DOI: 10.5061/dryad.8sf7m0cnt
title: The early life of a leaf-cutter colony constrains symbiont vertical transmission

description: The early life of a leaf-cutter colony is characterized by the dispersal
 of a female alate (winged “queen”) carrying a fungal pellet, and the
 subsequent establishment of a foundress (workerless “queen”) raising her
 incipient fungal garden and colony. The symbiotic roach Attaphila
 fungicola hitchhikes on female alates during leaf-cutter nuptial
 flights, which strongly suggests that roaches are vertically transmitted
 to foundresses and their incipient colonies; however, weak compatibility
 between roaches and incipient gardens may constrain roach vertical
 transmission.  This dataset contains data from an experiment in
 which the mortality of incipient fungal gardens and
 foundresses were scored in treatments with
 or without Attaphila roaches. Additionally, in roach
 trials we noted whether or not the roaches disturbed
 fungal gardens during observational bouts conducted during the experiment
 (see below for more detailed description of behavioral
 observations). Contrary to traditional assumptions, our results
 indicate that roaches harm incipient gardens, suggesting
 that roaches are not well adapted to use vertical transmission
 between colonies.  
description: This dataset was collected
 during experiments that were conducted with all replicates kept and
 observed at room temperature ( 22 - 24°C) in a lab at UT Austin. Chambers
 were checked for 1 minute every 24 hours in low-light conditions to
 determine mortality of fungal gardens, foundresses and roaches. The fungal
 garden was marked as effectively dead if it was dismantled and scattered
 in decaying clumps in upper and/or lower corners of the chamber and if the
 foundress did not tend any portion of the garden for at least 30 seconds
 (“uncaring” foundresses), or if the foundress was dead (without a
 caretaker, the fungal garden is effectively dead). Alternatively, the
 fungal garden was marked as living if the foundress tended a contiguous
 portion of the garden for at least 30s (i.e., the foundress’ head and
 mandibles maintained a position facing and over the garden, typically
 manipulating and antennating it).  Additionally, 30 minutes following
 initial set-up, each foundress chamber was observed for 3 minutes to
 determine if the inhabiting roach disturbed the incipient garden. Garden
 disturbance was scored if roach contact caused any observable movement,
 physical dislocation or fragmentation of the garden, and subsequently we
 categorized gardens as either “disturbed” (one or more observations of
 roach disturbance) or “undisturbed” (no observations of roach
 disturbance).   For the
 experiment, we collected paired female alate ants and roaches for use in
 the experiment, where ants collected from the field already had attached
 A. fungicola roaches. Using naturally paired ants and roaches ensured that
 both species came from the same natal colony, and thus controlled for
 potential intercolony differences (e.g., chemical profiles). We removed
 the wings of the female alates and placed the de-winged alate (herein,
 “foundress”) and her attached roach in a 5 cm. diameter container
 (“foundress chamber”) with 20 mg of fungal garden (“incipient garden”)
 from a lab colony. Notably, 20 mg is larger than the inoculum of fungus
 that foundresses initially regurgitate when founding a new colony under
 natural conditions (Marti et al. 2015).  Long-term survival in the
 laboratory of foundresses provided only with their inoculum is extremely
 rare complicating experimentation and highlighting the extreme fragility
 of this developmental stage.
description: Decriptions of variable labels in dataset: (1)
 <strong>Foundress + Roach:</strong> Treatment with foundress
 and fungal garden and roach  (2) <strong>No
 Roach</strong>:  Treatment with foundress and fungal garden (but no
 roach) (3) <strong>Flight:</strong> female
 alates and roaches collected during first (marked "1") or second
 (marked "2") flight (4)
 <strong>Chamber:</strong> Individual number assigned to each
 artifical foundress chamber during mortality experiment
 (5) <strong>day_fg_mortality:</strong> day of
 mortality of fungal garden in artificial foundress chamber. "0"
 indicates fungal garden did not die during experiment.
 (6) <strong>result: </strong>indicates if foundress
 was dead (marked "dead") or was not caring for fungal garden
 (marked "uncaring") on day of fungal garden death. An absent
 value indicates the fungal garden did not die during experiment and was
 still being cared for by foundress. (7)
 <strong>nest:</strong> name of leaf-cutter ant colony from
 which female alates and roaches were collected  (8)
 <strong>Fg_disturb: </strong>denotes if roach was observed
 disturbing fungal garden. "1" indicates roach disturbed fungal
 garden during observational bout, "0" indicates roach did not
 disturb fungal garden during observational bout.