California Native Plant Society
in collaboration with East Bay Municipal Utility District
Other Insects
All writing from May Chen's posts
Crab Spider-
Mecaphesa sp. (family Thomisidae
Its powerful front legs flexed back, a tiny Crab Spider, Mecaphesa sp. (family Thomisidae) has stationed itself on a petal of a buttercup flower.
Members of the family Thomisidae do not spin webs, and are ambush predators. The two front legs are usually long and more robust than the rest of the legs. Their common name derives from their ability to move sideways or backwards like crabs. Most Crab Spiders sit on or beside flowers, where they grab visiting insects. Some species are able to change color over a period of some days, to match the flower on which they are sitting.
Mecaphesa asperata, the Northern Crab Spider is found in North and Central America, and the Caribbean. The ambush predator generally lurks in similarly colored flowers for visitors such as bees and flies. It is similar in appearance to the better-known Goldenrod Spider, Misumena vatia. Mecaphesa can be distinguished in that the carapace, abdomen and legs are covered with numerous short stiff spines.
It is often assumed that Crab Spiders change colors to blend in with their surrounding. The truth is a little more complicated than that.
The spider can change its color between white and yellow to match the flower it is sitting on. The color change takes a few days. Maybe this spider has recently moved over from a nearby yellow flower?
There’s another trick that the spider might be playing that we are not aware of because we cannot see in the ultraviolet (UV) spectrum of light. It’s been discovered that Crab Spiders reflect UV light strongly. Most insects, notably the bees, see UV well, and favor sunlit flowers while foraging. Experiments have shown that flowers that have crab spiders sitting on them actually garner more insect visits than those that don’t! It is thought that perhaps color camouflage in the visible spectrum helps the spiders avoid vertebrate predators (birds, lizards, etc.), while the UV reflectance is useful for attracting insect prey.
Jewel Beetle (Woodboring Beetle)
sub genus Melantaxia (family Buprestidae)
Buprestids are sometimes also called Jewel Beetles because of their glossy, iridescent colors. The larger and more spectacularly colored ones are highly prized by insect collectors. Their elytra have been traditionally used in beetlewing jewelry in some Asian countries. The iridescence common to these beetles is not due to pigments in the exoskeleton, but instead is caused by structural coloration, in which microscopic texture in their cuticle selectively reflects specific frequencies of light in particular directions. Buprestid larvae are known as flathead borers. They bore through roots, logs, stems, and leaves of various types of plants, ranging from trees to grasses. Adult jewel beetles mainly feed on plant foliage or nectar, although some species feed on pollen and can be observed visiting flowers.
Members of the subgenus Melantaxia have an affinity for yellow flowers, such as buttercups and dandelions. I have seen them gather in large numbers to feed and mate on dandelion flowers.
Skin Beetle
A Skin Beetle, Cryptorhopalum sp. (family Dermestidae) is feeding on the pollen of Goldfield flowers.
Dermestidae are a family of Coleoptera (beetles) that are commonly referred to as skin of carpet beetles. Ranging in size from 1 to 2 mm, the beetles typically have clubbed antennae that fit into deep grooves. Most Dermestids are scavengers that feed on dry animal or plant materials, such as skin or pollen, animal hair, feathers, dead insects and natural fibers. The larvae are used in taxidermy and by natural history museums to clean animal skeletons.
Winter Ant
The American Ant, Prenolepis imparis is a widespread North American ant. A dominant woodland species, it is most active during cool weather, when most other ant species are less likely to forage. This species is one of a few native ants capable of tolerating competition with the invasive Argentine Ant, Linepithema humile. They are also aggressive toward other ants and produce abdominal secretions that are lethal to Argentine Ants. Prenolepis imparis is a generalist omnivore. Foragers are known for tending to aphids or scale insects from which they consume excreted honeydew, aggregating on rotting fruit, and exploiting protein-rich sources such as dead worms. The colony enters estivation (a hibernation-like state) and becomes inactive above ground for the warmer months, during which time eggs are laid and brood are reared. Reproductives overwinter and emerge on the first warm day of spring for their nuptial flight.
Seven-spotted Lady Beetle-
Coccinella septempunctata (family Coccinellidae)
Native to Europe, the Seven-spotted Lady Beetle, Coccinella septempunctata (family Coccinellidae) has been repeatedly introduced to North America as a biological control agent to reduce aphid numbers. It has since spread to many states, where it has outcompeted some native species. The Seven-spotted Lady Beetles are large; adults may reach a body length of 0.5 in. Their distinctive spots and conspicuous colors warn of their toxicity, making them unappealing to predators. When threatened, the beetles can secrete a fluid from joints in their legs which gives them a foul taste.
Spotless Lady Beetle-
Cycloneda sanguinea (family Coccinellidae).
The Spotless Lady Beetle, Cycloneda sanguinea is a widespread species of lady beetle in the Americas. It is a large lady beetle with red, unspotted elytra (wing covers) ranging from 4-6.5 mm long. The black and white marks on the head and pronotum are very distinctive, and they are also gender-specific. What we have here is a female. Males have a short white line between the two white spots on the pronotum. These lady beetles are very often found feeding on aphids on milkweeds, but also occur on a number of other plants.
Beeblossom Aphids-
Macrosiphum gaurae (family Aphididae)
A close-up view shows that the aphids have rather long legs, antennae and cornicles (“tail pipes” that dispense defense chemicals and alarm pheromones). It is a mature colony, with aphids of various developing stages or instars. Note the white exuvia, the shed exoskeletons left behind after an insect molts. An expert on iNaturalist has helped identify the aphids as the Beeblossom Aphids, Macrosiphum gaurae (family Aphididae).
Aphids (family Aphididae) are small sap-sucking insects in the order Hemiptera. Aphids usually feed passively on phloem of plants. Once the phloem vessel is punctured, the sap, which is under pressure, is forced into the aphid’s food canal. Aphids produce large amounts of a sugary liquid waste called “honeydew”. A fungus called sooty mold can grow on honeydew deposits that accumulate on leaves and branches, turning them black.
A typical life cycle involves flightless females giving live birth to female nymphs, - who may also be already pregnant, an adaptation called telescoping generations - without the involvement of males. Maturing rapidly, females breed profusely so that the population multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs. The life cycle of some species involves an alternation between two species of host plants. Some species feed on only one type of plant, while others are generalists, colonizing many plant groups. Some ants have a mutualistic relationship with aphids, tending them for their honeydew and protecting them from predators.
The Beeblossom Aphid, Macrosiphum gaurae feeds on plants in the genus Gaura and Oenathera (both in the Evening Primrose family, Onagraceae). These large, pink or green aphids are spindle-shaped, have long legs and antennae, and are widely distributed across the United States and Canada. They do not host alternate to other plants, remaining on their specific hosts year-round. Most aphids in the genus Macrosiphum are not tended by ants.
Lace Bugs (family Tingidae)
The Tingidae are a family of very small (2-10 mm) insects in the order Hemiptera that are commonly referred to as lace bugs. They are called lace bugs because the pronotum and fore wings of the adult have a delicate and intricate network of divided areas that resemble lace. Their body is flattened dorsoventrally, and the head is often concealed under the hood-like pronotum. Lace Bugs feed by sucking sap from plants, extracting the protein they need and excreting liquid waste as honeydew. The most common symptom of feeding is the stippled and mottled yellowish foliage. In heavy infestations, black sooty mold may develop on the honeydew, impairing photosynthesis by the plant. This may result in some dieback of twigs and branches and a reduction in flowering the following year. Tingids are usually host-specific and can be very destructive to plants. Each individual usually completes its entire lifecycle on the same plant, if not the same part of the plant.
The genus Corythucha is primarily distributed in the northern hemisphere, including Europe, North America and eastern Asia. The Chrysanthemum Lace Bug, C. marmorata primarily feeds on plants in the Asteraceae (sunflower family), including chrysanthemums, goldenrods, and sunflowers. The species may also infests other plant families such as Convolvulaceae and Solanaceae.
An adult Lace Bug is in the company of nymphs of various stages of development on this Grindelia leaf. The adult is pale, and has a lace-like pattern on the dorsum, while the nymphs are black and spiny.
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After mating, the female Lace Bug lays eggs on the underside of host plant leaves, often along the midrib. She may then cover the eggs with a protective, varnish-like coating of excrement. Depending on the species and climate, the eggs may hatch in a few weeks or overwinter until the next spring.
Unlike insects with more streamlined wings for speed, Lace Bugs are not strong or fast flyers. This means they must rely on passive defense, such as camouflage, to survive. The semitransparent, lacy texture of their wings and hoods allows light to pass through, creating a dappled appearance that helps the tiny insects blend in with the leaf’s surface. The complex patterns on the wings and hoods may also confuse or disrupt the visual perception of predators, making it harder to identify the insects as prey