Social behavior Eriogaster lanestris

1 social behavior

1.1 synchronous foraging
1.2 trail-based communication
1.3 thermoregulation

social behavior

e. lanestris highly social insect, particularly during larval stages. hence, small eggar larvae categorized gregarious caterpillars. living in large groups may make larval colonies more apparent visually-oriented predators, social structure has allowed small eggar evolve number of advantageous behaviors.

synchronous foraging

one benefit of grouping behavior found in e. lanestris increased foraging efficiency, achieve foraging in large group. colonies of caterpillars feed several times day, leaving tent group in search of food. exact mechanism larvae determine feeding times unknown, has ability of silk tent transmit vibrations throughout structure. caterpillars mobilize leave tent, others alerted vibrations time feed, facilitating movement of entire colony, allowing synchronous foraging. unlike many nocturnal foragers, e. lanestris feeds both during day , @ night, runs risk of detection visually-oriented predators during daytime foraging forays. however, leaving security of tent en masse instead of solitarily, caterpillars able minimize individual risk of predation , cooperate locate , reach best feeding sites.

trail-based communication

e. lanestris central-place foraging strategy in leave , return same site during each foraging outing, allows caterpillars communicate best nearby food sources, turning nest information center. caterpillars lay down silk trail when move outside of tent, creating network of trails lead home base. larvae can differentiate between new , old trails, preferring newer trails lead higher-yielding feeding sites. during synchronous foraging bout, larvae unsuccessful @ first return tent , pick fresh trails marked successful feeder. in addition indicating best feeding sites, silk trails allow caterpillars better grip substrate on traveling, further increases foraging efficiency , success.

thermoregulation

a mass of instar larvae.

another advantage provided small eggar’s sociality enhanced ability control temperature of immediate surroundings, or thermoregulate. e. lanestris ectothermic organism, meaning relies on surroundings regulate body temperature. caterpillars must maintain adequate body temperature in order move, metabolize, , develop properly. caterpillars have optimal temperature range of 30-35 °c, , when hatch in spring, ambient temperatures below threshold. small individual caterpillars have low capacity capture , retain heat, when 200 individuals group together, effective mass increases significantly, allowing them collectively retain more heat. layered tent structure functions further insulate caterpillars within inner chambers. on sunny days when air temperatures may lower ideal, caterpillars congregate on outer surfaces of tent in direct sunlight. black, furry bodies act absorb radiation , grouping serves more prevent heat loss. additionally, when caterpillars return tent after feeding, enter resting , digestion phase. metabolisms generate heat energy, can raise internal tent temperature as 3 °c. caterpillars enter later larval stages, seasonal temperatures may high, caterpillars found on shaded side of tent, away direct sun.