ACE Insect Biology & Identification 2 — Questions and Answers
Question 1: Which insect order is characterized by having scales on the wings and a coiled proboscis for feeding?
- Diptera
- Lepidoptera (Correct answer)
- Hymenoptera
- Coleoptera
Correct answer: Lepidoptera
Lepidoptera (moths and butterflies) are uniquely characterized by scales covering their wings and a coiled, sucking proboscis called a haustellum.
Question 2: What type of metamorphosis involves egg, nymph, and adult stages with no pupal stage?
- Holometabolous
- Hemimetabolous (Correct answer)
- Ametabolous
- Hypermetamorphosis
Correct answer: Hemimetabolous
Hemimetabolous (incomplete metamorphosis) insects pass through egg, nymph, and adult stages, with nymphs gradually resembling adults.
Question 3: The spiracles of insects are primarily used for:
- Detecting chemical signals
- Gas exchange during respiration (Correct answer)
- Filtering food particles
- Producing sound
Correct answer: Gas exchange during respiration
Spiracles are external openings of the tracheal system that allow oxygen intake and carbon dioxide expulsion in insects.
Question 4: Which of the following correctly describes the difference between mandibulate and haustellate mouthparts?
- Mandibulate mouthparts pierce and suck; haustellate mouthparts chew
- Mandibulate mouthparts chew solid food; haustellate mouthparts pierce and suck liquid (Correct answer)
- Both types are used for chewing but differ in jaw orientation
- Mandibulate mouthparts are found only in larvae; haustellate in adults
Correct answer: Mandibulate mouthparts chew solid food; haustellate mouthparts pierce and suck liquid
Mandibulate insects use hardened mandibles to bite and chew solid food, while haustellate insects use modified mouthparts to pierce tissue and suck liquid.
Question 5: In insect taxonomy, which term refers to the protective wing covers in beetles (Coleoptera)?
- Hemelytra
- Tegmina
- Elytra (Correct answer)
- Halteres
Correct answer: Elytra
Elytra are the hardened, sclerotized forewings of beetles that protect the membranous hindwings used for flight.
Question 6: The tarsal formula 5-5-4 in a beetle specimen indicates:
- The insect has 5 legs on the right side and 4 on the left
- Five tarsomeres on the front leg, five on the mid leg, four on the hind leg (Correct answer)
- The antennae have 14 total segments
- There are 5 abdominal segments and 4 thoracic segments
Correct answer: Five tarsomeres on the front leg, five on the mid leg, four on the hind leg
Tarsal formula describes the number of tarsomeres (tarsal segments) on the front, middle, and hind legs respectively, an important identification character in beetles.
Question 7: Which insect structure is homologous to the wings and is used for balance in flies (Diptera)?
- Cerci
- Halteres (Correct answer)
- Palps
- Parapods
Correct answer: Halteres
Halteres are modified hindwings in Diptera that function as gyroscopic balance organs during flight.
ACE Insect Biology & Identification 2
Which insect order is characterized by having scales on the wings and a coiled proboscis for feeding?