Test 2 Flashcards
Hymenoptera
Four wings, hind wings smaller
Primarily chewing type mouthparts
Bees form tongue like structure
Ovipositor sometimes modified into a sting (females only)
Trichoptera
Pupate in case-adults must swim to the top
Closely related to Lepidoptera
Hymenoptera social?
Many social as well as solitary species
Many bees and ant species are eusocial, with workers, soldiers, reproductives
Hymenoptera and sex
Haploid/diploid
Diploid-full complement of chromosomes
Haploid-only chromosomes from the female parent
Males produced from unfertilized eggs
Females come from fertilized eggs
Family Formicidae - the ants
About 9000 sp globally
Social insects
Colonies can exist for years
What defines an ant colony?
Queen-may be several
Workers, soldiers-all female
Males live just long enough to mate
Argentine Ants: Global power?
Colony stretches 3,700 miles across Europe
California colony covers 560 miles
Japan super colony
Are they all one monster colony?
Fire Ants
Over the entire Southern U.S.
Imported probably in the 1920s or 30s
Came from S. America
Females bite and sting
Forming a new ant colony
Swarming depends on warmth/humidity
Mating occurs in the air
New queens lose wings. Males die.
Managing Fire Ants
Use broadcast treatment spring and fall Baits (food plus poison) Broadcast insecticides Treat individual mounds Baits Insecticides Insecticide or boiling water drenches
Leaf Cutter Ants
Nearly all tropical Few animals known to grow own food Pieces of leaves are brought into colony Fungus is grown on the leaves Fungus is ants only resource Fungus and ants not known to live separately
Parasitoids
Predators kill and eat multiple pray
Parasites do not usually kill their hosts
Parasitoids lay eggs near or in host
Host is ultimately killed
Parasitoid wasps
Parasitoid wasps are solitary
Not aggressive
Females lay eggs in host
Parasitism specialize in one or a few types of prey
Order Hymenoptera: Family Sphecidae(mud daubers)
Females make mud nests
They provision the nests with spiders
The larvae develop on spiders
Often build in the same site for years
Females can sting, but they are unagressiveMud daubers
3 species to know in GA
Organ pipe mud daubers-
Prefer orb weaver spiders
Black and yellow mud daubers-
Nest is an unshaped lump
Prefer spiders found around vegetation-jumping spiders, crab spiders
Blue mud daubers
Take over old nests of other mud daubers
Prefer black widows and brown widows
Bumblebees hornets yellow jackets paper wasps
These form a social colony-not permanent
Fertilized females overwinter and start new nests in spring
The males and all the other females die in cold weather
In mild cold seasons, a colony may persist for several years
Integument
Outer layer of worm is chitin
Resilin
Elastic
Can store energy
Chitin
A sugar polymer
Provides toughness and flexibility
Molting
Or
Ecdysis
Only Immatures molt
Instars-period in between molts
Ecdysone-molting hormone
Insect growth
Juvenile hormone
Shedding the old skin
Insect distends with air or water
Ptilinum-inflatable sac on some flies
Insect distends after leaving old skin
Three sections of digestion/excretion
Stomodeum
Mesenteron
Proctodeum
(Front to back)
Stomodeum
Ingestion and digestion
Mesenteron
Not lined with chitin
Absorption
Proctodeum
Lined with chitin
Removes waste, regulates water, urea salts
Filter chamber
Specialized structure that allows fluid feeders to obtain more nutrients
Increases absorption area
Some hemipterans:aphids, leafhoppers, whiteflies
Digestion/excretion
Insect digestive system is typically made up of three sections
Stomodeum:ingestion,digestion
Mesenteron:absorption
Proctodeum:excretion,regulation
Some fluid feeders also have filter chambers to improve nutrient uptake
Aquatic/semiaquatic insects-ammonia waste
Terrestial insects-solid uric acid
Digestion and role of bacteria
Cellulose
few insects produce cellulase
Bacteria-few beetles
Protozoans-termites,roaches
Respiration
Relies heavily on diffusion
Spiracles
Up to ten pairs
One pair per segment
Circulation
Circulatory system does not transport O2 but distributes and filters
Insect blood is called hemolymph
Insects have an open circulatory system
Blood dumps at the end of aorta
Circulation is facilitated by the heart or dosal aorta
Insect nervous system
Central nervous system
Stomatogastric nervous system
Central nervous system
Neuron groups form ganglia
CNS:brain and segmental ganglia
Thoracic ganglia control legs/wings
CNS: Protocerebrum
vision,integration of multiple behaviors
CNS: deutocerebrum
Antennas inputs
CNS: Tritocerebrum
Connects to stomatogastric system; integrates input from other brain lobes
CNS:subesophageal ganglion
Mouthparts, salivary glands, neck muscles
Insect vision
Simple eyes-ocelli and stemmata
Compound eye
Ocelli
Do not detect images but rather changes in light intensity
Stemmata
Form images equivalent in quality to compound eye with much less ‘hardware”
Found in holometabolous larvae and other forms lacking compound eyes
Insect chemoreception
Taste and odor
May occur in mouthparts, legs, antennae, and ovipositors
Insect hearing
Insects hear with tympana
Usually located between the thorax and abdomen, but may be elsewhere
Insect and plants
About half of all insect spp are phytophagous meaning feed on plants
Key primary plant consumers competing with humans
Phytophagy has evolved repeatedly, probably from scavenging
Coevolution definition
Evolution of one group affects evolution of another group
Effects on plants from insects
Many interactions are not detrimental to plant
Types of interactions
Mutualism
Commensalism
Predation, parasitism, parasites
Competition
Mutualism
+ and +
Commensalism
+ and 0
Predation, parasitoids, parasites
+ and -
Competition
- and -
Insect/plant coevolution first interaction
Herbivory and accidental pollen transfer
Beetles
Important early pollinators
Well diversified in the Mesozoic era
Beetles may eat ovules of plant that was pollinated
Coevolution steps
Plant odor to attract insects from a distance
Flower color-insects’ color vision
Role of homopteran honeydew-
Aphids need protection so they secrete it as a form of food for the ants
Pollination
Pollen onto receptive stigma
Wind pollination
Mechanical transfer
Usually by insects
Birds, bats, and other animals can also be pollinators
Disadvantage of wind pollination
Untargeted
Decreased likelihood of out-crossing
Much larger production of pollen needed
Plants don’t disperse well
Advantages of wind pollination
Not dependent on a “third party”
No need to supply “reward”
Advantages of insect pollination
Facilitates out-crossing, even if plants very dispersed
Coupled with seed dispersal by birds and other factors, helps plant colonize new habitats more rapidly
Reliable dispersal facilitated plant specialization-greater diversification
Disadvantages of insect pollination
Third party involved
Plant must produce reward
