Social Insects Flashcards
Ants
Find food and return it while laying a trail. Tracked using three head movements: sinusoidal (searching for trail), probing (brief while finding trail), then following. Will follow trail of pygial gland extract but not poison gland extract.
Bee pheromones
Have glands all over body (including feet) producing pheromones. Queen bee can release Queen Mandibular Pheromone (QMP) and alarm pheromone. Alarm pheromone attracts workers (defence), produced by venom gland.
Venom gland is what is left behind after honey bee sting. Carries on releasing pheromones.
Eusociality
Most insect societies have singe reproductive with sterile workers.
Need high relatedness e.g. through haplodiploidy (females are diploid, males haploid)
QMP
Queen mandibular pheromone.
Continually made by queen, constantly detected and broken down by workers (so they know if queen is alive)
Remove queen and workers respond in 30 mins to raise new queen
Inhibitory pheromone making workers sterile or signal providing workers with information? Most evidence suggests honest signal of reproductive capacity.
Workers detect via AmOr11
Queenless ants
Have one reproductive individual (‘gamergate’ or ‘alpha’) and dominance hierarchy of potential replacements.
Alpha will block potential challengers. May also rub antennae of betas against her abdomen (where hydrocarbons come from) - saying smell me.
Split alpha and a beta –> beta will become alpha. Beta lays eggs and increases levels of 9-H. Alphas have specific hydrocarbons and some can cause regression of ovaries
If beta lays eggs, sisters will intervene and kill female that laid eggs.
Termites
If queen dies…
Royal pheromones
Actually classified as type of cockroach.
Eusocial but NOT haplodiploid. XY sex determination, a queen and a king, many castes.
Caste-specific CHC biosynthetic enzymes.
If queen dies, female neotenics (could become queens) are produced. Neotenics produce two compounds which inhibit the appearance of more neotenics (nBnB, 2M1B).Eggs also have these. Both physiological and behavioural role.
21C compound only present in king and queen. Tells workers they are royal. Induces head bobbing and antennation.
Insect colonies
Usually colonies are aggressive towards one another. Colony odour is flexible and changes with time, not genetically determined. CHCs change with diet.
Fungus
In some species of ant, if pupa is infected with fungus, is killed through biting and spraying with insecticide. Ants detect the fungus as infected pupae have different hydrocarbon levels.
