|THE METROPOLITAN NATURALIST
Ants Tending to the "Herd" of Leafhoppers
These ants appear to be "farming". Ants are known to tend to leafhoppers, which secrete a liquid that is
eaten by the ants. The sweet liquid secretion is called "honeydew". In exchange for the secreted food,
the ants protect the aphids or leafhoppers against predators. The ants also carry the aphids from place
to place, presumably to areas of better sap flow for the aphids to eat. This relationship is called
"mutualism" because both the ants and the aphids benefit. Ants may also keep leafhopper populations
in check, preventing them from overwhelming the host plant.
Similar mutualistic relationships have been described between ants and other animals and plants,
including aphids, caterpillars, mealybugs, and acacia trees.
These are often called Praying Mantis because of their habit of
holding the front feet together as if in prayer. These, I believe, are
Chinese Mantids. Brought to this country from Asia for pest control,
the Chinese Mantid has become well established and more
common than the smaller native species.
Swarming Honey Bees (Apis mellifera)
These honeybees are in the process of
forming a new hive. Called "swarming",
the queen bee leaves the hive to find a
new home and start a new colony. Some
workers stay behind to raise a new queen
and continue to maintain the old hive. This
swarm appeared to have left a hive that
was kept in the Bragg Nature Center for
educational purposes and is establishing
a new hive in a hollow oak tree.
Honey bees have almost disappeared in
the Baltimore-Washington area in recent
years. In fact the decline in honey bees
has been seen almost worldwide.
In the past Varroa mites were blamed for
the virtual elimination of feral (wild) bee
colonies here and are a major problem for
kept bees in apiaries. Varroa mites (Varroa
destructor and Varroa jacobsoni) are
parasites of honey bees. More recently a
mysterious loss of colonies has been
seen, called "Colony Collapse Disorder".
Colony collapse disorder has been
reported from North America, Europe, and
Asia. The bees mysteriously disappear as
though they just leave and never come
back. Another unusual characteristic of
this disorder is that the honey is left in the
hive and remains there untouched by
scavengers and honey thieves.
Many possible causes for colony collapse
disorder have been suggested including
electromagnetic radiation from cell
phones and pesticides. The pesticide
Pandora sphinx moth catterpillar (Eumorpha pandorus)
I can't imagine an uglier animal. This large brownish caterpillar with white spots has a cryptic
head, appearing as though the head end is the tail end.
This insect is well camouflaged as a green twig. Stick insects are herbivores, eating leaves
of trees and shrubs.
Imidacloprid appears to be a likely candidate at this
time. Imidacloprid causes confusion in insects and
may interfere with the orientation and
communication abilities of honeybees, resulting in
the bees leaving the hive to forage and not being
able to find their way home. This would explain the
disappearance of the bees without any bodies in or
near the hive.
Our once familiar honeybee is not indigenous to
North America, but was brought from Europe to
provide honey and to fertilize agricultural crops.
Honey bees have become important in fertilizing
both wild and cultivated plants since their