Dacne quadrimaculata
Species of beetle
From Wikipedia, the free encyclopedia
Dacne quadrimaculata is a tiny North American species of pleasing fungus beetle (family Erotylidae). It is placed in subfamily Dacninae, or – in taxonomic arrangements that prefer a more comprehensive subfamily Erotylinae – in tribe Dacnini of the Erotylinae.[1][2]
| Dacne quadrimaculata | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Clade: | Pancrustacea |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Family: | Erotylidae |
| Genus: | Dacne |
| Species: | D. quadrimaculata |
| Binomial name | |
| Dacne quadrimaculata (Say, 1835) | |
Description
About 2.4 to 3.5 mm long as adults, this is one of the smallest Erotylidae within its range. Like most of its close relatives, M.fasciata has elytra which bear lengthwise rows of small pits, and has a prothorax base that is almost as wide as the "shoulders". Its fourth tarsomere is not strongly reduced as in some other Erotylidae, and the end segment of its maxillary palps is cylindrical. The antennae have a round "club" at the tip. The coloration is brownish-black overall, with a reddish spot at the base and another at the tip of each elytron; these spots are the origin of its scientific name quadrimaculata, meaning "four-spotted" in Latin.[3]
Range and ecology
D.quadrimaculata is essentially restricted to North America east of the 100th meridian west. It is found from Ontario and Québec in Canada and Maine in the USA west to Manitoba, and in the south from North Carolina to Alabama and Texas.[3]
This beetle eats fungi as larva and adults, with a preference for bracket fungi. While it has been found on a wide range of fungus species from the orders Agaricales (e.g. Clavicorona of the Clavariaceae, Hypsizygus of the Lyophyllaceae, and Pluteus of the Pluteaceae), Polyporales (e.g. Piptoporus of the Fomitopsidaceae, Ganoderma of the Ganodermataceae, and Lentinus of the Polyporaceae), and – unusual for Erotylidae – Russulales (Stereum of the Stereaceae), they have a strong preference for oyster mushrooms (Pleurotus; Agaricales: Pleurotaceae) such the common oyster mushroom (Pleurotus ostreatus), and the Polyporaceae Cerioporus squamosus (dryad's saddle). While P.ostreatus is confirmed as larval food of D.quadrimaculata, the larval biology itself is not well known.[3][4]
On common oyster mushrooms, this species is sometimes found in mixed groups with the distantly related Erotylidae Triplax flavicollis and T.thoracica, which is unusual since pleasing fungus beetles usually associate only with their own species. Also, unlike D.quadrimaculata, these two Triplax species completely depend on P.ostreatus as food source; some resource partitioning mechanism to avoid competitive exclusion seems to be at work here.[3]