The Florida State Collection of Arthropods (FSCA) has over 30 separate collections of M. simoni from Florida. Most of these records are from Gainesville in Alachua County. The earliest such collection is 22 February 1981, one female taken by G.B. Edwards in a web under pine bark. Many of the Gainesville records are from the Doyle Conner Building prior to the initiation of a regular fumigation program.
A few records exist in Florida south of Alachua County. A female M. simoni was collected in Orange County, Lake Buena Vista, 3 February 1982, by J. Atwood, in a shipment of Jacaranda acutifolia Humb. & Bonpl. plants from California. As no records of this spider are known from California, it is likely that the spider entered the shipment after it arrived in Florida. Three juvenile specimens which appear to be M. simoni have also been found. A penultimate male was captured in Volusia County, Samsula, 4 February 1980, by J.N. Pott, on Draceana sp. An immature female was collected in Brevard County, Titusville, 22 February 1986, by A. Baker. Another penultimate male was found in Lee County, Alva, 28 August 1981, by C. Scharfenberg, on pothos, Epipremnum aureum (Linden & Andre) Bunt.
Recent surveys of arachnid populations from various Florida plant communities (e.g., Corey and Taylor, 1988, 1989; Corey et al. 1991) have been useful for recording the presence of particular species. Florida records for M. simoni collected by D.T. Corey are as follows: one female, Suwannee County, Suwannee River State Park, 1 May 1987; one female, Alachua County, Gainesville, 10 July 1987; five males, one female, Polk County, Lake Wales, 14 November 1986; one female, also from Lake Wales, 11 November 1987. All of these specimens were taken from pitfall traps.
Based on the above records, it appears that M. simoni has spread steadily eastward and southward into Florida since it was first collected in the state in 1966. Its synanthropic habits are well documented by its frequent occurrence in buildings and, to a lesser extent, on ornamental plants. However, several records of feral individuals indicate that it is equally at home away from human habitations. Leech (1972) noted that M. simoni is quite common in Mississippi and parts of Louisiana in the wild.
Males of T. brunnea are 4 to 5 mm in length; females only a slightly larger 4.5 to 5.5 mm. Both sexes of T. brunnea are similar in color. The carapace and legs are uniformly yellow-orange to orange. The abdomen is dark gray with lateral white patches and posterior chevrons dorsally, and a pair of pale spots on the venter. However, specimens from peninsular Florida frequently lack abdominal markings. In general, T. brunnea is smaller and more brightly colored than M. simoni.
One cause for concern about the presence of M. simoni in Florida is its potential effect on our only native amaurobioid, Titanoeca brunnea Emerton. Although T. brunnea is widespread in the eastern U.S., it only has been reported from Alachua, Hernando, and Putnam Counties in Florida (Leech 1972). The five FSCA records are from Alachua, Columbia, and Putnam Counties. The most recent record for T. brunnea in the FSCA is from western Alachua County, Green Acres, 8 February 1979, by G. Davidson, six males in a pitfall trap. There is also one earlier record with "habitat" data: Alachua County, Gainesville, 5 May 1964, collected by K.J. Stone, one male in a house. FSCA records for T. brunnea range from February to June. D.T. Corey (personal communication) has the following additional records: two males, Suwannee County, Suwannee River State Park, one May 1987; one male, also Suwannee River State Park, 28 April 1988; one male, Alachua County, Gainesville, 10 July 1987; one male Pasco County, New Port Richey , 6 May 1988; one female, Polk County, Lake Wales, 14 November 1986. Four new counties (Columbia, Pasco, Polk, and Suwannee) are added to the known Florida distribution of T. brunnea. All of Corey's records are from pitfall traps, in several cases from the same localities and collection dates as M. simoni. I have examined Corey's specimens and confirmed his records.
Leech (1972) reported T. brunnea as an inhabitant of leaf litter, whereas M. simoni apparently uses some larger structural feature, such as a log or board, from which to base its web. Is this a sufficiently distinct microhabitat difference to prevent competition between the two species? The last FSCA record of T. brunnea was from 1979, at approximately the same time that M. simoni began dispersing into peninsular Florida. Until recently, this seemed to indicate that M. simoni was displacing T. brunnea. All of the records of M. simoni from peninsular Florida have been since 1980, from situations similar to those previously reported for T. brunnea. However, the latter collections by Corey seem to indicate that the two species coexist.
Author: G.B. Edwards,
Florida Department of Agriculture and Consumer Services, Division of Plant Industry.
Originally published as DPI Entomology Circular 338.
Photographs: G.B. Edwards, Division of Plant Industry
Project Coordinator: Thomas R. Fasulo, University of Florida
Publication Number: EENY-322
Publication Date: May 2004
Copyright 2004 University of Florida
Featured Creatures
Department of Entomology and Nematology
Division of Plant Industry
Electronic Data Information Source
male
female