Nesting and Male Behavior in Dynatus nigripes spinolae 
(Lepeletier) 
(Hymenoptera, Sphecidae) 
Lynn Siri Kimsey 
Department of Entomology, University of California, Davis, CA 95616 
Dynatus nigripes spinolae (Lepeletier) is a very large impressive look¬ 
ing wasp in the family Sphecidae. It is quite rare in collections and 
until recently almost nothing was known of its biology. Males are 
readily distinguished from females by their oddly clubbed hind- 
femora and strongly produced nasiform clypeus. 
Individuals were first observed flying about one portion of Snyder- 
Molino trail on Barro Colorado Island in the Canal Zone in Panama. 
Further examination showed that all activity was centered around a 
small dead tree (Fig. 3) on the right side of the trail in a section of 
secondary forest dominated by Oenocarpus palm. All of this acitivity 
was observed between September 12, 1977 and September 17, 1977. 
The previous year this same species of wasp was seen near the same 
tree during the same season but no further observations were made. 
On the first day a female was seen working mud into a hole in the 
tree and removing material from inside the hole as well (Fig. 3a). She 
worked it into a ball with her mandibles and tossed it into the air with 
a flip of her head as far as half a meter away from the tree. Observa¬ 
tions made the previous year showed that this same hole had been 
used by nesting Centris vittata Lepeletier (Anthophoridae) in July, 
though it had been considerably enlarged since then. 
Two days later the hole was completely sealed and two Dynatus 
were observed mating on a lower part of the tree. The male sitting on 
top of the female grasped her around the prothorax with his mandi¬ 
bles (the strongly produced clypeus probably aids in this as well) curl¬ 
ing the tip of his abdomen beneath hers (Fig. 4). The male remained 
on top of the female for five minutes with actual copulation occurring 
several times, each lasting about one minute. The female finally be¬ 
gan moving restlessly and flew away. The male flew around the tree 
and then landed on the spot where the mating had occurred, about 
15cm above the ground. This was next to two holes, one sealed and 
the other open (Figs. 3e, f). The male remained within 5-10cm of these 
holes for most of the rest of the day. A female landed on the tree and 
began inspecting holes, when she got near the male jumped at her 
and she flew away. 
The next day observations were made for most of the day. The male 
was still sitting by the holes, though he flew at and around any large 
object approaching the tree. Another male landed on the tree and 
The Pan-Pacific Entomologist 54:65-68. January 1978 
