On February 10, 2013, I made a delightful discovery at Inokashira Park Zoo 's animal exhibit, which was open to the public.

When we lifted the "observation sheet" attached to the tree, we found the largest and most impressive ladybug in Japan, the "Tentaurus japonica," overwintering there.

In the plaza, we plant trees that serve as food sources for the insects we want to attract. For example, we plant akebia to attract the akebia leaf moth, gardenia to attract the hummingbird hawk-moth, and styrax to attract the styrax longhorn beetle.

Actually, we've planted trees to attract ladybugs, but they haven't been found in the plaza yet. Both the larvae and adults of ladybugs feed on the larvae of walnut leaf beetles, which feed on walnut leaves. We planted walnut trees hoping that if walnut leaf beetles came to the plaza, ladybugs would come in search of them, but we haven't found any walnut leaf beetles yet either.

However, there is a large Japanese walnut tree behind the "Squirrel Trail" in the park, and there have been previous records of tortoise beetles being observed there. The one found this time was probably an individual that grew up on this tree and came to the "observation sheet" in the plaza to overwinter. The "observation sheet" is a convenient device that makes it easier to find not only ladybugs, but also oak stink bug eggs, crab spiders, and Esaki's horned stink bugs, among other creatures that overwinter among the tree bark.

Searching for creatures in winter may seem unexciting at first glance, but the cold slows down their movements, and eggs and pupae remain motionless, offering an advantage that even young children can observe closely.

Although spring has officially begun, the cold weather continues. You can still enjoy watching the animals that are spending the winter in the wildlife plaza for a little while longer.

Photo above: Ladybug
Photo: Observation sheet
Photo below: Winter Animal Plaza

[Inokashira Park Zoo Education and Outreach Section, Mikako Takamatsu]

(February 15, 2013)