If you are looking for one of the world's most mysterious insects to return en masse to the Altoona area, you are going to have to wait several more years.
Residents of 17 Pennsylvania counties soon will see an emergence of periodical cicadas, commonly - but mistakenly - called 17-year locusts. "We think of them as the Methuselah of the insect world," said Gregory Hoover, senior extension associate in entomology in Penn State's College of Agricultural Sciences.
The cicadas surfacing this year are members of Brood II, which last was seen in 1996. In Pennsylvania, the Brood II insects appear in Berks, Bucks, Carbon, Chester, Dauphin, Delaware, Lancaster, Lebanon, Lehigh, Luzerne, Monroe, Montgomery, Northampton, Philadelphia, Pike, Schuylkill and Wyoming counties.
The insects also will emerge in all of Connecticut and New Jersey, and in parts of New York, Maryland, Virginia and North Carolina.
The periodical cicada is native to North America and exists nowhere else in the world. There are six species, three with a 17-year cycle and three with a 13-year cycle.
The cicadas that emerge each year are called a brood and are identified by Roman numerals. All eight broods that occur in Pennsylvania require 17 years to reach maturity.
Nationally, there are 12 broods of 17-year and three broods of 13-year cicadas, according to the magicicadas.org website.
Blair County has two different broods of periodic cicadas. In 2004, Brood X hit Blair and Bedford counties. Brood X will not emerge again until 2021. In 2008, Brood XIV hit northern Blair County (Tyrone and Bellwood). Brood XIV will not emerge again until 2025, said Tom Ford, a horticulture educator with Penn State Cooperative Extension.
"Unless there are cicadas transported in the rootballs of nursery trees sourced from another area that are planted in Blair County, we should not see any periodic cicadas in our county this year. We will, however, see the annual or dog-day cicadas in late summer," Ford said.
Lane Loya, associate professor of biology at St. Francis University, remembers when Brood X hit the area.
"I live in Hollidaysburg, and they were just everywhere," Loya said.
This year's invasion might not be extensive.
"Members of Brood II may not be as abundant in Pennsylvania as they were in the past or as other broods - such as Brood X in 2004 and Brood XIV in 2008 - in part because of development and habitat loss," Hoover said.
Periodical cicadas are not considered to be key pests, but they can cause damage, Hoover said.
Female cicadas damage trees, by cutting small slits into pencil size branches to deposit their eggs. These weakened branches often die, break and fall to the ground. The larvae hatch out and then crawl into the soil in search of tree roots from which they hope to feed for another 17 years. Most orchardists and nurserymen will delay planting new orchards or lining out young nursery stock when cicada broods are expected to emerge, Ford said.
The damage to young trees can be devastating, Ford said.
"In 2004 I had several small young trees in my landscape. The oviposition [laying of eggs] injury from the female cicadas essentially killed the tops of the trees," Ford said. "It has taken nine years of corrective pruning to rebuild the structure of these trees in the landscape."
Those traveling to eastern Pennsylvania should "enjoy this wonder of nature," Hoover said.
Mirror Staff Writer Walt Frank is at 846-7467.