Midterms Flashcards
a branch of biology that deals with the study of insects.
Entomology
refers to the temporary condition characterized by an excessive population of insect pests and causing losses to crops if not immediately controlled.
Insect outbreaks
a branch of Forest Biology that deals with the study of insects that affect forest products
Forest Entomology
Importance of Insects
-They serve as pollinators.
-They are agents of pest and disease control
-They are used as food for humans and livestock.
-provide other valuable goods
-They serve as agents of decomposition.
-They play an important role in maintaining soil productivity by enhancing soil fertility
-They have aesthetic values as reflected in the inspiration/
motivation they provide
- They are instrumental in the advancement of scientific researches or science and technology
Destructive nature of insects
Disease vectors
Inflict injuries to man
serious damages to forest products and crops
pests to livestock
A small arthropod animal that has six legs and generally one or two pairs of wings
Insect
Insects serve as ______________, which leads to hybridization that promotes
plant diversity.
Pollinators
Forest Plantations that are more susceptible to pests and diseases.
Monoculture Plantation
The study of the classification of insects
Taxonomy
Taxonomy is based on
__________ _________for the most part of the organism being grouped together.
Structural similarity
What phylum of species are characterized by jointed legs
Phylum Arthropoda
Classes under Phylum Arthropoda
- Insecta
- Arachnida
- Crustacea
- Diplopoda
- Chilipoda
A class with a single pair of legs
per body segment.
Chilopoda
Three major body segments:
Head, thorax, and abdomen
OC; primitive, wingless insects;
Apterygota
OC; winged insect;
Pterygota
OC; pterygotes with simple metamorphosis;
Exopterogota
- characterized by long and rounded jumping hind legs and
straight wings; include grasshoppers, field crickets, mole crickets,
walking sticks, praying mantis, and cockroaches.
Orthoptera
pterygotes with complete metamorphosis;
Endopterygota
feed on plants only.
Phytophagous
feed on animals.
Zoophagous
feed on other insects.
Entomophagous
two general types of
entomophagous insects:
- Parasite
- Predator
feed on dead or decaying plant or animal materials.
Saprophagous
feed on various (plant and animal) foods.
Polyphagous
feed on leaves of trees/ plants. Their feeding may reduce or stunt
tree growth or increase mortality depending on the severity of the damage
inflicted.
Defoliators:
beetles: adults invade trees or logs through the bark; larvae feed
on cambial region; adults may feed on cambium or solid wood;
Bark borer:
adult and/ or larval insects bore into the bark and wood/ or of
living trees or logs and may render the wood unfit for construction or other uses.
Wood borers:
adult and larvae destroy and distort buds and new shoots of young trees;
Bud and meristem feeders:
such as aphids and scale insects: adults and nymphs pierce host and withdraw nutrients causing decline in vigor and growth and death:
Plant’s juice/sap suckers
adults and larvae infect roots of healthy living trees and seedlings in forest and nurseries; feed on bark surface and roots and may consume the entire roots system.
Root and stem weevils:
Types of mouth parts
Chewing
Siphoning
Piercing-sucking
Chewing-lapping
Sponging
Chewing piercing
eggs are produced, fertilized and oviposited by the female such in moths
Oviparous
eggs are normally developed and fertilized but are retained and
hatched in the female body as in cockroaches, some beetles and flesh fly
Oviviparous
young (not eggs) are born/ produced as in humans
viviparous
refers to the inherent ability of insects to multiply as affected
by environmental factors.
Reproductive potential
The sum total of environmental factors that limits the
reproductive potential of organisms
Environmental resistance
appears suddenly in a small or restricted area and lasts for single
season and then subsides
Sporadic outbreaks
may occur at susceptible growth stages of crops as a result of
certain weather or environmental conditions.
Periodic outbreak
the science of the structure of insects.
Insect morphology
The anterior region of the insect body
carries the mouth parts, antenna, and the compound eyes.
Head
the individual units of the
compound eye
ommatidia
Mobile sensory segmented appendages. Functionally they are almost exclusively in sensory perception.
Insect antennae
Mouthparts that are directed backward below the insect’s body.
Opisthognathous
Mouthparts that are directed forward in front of the insect:
Prognathous
Mouthparts directed downward toward the ground. Used for grazing.
Hypognathous
Chewing mouthparts. Sclerotized mandibles (‘jaws’) which move side
to side for biting and chewing food particles.
Mandibulate
Sucking mouthparts. Often form tubular structures including beaks,
proboscis, and rostra:
Haustellate
Thorax: nearest to the head; holds the
front pair of legs
Prothorax
middle segment; holds the second pair of legs and the front pair of wings (fore wings)
Mesothorax
distal segment; holds the third
pair of legs and the hind wings.
Metathorax
The middle region of the body, bears the structures for locomotion-the wings and legs;
Thorax
leathery in texture as the
wings of grasshopper and insects in the orders
Orthoptera, Blattaria, and Mantodea.
Tegmina
hardened, heavily sclerotize like
the thick forewing of earwigs and
beetles that protects the hind wings
when at rest.
Eltyra
thickened forewings with membranous overlapping tips as those of the true bugs.
Hemelytra
knob-like specialized hind wing of a fly arising from the metathorax and supposedly aiding in balance and direction during flight.
Haltere
are highly modified for different functions, depending on the environment and lifestyle
of an insect.
Insect legs
Jumping legs as those of the grasshoppers.
Saltatorial
Running legs as those of the cockroaches.
Cursorial
Grasping legs as those of the praying mantis.
Raptorial
swimming legs as those of the dysticid beetles.
Natatorial
Digging legs as those of the mole crickets.
Fossorial
the posterior region of insects, contains the reproductive organs and the majority of the organ systems.
The abdomen
The dorsal and ventral abdominal segments
Terga and sterna
the breathing openings found on the
surface of insects.
Spiracles
are thread-like processes located at the end of the abdomen.
Abdominal filaments
The skeleton or supporting structure of an insect body
Exoskeleton
Functions of the Exoskeleton:
- Protection of the inner insect parts and organs
- As supporting structure
- Attachment of muscles
contains chitin, protein and pigments
Cuticle
cellular layer beneath the cuticle
Epidermis
non-cellular layer lies beneath the epidermis
Basement membrane
a nitrogenous polysaccharide with the formula (C8H13NO5) n. abundant in the softer parts of the procuticle and entirely absent in the epicuticle. Resistant substance insoluble to water, alcohol, dilute acid, and alkalis,
Chitin
Organ system of insects
Digestive
Reproductive
Tracheal
Circulatory
Nervous
Excretory
The excretory organs of insects and other terrestrial arthropods
Malphagian tubules
circulatory fluid
Hemolymph
Insects breathe through small tubes called _________ that pass throughout the body and are connected to the outside by special openings called ______________.
trachea, spiracles
animals. Two–thirds of all named
species on earth are ________
Arthropods
a thick bundle of nerves usually extending longitudinally through
the body from the brain.
Nerve cord
A process where insects shed and replace their exoskeleton with larger one as they grow
Molting
The life stage between each molt
Instar
a steroid hormone is secreted by a gland in the thorax, which is in turn controlled by a hormone from the brain. Whenever the brain receives the appropriate stimulus, the insect will molt.
Ecdysone
the way that insects develop, grow, and change form.
Metamorphosis
actually means “change”.
Metamorphosis
3 stages of Incomplete metamorphosis
Egg
Nymph
Adults
4 stages of complete metamorphosis
Egg
larva
Pupa
adult
the insect dormancy
Diapause
little or no metamorphosis
Ametabolous:
simple or gradual metamorphosis
-marked by three life stages: egg, naiad, and adult
Hemimetabolous:
characterized by a gradual development, the young being similar to adults except in the size of developing wing pads, ocelli, and reproductive organs;
Paurometabolous
complete metamorphosis
Holometabolous:
Egg shapes
a. Spherical
b. Elongated
c. Oval
d. Barrel shaped
production of eggs or young by an immature or larval stage of an animal
Paedogenesis
development of egg without fertilization
Parthenogenesis
hatching from egg
Eclosion
egg developing into two or more embryo
Polyembryony
Larvae of butterfly
Erucifrom
Larvae of Fly
vermiform
Larvae of Click beetle
elateriform
Larvae of aquatic beetle
campodeiform
Larvae of scarab beetle
Scarabeiform
the act of an adult insect leaving the pupal stage
emergence
a case formed by the hardening of the next to the larval skin.
puparium
the cast skin of an arthropod
Exuvia
What hormone inhibits metamorphosis of insects that does not reach the right size and stage of development?
Juvenile hormone
This muscle of the grasshopper is located in their hind leg and when contracts, the leg jerks backward, sending the insect into the air.
Extensor muscle
What species of insect lays egg that resembles plant seeds?
Walking Stick
What does IPM stands for?
Integrated Pest Management
This insect have only fewer than 20 known species, it is also endemic in southern and east Africa
Ice Crawlers
A disease caused by the carried virus of green leafhoppers and brown plant
hoppers.
Tungro
Insects serve as ______________, which leads to hybridization that promotes
plant diversity.
Pollinators
A product coming from Laccifer lacca.
Shellac
Mosquitoes - Anopheles spp. is known as malarial
Vectors
Insect Species that may cause pest or insect outbreak
Introduced or exotic
1It is the perceived condition of a forest derived from concerns about such factors as its age, structure, composition, function, vigor, and presence of unusual levels of insects or disease, and resilience to disturbances
Forest health
The forest has reached its peak of development.
Environmental view
A forest is in good health is a fully functional community of plants and animals and their physical environment. A healthy forest is an ecosystem balance
Ecosystem centered
non-interference with management objectives.
Utilitarian view
Factors Affecting Forest Health
Biotic and abiotic factors
