1 / 21

Insect Societies

Insect Societies. Lecture 21. Insect sociality. Co-operative behaviors Eusocial: co-operate in reproduction and have division of reproductive effort (bees, wasps, ants, termites) Subsocial : less developed social habits (many insects) Solitary: no social behaviors (most insects).

mab
Download Presentation

Insect Societies

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Insect Societies Lecture 21

  2. Insect sociality • Co-operative behaviors • Eusocial: co-operate in reproduction and have division of reproductive effort (bees, wasps, ants, termites) • Subsocial: less developed social habits (many insects) • Solitary: no social behaviors (most insects)

  3. Subsociality in insects • Aggregation • Often aposematic

  4. Subsociality in insects • Parental care • Without nesting (Belostomatidae example) • With solitary nesting (Silphidae example) • With communal nesting (Sphecidae example) • Nesting: eggs are laid in a pre-existing or newly constructed structure to which the parents being food supplies for the young

  5. Parental care without nesting • Giant water bugs (Belostomatidae) exhibit paternal egg-tending

  6. Parental care with solitary nesting • Carrion beetles (Silphidae: Nicrophorus) display extended biparental care of young and reproductive cooperation between the sexes

  7. Parental care with communal nesting • Digger wasps (Sphecidae) share nest with others and females remain in the nest and guard

  8. Subsociality in insects • Sterile soldier caste • Subsocial aphids (Pseudoregmasp.)

  9. Eusociality in insects • Division of labor, with a caste system involving sterile or non-reproductive individuals assisting reproductive individuals • Co-operation among colony members in tending the young • Overlap of generations capable of contributing to colony functioning Eusociality is only known from Hymenoptera (bees, wasps, ants) and Termitoidae (Blattodea)

  10. Eusociality in Hymenoptera • Queen, drones, worker, soldiers • Haplodiploid genetic system in which queens control the sex of their offspring • Males develop from unfertilized eggs, thus haploid • Females develop from fertilized eggs, thus diploid • Behavioral and chemical maintenance of monarchy • Division of labor by polyphenism or polyethism

  11. Haplodiploidy: a precursor to eusociality?

  12. SOL: Solitary SUB: Subsocial EU: Eusocial

  13. Wasp (Vespulasp.) • Female caste dimorphic (queen and worker) • Age polyethism • Newly emerged workers involve in nest construction and food distribution • Middle-aged workers involve in foraging • Old-aged workers involved in guarding

  14. Wasp Nest building

  15. Honey bee (Apismellifera) • Female dimorphism: queen and worker • Workers have wax glands and pollen-collecting apparatus (corbicula and combs), barbed stinger • Workers exhibit polyethism • Caste differentiation trophogenic (determined by food)

  16. Honey bee (Apismellifera)

  17. Ants (Formicidae) • Two major female castes: reproductive queen and workers • Some species have polymorphic workers: minor, media, major workers • Caste determination trophogenic

  18. Termites (Termitoidae) • Primary reproductives: queen and king • Supplementary reproductives: potentially reproductive, but with arrested development • Sterile termites: workers and soldiers (nasus) • Nymphs: developmental instars of reproductives • Larvae: instars of sterile lineages

  19. Role of JH in caste differentiation Physogastry: termite queen’s abdomen being distended to 500-1000% of its original size

  20. Evolution of eusociality • Kin selection: evolutionary strategy that favors the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction • rB > C where r = coefficient of relatedness, B = benefit gained by the recipient of altruism, C = cost suffered by the donor of altruism • Subsociality might be a precursor to eusociality

More Related