Silphidae - Diversity and Distribution

Diversity and Distribution

Silphidae beetles are ubiquitous and abundant. They are found worldwide. There are 46 different species of Silphidae located in North America, many of which are found in the United States.

• Heterosilpha ramosa is located in the western portion of the United States from California to New Mexico and up to Nebraska and Montana. It can also be found in southwestern Canada. It is noted for having a dark brown or black pronotum and elytra. It is most active throughout the warmer months of spring and summer and feeds on fresh carrion and that of advanced decomposition.

• Necrodes surinamensis is found throughout central and southern Canada and all throughout the United States, except in the Southwestern portion. It has a glossy black pronotum with dull elytra having pronounced longitudinal ridges and red markings at the tip. N. surinamensis is nocturnal and is active in the spring months. They are found on larger carcasses.

• Necrophila americana is found east of Texas up through Minnesota and in southeastern Canada. They are noted for a yellow pronotum with a black center and dull black elytra with crossed ridges making an oval shaped body. They are active during the daylight hours from spring through fall and feed on carrion and larvae of other insects present on the carcass.

• Nicrophorus americanus is located from Florida to east Texas up through Michigan, and sometimes in southeastern Canada. They have a long pronotum with orange or red markings down to the elytra. It is 30–35 mm long, making it the largest of the genus Nicrophorus. This species is rarely collected due to its nocturnal behavior and is considered an endangered species.

• Nicrophorus carolinus is noted for having a very narrow pronotum that is black and shiny on the anterior portion, yet dull on the posterior portion. It is also noted for distinct orange markings. It can be found along the Atlantic coast of Virginia through Georgia and the Gulf Coast of Texas and Alabama. It can also be found in north Texas, Colorado, and Wyoming, even some parts of Arizona.

• Nicrophorus investigator varies widely in color, but is noted for having a wide pronotum. It can be found in the northwestern United States, and along the U.S.-Canadian border, but has been found in New Mexico and Arizona. The pupal stages typically overwinter and the adult stages emerge in the summer.

• Nicrophorus marginatus has a glossy black pronotum with orange hairs located behind the head. The elytra are very short, glossy black with orange markings. They can be found in southern Canada and all throughout the United States except in Florida and Georgia. They are typically nocturnal and feed on maggots, and are known to bury animal carcasses to oviposit.

• Nicrophorus orbicollis is known for having elongated black pronotum and short black elytra with two rows of orange spots. They are located in southeastern and south-central Canada, east Texas and north to the Dakotas. They are nocturnal and are active in the warmer months of the year upon overwintering.

• Nicrophorus tomentosus is the easiest species to distinguish of Silphidae due to its small size of about 15 mm and dense gold hairs on its pronotum. It can be found in southeastern and central Canada and throughout the eastern and central United States except south Texas and Florida. Unlike other beetles of the same genus, instead of burying the carcass, they remove the soil from underneath it, allowing it to sink underground. They are active in the summer months.

• Oiceoptoma inaequale is black from the pronotum to the elytra and is located in the eastern United States and southeastern Canada. They are abundant from the spring through the fall, and are active throughout the day.

• Oiceoptoma noveboracense is noted for having a black or dark brown pronotum with orange margins, and a red-brown elytra with distinct longitudinal ridges. They can be found in southern Canada and the central United States. They are active during the day and abundant during the spring months, like most species of their genus, they also overwinter.

• Oiceoptoma rugulosum is dull, black and has an oval shaped body with four prominent longitudinal ridges on the elytra. They can be found in Florida, Texas and Louisiana. They prefer human remains where they prey on maggots.

• Thanatophilus lapponicus has a black pronotum with some bits of gold and gray, and a brown-black elytra. The body tends to have a textured appearance. It can be found in the northeastern United States and parts of southern California, New Mexico, Arizona, even Alaska and Canada. Prominent in the summer, but it can bear the cold. It thrives on fresh carrion and carcasses in advanced decomposition where it preys on insect larvae.

United Kingdom

• Oiceoptoma thoracicum http://www.panoramio.com/photo/35226116