Tuesday, June 14, 2016

Some Arthropods of the New Season: Part 1

(Note: Please see my beetle site, "Beetles of the Cuyamaca Mountains" if you are interested in San Diego County Coleoptera: http://www.beetlesofcuyamacamountains.net/index.html )

Over the past weeks (and months) there have been some nice warm days, and mild nights which brought out some insects and spiders around the house, and also elsewhere in the county. The El Nino winter only brought 28 inches to Cuyamaca Woods, and we had hoped for more to ease the drought. But we probably shouldn't complain TOO much! It seems to be a green and verdant spring.

Here are some Cuyamaca Woods observations from the past few weeks, followed by another post of insects seen at Culp Valley in the Anza Borrego Desert, Crest in eastern San Diego County, and Palomar Mountain this spring.

Camponotus sp. (carpenter ants), winged reproductive forms emerging from a nest near the water tank slope.

Some of the winged ants lined up in this manner after emerging from the nest. This was in April, when we had some rain recently.

Bristletail on the patio near the black light. Two ways to distinguish bristletails from silverfish are the posterior cerci on either side of the medial posterior filament (which are shorter than the medial filament and point somewhat posteriorly in bristletails and are longer and point at almost a right angle to the medial filament in silverfish). Also bristletails have small lateral "styli" on the abdomen, which can be seen between the second and third pairs of legs here.

Ceanothus Silkmoth (Hyalophora euryalis), an occasional visitor in spring. This one appeared at the patio black light on June 2.

A small species of bostrichid (a horned powder-post beetle). It is starting to unfurl its second pair of wings for flight. This little one was less than 10 mm long.

Mating crane flies (to be determined) on the patio - a common sight in spring if there is a light nearby!

A giant crab spider, Curicaberis sp., the first I have ever seen. Smaller than the Olios giganteus (another member of this family) that are so common here.

Ashy Gray Lady Beetle (Olla v-nigrum) - the black and red morph.

A click beetle (Lacon sp.) which appeared in the near garden on a warm day.

Styloxus fulleri, a fairly predictable visitor at the light in spring.

A better image of Trox fascifer than my last attempts. This is quite a small beetle, perhaps 6-7 mm long! A member of the Trogidae (hide beetle, with an appetite for skin, feathers, etc.), not Scarabaeidae.

One of the acorn beetles, Curculio sp. Females bore through the outer layer of an acorn with their long snouts, to deposit eggs, and the larvae feed on the juicy acorn meat.

This little beetle was confusing me, and looked a bit like a blister beetle at first (I thought). It is actually a member of a different family, the Anthicidae, or antlike flower beetles, in the genus Duboisius. It is quite small - about 10 mm long.

Microphotus angustus, a small firefly species. There are no firefly species with flying bioluminescent members in California. Apparently this is the only member of the genus Microphotus in California, although there are several species in Arizona. This is a male, who can (obviously) fly. The females are larviform, meaning lacking wings and resembling larvae. The females ARE bioluminescent, and are called "pink glow worms". Below are two photos of a female Microphotus that I found in Payson, Arizona a couple years ago, the second showing her glowing rear end. I haven't found a female Microphotus in Cuyamaca Woods yet, although Gary and I did see one at Palomar Mountain many years ago.

The same male Microphotus as shown above, but with his bulging eyes protruding a bit from under his pronotum. In the first week in June, quite a lot of Microphotus (around 15-16) came to the black light in the warm dry spell we had following our cool foggy period. Some were collected and sent for DNA analysis to the University of Florida.

A very uncooperative velvet ant (Dasymutilla aureola) spotted in the garden. She did not want to slow down for an instant, and this was about the best image I could get as she scrambled around (looking for the nests of bees or wasps that might contain larvae to be parasitized by her own larvae). These wingless forms are females. Below is a photo of a winged male of this species from San Diego County, found several years ago. 

Colonus (Thiodina) hesperus, male. Thanks to Tim Manolis and G.B. Edwards for helping identify it. This is a diminutive jumping spider, but he has some really sharp colors and markings when seen close-up!

Peucetia longipalpis (the Green Lynx), lurking on a potato plant in the garden


  1. Nice collection of critters that share our surroundings.

  2. The first week after we moved here (mid-June) we saw 2 glow worms. One on the 18th in the back yard and another on the 20th in the bushes out front. Here is a little gallery of them. I'm assuming these are the females of that Microphotus


    1. I would expect so. I've seen no females in the Julian area yet, although apparently they can be quite numerous.

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