Explanation of Names
Common name refers to this genus' practice of snaring prey in mid-flight by swinging a silk line with an adhesive blob on the end.
Numbers
15 species total in North America, north of Mexico.
Identification
Glistening appearance, like a fresh bird dropping, and pair of lumps on the dorsal surface of the abdomen seem to be genus-wide traits.
The female spiders can be narrowed down by whether they have abdominal humps or not. However, this field marking does not work for males which can have humps or no humps in the same species.
Range
The Bolas spiders can be found from New Hampshire to Minnesota to the southern states and west to California.
(1)
The only species in the west is M. cornigera.
The following species are found in the Eastern US:
-apalachicola: South Carolina to northern Florida (but based only on 3 specimens, as of Levi 2003)
-archeri: southern United States from South Carolina, Florida, and Alabama to Texas
-bisaccata: eastern United States
-cornigera: from Kentucky and Tennessee west to California and south to Central America
-hutchinsoni: northeastern United States, from New Hampshire and South Carolina to Minnesota
-phrynosoma: eastern United States
-stowei: widespread in the eastern United States
-timuqua: North Carolina to southern Florida (but only based on 4 collections, as of Levi 2003)
-yeargani: New York to Kentucky
Found only in Florida are:
-alachua: northern Florida
-felda: south-central Florida (but only one specimen found, as of Levi 2003)
-satsuma: central Florida (but only one female has ever been collected, as of Levi 2003)
-seminole: southern Florida (but only one female has ever been collected, as of Levi 2003)
Found only in southern Texas:
-alvareztoroi: southern Texas (as of Levi 2003)
-leucabulba: southern Texas (as of Levi 2003)
Food
Flying insects; certain species specialize on particular species of moths, to the point of releasing mimics of their pheromones in order to attract prey (virtually all male moths) within capture range.
Life Cycle
When egg sacs hatch they release immature females and *mature* males! Presumably an adaptation to avoid inbreeding. Males are short-lived and much smaller (obviously) than females.
Remarks
Egg Sacs are quite distinct.
M. phrynosoma
M. cornigera
Print References
Levi, H. W., 2003. The bolas spiders of the genus
Mastophora (Araneae: Araneidae). Bull. Mus. comp. Zool. Harv. 157 309-382. [available online from
here]
(2)
Gertsch, W. J., 1955. The North American bolas spiders of the genera
Mastophora and
Agatostichus. Bull. Am. Mus. Nat. Hist. 106: 221-254. [available online from
here]
(3)
Howell, Mike W. & Ronald L. Jenkins, 2004. Spiders of the Eastern United States: A Photograph Guide. Pearson Education, Inc. 176-180.
(1)
Gemeno, C., Yeargan, K.V., and Haynes, K.F. 2000. Aggressive chemical mimicry by the bolas spider
Mastophora hutchinsoni: identification and quantification of a major prey's sex pheromone components in the spider's volatile emissions. J. Chem. Ecol. 26(5):1235-1243. [article available online from the publisher; if you don't have a subscription, you have to pay per view. See
here for a link to purchase it.]
(4)Internet References
www.entoflorachne.com - Images (text in French).
Spiders of Texas - Lists 5 species as occurring in Texas.
EOL - Image of M. stowei.
