not considered a pest ..... Rumina sp.

2.' Shell not an elongate spire .......3.

3. Shell a flattened disc spiraling toward the center (Fig. 130); these snails mainly feed on other snails, they are not considered a pest,......Oxychilus sp.

4. Shell oval, with a large teardrop-shaped aperture which is approximately two-thirds the total shell length (these snails feed on algae and soft vegetable matter, they are not considered a pest, Fig. 131) ........Succinia sp.

4.' Shell globular, with the aperture approximately the shell diameter (Fig. 132) ..... Brown garden snail.

5. Breathing pore located in anterior half of mantle; back never keeled; posterior end rounded when viewed from above (Fig. 133); these slugs can do considerable damage, ...... Arion sp.

5.' Breathing pore located in posterior half of mantle; back keeled at least at posterior end which is pointed in dorsal view ....... 6

6. Back strongly keeled from the mantle to tip of tail; mantle grainy with center part bound by a groove (Fig.134); usually burrows in the soil and feeds on roots, ..... Greenhouse slug.

6.' Back keeled only near posterior end; mantle wrinkled in concentric circles, without a groove .....7.

7. Mantle and body with black spots; large slug (up to 150 mm) (Fig. 135).....Spotted garden slug.

7.' Mantle and back without well defined spots ........ 8.

8. Mantle and back with well defined, dark stripes; breathing pore not surrounded by a pale ring (Fig.136); exudes watery slime when irritated ......Lehmannia slug

8.' Mantle and back without well defined stripes; breathing pore surrounded by a pale ring....9

9. Medium sized slug (up to 50 mm) (Fig. 137); gray to reddish brown; exudes milky adhesive slime when irritated ..... Gray garden slug.

9.' Relatively small slug (up to 25 mm) (Fig. 138) light gray to blackish brown; exudes clear, watery mucus when irritated ..... Brown slug.