Of the many sounds of nature I enjoy, one of my favorites is the cacophony of a backyard filled with katydids, those big fat green bugs that start singing around dusk sometime in late summer. Later this month or during the first week of August, depending on the weather, the first ones will begin their annual symphony from the treetops of the more wooded suburbs.

When we first moved to New Jersey back in 1986, we lived in Paterson, where there are few trees and fewer katydids - at least in my old neighborhood. But when we moved to the foothills of the Highlands my desire to be serenaded by this creature's nightly symphony was finally satisfied. There is simply nothing like falling asleep to their sweet lullaby on a cool summer evening with all the windows open.

The katydids that are indigenous to our area are "leaf katydids." They are large, bright green winged insects that blend in with the green canopy of the maples and oaks and the other hardwoods of the deciduous forest. Good thing, too, because they make a succulent meal for a bat or any other winged critter lucky enough to discover one.

Katydids are members of the Orthoptera family and are relatives of crickets and grasshoppers. They hatch from eggs deposited the previous year on tree bark or branches sometime in July, then undergo several molts until reaching a healthy three inches in length.

God has a sense of humor and I believe he demonstrates it among the members of the animal kingdom in the unexpected twists exhibited by the sexes. With the birds, the males are the more attractive, the females being drab in coloration. A similar surprise has been engineered into the katydids - the males do all the talking. Their familiar song - "katydid, katy-didn't" — is made when the insect stridulates, or rubs its left wing on a ridge on the right one.

Interest in the katydid is apparently widespread and even passionate. I am not the only one in journalistic circles to write about them. The katydid has been the subject of editorials in some large newspapers. "A Bumper Year for Bugs" ran on The New York Times' Aug. 8, 1994, editorial page. The newspaper reported their songs were "(l)ouder, definitely louder. That is the emphatic if impressionistic judgment about the nightly katydid chorus this August, ventured by a dozen householders and nature-watchers from Georgia to Connecticut."

The katydids will soon be serenading those of us lucky enough to share our backyards with them for the rest of the summer and on into autumn, until the cold weather finally sounds the death knell and shuts down their little boomboxes for another year. But not to worry - these harbingers of summer will return to the trees on schedule next year, as they have done, like clockwork, for millennia.

If you are feeling left out at this point because you live in the heart of the city and don't get up to Garret Mountain that often to listen to the nightly serenade, don't worry. Nature has something else planned for you, but it's a daytime concert. The first cicadas crawl out of the ground early this month to begin their incessant buzzing.

Roy Troutman photos An annual cicada crawls out onto a branch, splits its skin and emerges as the adult.	An adult annual cicada on a weed. The bugs darken several hours after emerging.	Periodical cicadas (Magicicada) emerge every 13 or 17 years en masse in what are termed broods.

Cicadas are the other loud bug of the summer. Unlike the nocturnal katydid, cicadas produce their song during the day using a pair of tymbals, or ridged membranes, located underneath on their abdomen, a portion of which is hollow and acts as a resonating chamber.

There are two general types of cicadas: the annual and the periodical species, called Magicicada. Annual cicadas are fat green bugs that emerge during the first week of July. They spend anywhere from two to five years underground and their emergence is staggered, ensuring there is always a representative population of them in a given year. In contrast, the Magicicada are black with distinguishing red eyes. They emerge every 13 or 17 years, en masse.

The University of Michigan Museum of Zoology's Periodical Cicada page explains the reason behind this mass exodus of Magicicada:

"Although nearly all of the periodical cicadas in a given location emerge in the same year, the cicadas in different regions are not synchronized and may emerge in different years. All periodical cicadas of the same life-cycle type that emerge in a given year are known collectively as a single 'brood' (or 'year-class'). The resulting broods are designated by Roman numerals - there are 12 broods of 17-year cicadas (with the remaining five year-classes apparently containing no cicadas), and 3 broods of 13-year cicadas (with ten empty year-classes). As a result, it is possible to find adult periodical cicadas in almost any year by traveling to the appropriate location."

The last noteworthy emergence of Magicicada in New Jersey occurred in 1996 when the so-called Brood II blanketed the state in some regions. In Bedminster, the woods were literally alive with swarms that produced an eerie and deafening sound that propagated through the deciduous canopy like waves. It was reminiscent of the sound made by the mutant ants in the 1954 science-fiction thriller "Them." Large emergences can produce more than a million Magicicada per acre.

The emergence of Brood II was in stark contrast to the relatively disappointing no-show of Brood X last year. The 2004 emergence had been hyped by the media as "rival(ing) locust plagues promised in the Bible," says Dan Mozgai, who runs a Web site dedicated to cicadas called CicadaMania.com.

"People in New Jersey assumed that the entire state would be inundated, but this was not the case. In any given state in which Magicicadas emerge only a select number of counties and towns will experience them," he explains. "It is also common for cicadas to emerge in vast numbers on one side of a town, while on the other side of town, only a handful will emerge. A new housing development will probably have zero cicadas, while the woods across the road might be chock full of them."

We'll probably have to wait until 2013 for the next spectacular appearance of Brood II, although Brood XIV is scheduled to make an appearance in our area in 2008. Mozgai cautions it probably will not amount to much: "A few scattered emergences here and there, if at all, he says. "Brood II is the most impressive of the three broods that inhabit New Jersey."

Till then, aficionados will have to be content to listen to the daytime songs of the annual cicadas. Meanwhile another small consolation: Those of us who appreciate the nocturnal symphony of katydids can sleep with the windows open. n