Behavioral and Life-history Notes on Three Floridian Solitary Wasps (Hymenoptera: Sphecidae)

Krombein, Karl V. Behavioral and Life-History Notes on Three Floridian SolitaryWasps (Hymenoptera: Sphecidae). Smithsonian Contributions to Zoology, 46: 1 26, 1970.—A new trap to attract solitary twig-nesting wasps and bees was developed and tested in Florida. It permits observation and photography of the nesting behavior during nest construction and, subsequently, of the development of the progeny. Observations and photographs were made of the nesting behavior and subsequent development of three sphecid wasps, lsodontia (Murrayella) auripes (Fcrnald), Podium rufipes (Fabricius), and Trypargilum collinum collinum (Smith). Official publication date is handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. UNITED STATES GOVERNMENT PRINTING OFFICE WASHINGTON : 1970 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Price 40 cents (paper cover) Karl v. Krombein Behaviora l and LifeHistory Notes on Three Floridian Solitary Wasps (Hymenopter a: Sphecidae) The need to perform field tests on a new type of trap designed to attract solitary wood-nesting wasps and bees provided the incentive for a period of study at the Archbold Biological Station, Lake Placid, Florida, 7-26 April 1969. Normally during this season in southcentral Florida there is an abundance of many species of both woodand ground-nesting wasps and bees. However, populations were abnormally low during my stay, perhaps because the unusually cool wet winter of 1968-69 resulted either in delayed emergence or higher mortality of the overwintering insects. Nevertheless, there was a sufficient number of nesting individuals to determine that the new traps were acceptable as nesting sites to some species, and that they permitted photography of nesting behavior not possible with the kind of trap used in my earlier study (Krombein, 1967). The traps I used earlier consisted of a hole drilled in a stick of straight-grained white pine. Borings of four different diameters were used: 3.2, 4.8, 6.4, and 12.7 mm. These traps were reasonably satisfactory in my earlier work because I was unable to spend time in the field observing nesting behavior. The prospect that I would be able to make such studies in the near future, however, led me to devise an improved trap to facilitate field observations. For this pilot study I used cavities of 4.8, 6.4, and 12.7 mm in diameter. The cavities were made by routing out a round-bottomed channel of one of those diameters in a long piece of straight-grained white pine. The channels were routed to the same depth as the Karl V. Krombein, Chairman, Department of Entomology, National Museum .o/ Natural History, Smithsonian Institution, Washington, D.C. 20560. channel diameter. The pieces were then cut into 150mm lengths and one end of the channel plugged with a short piece of wood. The 4.8and 6.4-mm channels were made in pieces of wood 20 mm wide and the 12.7-mm channels in pieces 25 mm wide. A piece of clear Plexiglas ® y16" thick and cut to the same size as the strip of wood was then taped against the channel. Finally, a plain strip of wood 6 mm thick and the same length and width as the trap was fastened against the plastic with rubber bands so that the whole assembly presented a light-tight simulated boring. The trap components and their assembly are shown in Figure 1. When used in the field, the plain strip of wood could be readily removed to permit observation and photography of the nesting behavior. Bundles containing two traps of each diameter cavity were set out at 20 stations. The bundles were suspended from live or dead branches of turkey oak, scrub hickory, or other trees (Figures 2, 4, 5), and a few tied to a wooden frame supporting a Strophanthus bush (Figure 3). The traps were inspected periodically to determine when nesting began. Table 1 presents records for the maximum and minimum temperatures and rainfall at the Archbold Biological Station during the period that nesting was taking place. After the nests were gathered they were held at 72°-74° F in the Station laboratory until the morning of 27 April. From the morning of 28 April until emergence of adult wasps the nests were held at my home in Arlington, Virginia, where the temperatures ranged from maxima of 60°-70° to minima of 50°-a)°. I am most grateful to Richard Archbold and James N. Layne of the Archbold Biological Station for mak-