HOLD FOR RELEASE WEDNESDAY, OCT. 1, 1997 AT 2 P.M. E.D.T.
Contact: Blaine P. Friedlander, Jr.
Office: (607) 255-3290
Internet: [email protected]
Compuserve: Bill Steele, 72650,565
http://www.news.cornell.edu
ITHACA, N.Y. -- When female wasps return to the colony after foraging, some
females initiate aggressive encounters with males and stuff them -- head
first -- into empty nest cells, according to Cornell University research
reported in the Oct. 2 issue of the scientific journal Nature. Researchers
call this newly discovered insect behavior "male-stuffing."
"It's a strikingly aggressive behavior," said Philip T. Starks, Cornell
doctoral candidate in neurobiology and behavior. "In a wasp colony, the
behavior is normally somewhat aggressive, but no one has reported this
level of aggression between male and female nestmates before. We observed
sting threats, mauling, lots of antagonism. Perhaps it has not been
reported because 'male-stuffing' lasts only a few seconds and is thus easy
to miss."
The article, "Male-stuffing in wasp societies," researched and written by
Starks, from Andover, Mass., and Emily S. Poe, a Cornell senior from
Endicott, N.Y., appears in the Scientific Correspondence section of Nature.
Starks is working on his doctorate with H. Kern Reeve, Cornell assistant
professor of biology.
Poe and Starks observed and reported on two categories of the aggressive
interaction of the paper wasp, Polistes dominulus. Once food arrives for
the colony, the "initial stuffing" begins with antenna-to-antenna contact,
followed by grappling, biting and sting threats from the females. (Males do
not have stingers.) The female then forces the male into a nest cell, head
first. The second category of interaction the researchers observed was
labeled "repeated stuffing," which is characterized by the female biting
and pushing on the abdomen of the male, whose head and thorax already are
in the cell.
The researchers discovered this behavior while watching and transcribing
video recordings of interactions within a colony. Starks explained that
this behavior, if not seen on videotape, is difficult to spot because
":male-stuffing" happens so fast and since colonies typically have over 30
individuals, a single interaction can easily go unnoticed."
Sixty-six stuffing events were observed during a total of 24 hours of
videotape recorded from multiple colonies. The researchers reported that
none of the colony's queens stuffed males. Instead, all stuffing was done
by worker wasps.
While this behavior may seem strange to humans, the biological logic is
sound, according to the researchers. Worker wasps bring food back to the
colony and feed the needy reproductive destined larvae -- the colony's next
reproducing generation.
"Limiting food consumption by males may maximize the worker's inclusive
fitness," Poe said. "If you look at their behavior, it gets the males out
of the way. This contributes to the colony's fitness."
-30-
EDITORS: Hi-8 video is available.
RSS