Things I See Outside This Week

The gorgeous flowers of the  horse chestnut are blooming this week. Aesculus hippocastanum is commonly called European Horsechestnut or Common Horsechestnut. The massive trees are fast growers and need plenty of room to spread out and reach high. Never plant one near or under power lines. The panicle flowers are normally white with parts of pink and yellow. There is another variety with pink flowers as shown below. Horsechestnut fruit is not edible for humans and are called conkers. The shiny nuts look nice displayed in a dish for nature lovers, just don’t try to crack and eat them!

Red Horsechestnut Flower

Luna moth sighting have been reported around the state this week. They are a strikingly large and beautiful, with only a brief seven days of life in its adult stage. They are nocturnal spending the night seeking a mate with females laying eggs for next year’s generation. Occasionally they will fly towards a light even landing on a screen door with lights on inside. Host trees providing leaves for caterpillars to eat are walnut, hickory, sweet gum, and paper birch.

Luna Moth

In the vegetable garden asparagus beetles are very active, feeding, mating and laying eggs. As can be seen in the lower photo, eggs are laid on on point sticking horizontally at a 90 degree angle to the stem and off of the flower bud stem. Crush all eggs by running you hand up and down each stalk. Catch adults beetles and crush or drop into a container of soapy water to rid them from the asparagus patch.

Asparagus Beetle

Asparagus Beetle Eggs

Another oddity was sent to my office this week. This is an Apple Oak Gall produce by a developing tiny, cynipid wasp. The adult female wasp injects the egg and a chemical into leaf tissue, causing the leaf to distort and makes a home and food for the newly hatched larva. Once the larva is big enough, it pupates inside the gall, only coming out once the gall is empty and dry. There are not enough wasp and galls to cause harm to the tree, so they are only considered cosmetic not a pest.

Apple Oak Gall

Another gall I found this week was the Wool Sower Gall on a white oak tree.  The gall is caused by secretions from the developing wasp larva, secretions of , (Callirhytis seminator). These galls and wasp damage are also not harmful to the tree. The wasps are not dangerous to humans as they do not sting.

Wool Sower Gall on white oak.

Other galls we have seen in past made by insects are the grape tube gallmaker galls on grape leaves, (Schizomyia viticola). Grape tube gallmaker is a species of mite that forms a gall on New World grape leaves. Larvae feed inside the tubes and are free from predators as they feed on the deformed plant tissue. Again only cosmetic to the plant.

Grape Tube Galls on grape leaf.

Finger galls form on a cherry leaf below. Eriophyid mites are the gall makers here. They are microscopic mites developing inside the raised, malformed tissue. Mites can be identified by the structures they create on their host plant.

Finger Galls on a cherry leaf.

Velvetleaf galls on sweet birch develop from the feeding of the  velvet eriophyid gall mite.  Reddish-patches are called an erinea, can also occur on silver maple. (JLaughman photo).

The soil bacterium, Agrobacterium tumefaciens, can cause galls, tumors in this case, on the crown, roots and sometimes branches of susceptible host plants. Euonymus is commonly infected. The bacterium can enter a plant via any tissue damage that normally happens during pruning or transplanting. Agrobacterium tumefaciens is also used as a tool in the laboratory in genetic engineering to introduce genes into plants in a natural way.

Crown Gall, Agrobacterium tumefaciens.

-Carol Quish