The trilobite Needmorella new genus, with type species N. simoni new genus new species from the late Emsian to mid-Eifelian Needmore Shale of West Virginia, is a distinctive member of the subfamily Synphoriinae. It also occurs in the same formation in Pennsylvania and Virginia. It is not very similar to other Devonian representatives of the subfamily and is considered to have its origins in a morphologically less-derived ancestor because it shares certain similarities with Silurian genera, including the very short anterior cephalic border unmodified by crenulations or spines, S2 that is not largely reduced to a deep pit adaxially, the relatively low inflation of L3, and the well-defined interpleural furrows on the pygidium. Other particularly distinctive characters of the genus include the very long genal spines and the abaxially inflated and expanded posterior pleural bands on the thorax and pygidium that project slightly distally. The conventional concept of the Devonian synphoriine Anchiopsis Delo, 1935 appears to be incompatible with the holotype of the type species, judging from the early illustrations of the specimen, and the genus could be a synonym of Synphoria Clarke, 1894.

UUID: http://zoobank.org/4a820e27-54ec-4f7b-a408-675e62b75154

Ivyleaf morningglory weed-free period, weedy period, and density studies were conducted in 1993 and 1994 to determine the effects of soil-applied imazaquin and chlorimuron plus metribuzin on ivyleaf morningglory interference in soybean. A weed-free period of 4 wk was needed to maintain soybean yield equivalent to weed-free season long when herbicides were not used, but treatment with either chlorimuron plus metribuzin or imazaquin maintained yield comparable to weed-free at all intervals. Ivyleaf morningglory biomass was reduced by both herbicides across all weed-free periods. The period nontreated ivyleaf morningglory plants were tolerated without yield loss was only 2 wk, but this interval was extended to 8 wk after treatment with chlorimuron plus metribuzin or imazaquin. Without herbicides, soybean yield was reduced by four ivyleaf morningglory per m of row, but the highest population evaluated in this study (eight per m of row) did not reduce soybean yield after treatment with chlorimuron plus metribuzin or imazaquin. Ivyleaf morningglory biomass was reduced at all densities after treatment with either herbicide.

Solution pH from 6.0 to 8.0 did not affect the germination of Italian ryegrass, ‘Pensacola bahiagrass,’ or common bermudagrass grown in petri dishes in growth chambers. Seeding intervals following metsulfuron methyl application varied from species to species and between soil types. Greenhouse studies indicated that in an Okolona silty clay, common bermudagrass should not be planted until 12 wk after metsulfuron methyl application. Italian ryegrass showed no metsulfuron methyl injury at the 6-wk sampling date when no lime was added, indicating reseeding was feasible at this time; however, a 12-wk time interval was not sufficient when lime was applied. Pensacola bahiagrass was injured when reseeded at 12 wk, regardless of liming rate. In a Prentiss fine sandy loam soil, common bermudagrass could be reseeded 12 wk after application when no lime was added, but not when lime was added. Italian ryegrass and Pensacola bahiagrass should not be reseeded for at least 12 wk, regardless of lime rate. Field experiments, where metsulfuron methyl was applied to the field and seeding was carried out in the greenhouse, indicated on the Okolona silty clay that common bermudagrass reseeding could occur at all liming rates after 3 wk, and Italian ryegrass and Pensacola bahiagrass after 6 wk. In the Prentiss fine sandy loam, common bermudagrass reseeding could occur at 3 wk, regardless of lime rate. Italian ryegrass emergence was not affected when reseeded immediately after metsulfuron methyl application, but height was reduced for longer periods, and increased lime rate lengthened this interval. Pensacola bahiagrass reseeding was feasible at 3 wk.

Soybean and ivyleaf morningglory were grown alone and together to quantify water use and growth after treatment with soil-applied chlorimuron plus metribuzin, imazaquin, or no herbicide. Soybean water consumption was 22 ml pot−1 day−1 or more when grown alone or with another soybean, regardless of herbicide treatment. Ivyleaf morningglory grown alone or with another ivyleaf morningglory consumed ≥ 32 ml water pot−1 day−1 when no herbicide was applied. Treatment with chlorimuron plus metribuzin or imazaquin reduced ivyleaf morningglory water consumption to ≤ 4 ml pot−1 day−1. Water use was reduced with either herbicide when soybean and ivyleaf morningglory were grown together, indicating little or no water consumption by ivyleaf morningglory. Ivyleaf morningglory height, root length, leaf area, and dry matter were reduced by imazaquin or chlorimuron plus metribuzin. Soybean leaf area was also reduced by herbicide treatment or the presence of another plant. Soybean biomass was not reduced in any planting combination, except when two soybean were grown together and treated with imazaquin. Nontreated ivyleaf morningglory partitioned more biomass into the shoots than roots. Ivyleaf morningglory responded to herbicide treatment by partitioning more biomass into roots.

Soil-applied imazaquin or chlorimuron plus metribuzin reduced ivyleaf morningglory photosynthetic rate, leaf area, biomass, and seed production per plant compared to the nontreated control. Photosynthetic rate of ivyleaf morningglory was reduced a minimum of 53%, and total leaf area was reduced at least 67% with either herbicide, regardless of ivyleaf morningglory densities. Ivyleaf morningglory biomass and seed production were reduced at least 62% with either herbicide across all ivyleaf morningglory densities. Soybean leaf area, photosynthetic rate, and biomass were not affected by herbicide treatment or ivyleaf morningglory densities of 2, 4, 6, or 8 per m of row.

Soil-applied herbicides alone or followed by postemergence (POST) applications of CGA-277476 were evaluated for season-long weed control in soybean. Common cocklebur, hemp sesbania, and pitted morningglory control was not consistently improved with a soil-applied herbicide followed by a POST application of 79 g ai/ha CGA-277476. However, in locations with heavy weed pressure, a tank-mix of chlorimuron + metribuzin + trifluralin or imazaquin + pendimethalin followed by CGA-277476 improved common cocklebur, hemp sesbania, and pitted morningglory over CGA-277476 alone. Sequential application of CGA-277476 following SAN 582 improved weed control over SAN 582 alone. When weed pressure was not severe, there were no differences in control from CGA-277476 alone or following soil-applied herbicides. A POST application of CGA-277476 following soil-applied herbicides did not consistently improve soybean yield over CGA-277476 alone. Yield from soybean treated with SAN 582 was improved when CGA-277476 was applied. In contrast, when chlorimuron + metribuzin + trifluralin or imazaquin + pendimethalin were applied at planting, yield was similar with or without POST application of CGA-277476.

Field experiments were conducted at three Mississippi locations to evaluate potential antagonism when postemergence graminicides were tank-mixed with CGA-277476 and to determine if the antagonism could be overcome with an increase in graminicide rate. At all locations when the 1X rate of clethodim, fluazifop-P, or quizalofop was tank-mixed with 79 g ai/ ha CGA-277476, johnsongrass, broadleaf signalgrass, and barnyardgrass control was reduced 5 to 30%. When the graminicide rates were increased to 1.5X, antagonism was still present for fluazifop-P and quizalofop. However, 156 g ai/ha clethodim overcame the antagonism when tank-mixed with 79 g/ha CGA-277476 compared to 105 g/ha clethodim. CGA-277476 alone controlled barnyardgrass and broadleaf signalgrass 38 to 63% and johnsongrass 60 to 85%. There were no differences in soybean yields with graminicides applied alone or tank-mixed with CGA-277476.

Field studies were conducted from 1998 through 2000 to compare weed population shifts in soybean and cotton using a total glyphosate system, preemergence (PRE) herbicides followed by glyphosate, and a conventional herbicide program. In the first year of the soybean study, populations of hemp sesbania were highest for treatments of PRE herbicides followed by either glyphosate or the conventional herbicide program because of better control from the total glyphosate system. Barnyardgrass populations in the first year of the study for the nontreated plots were 0 plants/m2 but increased in the third year to 61 plants/m2. Flumetsulam plus metolachlor followed by glyphosate at the lower rates and the nontreated check were the only treatments in which there was an increase in barnyardgrass over the 3-yr study. Broadleaf signalgrass populations increased in the third year with 0.1 kg ai/ha flumetsulam plus 2.1 kg ai/ha metolachlor followed by 0.84 kg ae/ha glyphosate, primarily because of reduced competition from lower populations of other weeds such as hemp sesbania. Pitted morningglory populations for all treatments decreased in the third year because of good control of this species and the high level of interference from other weed species in the first 2 yr. Johnsongrass populations decreased in the third year with 0.4 kg ai/ha flumetsulam plus 1.1 kg ai/ha metolachlor followed by 0.84 kg/ha glyphosate. Johnsongrass populations decreased with timely glyphosate sequential applications, with 5 plants/m2 in 1998 and 0 plants/m2 in 2000. Yields increased from the first year to the second year, corresponding to reduced weed pressure, and yields varied from 710 to 1,420 kg/ha. Because of weed pressure, soybean yields were not different in any of the treatments, including the nontreated, although treatments changed the species present. In the cotton study, weed populations over the 3 yr decreased, with the most significant reductions from the treatments of fluometuron plus prometryn plus metolachlor followed by either pyrithiobac or glyphosate. Weeds that showed the most significant decline were barnyardgrass and hemp sesbania, whereas johnsongrass increased, with 27 plants/m2 in treatments of 0.6 kg ai/ha fluometuron plus 0.3 kg ai/ha prometryn plus 0.7 kg ai/ha metolachlor followed by 0.84 kg/ha glyphosate. Lint cotton yields varied from 0 to 128 kg/ha. Because of the weed pressure, cotton yields were not different in any of the treatments, although treatments changed the species present. This research has shown that weed species can decrease over time with the continued use of any of these herbicide programs.

Field research was conducted at three locations in Mississippi to evaluate CGA-277476 tank mixtures with four broadleaf herbicides for possible improvement of broadleaf weed control. Tank mixtures in this research were typically additive, although some instances of antagonism were noted. Control of morningglory (Ipomoea) species and hemp sesbania (Sesbania exaltata) was not consistently improved by the addition of acifluorfen, chlorimuron, fomesafen, or imazaquin to 59 or 79 g ai/ha CGA-277476. However, when a large population of weeds was present, the addition of acifluorfen, chlorimuron, or fomesafen to 59 or 79 g/ha CGA-277476 improved control over CGA-277476 alone. Prickly sida (Sida spinosa) was not controlled more than 68% with any treatment in this study; however, horse purslane (Trianthema portulacastrum) was controlled at least 90% with either 79 g/ha CGA-277476 alone or tank-mixed with acifluorfen, fomesafen, chlorimuron, or imazaquin. The addition of CGA-277476 to acifluorfen or fomesafen did not improve control over acifluorfen or fomesafen alone on any of the weeds evaluated; however, the addition of CGA-277476 to imazaquin improved hemp sesbania control over imazaquin alone. Tank mixtures did not result in yields greater than CGA-277476 alone in areas with moderate weed pressure, whereas in areas with severe weed pressure, tank mixtures improved soybean (Glycine max) yield over CGA-277476 alone.

The trilobite fauna of the middle Silurian (Telychian to possibly earliest Sheinwoodian) Tomcat Creek limestone in the Broken River Province of north Queensland is dominated by the suborder Illaenina, including illaenimorphs (Illaeninae and Bumastinae) and members of the Scutelluidae. Scutelluidae are most diverse, with eight genera, of which Dolabrapex, Iotoryx, Perizostra, and Quintonia are new. Perizostra is the first scutelluid with a cephalon that may be described as of phacomorph appearance. Illaenimorphs are represented by three genera, including Opsypharus, which is regarded as a senior synonym of Paracybantyx but distinct from Failleana with which it has been placed in synonymy by some authors. Thirteen species are new: Cybantyx? ergodes, Opsypharus pandanensis, Australoscutellum talenti, Dolabrapex acomus, Illaenoscutellum psephos, Iotoryx clarksoni, Japonoscutellum mawsonae, J. drakton, J. fractum, Kosovopeltis avita, Perizostra campbelli, Quintonia arata, and Q. pavo. A species of Stenoparia is placed in open nomenclature. The species of Australoscutellum, Illaenoscutellum, and possibly Kosovopeltis are the oldest known representatives of those genera. These genera and Japonoscutellum are also common in faunas from limestones of Wenlock to Ludlow age in central western New South Wales, reflecting the similarity in lithofacies. The monotypic Late Ordovician genus Craigheadia, which has been regarded as a scutelluid, belongs to the Lichidae and is probably a junior synonym of Leiolichas.

The trilobite Reedops is documented from strata probably corresponding to the middle part of the Talacasto Formation in the Sierra de las Minitas, at the northernmost extent of the Precordillera in La Rioja Province, northwestern Argentina. The specimens resemble the type species of the genus, R. bronni, indicating a Pragian (Early Devonian) age for the strata, and suggesting the occurrence at this time of faunal exchange between the Old World Realm, particularly the Bohemian area, and the Malvinokaffric Realm. The taxon represents the first Early Devonian macrofaunal element in the Malvinokaffric Realm with global biostratigraphical significance.

A distinctive new genus (Xyoeax) and two new species (Xyoeax eponcus, Scutellum sudorum) of styginid trilobites are described from the late Early Devonian (Emsian) Murrindal Limestone of eastern Victoria, Australia. Limited material of a third styginid species not belonging to any named genus is also described from the same locality. Xyoeax is considered to be closely related to Ancyropyge Clarke, 1891, and Weberopeltis Maksimova in Moore, 1959, and less closely related to Kolihapeltis Prantl and Přibyl, 1947. Weberopeltis is revised and newly diagnosed. Several species previously assigned to Weberopeltis are transferred to the new genus Exastipyx, which is considered to be related to Cornuscutellum Snajdr, 1960. Ancyropyge, Exastipyx, Weberopeltis, and Xyoeax all have pygidia with long pleural spines derived by reduction of the pleural field between the pleural ribs, whereas Kolihapeltis and Cornuscutellum lack pygidial spines. Pygidial morphology of Xyoeax type has thus arisen independently in separate styginid lineages. The type species of Altaepeltis Maksimova, 1968 is established as Weberopeltis bublitchenkoi Maksimova, 1960, by monotypy.

From the time I met David, at least 40 years ago, in Florence, he impressed me with his wide knowledge and liking of contemporary music. This and other matters were spoken of with fascination, rapid changes of thought and feeling. I shall miss him a great deal.