1. Some Orders of Insect Pests 511 Zoo
Prepared by: Dr. Reem Alajmi

2. Thysanura: The bristletails (silverfish and firebrats)
Adult Description and identification:
Mouthparts: chewing
Size: Common species are about 12 mm long.
Wings: None
Distinguishing characteristics: Elongate and somewhat flattened; body covered with scales; 3 caudal filaments, 2 lateral, 1 central..
Metamorphosis: None (ametamorphosis); immature (called juveniles) look like adults.

3. Thysanura: The bristletails (silverfish and firebrats)
Habitat: Debris, under bark, in buildings (some cool and damp, others warmer sites).
Pest or Beneficial Status: Primarily nuisance, some property damage by silverfish and firebrats (may feed on starch of book bindings, similar materials).

4. Left: a silverfish. Right: a firebrat

5. Ephemeroptera: The mayflies
Adults:
Mouthparts: None (vestigial)
Size: 2 – 32 mm long, plus long caudal filaments
Wings: Usually 4, some species only 2. Membranous, with numerous net-like cross-veins. Fore wings are larger, triangular.

6. Ephemeroptera: The mayflies
Other distinguishing characteristics: Short hair-like (setaceous) antennae; 2 or 3 long caudal filaments.
Habitat: Immature are aquatic; adults are found near water. Most nymphs feed on algae or decaying organic material; some are predaceous.
Metamorphosis: Incomplete (naiads do not look like adults and live in water; wing “pads” develop gradually and externally through successive stages.

7. Ephemeroptera: The mayflies
Immatures (called naiads):
Leaf-like abdominal gills; 3 long caudal filaments; (sexually immature pre-adult) emerges from the water, molts to the adult stage the next day.
Pest or Beneficial Status: Important fish food; indicators of water quality; mass emergence may be problematic.

8. Odonata: The dragonflies and damselflies
Adults:
Mouthparts: Chewing
Size: 20 to 135 mm.
Wings: 4, membranous, with numerous net-like cross-veins. Wings are marked by a stigma -- a thickened, darkened cell at the costal margin of the fore and hind wings.

9. Odonata: The dragonflies and damselflies
Other distinguishing characteristics: Very large compound eyes; short hair- like (setaceous) antenna
Suborder Anisoptera: dragonflies -- hind wings wider than front wings; wings held horizontally at rest.
Suborder Zygoptera: damselflies -- fore and hind wings similar in shape and narrowed at base; wings held together above the body when at rest.

10. Odonata: The dragonflies and damselflies
Left: A dragonfly (Texas A & M University). Right: A damselfly (University of Florida).

11. Odonata: The dragonflies and damselflies
Metamorphosis: Incomplete (naiads do not look like adults and live in water; wing “pads” develop gradually and externally through successive stages.)
Immatures (called naiads):
Aquatic; labium modified to catch prey; dragonflies with internal (rectal) gills; damsel fly naiads with 3 leaf-like gills at the end of the abdomen.

12. Odonata: The dragonflies and damselflies
Habitat: Immature are aquatic; adults are found near water. Nymphs and adults are predaceous.
Pest or Beneficial Status: Generalist predators; indicators of water quality.

13. Orthoptera: The grasshoppers, crickets, and katydids
Adult
Mouthparts: Chewing
Size: Moderate to large
Wings: 4, front wings (tegmina) are leathery, hind wings are membranous. Some are wingless. Wings (and legs) may bear sound-producing structures.

14. Orthoptera: The grasshoppers, crickets, and katydids
Other distinguishing characteristics: Elongate bodies; well-developed cerci; antennae are mostly long and filiform; the ovipositor may be long; hind legs of most are modified for jumping.

15. Orthoptera: The grasshoppers, crickets, and katydids
Metamorphosis: Gradual.
Immature (nymphs):
Are adult-like, and external wing pads develop as nymphs mature.
Habitat: Many types of vegetation

16. Orthoptera: The grasshoppers, crickets, and katydids
Pest or Beneficial Status: Some grasshoppers are crop pests; some crickets are household nuisance pests. In some parts of the world, migratory locusts occur in great numbers and destroy vast areas of crops and other vegetation.

17. Dermaptera: The earwigs
Adults
Mouthparts: chewing
Size: mm
Wings: 4 or none; forewings shortened and thickened; hind wings membranous and folded.
Distinguishing characteristics: Enlarged, pincer-like cerci.

18. Dermaptera: The earwigs
Habitat: Moist debris and decaying materials. Earwigs are nocturnal and feed on plants or decaying plant material; some are predaceous (and beneficial).
Metamorphosis: Gradual; nymphs resemble adults and share the same habitat. In those with wings, external wing pads develop as nymphs mature.
Immature (called nymphs): Similar to adults.

19. Dermaptera: The earwigs
Pest or Beneficial Status: Earwigs are usually pests only as nuisance creatures, but one species, the European earwig, Forficula auricularia L. (Dermaptera: Forficulidae), is a pest of vegetables, ornamental plants, and fruits. Its feeding leaves scars on the surface of apples and pears.

20. Hymenoptera (sawflies, parasitic wasps, ants, wasps, and bees)
Adult
Mouthparts: chewing or chewing/lapping
Size: Minute to large
Wings: 4 or none, front wing larger than hind wing, front and hind wings are coupled by hamuli to function as one.

21. Hymenoptera (sawflies, parasitic wasps, ants, wasps, and bees)
Antennae: Long and filiform (hairlike) in Symphyta; many forms in Apocrita
Other characteristics: Abdomen is broadly joined to the thorax in Symphyta; constricted to form a "waist"-like propodeum in Apocrita.

22. Hymenoptera (sawflies, parasitic wasps, ants, wasps, and bees)
Metamorphosis: Complete
Immatures:
In Symphyta, eruciform (caterpillar-like), but with 6 or more pairs of prolegs, all are plant- feeders.
In Apocrita, larvae have true head capsules, but no legs; some feed on other arthropods
Habitat: On vegetation, as parasites of other insects, in social colonies

23. Hymenoptera (sawflies, parasitic wasps, ants, wasps, and bees)
Pest or Beneficial Status: A few plant pests (sawflies); many are beneficial as parasites of other insects and as pollinators. Honey bees are important pollinators and produce honey. Stinging species can injure humans and domestic animals.

24. In a group of three, make small presentation within 2-3 slides for one of the insect pests order that is not mention in this lecture…