Entomology: April 14, 2006

  1. Neopterousexopterygotes (cont.)
  2. Order Mantodea (“mantis”=soothsayer, prophet): mantises
  3. Adult characteristics

**Overall: adaptations for predation and camouflage

a)Head (note eyes, ocelli-if present, mouthparts, other structures of note)

Only insect that can turn its head and look over its shoulder

b)Thorax

Elongate prothorax; pronotum is greatly expanded in some

Distinctive prolegs specialized for prey capture

  • How are the different leg segments (coxa, femur, tibia) specialized for prey capture?

Mid and hindlegs used for walking and stability

Wings in males? In females?

Leathery forewings (tegmina); membranous hindwings

c)Abdomen

Continuous with rear-portion of the thorax; relatively robust

Relatively short cerci

  1. Distinctive larval features

a)Larvae resemble miniature adults except for wings...

  1. Habitat

a)Most abundant in tropical regions

b)Found on vegetation; particular species are specialist mimics of particular plants (i.e. the orchid mantis dead-leaf mantises, etc…)

  1. Food/Feeding behavior

a)All species are lie-in-wait predators

Major means of prey detection? Types of prey?

  1. Locomotion/flight

a)Winged males use flight to locate females, otherwise flight is relatively unimportant

Will run or fly/glide to escape predators

  1. Selected aspects of reproduction

a)Males are smaller than females

b)Females sometimes eat males instead of mating, or even during the mating process.

At what point in the courting/mating process are males most in danger?

c)Adaptive value?

Good genes hypothesis

Nutrition hypothesis

Mate guarding hypothesis

d)Egg-laying: Females creates a frothy mass on vegetation into which she deposits her eggs. The foam hardens into a protective case.

e)Larvae

Upon emerging, a young mantid may feed upon its siblings.

  1. Other

a)Mantids in U.S.

b)Why were European and Chinese mantids introduced to the U.S.?

  1. Order Mallophaga (“mallo”=wool, “phaga”=eat): chewing lice
  2. Adult characteristics

** They are adapted as ectoparasites on birds (primarily) as well as mammals. All are very small and dorso-ventrally flattened.

a)Head (note eyes, ocelli-if present, mouthparts, other structures of note)

Approximately as wide as the rest of the body (compare to the Anopleura)

b)Thorax

No wings

Legs vary in length

  • Tarsi 2-segmented, often modified for clinging to feathers or hairs

c)Abdomen

Sometimes have scleritinized plates on tergum (dorsal ab)

No cerci

  1. Distinctive larval features

a)None

  1. Habitat

a)Ectoparasites (birds, mammals)

One species is specific to the pouch of pelicans…

  1. Food/Feeding behavior

a)Primarily feed on sloughed off organic material from hostbut may also pierce through skin/developing quill and feed on blood

  1. Locomotion/flight

a)No flight

  1. Selected aspects of reproduction

a)Eggs are laid on the host; many generations on the same individual

Will quickly die if removed from a suitable host.

  1. Other

a)Some species are specific to a particular body part

b)Transferred between hosts by direct contact

c)Transfer by phoresy (what is that?)

d)Mallophaga usually do not directly cause disease in their hosts, but some may be vectors for nematodes or pathogenic skin fungi.

Compare to Anopleura—which Order is better known for spread of disease

One species parasitic on dogs is an intermediate for a particular tapeworm. How can this tapeworm get transferred to humans?

  1. Order Anopleura (“ano”=without, “pleuron”=tail): crab lice, head and body lice, dog-sucking lice.
  2. Adult characteristics

** They are adapted as ectoparasites on a wide range of placental mammals (including marine mammals). All are very small, dorso-ventrally flattened.

a)Head (note eyes, ocelli-if present, mouthparts, other structures of note)

Clearly narrower than thorax (compare to Mallophaga)

b)Thorax

Quite wide compared to head

No wings

Short legs with 1-segmented tarsi with a “locking grip”

  • Fitted to hair width of host

c)Abdomen

Sometimes have scleritinized plates on tergum (dorsal ab)

No cerci

  1. Distinctive larval features

a)Nothing particular…

  1. Habitat

a)Worldwide; Clinging to hairs of mammals

  1. Food/Feeding behavior

a)Blood suckers!

  1. Locomotion/flight

a)No flight; Individuals probably don’t move much.

  1. Selected aspects of reproduction

a)Eggs laid directly on host; glued to the hair shafts.

  1. Other

a)Anopleura are highly host-specific and even location-specific

b)Pubic lice (or crab lice, Pthirus pubis)

How spread?

On what other animal is this genera found?

c)Head/body lice are two subspecies of Pediculus humanus

Where found? How spread?

On which other animals is this genus found?

d)Anopleura are vectors for transmission of more serious diseases, including epidemic typhus and trench fever, both Rickettsias.

What areRickettsias?

  1. Order Hemiptera (“hemi”=half): true bugs
  2. Adult characteristics

a)Head (note eyes, ocelli-if present, mouthparts, other structures of note)

Piercing-sucking mouthparts extend from the anterior portion of the head to form a long, multisegmented rostrum (or “beak”). The beak is tucked beneath the thorax and abdomen when not in use, and swings forward when needed.

  • Two pairs of sharp stylets are part of the rostrum

b)Thorax

Triangular-shaped scutellum on mesothorax

Forewings are “hemelytra”: basal portions are thickened and colored while the distal portions are membranous

  • Some wingless forms

Hindwings are membranous

Wings are held flat over body (Homoptera are not)

c)Abdomen

No cerci

  1. Distinctive larval features

a)Nothing distinctive

  1. Habitat

a)Three suborders correspond to different habitats

Suborder Hydrocorisae: water bugs (diverse aquatic habitats)

  • Various adaptations to the aquatic environment…

Suborder Amphicorisae: surface-dwelling bugs

  • How are these adapted to walk on water?

Suborder Geocorisae: terrestrial bugs

  1. Food/Feeding behavior (some select examples)

a)Giant water bugs can eat small vertebrates (small fish, frogs and birds)

b)Bed bugs eat blood meals

c)Some assassin bugs are also blood suckers and carry Chaga’s disease

d)The cotton stainer ruins cotton crops in a unique way (how?)

  1. Locomotion/flight

a)Some are decent fliers, even some of the aquatic forms

  1. Selected aspects of reproduction

a)Giant water bugs attract their mates via producing waves on the water; after mating, females glue the eggs to the backs of the males.

b)Plant bugs insert eggs inside of host plants

c)Several species provide care of eggs and young nymphs

  1. Other

a)Many species emit noxious substances from their metathorax; some nymphs emit noxious substances from their abdomen

b)NOTE: Much diversity. Be sure to read about the particular features of the Families that you collect.

Study questions

  1. See question 1 on April 7.
  1. Compare the Mallophaga to the Anopleura, pointing out key similarities and differences in both structure and habitat/habits.
  1. List/briefly describe the three Suborders of Order Hemiptera, and name representative members of each.
  1. Discuss the potential adaptive value for the consumption of male mantises by females.

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