Volume II, no. 4, Winter 1993Table of Contents
A new species of Purpuricenus in
Ohio -
Bob Androw
A New Species of Purpuricenus in OhioAn apparently new species of the cerambycid genus Purpuricenus Dejean has been found to occur in Ohio and is currently being described by workers in the western states. Its discovery came in a roundabout fashion, a result of work on another species of Purpuricenus thought to be new as well. Here's how it happened. A species of Purpuricenus, varying from all-black to black with red elytral markings, was being collected in the Rolling Hills region of west Texas. It differed greatly from any currently described species and was immediately considered to be new to science. Another species was being collected in Oklahoma. This species, black with the basal half of the elytra orange, was interpreted to match Chemsak's description of Purpuricenus linsleyi. In addition, a smaller species was also being taken in Oklahoma. This was determined to be Purpuricenus axillaris Haldeman, a typically eastern species. As greater series of all these species were amassed, a surprising problem was revealed. The supposedly new species from west Texas was actually P. linsleyi Chemsak. This species is quite variable but was described from fully marked individuals, not exhibiting the full range of the species variability. The species thought to be P. linsleyi in Oklahoma was actually P. axillaris Haldeman. And that left the small species in Oklahoma without an identity. So a new species was involved in the complex of species, but it was not the one that drew attention to the problem in the first place. While chatting with Dan Heffern of Houston, Texas, a longtime friend and fellow longhorn enthusiast, his decsription of this new little species sounded very much like specimens I had been collecting in Ohio. Until the summer of 1993 I had collected only two species of Purpuricenus in Ohio, P. humeralis (Fabricius) and what I thought was P. axillaris. I had wondered why the Ohio specimens of P. axillaris were so much smaller and paler in color than specimens that I had from other areas of the country. In actuality I had never collected P. axillaris but was getting the undesccribed species. As the genus was so well known in the East (or so I thought) I never looked closely at the specimens, and chalked up their appearance to geographical variation. This past summer I learned more about the habits of these two species. Purpuricenus n. sp. flies earlier than P. axillaris, in late June as opposed to late July and August for the latter species. As I always started bait-trapping in mid-June and quit when the Purpuricenus stopped coming to the traps, I was only collecting the earlier species and totally missing P. axillaris later in the season. This summer I was able to collect my first P. axillaris by bait-trapping in early August. In addition I reared one Purpuricenus n. sp. from a fallen branch of hickory that had been dead for two or more years. Linsley (1962) records the larvae of P. axillaris as girdling living branches from their host trees. To help separate the two species the following characteristics can be examined. In Purpuricenus n. sp. the basal half of the elytra are a pale orange, ranging to almost testaceous, while in P. axillaris the color tends more toward orange or red. The punctation of the elytra in the new species is much finer and less dense than in P. axillaris. The humeral angles of the elytra are nearly impunctate in Purpuricenus n. sp. (see figure 3 below) while they are densely punctate in P. axillaris (see figure 4 below). The new species is nearly glabrous at the base of the elytra, while P. axillaris has many short, erect black setae along the basal margin and along the sutural margin of the elytra. However, the pubescence does appear to vary somewhat. While the punctation of the pronotum of the two species is similar, the sculpturing of the pronotum differs greatly. In P. axillaris the discal tubercles are well developed, the lateral spines are large, and there is a polished callosity along the mid-line of the pronotum near the base (see figure 2 below). Purpuricenus n. sp. lacks this polished callosity, has smaller lateral spines, and has very low, poorly developed discal tubercles (see figure 1 below). The elytral apices in P. axillaris are strongly emarginate and bidentate (see figure 4), while in Purpuricenus n. sp. they are very shallowly emarginate and slightly dentate at most (see figure 3). The accompanying figures should help to illustrate these characters. By using a combination of characters, date of capture, and host if known, the two forms should be easy to separate. As soon as a formal description of the species is completed I will inform our readers as to the place of publication. In the meantime take a look at any specimens you may have in your collection. Should any of you possess any I would be pleased to receive the data from these specimens. So far, I have collected the new species at Lake Hope St. Pk. in Vinton County and George Keeney has taken it at Shawnee St. Fst. in Scioto County. I have also seen one specimen from West Virginia. It is suspected that the species is sympatric with P. axillaris throughout its range, but further study is needed to verify this. The discovery of this species has reminded me of the possibilities of finding new taxa in one's own backyard, so to speak, and of the danger in assuming that everything is as well-known as it appears. This also exemplifies why it is so important to sample an area over an extended period of time to truly understand the changing faunal components over a season. 
Fig.1 (top left): Purpuricenus n. sp., pronotum - lateral view, left
side. - Bob Androw More on Cicindela cursitans LeConteIn the spring 1992 issue of The Ohio Coleopterist, the editors reported new county records for Cicindelidae in Ohio. One of the species, Cicindela cursitans LeConte was reported from Scioto County as occurring along the Ohio River. A single specimen was collected by Bob Androw on 13-VII-1989 running on drying cracked mudflats. I was present on that collecting trip and have been looking for the beetle every year since, but was unsuccessful until this year. I now believe I was looking in the wrong place at the right time. About 2 p.m. on 26-VI-1993 I was making my regular pilgrimage to the Ohio River as I always do when I visit my family in Portsmouth. I was checking the area for Cicindela cursitans and as usual I wasn't having any luck. I began walking back towards my car along a path that was gently sloped and above where swell waters normally sit in the spring of the year. As I was nearing the top of the embankment I saw a flash dart across the path and apparently stop in a small tussock of grass. The movement of this creature was different from the myriad of small spiders that run on the river shoreline. It was much faster and more deliberate in its movement than that of the spiders. As the tiger beetle darted from the tuft and headed for the dense weed growth at the side of the path I knew I had found what I had been looking for. I quickly blocked its path with one hand and gently pinned it to the ground with a finger from the other. With a new search pattern in mind, I checked any openings in the weeds near the top of the embankment. The plant growth was dominated by Canada thistle, hedge bindweed, and lesser ragweed. Close inspection of the area yielded five more specimens, all caught by hand. The specimens were usually caught in small openings in the weeds on the river bank "terraces". The terraces are formed when high water cuts into soft steep embankments and forms what looks like stair steps. Two open pitfall traps with 70% alcohol in the bottom yielded another six specimens from 27-VI to 2-VII-1993. Since rain was threatening to wash out my traps, I placed rain shields over them on 2-VII. No new beetles were taken during that trapping period or during subsequent trapping intervals. I'm not sure if the rain shields somehow inhibited their capture or if it was merely the end of the adult activity period. It appears that a variable population exists in the area and I plan to do some more field study on this small flightless tiger beetle. Very little is known about the ecology of this species and this presents an excellent opportunity to study it. This beetle may be more common in the state than we initially thought. It's small size and quick, agile running skills make it a worthy match of any collector. It can be easily overlooked as it was occurring in what I wouldn't call a "typical" tiger beetle habitat. In this circumstance it appears to prefer areas of fairly dense weed cover 2 to 3 feet in height. When motionless, its dull greenish-bronze appearance lends itself very well to camoflauge the beetle against the dry river mud, dappled by the broken shade provided by the weeds. This beetle is apparently very tolerant of disturbance as the area is usually bush-hogged or sickle-barred every summer, is heavily traversed by fishermen, boaters, and sightseers, and is subject to extended periods of inundation by high water at least once every year. - George Keeney Collecting Tar Hollow State Park and ForestJune 19, 1993 was the first field trip for OC. We spent an enjoyable day and much of the night collecting Tar Hollow State Park and Forest. Tar Hollow, a beautiful park located in Ross County just east of Chillicothe, has a managed area of 16,127 acres of state forest and 619 acres of state park. This park is typical of the terrain found in southern Ohio with sharp relief created by the fast running streams and sharp ridgelines. The age of the forest varied greatly as controlled harvesting had been taking place in this area for some time. The weather was hot and dry so collecting was moderate and required a lot of effort to get the relatively few species collected. The low species number is not a reflection of the viability of the habitat but rather the effect of weather conditions. The area will certainly be on our list of places to return to when the conditions for collecting are better. We have put together a few highlights of the day's collecting and a list of the species encountered in Carabidae and Cerambycidae. In addition to these families specimens of Scarabaeidae, Curculionidae, Chrysomelidae, Cantharidae, Tenebrionidae, Buprestidae, Elateridae, Lampyridae, Erotylidae, and Cleridae were taken and are in the process of being determined. Carabidae For the carabid collector (or perhaps more accurately for the carabids) Tar Hollow contains a wide variety of habitats to explore. Small streams cut through sandy substrate and are convoluted into many loops and twists. These oxbows are often isolated from the main stream bed when water is low. Then, partially filled with leaves, they become small eutrophic pools. On the wet matted leaves at their margin Bembidion were found in good numbers together with Chlaenius emarginatus, Agonum fidele and Elaphropus saturatus. The steep sides of the valley that make up most of the park are thickly covered in leaf litter. However, in this zone only a few species could be found. These required considerable effort to collect. Turning rocks, peeling bark and walking with the headlamp after dark yielded Carabus goryi, Dicaelus teter, Platynus hypolithos, P. angustatus and Galerita bicolor. Higher up in the park areas recently cut for tree harvest provided edge ecotone where Pterostichus stygicus, Poecilus chalcites, Chlaenius tricolor and Cyclotrachelus sodalis were found. At a picnic area on a ridge top Notiophilus semistriatus was found abundantly. They could be collected by searching the mosses at the feet of large oaks in the cut grass area surrounding the picnic shelter. When four of us were crawling on hands and knees pursuing these small and fast moving carabids with our aspirators it was truly quite a site for passers-by. On one ridge a small pool of water, created by a seeping spring, in the otherwise dry wooded area was a small oasis for several Bembidion species and Agonum ferreum. Additionally some carabid larvae were found among the mud and leaves but they were not collected. Many of the remaining species were taken at either the blacklight or mercury vapor light. Ohio supports nearly 500 species of carabids and so has one of the most diverse carabid fauna in temperate North America. With this in mind a one-day sampling can only represent a fraction of the carabid species in Tar Hollow S.P. The 43 species listed below are very typical of the species which one would expect from a site in southern Ohio. Many more species are sure to be found with repeated sampling and the use of pitfall traps. Interestingly, one day of hand and blacklight/mercury vapor light collecting in other locations in Ohio have resulted in a similar number of species though composition is always somewhat different. I will return to Tar Hollow in 1994 to collect more beetles and plan to emplace pitfall traps to sample the carabids of this beautiful southern Ohio park. Carabidae collected on 19 June 1993 in Tar Hollow State Park and Forest, Ross County, Ohio. Determinations by K.W.Will, nomenclature follows Bousquet 1991.
Acupalpus testaceus (Dejean) Cerambycidae The park and forest are good collecting areas for the family Cerambycidae as well, having a variety of habitats. As one enters the park, there is an expanse of old field that butts up against the forested part itself. Young sassafras and sumac border the forest edge and many species of herbaceous plants can be found in the field proper. Continuing into the park one passes through a section of white pine that was planted many years ago and which supports populations of Monochamus spp. and Asemum striatum (Linnaeus). Beyond this stand of pine one enters the main part of the park, where the evening's blacklighting was done. Although collecting that night was less than exceptional, several nice things were taken, the most notable being Goes debilis LeConte. Collecting during the day was a little more productive, with most specimens being taken by beating or hand picking from a variety of wildflowers that were in bloom. In the higher areas of the forest cerambycids were taken from the blooms of wild rose, false Solomon's seal, fleabane, and elderberry. The wild rose was particularly attractive as beetles were arriving almost as fast as they were being collected. Several specimens of Gaurotes cyanipennis (Say) were taken from the trunk of a recently fallen wild cherry tree, and Rhopalophora longipes (Say) was beaten from the dead branches of redbud. Specimens of Neacanthocinus pusillus (Kirby) and Amniscus sexguttata (Say) were beaten from the fallen trunk of red pine, as were a variety of buprestids and clerids. As we moved down toward lower parts of the forest, different species were taken, most from the flowers of wild hydrangea that was blooming profusely along the edges of the creekbeds. The activity level of the cerambycids was not nearly as high as we expected though. Very few beetles were coming to the flowers despite the freshness of the blooms. This turned out to be typical for the season in general. The wild hydrangea did produce specimens of Trigonarthris proxima (Say) and T. minnesotana (Casey), as well as a variety of other lepturines. In all, 21 species of Cerambycidae were collected, an exceptionally low number considering the diversity of Ohio's fauna, for which over 275 species have been recorded. Collecting in the park and forest in the past has produced twice that number of species in a day's time, and given better weather conditions should do so again. This coming year's studies will hopefully prove this out. Cerambycidae collected on June 19, 1993 in Tar Hollow State Park and Forest, Ross County, Ohio. Determinations by R.A.Androw.
Amniscus sexguttata (Say) - K. W. Will & R. A. Androw |