Exam Time Flashcards
Arthropods
External skeleton invertebrates. Insects are within this class. Huge component of biodiversity.
Hexapoda
Adult insect.
6 legs
3 body regions
2 pairs of wings
1 pair of antennae
1 pair of compound eyes.
Undergo metamorphosis- adults use different resources to young.
Groups of Hexapoda
Lepidoptera
Diptera
Coleoptera
Hymenoptera
Ominoptera
Hemiptera
Hexapoda legs
Come from thorax. Broken into
3 parts each with a pair of legs.
Coxa, trochanter, femur, tibia, tarsi then pretarsus.
Myriapoda
millipedes- two pairs of legs per body segment and vegetarian. Decaying plant matter.
Centipedes- one pair of legs per body segment and predatory.
Both have one set of antennas
Crustaceans
Generally aquatic with some land dwelling- still got gills
Chelicerata
Mites, sea spiders, horseshoe crabs, scorpions and spiders.
Pedipalps no antennae.
Primary eyes and many secondary eyes
Groups found in Burgess Shale
Has high levels of hard and soft tissue detail from Cambrian
Radiodonts- largest things at thag point in sea. Eye stalks for predation with swimming appendages.
Trilobites
Crustaceans
Chelicerates
Lopodians- hydraulic legs on sea floor. Related to tardigrades and onchyophorans (velvet worms)
When do insects appear
First evidence in rhynie chert. 400MYA
Cell level detail preserved. Cyanobacteria, freshwater algae, plants and arthropods can be overages. Myriapoda and hexopods as well as spore rich coprolites. Arachnids too- and first penis.
Carboniferous swamp foresss
Lots of O2 in atmosphere. Widespread environment 327-299MYa. Vertebrates on land now.
Insect giantism happening. Likely due to large amounts of oxygen in atmosphere- respiratory system is limited. Giantism stopped when birds and pterosaurs evolved too.
Evidence of first insect-plant pollination. Similar to wasp and figs today
Lacewings
Convergent evolution with butterflies from Mesozoic. Has the same eye spot and filled in pollination niche
Integument
A network of features that forms the covering of an organism.
Insect colours
Mostly yellow, orange and red carotenoid or brown melanin in cuticle.
Green and purple from structural features of cuticle
Integument structure
Exocuticle, endocuticle, epidermis. With setes, gland openings and ridges for muscle attachment.
Cuticle is non-living and secreted by the epidermal cell. Epidermis is one layer of cells thick. Basement membrane under epidermis separates cells from hemolymph
Sclerotization
Cuticle becoming hard from chitin. Unmodified is translucent, pliable and resilient. Adults have proteins interwoven to make it dark and hard.
Ecdysis
Moulting of cuticle
Insect gills
Outgrowths of tracheal system covered by a thin layer of cuticular permiable to CO2 and O2. Leaf like in shape and located on sides or abdomen. Fanning movements to keep constant water supply
Pulsatile organs
As well as dorsal vessel insects have other structures to maintain circulation- wing bearing segments, bases of antenna and legs
Nervous system segments
Brain, subesophageal ganglion, thoracic ganglia, abdominal ganglia
Ptotocerebrum
Brain part 1. Associated with vison. Compound eyes and ocelli
Deutocerebrum
Brain part 2. Processes sensory information from antennae
Tritocerebrum
Brain part 3. Labrum and integrates the sensory inputs form proto and deuto cerebrums. Links brain with rest of nervous system
Sub-oesophageal ganglion
Neve system 1
Mandibles, maxillae, labium, hypoyhorax, salivary glands and neck muscles
Thoracic ganglia
Nerve system 5. Sometimes fused. Controls legs and wings
Abdominal ganglia
Nerve system 6
Abdominal muscles
Proprioceptors
Hair plates or position receptors. Mechanoreceptors. Hair sensillia are located in patches with a pleuron in Z shape (fold of intersegemntak membrane). Located in neck and joints of legs and palps.
Hydroreceptors and thermoreceptors
Humidity important to conserve water. Temperature and humidity receptor are in same sensillum. Short peg with no pore. Always on insect antennae
Campaniform sensilla
Mechanirdceptor. Dentrite in epidermis to cuticle from sensory neurone in epidermis. Can sense when cuticle is bending. Found throughout body but especially on legs and near wing base.
Trichofrom sensillae
Hair coming off cuticle with dentrite touching to sense movement. Mouthparts, legs, antennae and wings.
Chemoreceptors- taste
Gustatory receptor. Thick walled hairs with dendrite in with open tip or pit with several exposed to environment through a single pore.
Chemoreceptors-smell
Olfactory receptors. Usually thin walled pegs/cones/plates with many pores for airborne molecules tk diffuse. Send tired of many sensory organs.
Insecta subclasses
Hemimetabola (partial metamorphosis)
Molometabola (full metamorphosis)
Apterygota
Wingless and don’t metamorphosis. Less developed
Pterygota
Split into exo and ends
Exo- external wing development, incomplete metamorphosis, pupal stage absent and naiad or nymph as immature stage.
Endo- internal wing development, complete metamorphosis, has a pupal stage and immature is larva
Univoltine vs bivoltine
One generation vs two of offspring per year
Oothecae
Specialist structure eggs are laid in to protect them