bks@ALFA.berkeley.edu ( Brad Sherman ) (01/06/89)
The Megalopolis stretching some 50 miles from Sacramento to the San Francisco Bay Area is currently undergoing an invasion of (so-called Argentinian) ants. 1) What is the probable cause of this phenomenon? 2) With no indigenous anteaters, is available food the only limiting factor to the ant population? (This seems unlikely). 3) What is the order of magnitude of the number of neurons in an ant? 4) Any good basic books pertaining to ant physiology and behavior? -Brad Sherman( bks@ALFA.Berkeley.Edu) Sorry if this is this question is inappropriate for this group, but there doesn't seem to be a sci.naturalhistory.
kaufman@maxzilla.Encore.COM (Lar Kaufman) (01/06/89)
In article <18762@agate.BERKELEY.EDU> bks@ALFA.berkeley.edu ( Brad Sherman ) writes: >The Megalopolis stretching some 50 miles from Sacramento to the >San Francisco Bay Area is currently undergoing an invasion of >(so-called Argentinian) ants. > 1) What is the probable cause of this phenomenon? Probable cause is the introduction of a foreign species by human vector. Most likely brought in with foodstuffs. No adequate natural control, as you noted (next). > 2) With no indigenous anteaters, is available food the > only limiting factor to the ant population? (This seems > unlikely). Native competition may or may not suffice to control them. Probably not. Other opportunistic predators might increase in population at the unexpected increase in ant supply. Probably not. More likely scenario - The "fire ant" introduced in the southeast (is this the same ant?) some time ago, has spread throughout the southeast until contained by one of two factors: lack of adequate heat, and lack of adequate moisture. The fire ant has spread north above the Mason-Dixon line in places, I think. It cannot take really cold weather, but pockets of them have dug in around building foundations and such well to the north of their otherwise maximum northern range - they just need a certain minimum temperature for their winter "diggings." The fire ants' westward expansion was stopped at the desert southwest. If these are the same ants as the Argentinian ants you are describing, someone has helped them across the barrier - probably by transferring eggs in a quantity of dirt. You can then expect them to expand eastward and northward. The barriers to further expansion wouldn't necessarily be cold and aridity; they could be altitude and wetness, for example. Attempts to hold the line on the fire ant failed miserably. They can be eradicated in isolated areas by topical application of Amdro(tm) a pesticide that has unfortunate consequences for fishes and some other critters. [ stuff I can't respond to, deleted ] > >Sorry if this is this question is inappropriate for this group, >but there doesn't seem to be a sci.naturalhistory. It sounds like this would have fit nicely in the proposed sci.environment group. Voting is going on now, I think. -lar Lar Kaufman <= my opinions Fidonet: 1:322/470@508-534-1842 kaufman@multimax.arpa {bu-cs,decvax,necntc,talcott}!encore!kaufman
dmark@cs.Buffalo.EDU (David Mark) (01/06/89)
In article <18762@agate.BERKELEY.EDU> bks@ALFA.berkeley.edu ( Brad Sherman ) writes: >The Megalopolis stretching some 50 miles from Sacramento to the >San Francisco Bay Area is currently undergoing an invasion of >(so-called Argentinian) ants. > 1) What is the probable cause of this phenomenon? I imagine they came in with agricultural or horticultural products (live plants with soil. Anyone actually *know*? > 2) With no indigenous anteaters, is available food the > only limiting factor to the ant population? (This seems > unlikely). Flickers (ground-loving woorpeckers, Colaptes auratus) eat ants. Maybe other insects; perhaps the weather; probably the USDA :-) > 3) What is the order of magnitude of the number of neurons > in an ant? There was an article in _Science_ in 1987 about the 'mental maps' of honeybees. I seem to recall about 10megs of neurons (but how many bytes per neuron?). > 4) Any good basic books pertaining to ant physiology and > behavior? Sorry, I don't know of any specific. But I found lots of ant books in the University library here a couple of years ago. dmark@cs.buffalo.edu
mmm@cup.portal.com (Mark Robert Thorson) (01/07/89)
Argentine ants are ordinary little household ants. Fire ants are big, and have a nasty bite (hence the name). Fire ants build anthills which are about a foot high and three feet in diameter (dimensions may vary). Insects have about 100,000 to 1,000,000 neurons each. Ants are probably toward the low end of this scale. I don't remember the title, but I believe E.O.Wilson has written a book on ant behavior. E. O. Wilson is best known for his book Sociobiology, which caused a revolution in thinking about the biological substrates of animal behavior. I haven't been invaded with ants. I get invaded in the hottest days of summer, apparently because the ants get more desparate for water.