Lecture 2 Flashcards
The head of an insect is
composed of a series of
segments, which are
specialized for
- food gathering &manipulation,
- sensory perception, and
- neural integration
are tiny simple eyes that detects
differences light intensity, which may contribute to
Ocelli
To control of locomotion
The anterior area below
the dorsum of the head,
between and behind the
eyes is the __.
vertex
The area below the
compound eye, on the
side of the head, is the
___.
gena.
➢The liplike sclerite is the
clypeus
- For chewing
- Upper jaw, just below the clypeus
- For grasping
- Mandibles
- Labrum
- Maxillae
The head has a pair of small teeth or
blunt angles anterior to the posterolateral spines. Used in Antkey to separate Atta sexdens from Atta
cephalotes.
Cephalic spines
This character state was used by Wilson (2003) to distinguish Pheidole flavens from
Pheidole moerens.
Carinae
Theposterolateralportion of cephalic
dorsum sculptured with punctures, rugae or some combination, but never smooth and shining. Best viewed in profile.
Cephalic sculpture
Mouthparts of an Insect 2 categories
- Chewing: Mandibulate
- Sucking: Haustellate
The five primary parts of the insect
“mouth” are:
1)The clypeus
2)The “upper lip”, or labrum
3)Two “jaw-like structures”, or
mandibles
4) The maxillae (sing. maxilla)
5) The “lower lip”, or labium
Haustellate 2 subgroups:
1. needle-like projections
used to penetrate plant and animal
tissue.
- Those that do not.
- Stylets (Diptera, Hemiptera, Siphonaptera)
- Nonstylate mouthparts - Mouthparts lack stylets (Lepidoptera)
The teeth at the apex
of the mandibles
form a vertically
arranged fork of two
or three enlarged,
frequently spiniform
teeth.
Apical FORK
usually forms the anterior margin of the head in full-face view
Anterior clypeal margin
Antennae vary greatly among
insects, but all follow a basic plan:
segments 1 and 2 are termed the ___ & ___ , respectively. The remaining
antennal segments (flagellomeres) are jointly called the ___.
scape and pedicel
flagellum
Antennae function almost
exclusively in ___.
Some of the information that can
be detected by insect antennae
includes:
sensory perception
motion and orientation, odor, sound, humidity, and a variety of chemical cues.
Antennal types and structures
- Antennal Ridge
- Antennal scapes
- Antennal club
The insect thorax is divided
into three parts:
- prothorax (pro=first),
- mesothorax (meso=middle),
- metathorax (meta=last).
(Thorax)
Each segment consists of hardened plates, or sclerites.
____ are called nota (sing. notum),
____ are called pleura (sing. pleuron),
and ____ are called sterna (sing. sternum).
Dorsal sclerites
lateral sclerites
ventral sclerites
Each of the three thoracic segments contains one pair of legs. Wings are found only on the ____
meso- and metathoracic segments.
Insects have evolved many
variations of the wing. ____ is a commonly used taxonomic character, especially at the family and species level.
__ are thin and more or less transparent. This type of wings is found among the ____
Wing venation
Membranous wing; Odonata and
Neuroptera.
(Wings)
___ are an extreme modification among the order Diptera (true flies), in which the hind wings are reduced to mere nubs used for balance
and direction during flight.
Halteres
(Wings)
___ (sing. elytron) are the hardened,
heavily sclerotized forewings of beetles (Order Coleoptera) and are modified to protect the hind wings when at rest.
Elytra
(Wings)
A variation of the elytra is the
___. The forewings of Hemipterans are said to be ____ because they are
hardened throughout the proximal
two-thirds (approximately), while
the distal portion is ___
.
Unlike elytra, hemelytra function
primarily as ___. In both
cases, the membranous hind wings
(when present) are used in flight
and are folded beneath the
forewings when at rest.
hemelytra; hemelytrous
membranous
flight wings
(Legs)
The fore-legs are located on the
___, the mid-legs on the
___, and the hind legs on
the ___.
prothorax
mesothorax
metathorax
Each leg has six major components, listed here from proximal to distal:
- coxa (p1. coxae),
- trochanter,
- femur (p1.femora),
- tibia(p1.tibiae),
- tarsus (p1. tarsi),
- pretarsus.
(Legs)
The femur and tibia may be modified with spines. The tarsus appears to be divided into one to five
“____” called ___.
pseudosegments
tarsomeres
Leg Types and Function:
Used for walking/running. Some textbooks distinguish two by calling walking legs ambulatory or gressorial but the leg structure is basically the same.
Cursorial
Leg Types and Function:
Fore legs modified for grasping. These are often associated with Preying Mantids
Raptorial
Leg Types and Function:
Fore legs and tibiae specialized for digging; common in ground-dwelling insects.
Fossorial
Leg Types and Function:
Hind legs adapted for jumping; characterized by an elongated femur and tibia.
Saltatorial
Leg Types and Function:
Fore or hind legs adapted for swimming; characterized by elongated setae on tarsi
Natatorial
Is the dorsal sclerite of the prothorox, which can be highly modified in various groups such as the Homoptera, Blattaria & Coleoptera
Pronotum
(Abdomen)
The dorsal and ventral abdominal segments are termed ____ (singular tergum) and ___ (singular sternum), respectively.
terga
sterna
(Abdomen)
usually can be found in the conjunctive tissue between the terga and sterna of abdominal segments 1-8.
Spiracles
(Abdomen)
Reproductive structures are located on the ___ in males (including the aedeagus,
or penis, and often a pair of claspers) and on the _____ in
females (female external genitalia copulatory openings and ovipositor).
9th segment in males
8th and 9th abdominal segments
