Midterm Flashcards
1
Q
What is the largest & oldest collection of insects in the world?
A
Musee National d’Histoire Naturelle
In Paris
~ 40m specimens
2
Q
What is the largest collection of insects in North America
A
National Museum of Natural History
In DC
~35m specimen
3
Q
What is the largest collection of insects in Canada?
A
Canadian National collection of insects
In Ottawa
~17m specimens
4
Q
How many insects are at the Lyman Museum?
A
~3m specimens
Largest university collection
5
Q
Why are insect collections important?
A
Long-term data (see distribution patterns, activity patterns, changes over time…)
Availability for other researchers
6
Q
What is required for specimen to be of scientific value?
A
Locality of capture (country, region, GPS coordinates)
Date of capture (month uses roman numerals)
7
Q
What are threats to insect specimens?
A
Be eaten by museum pests
Mold
Fading
Dust, damage
8
Q
What is abundance?
A
The number of individuals.
* insects have probably the largest biomass of all terrestrial animals
9
Q
What is diversity?
A
The number of species.
* Insects represent ~80% all known living organisms
10
Q
What major biome or habitat has not been colonized by insects?
A
Marine environments
11
Q
What are the reasons for insect success?
A
Ancient lineage Presence of an exoskeleton Presence of wings Small size Complete metamorphosis High reproductive capacity
12
Q
What are the advantages of being an “old lineage?”
A
Ready to exploit new environments
Less competition
13
Q
What are the advantages of an exoskeleton?
A
Protection from physical damage
Discourage predators
Protective barrier between living tissues & environment
Protective against desiccation
14
Q
What are the advantages of having wings?
A
Advantage in finding food & mates
Able to easily escape from enemies
Freely move from one habitat to another to find better conditions
15
Q
What are the advantages of small size?
A
Need little food (more able to feed on one food source)
Able to exploit microhabitats (for food, protection, & resting)
16
Q
What is the advantage of complete metamorphosis?
A
Different body forms = different habitats and food so no need to compete for resources
17
Q
What are the advantages of a high reproductive capacity?
A
Insects lay large number of eggs & have short generational time =
Populations build up faster & have a faster rate of mutation
18
Q
What are the benefits of insects?
A
Pollination Food source Nutrient cycling Soil improvement Control of other organisms Medicine & genetics Biological indicators Commercial products Aesthetics & cultural use
19
Q
What are some crop plants dependent on insects for pollination?
A
Apples Pears Cherries Strawberries Cucumbers Squash Onions
20
Q
Which insects are the most important pollinators?
A
Bees
21
Q
What is the study of insects as human food called?
A
Entomophagy
22
Q
What are the differences between insects and steak in nutrients?
A
Insects = 200 cal per 100g (20% protein, 5mg iron) Steak = 250 cal per 100g (27% protein, 3.5mg iron)
23
Q
What is the legal tolerance for insects in broccoli?
A
60 aphids/100g
24
Q
What is the legal tolerance for insects in chocolate?
A
60 microscopic insect fragments/100g
25
What is the legal tolerance for insects in canned goods?
30 fly eggs & 2 maggots/100g
26
What is the importance of scavenger insects?
Involved in decomp. of organic matter& nutrient cycling
27
What type of insects are scavengers?
Carrion beetle
Dung beetle
Flesh flies
28
How do insects improve soil?
Aerate the soil
| Improve physical properties & add to its organic content
29
What insects are soil insects?
```
Proturans
Springtails
Diplurans
Termites
Ants
Beetle larva & fly larva
```
30
What is the important of parasitoids & predators?
Used in biological control of insect pests
31
What is the importance of insects in medicine?
Maggot therapy
32
What is maggot therapy?
The treatment of infected & gangrenous wounds by the use of maggots
33
Why are fruit flies used to study genetics?
Fast generation time
High reproductivity
Large chromosome
Small number of chromosomes
34
What insects are used as biological indicators of pollution & habitat change in stream ecosystems?
Chironomid larva (bloodworms)
Stoneflies
Mayflies
35
What is forensic entomology?
The use of insect knowledge in the investigation of crimes
36
What are commercial products derived from insects?
Honey (a multi-million dollar industry)
Beeswax
Silk (produced by silkworm moth)
Red dyes (made from female cochineal insects)
37
How much silk is made from a single cocoon?
About 500-900 meters
38
What do cochineal insects produce to create red dye?
Carminic acid as defense against predation
39
How many insects are considered pests?
~10,000 (1%)
40
When are insects considered pests?
When they come into conflict with human (directly or indirectly)
41
What are the types of insect pests?
```
Plant pests
Stored product pests
Household pests
Direct human pests
Livestock pests
```
42
What are plant pests considered?
The most important plant-feeding animals. They consume more plants than all vertebrate herbivores combined
43
What kind of insects are plant pests?
Herbivorous or phytophagous insects
44
What does phytophagous mean?
Insects that feed on the tissue of living plants (do not consume pollen or nectar)
45
When are phytophagous insects beneficial?
They can eat invasive plants or weeds
46
Why are plant pests considered pests?
They attack crops, cultivated plants, garden flowers, forest trees, etc.
47
What is a host plant?
A plant upon which an organism lives and/or eats.
| An insect can have one or multiple host plants
48
What are the types of plant pests?
Monophagous
Oligophagous
Polyphagous
49
Monophagous
Specialists & host specific
Feed on only one species or genus
Ex. Monarch eats milkweed
50
Oligophagous
Feed on various plants in a single family
| Ex. Colorado potato beetle
51
Polyphagous
Generalists. Feed on a variety of plants of unrelated families
Ex. Med fly, gypsy moth
52
What are the direct ways an insect can damage a plant?
Direct feeding (chewing, sucking, tunnelling)
53
What are the indirect ways an insect can damage a plant?
Indirectly (transmission of plant diseases)
54
What are major crop plant pests?
Boll weevil
Colorado potato beetle
Mediterranean fruit fly
Desert locust
55
What are major forest plant pests?
```
Lymantria dispar (gypsy moth)
Emerald ash borer
Asian longhorned beetle
```
56
Boll weevil
Plant pest: monophagous (cotton)
Eradicated from most states
Control: insecticides, pheromone mass trapping
57
Colorado potato beetle
Plant pest: oligophagous
Feed on family Solanaceae (potato, tomato, eggplant, pepper)
Control: hand picking, crop rotation, bacterial control (Bt); resistant to many insecticides
58
Mediterranean fruit fly or medfly
Plant pest: polyphagous
Over 260 different hosts (mostly fruit, but flowers, vegetables, & nuts)
Control: sterile insect technique (release of sterile males to mate)
59
Desert locust
Plant pest: polyphagous
Eat crop & non-crop plants
Different species invade different parts of the world
60
Lymantria dispar (Gypsy moth)
Plant pest: polyphagous
Feeds on ~300 species of trees (caterpillars only)
Introduced from Europe
61
Emerald ash borer
Plant pest: monophagous (ash trees)
Larva bore into wood, difficult to detect
Native to Asia, invasive to N.A.
62
Asian longhorned beetle
Plant pest: polyphagous
Attack multiple species of trees
Larva bore into wood
Native to Asia, invasive to N.A. (eradicated in Canada)
63
What do stored product pests do?
Contaminate large containers of stored food products
| Feed directly on the product or on mold
64
What kind of insects are stored product pests?
Mostly beetles & moths
| Most species have a worldwide distribution
65
What are some species of stored product pests?
Rice weevil
Indian meal moth
Foreign grain beetle
66
What do household pests do?
Contaminate food
Damage clothes or house
Feed on humans
67
What are some species of household pests?
```
Bed bugs
Indian meal moth
Ants
Cockroaches
Clothes moths
Carpet beetles
Booklice
```
68
What do direct human pests do?
Biting, stinging (cause minor or serious effects)
| Disease transmission
69
What are the two types of direct human pests that are involved in disease transmission?
Biological vectors
| Mechanical vectors
70
What are biological vectors?
Insects play a major role in the life cycle of the pathogen
| Mostly blood feeders
71
What are mechanical vectors?
Insects are passive carriers, carrying pathogens on its body or mouthparts
72
What are the types of direct human pests?
```
Biting insects (mosquitoes)
Stinging insects (bees)
Endoparasitic insects (botfly)
Ectoparasitic insect (lice)
```
73
What are the types of livestock pests?
```
Biting insects (stable flies)
Endoparasitic insects (botflies)
Ectoparasitic insects (fleas)
```
74
How do humans affect the population of pests?
Monoculture (cultivation of a single crop)
Irrigation canals (avoiding stagnant water)
Intercontinental transport
Overuse of insecticides
75
What are the cost difference between detrimental & beneficial insects?
Annual losses in US: ~$5 bill
| Annual benefits in US: over $19 bill
76
What are the general characteristics of Class Insecta?
Presence of exoskeleton
Bilateral symmetry
Body divided into segments or metameres (divided into head, thorax, abdomen)
77
What is tagmosis?
The organization of the body into major units
78
What are the segments of the tagmata?
Whole insect = 20 primitive segments
Head = 6 segments
Thorax = 3 segments
Abdomen = 11 segments (primitive); 10 segments (modern)
79
What is the head specialized for?
Sensory function & feeding
80
What is the thorax specialized for?
Locomotion
81
What is the abdomen specialized for?
Reproduction
| Also circulation, digestion & excretion
82
What are the types of joint appendages?
Feeding
Walking
Sensory
83
What kind of circulatory system do insects have?
Open circulatory system
84
How does respiration occur?
Via spiracles & trachea
or
gills
85
What do the excretory system consist of?
Malpighian tubules
86
What are the general properties of the exoskeleton?
Supports body & maintains its form
Lines the tracheal system + portions of digestive & reproductive system
Provides surfaces for muscle attachment
Provide structural rigidity at sclerotized regions
87
What are individual sections of the sclerotized region called?
Sclerites
| There are membranous regions between the sclerites that permit movement & flexibility
88
What are the color pigments & patterns of the exoskeleton for?
Defense
Courtship
Intraspecific recognition
Thermoregulation
89
The exoskeleton color pigments/patterns do what kind of defense?
Warning coloration
Mimicry
Distraction
Camouflage
90
What is aposematic coloration?
Conspicuous coloration or markings of an animal serving to warn off predators
91
What are the types of insect coloration?
Pigmental
| Structural
92
What is pigmental coloration?
Derived from food or other pigment deposition
93
What is structural coloration?
Derived from the cuticle & its irregularities
94
What are the 3 layers of the exoskeleton?
Cuticle
Epidermis
Basement membrane
95
Where does the cuticle come from?
Secreted by the epidermis
96
What is the structure of the cuticle?
Acellular
Complex
Multilayered
97
What does the epidermis do?
Secretes cuticle
| Forms external sensory receptors
98
What is the structure of the basement membrane?
Acellular
| Thin
99
What does the basement membrane do?
Separates hemocoel from epidermis
100
What are the parts of the cuticle?
```
Epicuticle
Procuticle (differentiates into exocuticle & endocuticle)
```
101
Which part of the cuticle is sclerotized?
Exocuticle
102
Which part of the cuticle is unsclerotized?
Endocuticle
103
Which part of the cuticle is waxy?
Epicuticle (protection & impermeability)
104
What are the types of cuticular extensions?
Rigid non-articulated
| Movable articulated
105
What are rigid non-articulated cuticular extensions?
Spines. They are large and heavily sclerotized
106
What are movable articulated cuticular extensions?
Setae. They are sunk into a cuticular socket
107
Setae are:
Sensory hairs
Multicellular
Associated with sensory cells and 2 other specialized epidermal cells
108
What is molting?
The entire process of preparing for, undergoing, & recovering from ecdysis
109
What is ecdysone?
The hormone produced to activate epidermal cells to secrete a new exoskeleton
110
What is apolysis?
The separation of the old cuticle from the epidermis
111
What is ecdysis?
The process of shedding the old cuticle
112
What is the exuvia?
The old cuticle
113
What is a teneral?
A soft, newly emerged insect (just after ecdysis)
114
What is tanning/sclerotization?
The stiffening & darkening of the cuticle
115
What are the steps of the molting process?
1. Ecdysone is released (by prothoracic gland). The activation of epidermal cells (their inc. in size)
2. Apolysis occurs. Epidermis secretes molting fluid that will digest old endocuticle only (not exocuticle)
3. The epidermis secreted new cuticle (epicuticle & procuticle)
4. Ecdysis starts. Insect swallows air or water to split old cuticle. The insect pulls out of old cuticle
5. Insect continues swallowing air/water to inc. hemolymph pressure to inflate body (spreads wings)
6. Tanning/sclerotization occurs. The procuticle differentiates into exocuticle and endocuticle
116
How many times do most insects molt?
Between 4-8 times in their life
| * some wingless hexapods continue to molt after reaching adult stage
117
What does the head consist of?
```
Eyes
Paired appendages (antennae, mouthparts)
```
118
Types of mouthparts:
```
Mandibulate mouthparts (more primitive; able to chew)
Haustellate mouthparts (more specialized; able to suck): multiple types
```
119
Types of haustellate mouthparts:
```
Chewing-lapping
Piercing-sucking (true bugs)
Siphoning (or sucking)
Sponging
Cutting-sponging
```
120
What is a proboscis?
Beak used to suck liquid
121
What are the orientations of the head?
Hypognathous
Prognathous
Opisthognathous
122
Hypognathous
Directed ventrally (downward)
123
Prognathous
Directed anteriorly (forward)
124
Opisthognathous
Directed posteriorly (backward)
125
What are the main divisions of the antennae?
Antennal sclerite
Scape
Pedicel
Flagellum
126
What is the purpose of the antennae?
Smell
Hearing
Feeling
127
What are the types of eyes in adults?
```
Compound eyes (consist of individual ommatidia)
Ocelli
```
128
What are the segments of the thorax?
Prothorax
Mesothorax
Metathorax
129
When are all the segments of the thorax the same size?
In wingless insects and immature insects
130
When are mesothorax and metathorax enlarged compared to the prothorax?
In winged insects
131
How are the segments of the thorax divided?
Notum (dorsal region): further divided
Sternum (ventral region)
Pleuron (lateral region)
132
What is the pronotum?
The dorsal region of the prothorax
It is often sclerotized & prominent (can form shield over head)
Can be modified
133
What is the mesonotum?
The dorsal region of the mesothorax
134
What is the metanotum?
The dorsal region of the metathorax
135
What are the segments of the legs?
```
Coxa
Trochanter
Femur
Tibia (usually w/ spines)
Tarsi (divided into tarsomeres)
Tarsal claw (part of pretarsus)
```
136
Whats on the pretarsus?
Last segment
| Consists of claws with various pad-like or bristle-like structures
137
What are legs typically adapted for?
walking (ambulatory)
| Running (cursorial)
138
What can the legs be modified for?
```
Jumping (saltatorial)
Grasping (raptorial)
Digging (fossorial)
Swimmng (natatorial)
*Usually only one pair is specialized for each action
```
139
When are fully functional wings found?
In the adult stage
*Exception: mayflies
Usually membranous
140
Why are flies different with their wings?
Only have one pair
| The hind wings are modified into organs of equilibrium (stabilizers): called halteres
141
Halteres are:
Hind wings that are modified into organs of equilibrium (stabilizers)
142
Where are modifications of wings usually found?
Forewings
143
What are the modifications of wings?
Tegmina
Elytra
Hemelytra
144
What are tegmina?
Thicker, leathery forewings
| Found in praying mantis, cockroaches, earwigs, grasshoppers
145
What are elytra?
Heavily sclerotized forewings
| Found in beetles
146
What are hemelytra?
Forewings with thickened basal section & membranous apical section
Found in Heteroptera (true bugs)
147
What are variations within membranous wings?
Smooth or covered in microtrichia (small hairs)
Can be partially/fully scaled
Can be patterned
148
What are microtrichia?
Small hairs
149
How are wings supported?
With sclerotized veins
| Can be longitudinal or cross-veins
150
What are the regions of the abdomen?
Tergum (dorsal region)
| Sternum (ventral region)
151
What is the hard plate of the tergum called?
Tergite
152
What is the hard plate of the sternum called?
Sternites
153
What are segments 1-7 of the abdomen called?
Pregenital segments
| *Usually have no appendages (exceptions = silverfish with styles & immature insects with prolegs and gills)
154
What are segments 8-11 of the abdomen?
Contain non reproductive and reproductive appendages
155
What are the non-reproductive appendages of segments 8-11 of the abdomen?
Cerci
They are paired appendages at posterior end of abdomen
Normally used as sensory organs (can be modified into defensive organ)
156
What is the ovipositor?
Tubular structure in females used for egg-laying
Can be modified for piercing and sawing
Are external
157
What is the male copulatory organ?
Aedeagus
| They can be external
158
What are the immature stages of insects?
Nymph (or naiad)
Larva
Pupa
159
Nymphs:
An immature stage of an insect with incomplete metamorphosis
160
Naiads:
An aquatic gill-breathing nymph
161
Larva:
An immature stage (between the egg & pupa) of an insect with complete metamorphosis
Can have legs or be legless
Ex. caterpillars, grubs, maggots
162
Pupa:
Resting, non-feeding stage between larval & adult stage of an insect with complete metamorphosis
Can be enclosed (in puparium or cocoon) or exposed
Ex. chrysalid
163
Imago:
The last stage of development of an insect. The adult stage (sexually mature)
164
What are instars?
Insects between successive molts
| First instar = after hatching & before first molt
165
What are the three patterns of development?
Ametabolous
Hemimetabolous
Holometabolous
166
What is ametabolous development?
No metamorphosis
Egg -> nymph -> adult
Nymphs: no changes except for smaller size and sexually immature
Found in primitive, wingless insects
167
What is hemimetabolous development?
Incomplete metamorphosis
Egg -> nymph/naiad -> adult
Nymphs: smaller size, lack fully developed wings, sexually immature
Found in exopterygote insects
168
What are exopterygote insects?
Insects whose wings develop on the outside
169
What is holometabolous development?
Complete metamorphosis
Egg -> larva -> pupa -> adult
Larval stage is very different from adult
Found in endopterygote insects
170
What are endopterygote insects?
Insects whose wings develop internally
171
How many muscles do grasshoppers have?
900 muscles
172
How many muscles do caterpillars have?
Between 2000 & 4000 muscles
173
What is the purpose of muscles in an insect?
Body support & posture maintenance
Locomotion
Flight
Movement of viscera
174
How much can insects lift/pull?
Over 20x their weight
175
How far can insects jump?
Many times their own length
176
What are the types of insect muscles?
Skeletal muscles
| Visceral muscles
177
Skeletal muscles are:
Attached to integument
| Move various parts of the body, including appendages (includes flight muscles)
178
Visceral muscles are:
Surrounding the heart, digestive tract, & reproductive system
Produce peristaltic movements
179
What are the types of flight muscles?
Direct flight muscles (primitive)
| Indirect flight muscles
180
Which type of flight muscles are connected to the wings?
Direct flight muscles
181
Which type of flight muscles are attached to notum and sternum?
Indirect flight muscles
182
Direct flight muscles are:
Slower (30 beats/sec)
Independent between pairs of wings
Found in dragonflies, damselflies
183
Indirect flight muscles are:
```
More efficient (up to 1000 beats/sec)
Found in most insects
Move because deformation of thoracic segments
```
184
Where are muscles attached?
Insect with exoskeletons: at apodemes (ingrowths of the insect's exoskeleton)
Insects with soft bodies: muscles contract against hydrostatic skeleton
185
What is different about an insects respiratory system?
Separate from circulatory system (hemolymph does not carry O2 and CO2)
Insects do not have lungs
186
What are the two types of respiratory system?
Open tracheal system
| Closed tracheal system
187
How does the open tracheal system work?
1. O2 enters via spiracles (located along exoskeleton)
2. O2 moves down trachea to tracheoles
3. Tracheoles contact all internal organs & tissues
188
How is the tracheal system connected?
Transverse commisures
| Longitudinal tracheal trunks
189
Transverse commissures:
Connect tracheae on opposite sides of the body
190
Longitudinal tracheal trunks:
Connect tracheae from adjacent spiracles on same side of the body
191
How many spiracles are there usually?
2 pairs on the thorax
| 8 pairs on the abdomen
192
Why do spiracles close for extended periods of time?
To avoid water/chemicals
| To live underwater for extended times
193
What are air sacs?
Enlarged trachea for reserves if spiracles are closed
| They assist in ventilation
194
When is passive diffusion of O2 used?
For smaller or less active insects
195
When is ventilation of O2 used?
For larger or very active insects
| They pump thorax and abdomen to increase rate of diffusion
196
What is a modified open tracheal system?
Contains only one spiracle (the terminal spiracle)
Found in some aquatic insects
In the form of a breathing tube
197
What is a closed tracheal system?
No functional spiracle
| O2 enters via diffusion through the body wall (cutaneous respiration) or tracheal gills
198
What kind of circulatory system do insects have?
Open circulatory system: hemolymph circulates around internal organs with few veins to direct hemolymph
199
What is hemolymph?
Plasma containing water, ions, blood cells, amino acids, lipids, etc.
It is responsible for all chemical exchanges between tissues (hormones, nutrients, waste removal)
Plays a role in thermoregulation, molting process, and protection against predators
Serves as a water reserve
200
What is the dorsal vessel?
Tube running longitudinally through thorax & abdomen
Collects hemolymph in abdomen and conducts it forward to the head
Anterior part: aorta
Posterior part: heart
201
What does the anterior part of the circulatory system do?
Carries blood to the head (no valves or chambers)
202
What does the posterior part of the circulatory system do?
Divided into chambers separated by ostia (openings in dorsal vessels; valves to ensure one way flow)
203
What is the dorsal and ventral diaphragm?
Facilitate circulation by dividing body cavity into compartments
204
What is the accessory pulsatile organ (of antennae)?
Assist blood pumping into appendages
| Present at base of antennae, legs, & wings
205
What is the complete digestive system?
A tube that runs from mouth to anus
206
What are the three parts of the digestive system?
Foregut
Midgut
Hindgut
207
What does saliva include?
Digestive enzymes
| Anticoagulant in blood-feeding insects
208
What does the foregut do?
Ingestion
Temporary storage
Grinding
209
What are the components of the foregut?
Pharynx
Oesophagus
Crop (food storage)
Proventriculus (grinding organ only present in insects feeding on solid food)
210
What does the midgut do?
Production and secretion of digestive enzymes
211
What are the components of the midgut?
```
Gastric caecum (provide extra surface area for secretion of enzyme or absorption of nutrients)
Ventriculus (primary site for enzymatic digestion of food & absorption of nutrients)
Peritrophic membrane ( protects digestive cells without inhibiting absorption of nutrients)
```
212
What does the hindgut do?
Absorption of water, salts, & other molecules
| Elimination of waste products through anus
213
What are the components of the hindgut?
Ileum, colon, & rectum (regulate absorption of water & salts from waste products)
Anus
Malpighian tubule (excretory organ)
214
How much water is removed via the ileum, colon, & rectum?
90% of water
215
What is the malpighian tubule?
Removes nitrogenous waste & water from hemolymph
| Creates primary urine discharged into hindgut
216
What is the neuron?
A specialized cell
Basic component of nervous system
Consists of: dendrites, cell body, axons, synapses
217
What are the types of neurons?
Sensory neurons
Interneurons
Motor neurons
218
What is a sensory neuron?
Located near integument in PNS
Associated with sense organs
Receive stimuli from environment & transmit to CNS
219
What is an interneuron?
Located within ganglia of CNS
| Receive info from sensory neurons & transmit to motor neurons
220
What is a motor neuron?
Located within ganglia of CNS
| Receive info from interneurons & transmit to muscles
221
What does the peripheral nervous system consist of?
All sensory neurons of sense organs & motor neuron axons
222
What does the central nervous system consist of?
Principal division = series of ganglia
Brain: 3 fused ganglia. Innervates eyes & antennae. Handles all signals arriving from body
Suboesophageal ganglion: control mouthparts & salivary glands
Ventral nerve cord: ganglia of ventral nerve cord. Double w/ series of ganglion. Innervates legs, flight muscles, & control activities of each segment
223
What does the visceral nervous system do?
Innervates parts of gut, reproductive organs, & tracheal system (including spiracles)
224
How is sensory perception achieved?
By means of sensory organs (receptors or sensilla)
Usually microscopic
Found on/underneath cuticle
Are small hairs, domes, etc.
Scattered or aggregated (aggregated can form organs)
225
What are the types of sensilla?
Mechanoreceptors
Chemoreceptors
Photoreceptors
226
Mechanoreceptors:
Detect physical forces (touch, tension, or vibrations)
| Types: auditory receptors, tactile receptors, proprioceptors
227
What are auditory receptors?
Mechanoreceptors that respond to vibration
228
What are tactile receptors?
Mechanoreceptors that perceive stimuli which arise outside the insect (touch, movement)
229
What are proprioceptors?
Mechanoreceptors that respond to deformation, tensions, & compressions in the body
They provide info on posture & position
230
What are trichoid sensilla?
Sensory hairs that perceive movement of hair in its socket via currents of air or water & direct touch
Most common and least modified form of mechanoreceptors
Act as tactile, auditory, or proprioceptors
231
What are campaniform sensilla?
Domelike plates that respond to pressure & cuticle deformation
Found on base of wings & halteres
Act as proprioceptors
232
What are chordotonal sensilla?
Internal sensilla that are sensitive to pressure changes & muscle tension
Attached to cuticle at one or both ends
Act as auditory or proprioceptors
233
What are Johnston's organ?
Chordotonal sensilla clustered together (highly evolved auditory organ)
Present in the second antennal segment (pedicel) of all insects
It detects movement of the antennal flagellum
234
What is the tympanal organ?
Specialized auditory organ found in few insects
Sensitive to airborne vibrations
Consists of a thin cuticle (tympanum) lying on top of an air-sac linked to chordotonal organs
235
What are chemoreceptors?
Involved in the smell (olfaction) and taste (gustation)
Sensory dendrites are exposed to the environment through small openings in the cuticle
Can be uniporous or multiporous
236
Olfactory receptors:
Perceive chemicals in a vapor state (airborne)
Can detect chemicals in air in low concentrations
Large number of sensory neurons
Mostly found on antennae
Usually multiporous
237
Gustatory receptors:
Perceive chemicals in aqueous state
Can only detect chemicals in high concentrations
Very abundant on mouthparts (also on tarsi, antennae, or ovipositors
Usually uniporous
238
What are photoreceptors?
Detect light energy
Types are: compound eyes, ocelli, stemmata
Sometimes integument can perceive light (called dermal detection)
239
Compound eyes:
Photoreceptors
Principal visual organ of insects (movement, forms, light, color)
Can be close to 360 field of vision
Found in most adults & nymphs
Ommatidia are the individual components on the compound eye (can be between 5-30,000)
240
Ocelli:
Photoreceptors
Found in addition to compound eyes in many insects
Can't perceive images, but only detect changes in light intensity
Usually have 3 ocelli
241
Stemmata:
Found mostly in insect larva
Are lateral ocelli
Do not perceive images but can provide info about light intensity, size, shape, movement, & color of objects
Have 1-6 on each side of the head
242
What are benefits of insect vision?
Can detect movement much faster than we do
Have wide field of vision (up to 360deg)
See different part of the spectrum than humans (shift toward shorter wavelengths: ultraviolet, not red)
Can see patterns on flowers invisible to humans
243
What are the components of the female reproductive system?
Paired ovaries w/ multiple ovarioles
Paired oviducts that receive mature oocytes from ovaries
Move into common oviduct
Common oviduct opens into genopore (via genital chamber)
Spermatheca stores sperm
Spermathecal gland provides nourishment for spermatozoa
244
How many ovarioles are there per ovaries?
Usually between 4-8 in each ovary
Queen honeybee = 150-180 per ovary
Termite queen = 2000+ per ovary
245
How does fertilization occur with spermatheca?
Female controls liberation of spermatozoa; synchronous with movement of egg in oviduct
246
What are micropyle(s)?
Openings in the egg shell
| How sperm enters the egg
247
What are the functions of the accessory gland of the female reproductive system?
1. Secrete material used to glue or cement eggs to the substrate
2. Secrete protective coating on the eggs (ootheca)
3. Secrete silken stalk in lacewing
4. Act as a poison gland (in many hymenoptera)
5. Act as milk gland in tsetse flies
248
What are the components of the male reproductive system?
Paired testes w/ multiple sperm tubes
Vas deferens below testes allows sperm to move down
Seminal vesicle is the expansion of each vas deferens (stores sperm)
Ejaculatory tube is the combination of the vas deferens
Aedeagus is where the sperm leaves the body
249
Sperm tube:
Where spermatozoa are produced
| Each tube consists of sperm cells in progressive stages of maturation
250
What are the functions of the accessory glands in the male reproductive system?
1. Produce seminal fluid (nourish spermatozoa during transport OR serves as carrier for spermatozoa & activator, induces motility)
2. Altering female behavior (inc. egg production & stimulate oviposition OR dec. receptivity of female to other males)
3. Formation of mating plug
4. Formation of spermatophore
251
Sexual reproduction with indirect sperm transfer:
Mostly in primitive wingless insects
| Male deposits spermatophore on ground (female settles over it and takes it into genital opening)
252
How do males increase chance of female encounters with spermatophore?
Produced when females are in aggregations
| Produced in large numbers
253
Sexual reproduction with direct sperm transfer:
1. Copulation: aedeagus of male enters female
Species-specific position: prevents interspecific mating
2. Haemocoelic insemination: injection of sperm into body wall of female (in bedbugs (via organ called spermalege) & twisted-wing parasites (via females cephalothorax))
254
What is parthenogenesis?
Type of asexual reproduction
Eggs develop without being fertilized
Can be obligatory (no males) or facultative
255
When is facultative parthogenesis used?
In stick insects: if males are unavailable (only females produced)
In aphids: According to season
In bees, ants, & wasps (Hymenoptera): optional to fertilize eggs. Will determine the sex of the offspring (sex = female (XX); no sex = male (XO)(haplodiploidy)
256
How is sex determined in insects?
XO sex-determination: XX = female; XO = male
257
What is oviparity?
Production of eggs that hatch outside body
Embryonic development starts outside body
Found in most insects
258
What is viviparity?
Give birth to live young
Embryonic development completed in female
Found in some silverfish, cockroaches, flies, beetles, & aphids
259
What are the means of location and recognition of a mate?
Swarming
Flashing (visual signals)
Singing (acoustic signals)
Pheromones (chemical signals)
260
Swarming to mate:
Only males
Use visual markers
Good when individuals are rare or dispersed
In: mayflies, flies, butterflies
261
Flashing to mate:
Both sexes produce light
Females often flightless (respond to flashing of male)
Duration & frequency is species-specific
In: fireflies
262
Sound production to mate:
Only males sing
Various methods: stridulation (rubbing together body parts); vibrations of tymbals (special membranes); striking body parts against substrate
263
Pheromones to mate:
Produced by female
Detected by male's antennae (have larger antennae)
Can detect low levels
Great way of finding mate over long distance
264
What can courtship include?
```
Visual displays
Tactile stimulation
Pheromones
Singing
Nuptial gift
```
265
Visual displays to courtship:
Performed by males
| Includes: movement of body parts, display of color patterns, elaborate dances
266
Tactile stimulation to courtship:
Rubbing of antennae, palps, legs, abdomen, etc.
Important for final species recognition
Immediately before & during copulation
267
Pheromones to courtship:
Close range recognition
Sexual excitation
Androconia: male Lepidoptera can have scent scales on wings
Abdominal hairpencils: male Lepidoptera can have brushes that release pheromones
268
Singing to courtship:
Different sounds produced in close-range courtship
269
Nuptial gift to courtship:
Males provide food to inc. mating chance
Dance flies: silken ball that MAY contain prey item
Ultimate nuptial sacrifice: cannibilism of male
Spermatophylax: sperm-free portion of spermatophore which is eaten by female
270
What is sperm competition?
Sperm from two or more males compete to fertilize the eggs
271
Ways of sperm competition?
1. Displacing sperm of other males
a. pushing sperm to back of spermatheca
b. direct scooping or indirect flushing out
2. Reduce effectiveness or occurrence of sebsequent inseminations
a. mating plugs
b. prolonged copulation
c. dec. receptiveness of female to other males
d. Improved structures for gripping female during copulation
e. guarding females until oviposition
272
What are the insect hormones?
Ecdysone: initiates molting process
| Juvenile hormone: metamorphosis inhibiting hormone
273
What is the ecdysone hormone?
Initiates molting process
| Released by prothoracic gland
274
What is the juvenile hormone?
Metamorphosis inhibiting hormone
Keeps insects in nymphal or larval form
Released by endocrine glands called Corpora allata
275
What happens when juvenile hormone + ecdysone is present?
Metamorphosis into next immature instar
276
What happens when juvenile hormone is absent?
Metamorphosis into pupa or adult
277
What happens when the corpora allata is removed?
Premature metamorphosis = small adult
278
What happens when the corpora allata is added?
An additional instar = giant adult
279
What are semiochemicals?
Chemicals released outside the body to communicate with individuals:
Of the same species (pheromones)
Of different species (allelochemicals)
Released by exocrine glands
280
What kinds of pheromones are there?
```
Sex pheromones
Aggregation pheromones
Spacing pheromones
Trail-marking pheromones
Alarm pheromones
Social pheromones
```
281
Sex pheromones:
Sex attractant over long distances (female)
Courtship chemicals over short distances (male)
Used in pest management
282
Aggregation pheromones:
Cause individuals of the same species to crowd around the sources of the pheromones:
Inc. chance of mating
Provide security from predation
Maximum utilization of a scarce food resource
Overcoming host resistance
283
Spacing pheromones:
Cause individuals to keep their distance from each other
Limit number of species found on a food resource
Oviposition marking pheromone: inhibits further oviposition of same host
284
Trail-marking pheromones:
Used to communicate info on location of a food source
| Reinforce chemical markers as individuals walk through
285
Alarm pheromones:
Used to signal danger which cause the insects to disperse away from source of danger or attack enemies
286
Social pheromones:
Regulation of colony structure
| Ex. Queen honeybees produce pheromones to inhibit development of worker's ovaries
287
What are types of allelochemicals?
Kairomones
Allomones
Synomones
288
What are kairomone allelochemicals?
Chemicals that benefit the receiver but disadvantage the producer
Act as host attractants
Ex. chemicals from a damaged tree
289
What are allomone allelochemicals?
Chemicals that benefit the producer by modifying the behavior of the receiver
Receiver has neutral effect or is disadvantaged
usually defensive and/or repellent secretions
Ex. repellent odors of ladybugs advertising bad taste; orchid flowers produce sex pheromone mimic of bees/wasps
290
What are synomone allelochemicals?
Chemicals that benefit both producer & receiver
| Ex. flower scent attract pollinators
291
How many Hexapoda orders are there?
~32 known
| Number varies depending on classification used
292
When did primitive winged insects appear?
~350 MYA
293
When did the first insects appear?
~400 MYA
294
When was the first great radiation of insects?
After winged insects appeared
295
When did the first flowering plants appear?
~145 MYA
296
When was the second great radiation of insects?
After the first flowering plants appeared
297
What is the difference between Class Entognatha & Class Insecta?
Entognatha: concealed mouthparts enclosed in folds of head; indirect sperm transfer, oviparous, small size, ametabolous (except protura)
Insects (Ectognatha): mouthparts visible; either apterygotes (wingless, ametabolous) or pterygotes (winged/secondarily wingless)
298
What are the types of pterygota insects?
Paleoptera (primitive wings)
| Neoptera (new wings)
299
Order Protura
```
Proturans
Lack eyes & antennae
Forelegs enlarged with many sensillae
Cerci absent
Anamorphic development (abdominal segments added during first 3 molts)
```
300
Order Collembola:
```
Springtails
Globular to elongated body
Most familiar entagnatha
Cerci absent
Furcula (jumping)
Collophore
Spermatophore on stalks
```
301
Order Diplura
```
Diplurans
Elongated body
Unpigmented
Lack eyes
Long antennae
Pair of cerci
```
302
Archaeognatha:
```
Jumping bristletails
Indirect sperm transfer
Nocturnal
Thorax arched
Compound eyes large & together
Jump by rapidly flexing abdomen
Cement themselves with fecal material before molting
```
303
Zygentoma:
Silverfish & firebrats
Flattened body
Compound eyes small & widely separated
Mostly nocturnal
304
Ephemeroptera:
```
Mayflies
Vestigial mouthparts
Sexual dimorphism: males = bigger eyes & longer front legs
Swarm in flights
2 winged stages: subimago & imago
Molt 20-30 times
```
305
Odonata:
Dragonflies & damselflies
Acute vision: large compound eyes w/ ocelli
Suborders: Anisoptera (dragonflies) & Zygoptera (damselflies)
Legs long for perching & holding prey
Chewing mouthparts
Mate in wheel position
306
Odonata nymphs:
Anisoptera (dragonflies): have gills inside rectum (draw in water to breath and move)
Zygoptera (damselflies): leaflike gills at end of abdomen (to breath and move)
Leave water to molt to adult stage
307
Orthoptera:
```
Grasshoppers, crickets, & katydids
Most have wings (some wingless)
Jumping hindlegs
Chewing mouthparts
Tympana present
Suborders: Caelifera (short-horned Orthoptera); Ensifera (long-horned Orthoptera)
```
308
Caelifera:
```
Short-horned Orthoptera
Acrididae (grasshopper)
Romaleidae (lubber grasshopper)
Tetrigidae (pygmy grasshopper)
Antennae much shorter than body
Short & stout ovipositor (lay egg pods directly into soil)
Tympana on first abdominal segment
Rub tegmina against hind legs
Diurnal
Phytophagous
```
309
Ensifera
```
Long-horned Orthoptera
Gryllidae (crickets)
Tettigoniidae (katydids/long-horned grasshoppers)
Antennae usually longer than body
Long ovipositor & long cerci
Tympana on foretibiae
Rub tegmina together
Nocturnal
Omnivorous
```
310
Phasmatodea:
```
Walkingsticks and leaf insects
Chewing mouthparts
Phytophagous
Some have wings
Forewings = tegmina
Sexual dimorphism is common: females = larger; males = more developed wings
Parthenogenetic usually
```
311
What is the defense of Phasmatodea?
Camouflage
Autotomy (losing limbs voluntarily: will regrow if immature)
Behavior: catalepsy (playing dead), imitation, rocking
Chemicals
Spines
Nocturnal
312
Grylloblattodea:
Rock crawlers or Ice crawlers
Limited temperature tolerance (between 1-4C)
Omnivorous
Small order (26 species)
313
Mantophasmatodea:
```
African rock crawlers
Most recently discovered order
Small order (15 species)
Wingless
Chewing mouthparts
No raptorial forelegs or jumping hindlegs
Nocturnal
Carnivores
```
314
What are the orders in the Superorder Dictyoptera?
Mantodea
Blattodea (Isoptera)
Have similar proventriculus (grinding organ)
Have ootheca
315
Mantodea:
```
Mantids
Elongated prothorax
Chewing mouthparts
Head hypognathous & triangular
Larger, lateral compound eyes
Forelegs raptorial w/ long coxae
Forewings = tegmina
Predacious (attack small animals)
Reproduction: male = aggressive pre-copulatory behavior (jumps on female); female = aggressive copulatory/postcopulatory behavior
Ootheca overwinters on twigs/stems
~2,000 species (3 in CA: ground mantid is only native species)
```
316
Blattodea:
```
Cockroaches
Most primitive (unchanged for 320 MY)
Head concealed by pronotum
Chewing mouthpart
Hypognathous head
Filiform antennae
Tegmina (wings may be absent)
Cursorial legs
Cerci present
~4,000 species
Omnivorous
Nocturnal
Facultative parthenogenesis
Oviparous or Oviviviparous
Native species: hooded cockroach, wood cockroach
Extremely resistant (live for a month without food, 30 mins without air)
```
317
What is oviviviparity?
Egg development inside body
| Give birth to live young
318
Isoptera:
Infraorder of Blattodea
Termites
Only hemimetabolous insects with true social behavior (castes, overlapping generations, cooperative care of young)
Chewing mouthparts
Herbivores
Have intestinal microorganisms that can digest cellulose (transfer via proctodeal trophallaxis)
~3,000 species
Nests called termitaria
Ecological importance: soil aeration, wood decomp, major source of methane
319
What is proctodeal trophallaxis?
Transfer of material between individuals via mouth-mouth or anus-mouth
320
What is the caste order of Isoptera?
Workers: sterile, wingless, blind, m. & f., most numerous, weakly sclerotized, build & repair nests, gather food, feed soldiers & reproductives
Soldiers: sterile, wingless, blind, m. & f., have large sclerotized heads & large mandibles, defend colony
(Nasute termites: soldiers with reduced mandibles, but forward prolongation of head that eject sticky poisonous substance)
Queen: reproductive caste, wings present, king fertilizes queen in nest, first born nymphs care for queen, can produce thousands of eggs per day, most fertile insects known
321
What are termitaria?
Nests of termites
Below or above ground
Types:
1. Galleries excavated in dead wood
2. Arboreal "carton" nests in trees made of chewed wood, saliva, & fecal matter
3. Small soil hills or large mounds (live under mounds for max ventilation)
