Some of you will recall my earlier post on baited, buried traps where I put out rotten liver and cheese baited traps underground in various places in California. I have taken them all in and sorted out the bodies over the past couple weeks. I put out about eight traps per site in the following locations (see the map): [A] San Joaquin River Gorge, in Gray Pine, Oak, Manzanita scrub, [B] Portola Redwoods State Park , in redwood, Douglas Fir, Oak forest and [C] Mangini Ranch near Concord, in Oak woodland.
The big score was 26 specimens of Anillodes ?debilis from Portola. These are tiny, blind soil-dwelling beetles, very obscure, the group is unrevised and the beetles are rarely collected. This is probably the largest series of Anillodes ever collected.
Other cool tiny, blind beetles include the latridiid beetle Fuschina occulta from the Mangini Ranch site and catopocerine leiodids, probably a couple species of Pinodytes, found in traps from both Portola and SJRG .
Of particular interest to me, was the two dozen or so Pterostichus (Leptoferonia) angustus in the Mangini Ranch traps. This is not a rare species, but it is strongly seasonal and uncommon in surface pitfall traps. It can be collected by rolling rocks and logs, raking leaf litter while headlamp searching at night and sifting litter. I have collected them around Concord and through the range of the species, but they are no where close to being in the top 10 most common carabid beetle species in the Mangini area and it would take a lot of effort to get more than a dozen. However, in the Mangini traps they were the only carabid species. There are several other Leptoferonia species only known from the types or very few specimens and I think these traps placed in the areas those species are known from could be the way to collect them.
Overall the traps were successful, although there was a lot of variation between individual traps. Other beetles in the traps include 3-4 spp of Histeridae, a variety of staphylinids, an assortment of leiodids (cholevines?), assorted small tenebrionids. Although based on only one year, my impressions are that 1. liver was better than cheese, 2. larger volume traps where slightly better than smaller ones (but much harder to dig in and out), 3. wet coastal habitat was better than inland, 4. traps between 8-12 inches deep did best (but shallower under thick leaf litter also did well, but got more surface fauna) and 5. traps in very dry areas like the SJRG did poorest and may need to be buried much deeper. I definitely will put out more next year. I am already considering where they might go. SoCal? NorCal? SO much California and too little of me. Maybe others will give these traps a try.