Building Beetle Mounds and a bit about Rove Beetles

Today while catching up on posting at Cheryl's My Wildlife Sanctuary Blog, I came across what is a rather nice idea. Creating habitat for beetles in a nice suburban garden. It can takes years for the accumulation of decaying materials so a little help from a habitat gardener should speed things up.
Click here to read how Cheryl came to build a beetle mound

In this picture,on the right center, you can see how the beetle mound relates to the rest of the garden.

Thanks for allowing me to use the pictures Cheryl.

Why would anyone want to encourage more beetles?

Most of the thousands of beetle species are beneficial insects,helping to control many pest insects,including biting flies,mosquitoes and fleas. In agricultural settings they (depending on species) consume root maggot eggs and larvae, mites, small soil insects, insect eggs and small insects on foliage. So everyone benefits from a variety of beetles being about.

Non-flying crawling beetles tend to move slow and are of most use very near their food supply.

But the average garden does not accumulate the decaying mounds of organic matter found in natural areas where beetles may lay eggs and overwinter. So Cheryl took it upon herself to give aid.

Good idea! (She lives in the UK)

The rove beetles (Staphylinidae) constitute the largest and most diverse group of beetles in North America, accounting for roughly 4000 named species.

There is a great article about rove beetles at this

Florida University Website that is relevant to all of north america.

Excerpt....

Staphylinidae occupy almost all moist environments throughout the world. Because none of them is truly aquatic, they do not live in open waters; although winged adults may be skimmed from the sea surface far from land, their presence is due to misadventure but attests to their dispersive ability.

They live in leaf litter of woodland and forest floors and grasslands. They concentrate in fallen decomposing fruits, the space under loose bark of fallen, decaying trees, drifted plant materials on banks of rivers and lakes, and dung, carrion, and nests of vertebrate animals.

Several hundred species live only on seashores. Many are specialized to existence in nests of social insects.

Many inhabit caves, underground burrows of vertebrate animals, and smaller soil cavities, even of burrows that they (a few of them) excavate.

Many live in mushrooms.

Adults and even larvae of a few are associated with living flowers.

Others climb on plants, especially at night, and hunt for prey.

A few seem to live with terrestrial snails.

Their distribution in arid environments is restricted to moist microhabitats.

Food

many Tachyporinae, most Aleocharinae, Pselaphinae, Euaesthetinae, Steninae, Paederinae, and Staphylininae), representing the bulk of species in the family, so that it may be said that most Staphylinidae -- tens of thousands of species -- are facultative predators. Some have specialized, for example Oligota (Aleocharinae) as predators of mites, Erichsonius (Staphylininae) as predators of soil-inhabiting nematodes, Odontolinus (Staphylininae) on mosquito larvae in water-filled flower bracts of Heliconia (Heliconiaceae), and Eulissus (Staphylininae) on adult dung-inhabiting scarab beetles. Aleochara (Aleocharinae) has evolved to become parasitoidal in fly puparia.

Relationships with Higher Plants

Adults of some Omaliinae are attracted to flowers, and some of these have been demonstrated to pollinate the flowers. An example is Pelecomalium testaceum (Mannerheim) (Omaliinae), which pollinates Lysichiton americanum Hultén & St. John (Araceae) in the mountains of the Pacific coast of the USA and Canada. It is conceivable that Polyobus spp. (Aleocharinae) do the same for Espeletia spp. (Asteraceae) in the northern Andes of South America. Charoxus spp. (Aleocharinae) have a different, but yet highly specialized obligate relationship with plants -- the adults are attracted in the Neotropical region to the syconia of Ficus spp. (Moraceae) within which they oviposit, but the adults and larvae feed on pollinating wasps (Agaonidae) of those fig flowers.

Nests of Vertebrates

Some staphylinid species have specialized to live in the nests of vertebrates, especially tortoises, birds, and rodents. Their prey seems to be mainly the larvae of fleas and flies.

In Florida (USA) where populations of the tortoise Gopherus polyphemus (Daudin) (Testudines: Testudinidae) are declining through habitat loss and disease, populations of the staphylinid inhabitants of its nests also must be declining.

Names of species of Staphylinidae found in birds' nests were compiled almost 30 years ago, but there is little information on their behavior.

In central Asia, where sylvatic plague is endemic, some staphylinids are credited with suppressing flea populations, and thus help to suppress transmission of plague.

Adults of Amblyopinus and close relatives (subtribe Amblyopinina of subfamily Staphylininae) occur in the fur of some rodents in Central and South America. For years they were suspected of being parasites of these rodents, and taking blood from them.

Now, however, they are believed to be phoretic on the rodents, thus being transported from nest to nest.

They oviposit in the nests, and larvae feed as predators there of other arthropods.

Causes of Mortality

Natural Enemies

Scattered evidence needing review suggests that spiders, various insects (including Reduviidae, Carabidae, Asilidae, Formicidae, etc.)

amphibia, reptiles, birds, and bats, include Staphylinidae among their diets.

Among the parasites,

fungi play a major role,

and hymenopterous parasitoids, nematodes, and Nemata, a relatively minor role.

In temperate regions of the world,

as contrasted with tropical regions,

( staphylinids may achieve very high population levels at the soil in tropical regions)

at least at lower altitudes,

ants are ubiquitous and staphylinids less numerous in numbers of individuals; this suggests that ants may limit population levels of staphylinids in tropical regions.

Pesticide use

There is a growing literature about non-target effects of chemical pesticides on Staphylinidae in agricultural crops and turf grass, to the point where Aleochara bilineata (Gyllenhal) (a demonstrably beneficial species) has become a favored test animal for the effects of insecticides, herbicides, and plant-growth regulators. Destruction of natural habitat by humans, especially in the tropics, undoubtedly contributes to the rarity of many poorly-known staphylinid species