Archive

Tag Archives: flies

It lurks among the flowers of the Swiss chard. This assassin bug waits quietly, alert and ready to pounce. It sees me, which makes it hard to photograph because it keeps moving around to the far side of the stalk. Like most predators, it has an intelligent, deliberate way of behaving.

This one is in the family Reduviidae (reh-doo-VEE-ih-day, Wikipedia), possibly related to the European species Coranus griseus (photo at Flikr by Joao Coelho), but most likely not the same species. Note the characteristic “hunchback” appearance and the spotted edge of the abdomen.

Assassin bugs are related to the non-predatory shield bugs (here’s a previous post about a shield bug).

Some can administer a painful, venomous bite with their piercing mouthparts. They violently attack their prey, which can be much larger than themselves, and subdue it with a poison bite. Then they suck out the prey’s inner fluids, leaving behind an empty shell.

These are vicious little hunters. Some assassin bugs even specialize on mammalian blood, including the notorious kissing bug of Mexico and the southwestern US, also in the Reduviidae (basic kissing bug facts from University of Arizona).

Several days after the first pictures were taken, this pair were discovered in a state of mutual … well, they were having a good time, no doubt. They were on this chard flower stalk all morning and all afternoon, and they were still together at dusk.

The next morning they had gone away.

Looking at insects like these, one might wonder at their form. From an evolutionary perspective, what is the advantage of the sharp-edged shoulder humps? Why are there prominent spots along the edges of the abdomen? Are these sexually selected traits like guppy colors or deer antlers? Do they serve some other function?

Assassin bugs like to hang out in flowers, waiting for… well, this little critter, for example, a flower fly in the Syrphidae who is happily eating pollen among the same chard flowers. I think this lucky one got away.

Look to this previous post for another flower fly.

It seems like there have been a lot of posts about flies lately, no?

When the post on turning the compost came together it was slightly frustrating not to have a good picture of a black soldier fly (Hermetia illucens) (Wikipedia). Now a big beautiful female has posed for us on a runner bean leaf, so here is her portrait.

With their jet black wings, antennae, and body and brightly contrasting white leg segments, these rather large flies (as big as a large bean) are among the most distinguished looking insects in the garden. As adults, they do not eat – in fact, they have no functioning mouth parts. They are also surprisingly tame – they can often be picked up easily in the hand, where they might just walk around instead of flying away.

This female’s bulging abdomen is loaded with eggs. Now that she has mated and become gravid, her only goal in life is to find some nice organic matter where her babies can grow. Quite possibly her target will be our box of fresh kitchen scraps:

more fly posts:

two gorgeous flies

just an ordinary fly?

There it is, resting on a leaf. Looks like an ordinary housefly, (Musca domestica), but it might not be. The family Muscidae (Wikipedia) includes about 450 species in California alone, and more than 4000 worldwide. Many of them share the familiar “housefly” appearance, with gray color scheme and dark longitudinal streaks on the top of the thorax.

There are also flies in the Calliphoridae (blow flies), Sarcophagidae (flesh flies) and Tachinidae (mostly parasitic flies) that have a similar appearance. It seems like the “house fly plan” is a fairly successful shape, size, and look for such insects.

Because there are so many species and they look so similar, identifying small, nondescript flies is one of the hardest things an entomologist might have to do. It might involve counting hairs, studying wing vein patterns, or examining their genitalia under a microscope.

No matter what kind of fly this is, it is welcome in my ecogarden.

Here’s another post about beautiful flies.

There are estimated to be more than 200,000 different species of flies, midges, gnats, and mosquitos in the world, but only about half of them are known and described. All belong to the order Diptera (Wikipedia article), whose name means “two winged.” The only insect order with more species is the beetles.

There are many species of green bottle flies (Wikipedia) that look very similar. All belong to the family Calliphoridae (Wikipedia), also known as blowflies. That family contains roughly 1,100 species. It is a huge, complex family whose internal relationships are disputed. Some entomologists think there may be several separate lineages in the family, from different origins.

Like many blue or green animal colors in nature, the shiny luster of these flies comes from light diffraction through tiny structures in the surface of their body, not from any kind of pigment. As a result, the color can change depending on the angle of the light. Blue jays, peacocks, and Morpho butterflies also get their blue and green colors from diffraction of light.

Blowflies in general, and green bottles in particular, are incredibly sensitive to the smell of dead flesh. They are often the first insects to arrive when an animal dies. Forensic entomologists can estimate the time of death of an animal or human by looking at the life stages of blowfly maggots and other insect larvae within the body.

The little beauty shown here bopped around the garden for almost an hour while I was photographing all sorts of stuff. I kept finding it basking in the sun. The rock must have been especially warm, because it hung out there for a long time.

How curious and strange, that this beautiful green-gold work of art spent its early life completely surrounded by a dead animal’s rotting body.

Not long after our green friend flew away, a different beauty showed up. This syrphid fly (flower fly / hover fly) was uncharacteristically just sitting there among the Bacopa flowers. Usually they are seen hovering almost in place, or darting from one flower to another.

The family Syrphidae (Wikipedia) has even more species than the Calliphoridae, numbering more than 6,000. Most of the adults eat pollen or drink nectar. The larvae have more varied food – some of them are valuable predators, eating aphids and other small insects found on plants.

Two flies, just hanging out in the sun. Who wants to fly around when you can just soak up some rays on a nice green leaf or rock?

Here’s another post about interesting flies.