Other Insects

A few more insects examples of Torrey Pines State Natural Reserve

Sandwasp
Sandwasp. Photo by
Margaret Fillius

Some other insects seen are bumblebees, dragonflies, grasshoppers and various plant bugs and beetles. If visitors are at the right places at the right times, they may see special insect activity. For example, in the spring along the bluff part of the Guy Fleming Trail where there is soft sand, visitors may observe the sand wasps digging small tunnels, in each of which an egg will be placed. The developing larvae feed on small insects brought to the tunnels by the adult wasps. Also along this part of the trail in the soft sand, the conical depressions of antlions are often seen. These are the larval form of a flying insect; they are just under the surface at the bottom of the pits, where they feed on any ants or other small insects that fall into the pits.

When we think of pollination of plants, we usually think of bees, but surprisingly, an equal role is played by the two-winged flies (Order: Diptera), Beetles (Order: Coleoptera), and moths and butterflies (Order: Lepidoptera).

Some kinds of flies, for instance, are the only pollinators for certain kinds of plants, as the rare Giant Flower-loving Fly (Rhaphiomidas acton), Apioceridae, which has been shown as the primary pollinator for the equally rare and endangered Giant Woolly Star (Eriastrum densifolium spp. sanctorum) in the Santa Ana River Bed. Lepidopterans of the genus Tegeticula, Yucca Moths, are the only pollinators of the Yuccas. Coleoptera, such as the Meloidae, Blister Beetles and Cerambycidae, Longhorn Beetles are in great part responsible for pollinating many plants.

Hemiptera (True Bugs)

Trichocorixa reticulata – Saltmarsh Water Boatma

Saltmarsh Water BoatmanAdult: 2-3.5 mm

Order Hemiptera/ Family Corixidae – Water Boatmen

The saltmarsh water boatman is abundant in still to slow-moving water and shallow tidal pools at the lagoon where it feeds mainly on algae and may also scavenge on animal remains. The mouthparts of the Corixids are different from other true bugs. Instead of sucking juices, they are designed to rasp away and swallow diatoms and other particles of plant and animal food whole. Within the gullet, there is a muscular grinding “mill” called the masticator which processes the food particles before they enter the gut – much like the gizzard of a bird. Eggs are laid on submerged stones, seashells and other hard debris, tethered in place by a short stalk.

Chlorochroa sp. – Green Stink Bug

Green Stink BugAdult: 15-18 mm

Order Hemiptera/ Family Pentatomidae – Stink Bugs

These insects are widely distributed and common on a wide variety of native and cultivated plants. The fetid apple odor is familiar to most gardeners. Such odors are widely used in the insect world to warn potential predators that it is not going to be a particularly tasty meal. This defense mechanism has evolved as insects adapted to feeding on plants that contain toxic oils and resins, storing these allomones (defense chemicals) into glands, according to different species, on various parts of their bodies.

Neuroptera (Net-winged insects)

Agulla sp – Snakefly

SnakeflyAdult: to 25 mm to wing tips

Order Neuroptera/ Family Raphidiidae – Snakeflies

The snakeflies are common under bark of conifers in the larval stage where they prey on bark beetles and other subcortical insects. The hard-to-see adults are commonly on plants where they prey on many kinds small soft-bodied insects. The long strap like filament seen at the caudal end of the female specimen in the photo is the ovipositor. With this she can probe into the crevices of bark to lay her clusters of eggs. These insects were given their common name because of their habit of raising their heads on the elongated “necks” (prothoracic segment) like a snake that is ready to strike.

Plega signata – Brown mantispid

Brown MantispidAdult: 20 mm to wing tips

Order Neuroptera/ Family Mantispidae – Mantis-like lacewings

It has been suggested that these insects are, in the larval stage, internal parasites of Noctuid (looper) moth pupae, (Powell and Hogue, 1979, California Insects). These, like many other members of the Order Neuroptera are nocturnal and often attracted to lights Though rarely noticed, this particular species is very adaptable as to habitat and quite common in Southern California from desert to coast.

Odonata (Dragonflies and Damselflies)

Anax junius – Green Darner

Green DarnerAdult: 70-80 mm
Wingspan: 100 mm

Order Odonata/ Family Aeshnidae – Darners

The most conspicuous insects of the freshwater pond community, these large dragonflies are often seen coursing over cattails and bullrushes in their search of prey or mates. And though aquatic in the larval stage, they will also range far from water into urban areas. The predatory naiads, patterned in shades of brown and green live among the stems of submerged vegetation. Eggs are not dropped onto the water’s surface, as with many other dragonflies, but inserted into submerged, water-soaked stems of cattails or bullrushes.

Diptera (Flies)

Mallophora fautrix – Bee killer

Bee KillerOrder Diptera; Family Asilidae – Robber Flies

Adult: 16-18 mm

These robust flies, which mimic bumble bees are common to open sunny locations where they await on twigs for passing prey. They will hunt just about any flying insect but favored prey seem to be honey bees (Apis mellifera), which are taken on the wing as they visit flowers. The fly pierces the bee with blade-like mouth parts just behind the head into the thorax, immobilizing by severing the thoracic nerve, and carrying it back to its perch, drinks it dry. Larvae are undescribed.

Heterostylum robustum – Beefly

BeeflyOrder Diptera; Family Bombyliidae – Bee flies

Adult: 10-12 mm

A widespread species, this bee fly is fairly common to upland/transitional areas of the reserve. It, like other members of this large family, is a parasite. It was seen hovering over the brood burrow of a Ammophila wasp on the old salt panne on the eastern reach of the lagoon as the wasp worked to provision the nest with a caterpillar. The fly would not land on the lip of the burrow, but it hovered in the air above, bent the tip of the abdomen forward and squirted its eggs into the opening. The white eggs are tiny and adhere to the inner wall of the burrow. This might be a behavior to insure that the fly will be in no danger of being caught or stung by the host. The species is described as being an important parasite of the alfalfa bee (Nomia melanderi) in California.

Blattodea (Cockroaches and Termites)

Arenivaga sp. – Sand roach

Sand RoachAdult wingless female: 12 mm
Adult winged male: 20-30 mm to wing tips

Order Blattodea/Family Polyphagidae – Sand Roaches

Sand and desert roaches feed on a variety of detritus and dead animal materials. The wingless females and immature stages are mistaken as beetles because of their smooth rounded outline. They feed on the surface of the sand from sunset and during the night and will burrow into the sand if disturbed.

Parcoblatta sp.

German RoachAdult male: 25 mm

Order Blattodea/ Family Blatellidae – German roaches

Though it belongs to this family, this woodroach is not from Germany, but only related, having the characteristics, (taxa), of those species in Blatellidae. The woodroaches are common to Torrey Pines Reserve as well as eastward in the county in chaparral, oak and coniferous forest where they scavenge in rotting wood. The wingless females are often found under bark of dead trees. This species has not been observed as a household pest.

Next topic: Spiders