It’s Time for the Bug Days of Summer

Late summer may be known for its tomatoes and bright golden flowers, but summer’s heat also brings out the bugs. At no other time of the year is the garden so alive with their activity.

Hundreds of little dull orange lawn skippers flutter around the heliotrope in my backyard. Vying for room at this floral trough are painted ladies, swallowtails, sulfurs and my personal favorite, the mourning cloak.

Mud daubers are building their huts in my garage, occasionally dropping little balls of mud on my workbench, and paper wasps are hard at work under the eaves.

Garden spiders work their webs by the outdoor lights, carefully constructing new ones each evening. You can tell how successful their night has been by the holes in the webs the next morning. And there’s no shortage of moths to snare in late summer.

There are also insects munching and chewing things in the garden. But for the most part, the insects of August are adults that have outgrown their destructive days as larva and caterpillar.

They are busy preparing for their own young, whether that means simply staying alive long enough to lay eggs that will winter over in the garden, or building elaborate shelters of mud. Many insects die at the end of summer, when the egg-to-adult cycle begins again.

Summer is also the season of the predators, so any caterpillars that haven’t turned into moths had better beware.

Of the predators, I think the wasps are my favorites, and they’ll be yours too when you catch sight of one bringing a fat caterpillar or cutworm back to its nest.

Before readers throw up their arms in alarm, note that I am not talking about yellow jackets or ground hornets--believe me I’m as tired and wary of these two as the next fellow--I’m talking about the big thread-waisted wasps of the garden, the nonaggressive kinds like the golden polistes and the mud dauber.

Sometimes golden polistes work beside me in the garden. While I pull weeds, they fly quietly through the leaves of plants looking for caterpillars.

Unlike most gardeners, they know to look on the undersides of leaves for the larvae that are making all those holes.

Superficially, this wasp does look like a big yellow jacket, but it has a narrowed waist and an abdomen that is mostly yellow, not evenly striped black and yellow like a yellow jacket’s.

The golden polistes have no interest in us or our food. Obviously they can sting, but they are not aggressive, as hornets and yellow jackets are.

They make those neat upside-down papery nests that you find attached to eaves, and stuff each cell with a skinned and chewed caterpillar.

Mud daubers prey on summer’s spiders. There are several of their nests in my garage, but I don’t mind because they are another nonaggressive whose sting is reportedly mild. These have very long, thread-like waists and are more black than yellow.

They fly in and out my window, buzzing over my head, carrying home mud and spiders for their nests.

The larvae grow over winter and hatch in late spring, when the nest is abandoned, but another spider hunter may move in, the shiny blue-green or blue-black blue mud wasp.

According to the late entomologist Charles Hogue (author of “Insects of the Los Angeles Basin,” a truly fascinating field guide), these squatters have actually been observed jiggling webs to make curious spiders come out and take a look. Surprise!

Summer’s spiders are equally fascinating and, though it would be nice if they caught only garden pests, they do not discriminate; you’ll find as many lacewings in webs as aphids.

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One of the most interesting spiders doesn’t make a web, and you’ll have to look closely to spot it. Crab spiders often match the color of the flowers they wait in ambush on, legs pulled back, ready to pounce. They can change color, but only slightly, so when you see yellow spiders on yellow flowers or red spiders on red flowers, they are different kinds.

At this time of the year, shrubs are often covered with the funnel-like webs of the grass spiders. In my garden, there get to be so many webs that I have to blast them off with a spray from the hose if I am to see the green of the shrub.

The big orb weavers (or garden spiders) are the most conspicuous spiders of late summer. They grow so fast at this time of the year that gardeners may suspect they are seeing a different spider each day, and they make big webs, large enough to snag me on occasion.

Some are colorful, including the black-and-yellow golden orb weaver and the araneus, which is a coppery red. All make neat webs of concentric circles.

The araneus can make huge webs, up to eight feet across with strands that are sticky and strong. Run into one of these in the night (orb weavers are nocturnal) and it will practically knock you down.

Walking into any orb weaver web is no fun, but disturb them a few times and they will move higher into trees and shrubs, where you can simply watch them grow fatter and fatter, silhouetted against the sky.

Moths are a frequent meal for orb weavers, one reason they like to build webs near outdoor lights, and at this time of year there is no shortage of moths.

There are the 4-inch sphinx moths, the adult form of the dreaded tomato hornworm (that green larva the size of a Buick that is eating your tomato vines).

The moths hover around flowers like hummingbirds in the evening, and my cats’ idea of a big catch is to land one. I wish I could take credit for training them to catch moths instead of birds, but they learned this on their own. Perhaps they think the sphinx moths are hummingbirds, or maybe that’s just what a gardener’s cats do.

There are other, more colorful kinds of sphinx moths that are attracted to lights, such as the white-lined sphinx with its orange wing insignia. It’s slightly smaller but still big enough to be a bomber in the insect air force.

A couple of my favorite summer moths can be found during the day stuck snugly to things, as if they had been plastered on.

The omnivorous looper moth has dusky orange wings almost two inches across. When it’s resting, the wings are held straight out and flat against its perch. It looks as if you would have to pry them off with a knife. Unfortunately, the larva of this moth lives up to its name, munching on a great variety of plants.

Loopers and measuring worms (or inchworms) are those pesky caterpillars that move their front feet first, then arch their backs and let their rear feet catch up.

Another common summer moth is the bark-colored McDunnough’s Pero, which is invisible when resting on a limb. Only when it’s resting on a stucco wall can you see its amazing camouflage pattern.

The little moth-like butterfly that is so common on Heliotropium arborescens--the best of my butterfly-attracting plants--is properly called a fiery skipper. It is also called a lawn skipper, since it darts around lawns and its larva feeds on lawn grasses. I don’t know why I have so many because I have almost no lawn.

I know why we have the dramatic yellow tiger-striped anise swallowtails, because I grow anise for the kitchen.

Another skipper, the larger funeral duskywing--with nearly black wings edged in white--is another common sight on the heliotrope. The heliotrope also attracts mourning cloaks, an even bigger butterfly that has black wings with a wider yellow edging and a row of dark blue dots above the yellow.

When one of these comes floating through the garden, it takes me right back to my childhood when I saw hundreds of them on warm summer days. Modern pest control seems to have made a significant dent in the population.

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The larvae nibble on all sorts of ornamental trees, including elm, willow and poplar, even the fall-blooming Chorisia speciosa.

Some people keep records of birds that visit their gardens; my wife and I record butterflies. So far this August, we’ve seen the four mentioned above, plus the occasional orange-and-black painted lady, a red admiral, one buckeye (which is getting to be a rare sighting), an orange sulfur, a hairstreak and, of course, lots of those white butterflies that hatch from the green European cabbage loopers that eat so much of the winter vegetable garden.

Most of these insects and arachnids are welcome in my garden (one reason I try not to spray, even with so-called “organic” pesticides), but I draw the line when they come in the house.

Those that just fly or crawl in by mistake get an escort out. A few prefer living indoors, such as the other common spider of summer, the cobweb spider.

Many mistakenly call these long-legged creatures “daddy longlegs,” but that is another beast. The sowbug-sucking daddy longlegs aren’t true spiders, having a body that appears to be one piece. Cobweb spiders have a separate abdomen.

Daddy longlegs mostly live outside (and on the floor of my garage, which sometimes feels like an insect zoo) and leave a tell-tale midden of spent sowbugs.

Cobweb spiders make the very sloppy webs we call cobwebs, and this arachnid gets vacuumed up whenever I spot one, though I’m sure I’ve heard a few whisper in a sultry spider voice, “Why can’t we just get along?”