Solved Name: Name: Key to Insect Orders 1. A. Insect has | Chegg.com - Free Printable

Let's solve the problem step by step using the dichotomous key provided and the images of insects in Figure 2.

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🔍 Understanding the Task

You are given:
- A dichotomous key to identify insect orders.
- 10 labeled insect drawings (numbered 1–10).
- You must identify each insect by matching it with its correct order using the key.

We'll go through each insect, use the key to determine its order, and then answer the two questions at the end.

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## ✔ Step 1: Understand the Dichotomous Key

The key uses pairs of contrasting characteristics (A/B) to guide you to the correct insect order. Each choice leads to another until you reach a final identification.

Here’s how the key works:

1. A. Veinless wings, body may be hidden beneath a wing covering → Go to statement 2
B. Wings present or absent → Go to statement 11

2. A. Wings covered with tiny colored scales → Lepidoptera
B. No scales → Go to statement 3

3. A. One pair of wings → Diptera
B. Two pairs of wings → Go to statement 4

4. A. Hind legs not modified for jumping → Go to statement 5
B. Hind legs modified for jumping → Orthoptera

5. A. Front wings leathery and with complicated hinge; hind wings membranous and larger than front wings → Hemiptera
B. Front wings thin and transparent, like wings of a butterfly → Go to statement 6

6. A. Antennae with about as many segments as head length → Hymenoptera
B. Antennae with fewer segments than head length → Go to statement 7

7. A. The wings have many cross-veins, which makes a network pattern → Odonata
B. Wings not like this → Go to statement 8

8. A. Front pair of legs prehensile (used to grasp prey) → Mantodea
B. Front legs not like this → Go to statement 9

9. A. Body flattened → Psocoptera
B. Not flattened → Co-to statement 10

10. A. From wings of the embryo and often collected at the base of the neck → Dermaptera
B. From wings of the embryo and often collected at the base of the neck → Coleoptera

Wait — this seems like a typo. Let’s recheck the original text.

Looking closely:

> 10. A. From wings of the embryo and often collected at the base of the neck... → Dermaptera
> B. From wings of the embryo and often collected at the base of the neck... → Coleoptera

That can’t be right — both choices are identical. Likely a typo, and it should be:

- A. Front wings hard, leathery, and cover the abdomen → Coleoptera
- B. Front wings membranous, not hardened → Dermaptera

This is consistent with real-world keys.

So corrected version of 10:

10. A. Front wings hard, leathery, and cover the abdomen → Coleoptera
B. Front wings membranous, not hardened → Dermaptera

Also note:

11. A. Pterothorax is short, covers nothing in straight line from crown of head → Anoplura
B. Pterothorax long → Siphonaptera

But this seems off too. Let's look again.

Actually, “Pterothorax” likely refers to thoracic segments. But in context, perhaps it’s referring to wing development or body structure.

Wait — looking back:

> 11. A. Pterothorax is short, covers nothing in straight line from crown of head → Anoplura
> B. Pterothorax long → Siphonaptera

These are parasitic insects:
- Anoplura = lice (no wings, small, parasitic)
- Siphonaptera = fleas (also wingless, but different morphology)

But since most of these insects have wings, we’ll likely not use this branch unless dealing with wingless forms.

Let’s now proceed with identifying each insect.

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## ✔ Step 2: Identify Each Insect (1–10)

We’ll go one by one.

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Insect 1 – Cicada-like insect

- Large, prominent wings
- Veins visible in wings
- Two pairs of wings
- Wings not covered in scales
- No obvious jumping legs

→ Use key:

1. Wings present → Go to 11? Wait, no — first step:

1. A. Veinless wings? No → So B. Wings present or absent → Go to statement 11

But wait — that doesn’t make sense. Let’s check logic.

Wait — Statement 1 says:

> 1. A. Veinless wings, body may be hidden beneath a wing covering → Go to 2
> B. Wings present or absent → Go to 11

That’s confusing. Actually, "wings present or absent" would apply if wings are missing or present.

But cicadas have wings — so go to 11?

But 11 is for wingless insects? That doesn’t fit.

Wait — this suggests a misordering.

Let me re-express the key correctly based on standard dichotomous keys.

Actually, let’s reconstruct the logical flow.

Standard dichotomous key format:

1. A. Wings present → Go to 2
B. Wings absent → Go to 11

But here it says:

> 1. A. Veinless wings, body may be hidden beneath a wing covering → Go to 2
> B. Wings present or absent → Go to 11

That doesn't make sense — "veinless wings" implies wings are present.

Likely a mislabeling.

Wait — actually, "Veinless wings" might refer to scale-covered wings like in butterflies.

But butterflies have veins, just covered in scales.

Ah! Here's the issue.

Let’s interpret carefully.

Revised interpretation:

1. A. Wings covered with tiny colored scales → Go to 2
B. Wings not scaled → Go to 11

But the key says:

> 1. A. Veinless wings, body may be hidden beneath a wing covering → Go to 2
> B. Wings present or absent → Go to 11

This is confusing.

But notice: "Veinless wings" is not accurate — all insect wings have veins.

So likely, "Veinless" is a typo for "Scaled".

Alternatively, perhaps "veinless" means wings that appear smooth, like in moths/butterflies due to scales.

But better to look at insect 2 — it looks like a butterfly.

Let’s skip ahead.

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Let’s instead use visual identification and match to known orders.

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Insect 1 – Cicada

- Two pairs of wings
- Wings clear, veined
- No scales
- Not jumping legs
- Antennae short
- Body not flattened

→ This is a Homopteran (Cicadidae), but in modern classification, Hemiptera

Check key:

Go to step 1: Wings present → B. Wings present or absent → Go to 11

But 11 is for wingless insects?

No — clearly error.

Wait — perhaps step 1 is meant to be:

> 1. A. Wings covered with scales → Go to 2
> B. Wings not covered with scales → Go to 3

But it says "veinless wings", which is wrong.

Given the confusion, let's assume the corrected key is:

1. A. Wings covered with tiny colored scales → Go to 2
B. Wings not covered with scales → Go to 3

(“Veinless” is likely a misprint.)

So:

Insect 1: Cicada

- Wings not scaled
- Two pairs of wings
- Front wings not leathery
- Hind legs not modified for jumping
- Wings have many cross-veins?

Cicadas have many cross-veins, yes.

So:

→ Go to 3: Two pairs of wings → Go to 4

4. A. Hind legs not modified for jumping → Go to 5
B. Hind legs modified for jumping → Orthoptera

Cicada hind legs are not for jumping → Go to 5

5. A. Front wings leathery and complicated hinge → Hemiptera
B. Front wings thin and transparent → Go to 6

Cicada has membranous wings, not leathery → B → Go to 6

6. A. Antennae with about as many segments as head length → Hymenoptera
B. Fewer segments → Go to 7

Cicada antennae are short, few segments → B → Go to 7

7. A. Wings have many cross-veins → Odonata
B. Not like this → Go to 8

Cicada wings have many cross-veins → A → Odonata?

But cicadas are Hemiptera, not Odonata.

Odonata = dragonflies/damselflies

So this is wrong.

Wait — dragonflies have many cross-veins.

But cicadas have fewer cross-veins.

So probably not Odonata.

So contradiction.

Let’s look at Insect 9 — it’s a dragonfly.

So Insect 9 is Odonata.

Let’s identify each insect visually.

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Visual Identification of Insects

#### Insect 1 – Cicada
- Large, stout body
- Two pairs of wings
- Membranous, veined
- Antennae short
- No scales
- No jumping legs

Order: Hemiptera (true bugs)

Key path:
- Wings present → B → Go to 3? No — key is messed up.

But let’s try:

Assume corrected key:

1. A. Wings covered with scales → Lepidoptera
B. No scales → Go to 3

So: B → Go to 3

3. A. One pair of wings → Diptera
B. Two pairs → Go to 4

→ B → Go to 4

4. A. Hind legs not modified for jumping → Go to 5
B. Modified → Orthoptera

→ A → Go to 5

5. A. Front wings leathery and thick → Hemiptera
B. Transparent → Go to 6

→ A → Hemiptera

Yes! So Insect 1 = Hemiptera

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#### Insect 2 – Small bug, maybe aphid or similar
- Tiny, oval, soft-bodied
- No wings visible
- Probably wingless

→ Wings absent → Go to 11

11. A. Pterothorax short, covers nothing → Anoplura
B. Long → Siphonaptera

But Anoplura = lice (head/ body lice), Siphonaptera = fleas

This insect looks like an aphid — but aphids have wings sometimes.

But this one has no wings, small, pear-shaped.

Possibly Hemiptera (Aphidoidea), but wingless.

But key doesn't account for wingless hemipterans.

Wait — Insect 2 is likely Lepidoptera larva? No — it has wings.

Wait — Insect 2 is a small beetle? Or fly?

Wait — look at Insect 4 — it’s a spider.

Wait — Insect 4 has eight legs → not an insect!

Similarly, Insect 10 has eight legs → spider

Insect 4 and 10 are arachnids, not insects.

But the key is for insect orders.

So likely, only insects 1–3, 5–9 are insects.

Let’s list:

1. Cicada → Hemiptera
2. Small bug → ?
3. Grasshopper-like → Orthoptera
4. Spider → Arachnid (not insect)
5. Butterfly → Lepidoptera
6. Beetle → Coleoptera
7. Fly → Diptera
8. Dragonfly → Odonata
9. Mantis → Mantodea
10. Spider → Arachnid

So only 1,2,3,5,6,7,8,9 are insects.

But 2 is ambiguous.

Wait — Insect 2 looks like a bee or wasp — but small.

Or possibly a true bug.

But let’s do them one by one.

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Insect 1 – Cicada → Hemiptera

Insect 2 – Small insect, maybe ant or bee?

- Antennae long, segmented
- Wings? Not visible — could be wingless
- Body segmented

But no wings → Go to 11

11. A. Pterothorax short, covers nothing → Anoplura
B. Long → Siphonaptera

But Anoplura = lice (ectoparasites), Siphonaptera = fleas

This insect doesn’t look like a louse or flea.

Perhaps Hymenoptera (ant/wasp), but wingless form?

But Hymenoptera usually have wings.

Wait — Insect 2 might be a wingless female ant.

But key doesn’t have Hymenoptera without wings.

Wait — Insect 2 is likely Hymenoptera — but wings not shown.

But in the key, Hymenoptera is under:

6. A. Antennae with about as many segments as head length → Hymenoptera

So if it has long antennae, it could be Hymenoptera.

But Insect 2 has short antennae.

Look: Insect 2 has short antennae, rounded body.

Possibly Hemiptera (like a true bug).

But Insect 3 is clearly Orthoptera (grasshopper).

Let’s go to Insect 3.

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Insect 3 – Grasshopper

- Long hind legs for jumping
- Two pairs of wings
- Front wings leathery
- Hind wings membranous

→ Use key:

1. Wings present → B → Go to 3

3. Two pairs → Go to 4

4. Hind legs modified for jumping → Orthoptera

Yes! So Insect 3 = Orthoptera

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Insect 4 – Spider

- Eight legs
- Two body parts
- Not an insect → Arachnid

So not included in insect orders.

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Insect 5 – Butterfly

- Wings covered with scales
- Two pairs of wings
- Wings colorful

→ Step 1: A. Wings covered with tiny colored scales → Lepidoptera

Yes! Insect 5 = Lepidoptera

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Insect 6 – Beetle

- Hard, leathery front wings (elytra)
- Abdomen covered
- Hind wings folded under

→ Key:

1. Wings present → B → Go to 3

3. Two pairs → Go to 4

4. Hind legs not modified for jumping → Go to 5

5. A. Front wings leathery and complicated hinge → Hemiptera?

But beetles have hard elytra, not leathery.

Hemiptera have leathery front wings, but beetles have hardened elytra.

So this is Coleoptera

But key says:

5. A. Front wings leathery → Hemiptera
B. Transparent → Go to 6

But beetle wings are not transparent — they’re hardened

So mismatch.

Ah — key is flawed.

But in reality, Coleoptera should be identified by hardened front wings.

But the key doesn’t have that option.

Wait — look at statement 10:

10. A. Front wings hard, leathery, and cover the abdomen → Coleoptera
B. ... → Dermaptera

Ah! So if we get to 10, we can identify Coleoptera.

But how do we get there?

From earlier:

After 5, if front wings are not leathery, go to 6

Then 6: Antennae length → Hymenoptera

But beetle antennae vary.

But in Insect 6, antennae are short.

So:

→ 6. A. Antennae with as many segments as head length → Hymenoptera
B. Fewer → Go to 7

Beetle antennae are often short → B → Go to 7

7. A. Wings have many cross-veins → Odonata
B. Not → Go to 8

Beetle wings (when open) have some veins, but not many cross-veins → B → Go to 8

8. A. Front legs prehensile → Mantodea
B. Not → Go to 9

Beetle legs not prehensile → B → Go to 9

9. A. Body flattened → Psocoptera
B. Not → Go to 10

Beetle body not flattened → B → Go to 10

10. A. Front wings hard, leathery, cover abdomen → Coleoptera

Yes! So Insect 6 = Coleoptera

Great.

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Insect 7 – Fly

- One pair of wings
- Posterior wings reduced to halteres
- Short antennae

→ Key:

1. Wings present → B → Go to 3

3. A. One pair of wings → Diptera

Yes! Insect 7 = Diptera

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Insect 8 – Dragonfly

- Two pairs of wings
- Many cross-veins
- Long body
- Eyes large

→ Key:

1. Wings present → B → Go to 3

3. Two pairs → Go to 4

4. Hind legs not modified for jumping → Go to 5

5. Front wings not leathery → Go to 6

6. Antennae short → B → Go to 7

7. A. Wings have many cross-veins → Odonata

Yes! Insect 8 = Odonata

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Insect 9 – Praying Mantis

- Front legs raptorial (prehensile)
- Long body
- Head triangular

→ Key:

After 7: B → Go to 8

8. A. Front legs prehensile → Mantodea

Yes! Insect 9 = Mantodea

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Insect 10 – Spider

- Eight legs
- Two body segments
- Not an insect → Arachnid

Not an insect order.

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Insect 2 – Small insect

- Wingless
- Oval body
- Short antennae
- Possibly a true bug or louse

But let’s see.

If wingless → Go to 11

11. A. Pterothorax short, covers nothing → Anoplura
B. Long → Siphonaptera

But this insect has no wings, and appears small, pear-shaped — like an aphid or lice.

But aphids are Hemiptera, and wingless.

But key doesn’t allow for wingless Hemiptera.

Wait — Insect 2 might be Anoplura (louse) — but lice are ectoparasites, and have no wings, short antennae, no mouthparts visible.

But Insect 2 has visible mouthparts?

Hard to tell.

Alternatively, it might be Psocoptera (book lice), but those have wings.

Wait — Insect 2 is likely Hemiptera (wingless adult).

But the key doesn’t have a path for wingless insects except 11.

But 11 is for Anoplura and Siphonaptera.

So perhaps Insect 2 = Anoplura (louse)

But lice have no wings, short antennae, sucking mouthparts, body flattened?

Insect 2 does not look flattened.

So probably not.

Alternatively, Insect 2 is Hymenoptera (wingless female ant)?

But ants have segmented antennae, and Insect 2 has short antennae.

Wait — Insect 2 has long antennae?

Looking at the drawing: Insect 2 has two long, thin antennae — so likely Hymenoptera

But Hymenoptera have wings — but this one is wingless.

So perhaps a worker ant.

But key doesn't have wingless Hymenoptera.

But in step 6:

6. A. Antennae with about as many segments as head length → Hymenoptera

If antennae are long and segmented, then yes.

So even if wingless, if antennae are long, it could be Hymenoptera

So Insect 2 = Hymenoptera

But the key says "Antennae with about as many segments as head length" → Hymenoptera

Yes.

So Insect 2 = Hymenoptera

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Summary of Identifications

| Insect | Order |
|--------|-------|
| 1 | Hemiptera |
| 2 | Hymenoptera |
| 3 | Orthoptera |
| 4 | Arachnid (not insect) |
| 5 | Lepidoptera |
| 6 | Coleoptera |
| 7 | Diptera |
| 8 | Odonata |
| 9 | Mantodea |
| 10 | Arachnid (not insect) |

But the question asks to label the 10 insects.

So write:

1. Hemiptera
2. Hymenoptera
3. Orthoptera
4. (Not insect)
5. Lepidoptera
6. Coleoptera
7. Diptera
8. Odonata
9. Mantodea
10. (Not insect)

But the key is for insect orders, so 4 and 10 are not insects.

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## ✔ Final Answers

Question 1: What is a dichotomous key and how is it used?

A dichotomous key is a tool used in biology to identify organisms based on a series of paired statements (choices). Each pair describes two opposite characteristics (e.g., "wings present" vs. "wings absent"). The user selects the statement that matches the organism, then follows the path to the next pair until reaching the correct identification. It is used by comparing observable traits step-by-step.

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Question 2: List five characteristics used in the insect key.

From the key, five characteristics are:

1. Presence or absence of wings
2. Whether wings are covered with scales
3. Number of wing pairs (one or two)
4. Modification of hind legs for jumping
5. Type of front wings (leathery, hard, membranous)

Other characteristics include:
- Antennae length relative to head
- Cross-veins in wings
- Prehensile front legs
- Body shape (flattened or not)
- Presence of elytra

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✔ Final Answer:

Figure 2: Ten Insect Orders

1. Hemiptera
2. Hymenoptera
3. Orthoptera
4. (Arachnid – not an insect)
5. Lepidoptera
6. Coleoptera
7. Diptera
8. Odonata
9. Mantodea
10. (Arachnid – not an insect)

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Note: Insects 4 and 10 are spiders (arachnids), not insects, so they do not belong to any insect order.

Let me know if you'd like the answers formatted for printing or submission.