Arthropoda IX - Hexapoda (II) Flashcards
Ancestral Mouthparts (chewing)
Grasshoppers have this type
Labrum: the upper lip of the mouth
Mandibles: 2 of these (pair)
Hypopharynx: tongue with salivary glands
Maxilla (1st): food handling using these 2 (pair)
Labium (2nd maxillae fused)
Housefly and Horsefly mouthparts
The labium is used for sponging up liquid food
Housefly have lost mandibles and 1st maxillae
Horsefly use mandibles to slice into prey
Butterfly sucking mouthparts
The mandibles and labium are not well developed
The 1st maxillae form a sucking tube
Mosquito Piercing & Sucking mouthparts
The labrum, mandibles, maxillae and hypopharynx form the elongated needle for puncturing
Labrum: forms tube
Mandibles: Hold the wound open
Maxillae: Cut into skin
Hypopharynx/salivary channel: makes you itchy
The labium forms a protective sheath, and it also supports the needle when sucking
Insect vectors
Mosquitos - malaria & many others
Tse tse flies - African sleeping sickness (Tropansoma)
Rhodnius prolixus (kissing bugs) - Chaga’s disease (Tropanosoma)
Bubonic plague - rat fleas
Apterygotes
Wingless Insects (ancestrally)
Pterygotes
Winged Insects (or secondarily lost)
Ametabolous
Juveniles resemble the adults-only smaller and sexually immature
They have the same habitat and diet
Hemimetabolous
Exopterygote
Juveniles resemble parents somewhat
They are missing their wings and they develop externally with each moult
Holometabolous
Endopterygote
Larvae do not resemble adults at all
Adult and larva have different roles, thus different niches
Develop adult structures internally (imaginal discs)
Larva develop into pupa where adult structures are projected to the outside of the body
Defensive Strategies (3)
Morphological
Behavioural
Chemical
Morphological Defense
Crypsis - shape and colour matching
Behavioural Defense
Flight
Projectile defecation and petiole clipping (hides evidence of their browsing)
Behavioural crypsis
Chemical
Venomous stings
Sticky threads to entangle
Reflex bleeding
Toxic sprays
