Insect Ecology and Conservation Final

Eusociality Threshold

E.O Wilson

Eusociality is irreversible (wrong)

Why does doug like oak trees so much?

keystone family (Quercus)

highest biodiversity value

sequester more CO2

good soil stabilizers

make the best leaf litter

promote healthier watersheds

Eusociality has evolved independently ___ times

18

1 group of thrips

1 group of Platypolid beetles

Naked mole rats

1 species of snapping shrimp

Termites

1 group of aphids

12 taxa of haplodiploid hymenoptera

Superorganism Eusociality Hypothesis

compares insect colonies and metazoan bodies

Workers should be competing to spread their own genes because they aren’t clones

Group Selection Eusociality Hypothesis

Wynne Edwards and E.O. Wilson + D.S. Wilson

selfish gene in group A, altruistic genes in B+C

selfish group less efficient

selfish population has to go extinct faster than the lifetime of the altruistic populations

confusing

Handicap Principle Eusociality Hypothesis

Zahavi

if altruistic and survive, it means ur really strong/good genes

explains altruistic behavior rather than eusociality

Kin selection Eusociality Hypothesis

W.D. Hamilton

split up genetics (haplodiploidy)

(i dont get it)

Polygyny, multiple queens

each additional queen decreases the reproductive value of all queens, reduces worker value

starting a new colony gets really hard, queens join colony born from instead of starting a new one

more individuals in a colony, more likely to survive attack

Classical darwinian fitness

absolute fitness in terms of the number of offspring surviving to reproductive maturity

inclusive fitness

measured by all genes plus behavior that affects other generations

inclusive fitness effect

B / C = benefit to recipient / cost to donor

when altruism will be favored = B / C > 1/r (r = coefficient of relatedness between offspring)

altruism

behaves toward another individual of the species to increase classical fitness of that individual, to the detriment of self

Eusociality

cooperative brood care

generation overlap

reproductive division of labor

Parental Manipulation Eusociality Hypothesis

Richard Alexander

queen lives longer and layers broods to get first daughters to stay and rear second brood

Selective forces maintaining eusociality

Queens invest equally in both sexes

workers rear 3 sisters for every brother in order to keep a genetic benefit as workers are only 1/4th related to brothers

Why do insects fly into lights

dorsal light response

night flying insects orient themselves with the light of the moon

Carrying Capacity

#of individuals of a species that can be sustainably supported without degrading the resource base

when the carrying capacity is exceeded it degrades

Broad parental care

all pre and post zygotic investment,

• egg production

• nest prep

• oviposition site

  • mate selection

Narrow parental care

postzygotic reproductive investment

When will maternal care evolve

1. when the benefit is so large it exceeds costs (social hymenops)

   1. when the cost is so low the benefits are always higher (everything else)

Costs of maternal care

1. risky

2. reduces fecundity

3. delays reproduction

   1. constrains foraging

How do asocial species protect their young

spread reproduction over time and space (lay some eggs, move on, lay some eggs)

hide eggs

why should males NOT care about their kids

paternity

sperm is cheap

paternal care

usually predators that guard eggs from more than one female, but demands mating before they allow female to add eggs to clutch, verifies paternity

offered to females as a nuptial gift (ill protect them for u mama)

Belastoma water bugs, rhinoceros assasin bugs, lethocerine water bugs

Biparental care

passalid bess beetles

nicrophorus burying beetles

primary role of males is to guard paternity

four ecological responsibilities of every landscape

support food webs

sequester Co2

clean and manage water

support pollinators

why are caterpillars so tasty tasty

soft

large

nutritious

low chitin

carotenoids!

how to help the bugs?

shrink the lawn

plant keystone species

use yellow lights

if insects were to disappear…

we die ig idk

Maternal care

old as hell

wasn’t a big evolutionary step:

• no morphological changes necessary

• no advances in defence behavior

  • no physiological changes in oogenesis

E.O. Wilsons proposed 4 types of selection pressure for maternal care

1. stable environment

2. physically harsh environment

3. specialized food resources

4. predation

this is stupid and dumb

habitat fragmentation

corridors are the SOLUTION

biological interactions are essential to ecosystems because they…

1. increase stability

2. improve biogeochemical processes

3. increase productivity

4. decrease susceptibility to biotic invasions