Some Orders of Insect Pests

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

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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).

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Left a silverfish. Right a firebrat
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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.

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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.

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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.

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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.

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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.

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

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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.

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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.

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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.

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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

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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.

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Dermaptera The earwigs

• Adults
• Mouthparts chewing
• Size 4 - 30 mm
• Wings 4 or none forewings shortened and
  thickened hind wings membranous and folded.
• Distinguishing characteristics Enlarged,
  pincer-like cerci.

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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.

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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.

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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.

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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.

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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

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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.

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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
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