Adult: 25mm.
Order Hymenoptera/ Family Sphecidae – Thread-waisted Wasps
This familiar species is commonly seen around wet areas where the females gather mud with their mandibles, taking it to some secluded or protected spot to build their mud nests. This can be under the eaves of houses, bridges, wood piles or even in the wheel wells of old abandoned cars. How many trips to build each single cell cannot be calculated, but a single concentric layer at approximately 1/16” wide and ¾” long may take several. You can often see the layers as rings in the mud going end to end. The cells are provisioned with various spiders which are paralyzed and a single egg is lain within each cell, then sealed. In the picture, you can see what is left of the pupae which never matured. This was probably due to attack by parasitic wasps or flies. These parasites usually lay their eggs in the open cell while the wasp is away to get more provisions. Another wasp which is often seen visiting the old nests of the Yellow and Black Mud Dauber is Chalybion californicum, the Blue Mud Dauber, a beautiful steel blue species, which cleans out and patches up the old abandoned cells for her own brood.
Adult: Female 18mm. Male 10mm
Order Hymenoptera/ Family Mutillidae – Velvet Ants
Females are wingless, the males winged. This species is most common on the dune areas at the Reserve. Clad with long hairs, like dune insects in general, this creates an air space around the insect should the sand cave in upon it. This helps the insect to better free itself and also protects the body from the abrasion of the sand. Sacken’s Velvet Ant is parasitic on a number of types of bees and wasps, but is often seen to enter the burrows of sand wasps, Bembix spp.. The integument of Mutillid wasps is so hard that it is very difficult to pierce them with a steel insect pin. With such armor they are well protected from the stinging insects which they attack, and are also provided with a severe stinging ability for any potential predators. Range for this and the following species is throughout most areas of the state at lower elevations where there is suitable habitat.
Dasymutilla coccineohirta – Red-haired Velvet Ant
Adult: Female 11mm. Male 7-8mm.
The Red-haired Velvet Ant is most commonly seen along dusty or sandy paths at the Reserve. Host preferences are little known. Do not pick up Mutillids, the sting is memorable!
Adult: Female 30mm. - Male 22mm.
Order Hymenoptera/ Family Anthophoridae/ Subfamily Xylocopinae - Carpenter bees
These are the largest bees in
California and common throughout San Diego County at lower elevations from
coast to foothills. Like many different kinds of animals often do, the
males and females exhibit sexual dimorphism, the females black, the males
blonde.
The remarkable males, rarely noticed, are extremely active in the early
spring when they set the stage for their trysts with the females, each
guarding a particular area near the dead trees or telephone poles from
which they were born. They circle their area at dizzying speeds and often
stop to hover and watch for intruders of their own kind, which they will
chase away, but never seem to land and rest.
The black females were seen hovering and landing at the top of an old
telephone pole used by a Kestrel as a perch in the natural area between
Carmel Valley Road and the railroad tracks, indicating a nesting site. The
bees often use such old weathered poles, timbers and dead trees as the
wood begins to disintegrate. A full description of their nesting habits
can be found in California Insects by Powell and Hogue. Watch for
these bees visiting any large yellow flowers in your neighborhood. The
introduced Cassia didymobotrya will always attract them if they are
in your area.
Adult: Wingspan; 84mm./Body; 40mm.
Order Hymenoptera/ Family Pompilidae - Spider wasps
This large wasp hunts spiders of
the genus Eurypelma, tarantulas, which are fairly common to the
upland areas of the reserve. The spiders are usually hidden either in
burrows or under stones during the day but become active at dusk to early
morning. They are not as large as the tarantulas often seen crossing roads
in the desert, but have a legspan to about 10cm. or more. The female wasps
may dig a burrow a foot or more below ground to deposit the immobilized
spider and lay a single egg on it, returning to the surface to seal it.
The adult Pepsis spp. feed on nectar and pollen of mostly
Asteraceae at the reserve, but are also fond of the introduced sweet
fennel Foeniculum vulgare. This species is most active from June to
November.
Adult: Body 30mm. Wingspan 45mm.
Order Hymenoptera/ Family Sphecidae - Thread-waisted wasps
The western cicada killer ranges
throughout the county in a variety of habitats. The female is able to
carry a large cicada in flight. She digs a single-celled chamber in soft
earth, deposits the paralyzed cicada and lays a single egg on it. The
female specimen pictured was found at Los Peñasquitos
Lagoon area.