Insect 3

Question 1

What is ametabolous development?

Answer 1

Sequential moults but only get increase in size

Only relevant for apterygote insects

Question 2

What is hemimetabolous development?

Answer 2

Egg hatches to a nymph and then develops/moults into an adult

Incomplete metamorphosis

Question 3

What is holometabolous development?

Answer 3

Egg to pupa to sub-adult to adult

Question 4

Give some features of the order plecoptera (stoneflies)

Answer 4

Reduced ovipositor (eggs are dropped into water in flight)

Pulsatile organ (accessory heart) associated with the cerci

3-segmented tarsi

High oxygen requirement

Question 5

Give some features of the order Phasmatodea (stick insects)

Answer 5

All herbivores

Pair of defensive glands inside the prothorax

Fusion of the thorax with the 1st abdominal segment

Claspers (vomer) present on males

Crypsis associated with host plant speciation

Question 6

Give some features of the order Orthoptera (grasshoppers and crickets)

Answer 6

Cryptopleuron (lateral extension of the pronotum)

Saltorial hindlegs

Wings inclined over abdomen at rest

Question 7

What can the Orthoptera be divided into? Give features of each

Answer 7

Suboder Ensifera (crickets):

-fine antennae > 30 segments
-biting/shearing mandibles
-auditory organs on legs (protibia)

Suborder Caelifera (grasshoppers)

-short,robust antennae < 30 segments
-chewing mandibles
-abdominal auditory organs

Question 8

Give some features of the order Mantodea (mantises)

Answer 8

Enlarged, raptorial forelegs -for prey capture

Femoral brush on front leg

Extraordinary head mobility

Ootheca (egg mass) embadded in protective froth

Elongation of the thorax

Development of a cyclopean metasternal ear

Camouflage and mimicry

Question 9

Give some features of the Blattodea (cockroaches)

Answer 9

Wrap-around eyes

Dorso-ventral flattening

Slightly hardened, leathery front wings

Maternal and biparental care

Question 10

What was the Order Isoptera? Give some features and why it no longer exists

Answer 10

Termites

Show eusociality

Mounds act as homeostasis mechanisms

Found to be sister group of the cockroaches and so now come under the Blattodea

Question 11

Give some features of the order Thysanoptera (thrips)

Answer 11

Wings strap-like with fringe of long setae

Right mandible is reduced and the left mandible is inflexible

Pre-adult instar is inactive, non-feeding and pupa-like

Haplodiploid - males are from unfertilised eggs

Question 12

Give some features of the order Hemiptera (true bugs)

Answer 12

Mouthparts fused to form piercing, sucking beak or rostrum

Mostly herbivorous - feed on plant vascular tissue

Major plant pests

Viviparity and parthenogenesis in some groups

Question 13

What are the different types of Hemiptera? Give features of each

Answer 13

Sternorrhyncha e.g. aphids:

-fine, hairlike stylets
-parthenogenetic vivparity
-reduced or lost ovipositor
-phloem feeding + honey dew secretion

Auchenorrhyncha e.g. cicadas:

-elaborate acoustic organs on legs
-enlarged clypeus (forhead)
-clibarial pump
-xylem feeding