The Oil Beetles of Eliza Howell Park

I see Oil Beetles — large, dark, metallic-looking beetles – in Eliza Howell Park only in October and November. They are not particularly photogenic or otherwise likely to catch someone’s attention, but their story is part of the fascinating natural world that exists right here in the neighborhood.

I last saw one in 2019 on November 25, as it and I were walking on the park road.

Oil Beetles, a type of Blister Beetle, are nearly an inch long and, when I see them, are walking slowly on the ground in or near the fields in the park. My earliest 2019 observation was on October 17 (next picture). They are not numerous; even in their “season” I do not see them on every visit.

Oil Beetles are flightless. The adults emerge in the Fall and proceed in their slow and somewhat cumbersome walk toward a good place to winter in the soil. Based on the published research I have consulted, I think the female lays eggs in the spring, but I have seen them mating in the Fall. This pair was photographed in early November.

They are called “Oil” Beetles because, like other Blister Beetles, they can secrete oily droplets from their leg joints when threatened. This “oil” contains a toxic chemical (cantharidin) that can cause painful blisters on human skin.

They have no hind wings and the short front wings cover only a small part of the large abdomen.

Some Oil Beetles spend the immature phases of life in parasitic fashion in the nests of ground-nesting bees, eating the food that is brought in for bee larvae. 

There is much I don’t know about these beetles, but they now have my attention. I am sure that I will think of Oil Beetles when I next see ground-nesting bees.

 

Oriental Bittersweet: November Fruit

When the bright red and gold leaves of the Fall have fallen by the middle of November, there remains another red and gold attraction in Eliza Howell Park: the fruit of the Oriental Bittersweet.

Though there are still a few remaining honeysuckle berries that the birds have not quite finished, bittersweet can be considered the last fruit of the season. As recently as September, it showed little indication of the starring role it would later play.

Oriental Bittersweet is a vine that was brought to this country in the 1800s and has now spread widely. There is also a native North American Bittersweet vine, but the ones that I watch in Eliza Howell are the Oriental variety. It grows and spreads rapidly and can climb dozens of feet. The next picture shows the twinning nature of the vine; the following one gives an indication of its ability to climb trees.

The outer seed covering totally hides the fruit inside until late Fall. Birds are not attracted until the outer shells begin to open, allowing access to the red fruit, usually after the bittersweet leaves have already fallen. 

The gold shell, which opens in three parts, remains attached for a time (contributing to the attractive red and gold look) and later drops to the ground. The red fruit may hang on well into winter.

Though Oriental Bittersweet might make for an attractive home decoration at this time of the year, people are rightly advised not to pick and transfer. Unless the seeds are very carefully disposed of, new plants could sprout, spreading the aggressive and hard-to-control vine. It is considered an invasive plant that may damage the environment.

The word “bittersweet” means pleasure accompanied by some negative feelings, sweet with a bitter aftertaste. The pleasure of seeing the red and gold fruit of Oriental Bittersweet can indeed be a bittersweet experience.

 

The River, the Season, the Weather: Tracking Fall 2019

I often stop on the footbridge during my walks in Eliza Howell Park, stop and take a picture, looking upstream the Main branch of the Rouge River. These pictures help me track seasonal changes and fluctuations in water level.

Below are 8 photos taken on different days during the four weeks from October 16 to November 13, 2019. Some from sunny days and some from cloudy days, these pictures presdent the progress of Fall this year.

October 16, 2019  (9:47 a.m.   Approximately 50 degrees F)

October 20, 2019 (3:04 p.m.   Approximately 60 degrees F)

October 24, 2019  (11:23 a.m.  Approximately 50 degrees F)

October 27, 2019   (11:57 a.m.  Approximately 45 degrees F)

November 1, 2019   (9:31 a.m.   Approximately 35 degrees F)

November 4, 2019   (10:22 a.m.   Approximately 45 degrees F)

November 8, 2019   (10:07 a.m.   Approximately 25 degrees F)

November 13, 2019   (10:52 a.m.   Approximately 15 degrees)

The changes from the middle of October to the middle of November, always dramatic along the river in Eliza Howell Park, were even more dramatic this year because of the unusually heavy snow of November 11.