What are those ladybugs doing?
A friend who lives near us dropped me a line the other day. She
and her two sons, Connor and Rory, took advantage of a short spell
of unseasonably warm weather to explore Pinnacles National
Monument.
What are those ladybugs doing?
A friend who lives near us dropped me a line the other day. She and her two sons, Connor and Rory, took advantage of a short spell of unseasonably warm weather to explore Pinnacles National Monument.
While there, the trio encountered what was described as tons of ladybugs, and naturally, they wondered why they were there.
Connor and Rory are Sparky the Wonder Dog’s appointed guardians when we’re away, so anyone who regularly reads this column knows we regard them as young men of the highest character.
If they say there are tons of ladybugs at Pinnacles, there are.
We’ve also encountered enormous aggregations of ladybugs on warm winter days ourselves. The Soquel Demonstration Forest, the Forest of Nicene Marks and Henry Coe State Park have all produced areas in which one could just sweep up jarfuls of the colorful insects with a few swipes of a hand.
What’s going on here?
The answers are on the excellent Web site maintained by the staff at Pinnacles.
There are many species of ladybugs. These are convergent ladybugs.
According to the park’s Web site, “a well-fed ladybug can release up to 400 eggs during her lifetime. In March and April, the clusters of yellow eggs hatch, and the tiny larvae gorge for three or four weeks. As they grow, the larvae shed their skins, going through four stages of shedding before entering a one-week pupal stage.
“The black, yellow-to-red spotted pupae attach to leaf surfaces by their tails. Five to seven days later, the pupal skins split, and the young adults emerge. The adult convergent ladybug is distinguished by a pair of converging white stripes on its black thorax.
“Kenneth Hagen, who has studied the convergent ladybug for a number of years, notes that ‘a single acre of alfalfa infested with aphids during the spring may yield more than 50,000 adult convergents by late May.’
“Since the food supply often has been depleted by the larvae, adults migrate to the mountains in late May to early June. Huge swarms fly into the upper canyons. Upon arrival they feed on aphids if available, but more often pollen is the main food source in the mountains. The pollen produces fat to tide the ladybugs over their nine-month dormancy. Congregating by the thousands, they overwinter in tight clusters, called aggregates, under fallen leaves and ground litter near streams.
“The clear, warmer days of early spring trigger the ladybugs to break up the aggregates and begin several days of mating. This is when a visitor to Pinnacles National Monument is most likely to note large gatherings of ladybugs, particularly along the Bear Gulch and Old Pinnacles Trails and at the Moses Springs Picnic Area.
On a windless day when the temperatures reach at least 55 degrees F, the beetles’ minimal flying temperature, they begin their return migration back to the valleys and fields. As the temperature drops late in the day, the ladybugs too drop to earth, returning to the valleys to lay their eggs and die, beginning a new cycle of life and helping the orchardists, vintners, and farmers to keep their crops pest free.”
The park Web site is always worth a look before visiting. For example, last week the site revealed that the Balconies Caves complex was closed due to flooding. As wildflowers emerge, updates get posted. There’s a wealth of information on the many bees found in the park – there are more species of bees documented there than anywhere else in North America. And there’s even a “condor cam” capturing the park’s California Condors.
