NOVEMBER
2005

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

11-23-05

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Holiday House Guests Sometimes Thick as Fleas on Dogs


During the holiday season, houseguests are common. As thick, some might say, as fleas on dogs. An important part of the holiday season is socializing with relatives, friends, co-workers and neighbors. Of course, meaningful seasonal gatherings often involve a well-appointed table. Food and guests are essential ingredients in most holiday festivities.

Some insects are also known to entertain guests. However, entertain might not be the correct description for this relationship among insects. For sure, the presence of guests among insects has nothing to do with holidays. But food does appear to be a major reason that some insects are dubbed guests. It is entirely appropriate that most insect species that tolerate guests are social creatures -- bees, wasps, ants and termites.

There are many kinds of arthropods, including arachnids, pillbugs and insects, that live in the nests of social insects. More than 3,000 species of houseguests are associated with ant nests. The social insects are great hosts for such guests. The nest provides a hiding place from predators and parasites. Generally, the temperature of the nest is greater than outside, and food is available.

Scientists have even given names to the creatures that live in the nests of insects. For instance, guests of ants are called myrmecophiles, which means ant loving. In the same way, termites host guests called termitophiles. A few of these guests are not there of free will. Some are actually captives. This is true of the slave-making ants that raid other ant nests and bring back pupae and larvae to rear as slaves.

One species of ant is even called the guest ant. This ant lives with another species of ant. The guest ant and the host ant live in the same colony. The guest ant does not leave the colony to collect food. It feeds on food regurgitated by the host ant. The guest ant gets a host ant to regurgitate by stroking its back. Such behavior seems to support the old idea of the value of scratching someone's back!

Some of the guests of social insects do earn their keep. For instance, some beetles known as hister beetles are scavengers that feed on debris in the nests of ants. A couple of caterpillars are found in the nests of bumblebees and wasps and apparently are also scavengers. Some syrphid flies live in the nests of social insects, where they feed on waste material. None of the host insects bother these guests. Apparently, there is value to having a good clean-up crew in the house.

In some instances, the guests in ant nests are given the royal treatment without having to provide sanitation work. For instance, there are several species of rove beetles that visit ant nests. But these beetles, like any well-mannered guest, come bearing gifts. They have tufts of hairs on their body that secrete material that the ants like. The ants even regurgitate food for these guests. One such beetle is actually fed by the ants. A "hostess with the mostess," one is to assume.

Helping clean up is a nice gesture on the part of a guest. Begging for food would seem to be a little crass but is not detrimental to the host. Some guests, however, have been known to take advantage of the hospitality of their hosts. For example, consider a small beetle with clubbed-shaped antennae. This beetle enters an ant nest and is welcomed by the inhabitants. At some point this guest turns killer. It grabs the ant by the gaster, that connection between the thorax and abdomen, and begins to devour the victim. I can see the headlines: "Guest Murders Host at Holiday Party."

But the biggest problem for holiday hosts is guests that stay too long and wear out their welcome. So, too, with the insects. Some ant nests include two species of ants in an arrangement best described as cohabitation, where the species share nest duties but raise their own young. Sometimes the arrangement slides off into hostility. Yes, both insect and human guests can sometimes wear out their welcome. Even during the holiday season.

 

 

Writer: Tom Turpin
Editor: Olivia Maddox