Showing posts with label Mound Builder Ants. Show all posts
Showing posts with label Mound Builder Ants. Show all posts

Thursday, December 24, 2009

Snowy Ant Hills

I like to take advantage of opportunities that allow me to see the prairies in a slightly different format. The Mound Builder Ants are an integral part of the prairie ecosystem and I love to watch as they interact with the rest of the prairie components. It’s hard to get a feel for the numbers of mounds that are hidden in the fields of tall grass. The recent snow has turned each snow capped mound into a shining beacon.

In its normal condition, this mound would have been perfectly camouflaged. Now it reveals its presence and makes me wonder what the tens of thousands of communal lives are doing beneath the icy cap. Speaking of thousands, one of the items on my list of things to do is to construct an ant farm large enough to house one of these colonies. I’m not sure my wife would want me keeping it in the house.

Bare earth still holds enough warmth to melt snow, but the elevated mounds cool more quickly and are able to maintain the snow cover. I suppose the mounds tend to moderate the rate at which temperatures change below. This would give chilly ants an advantage if they had to retreat from dangerously low temperatures. The mounds look to me like the dorsal fins of a school of hungry grass sharks.

A solid snow cover will reflect the sun’s heat for a long time before beginning to melt. Once the dark soil of the mound is exposed, the remaining snow quickly disappears.

When I first saw these mounds I thought the steeper looking right side was just an illusion attributed to the fact that the left side had to extend down slope. Measurements revealed that the right side actually was steeper than the left. Besides traveling in the direction of the ground slope, the left side faces the prevailing wind. Is the wind strong enough here to influence the shape of the mound, or is this design that of the ants. Yet another riddle for me to solve.

Tuesday, August 18, 2009

Ants and Treehoppers

These treehoppers are being protected by a squad of ants. In this case, it’s the Allegheny Mound Builder Ants providing the bodyguard service. These seem to be the dominant ants in the area.

Treehoppers penetrate the plant stem with their tube-like mouth and drink the sap. Like many insects that feed in this manner, the treehoppers discharge from their bodies a sugary solution called honeydew. Many insects are attracted to the honeydew, but it’s usually the ants that claim this bounty and aggressively defend the source.

When undisturbed, the ants spend their time collecting honeydew and tending to the treehoppers. If not taken by the ants, the honeydew will begin to grow mold that may cause the death of the treehoppers. The ants get fed and the treehoppers are relieved of a dangerous byproduct.

The slightest disturbance will cause ants to strike a defensive pose with antennae raised and mandibles open.

The collection of treehoppers typically consists of a few adults and many nymphs. The adults are winged and may leave to establish colonies on new plants.

Colonies can grow to be quite large. I found all of these colonies on Giant Ragweed plants. There was not one plant that didn’t have at least one treehopper colony.