Profile of the southern corn billbug, Sphenophorus callosus Oliver, an important pest of corn in eastern North Carolina

ABSTRACTEnviron. Entomol. II: 954-957(1982) Host range of the southern corn billbug, (SCB), Sphenophorus callosus (Olivier) (Coleoptera: Cur­culionidae), was tested with 14 crop and weed species by artificially infesting plants with SCB adultsand eggs; field observations were also made. Of 14 species tested, only corn, Zea mays L., and yellownutsedge, Cyperus esculentus L., allowed completion of larval development, although adults fed on awider variety ofplants. Scirpus cyperinus (L.) Kunth (Cyperaceae) was found to be a new SCB larvalhost from field observations. Overwintered SCB adults were fed sections of greenhouse-grown cornand four weed species in the laboratory. Survival was highest on corn and yellow nutsedge and loweston common larnbsquarters, Chenopodium album L. SCB were able to produce mature eggs only iffedeither corn or yellow nutsedge. Many Sphenophorus spp. weevils are economic pestsofgrass crops (Satterthwait 1932). One species, S. cal­losus (Olivier), the southern corn billbug (SCB), is animportant pest ofcorn in eastern North Carolina. Webs­ter (1912), Metcalf(1917) and Satterthwait (1931) listednine genera (24 species) ofGraminae, Cyperaceae, andJuncaceae as hosts of SCB.Because of the restricted host range of SCB and itssedentary habits, early workers (Webster 1912, Metcalf1917) suggested crop rotation as a control measure.However, since that time, the eastern North Carolinaagroecosystem has changed greatly with respect tocropand weed species. This study was conducted to providemore information on the host range ofadult and larvalSCB in the current corn-soybeanagroecosystem ofeast­ern North Carolina so that the basis for continued useofcrop rotation as a management tactic could be eval­uated.Materials and MethodsAdult and Larval Host RangeDuring field studies of SCBbiology from 1978 to1980, observations were made on SCB adult feedinghabits in over 15 commercial corn fields (principally inWashington, Tyrrell and Hyde Counties, N.C.). Plantspecies on which adults were seen feeding were in­spected later for SCB eggs and larvae.Various grasses, sedges, rushes and related plantsgrowing in drainage canals and uncultivated areas nearthe above infestations ofSCB were sampled in late Julyto August; the period of greatest abundance of SCBpupae and teneral adults (Wright 1981). Specimens col­lected were preserved in alcohol orreared to adult emer­gence. Samples ofweevil-infestedplants were identified.Studies were conducted at the Tidewater ResearchStation (TRS), Plymouth, N.C., in 1978 to 1980 to de­termine the acceptability ofvarious plants for SCB adult

Core Ideas Living mulch cover crops help stabilize erosive soils during corn production. Wide rows enable the living mulch cover crop to re‐establish for subsequent cropping. Herbicide bands must be kept to a minimum width to permit living mulch. Removal of crop residue is essential for white clover to perenniate in the living mulch system. White clover can supply over 100 kg ha−1 N to corn in the living mulch system. The area dedicated to corn (Zea mays L.) production increased 50% in the southeastern United States between 2006 and 2016, but producers need to find production systems that mitigate environmental impacts on erosive soils. Utilizing a perennial legume in a living mulch system may help stabilize the soil. The objectives of this study were to identify the most successful herbicide banding pattern (20 or 40 cm), corn row spacing (75 or 90 cm), and corn population density (60,000 or 90,000 plants ha−1) to optimize potentially mineralizable nitrogen (PMN) from white clover (Trifolium repens L.) and maximize clover regrowth in a living mulch system. Plots were established at Floyd and Oconee Counties, Georgia, and tested over 2014 and 2015. Clover persistence and regrowth was best when initial clover suppression used a 20‐cm band and corn was planted on 90‐cm rows. Herbicide‐induced PMN was greater for the wide herbicide band width, but shade‐induced PMN was greater from the narrow band width. Corn shaded the clover at approximately 40 d after planting (DAP) and clover responded by senescing biomass as shading increased. Shading resulted in the majority of PMN regardless of other treatments variables. Corn grain yields were greater in the high population treatments, but there was a year × location × herbicide band width interaction. Considering clover persistence, PMN, and corn grain yield, we conclude that corn planted on 90‐cm rows in 20‐cm wide herbicide bands of dead clover is the best treatment for the living mulch system.

Stink bugs (Hemiptera: Pentatomidae) are the most important economic pests of field corn (Zea mays L.) in the southeastern United States. The most common pest species include the brown stink bug, Euschistus servus (Say), green stink bug, Chinavia hilaris (Say), and southern green stink bug, Nezara viridula (L.). Stink bugs are highly mobile and feed on a wide range of crops and wild hosts across the highly fragmented southeastern landscapes. Because of their strong dispersal ability and the sporadic nature of their occurrence in corn, effective monitoring and implementation of control tactics can be challenging to prevent yield losses in field corn. This article provides an overview of the current literature on key stink bug species in the southeastern United States associated with corn production. A key focus of this review is on the seasonal dynamics of stink bugs in southeastern agroecosystems as related to their pest status in field corn. We discuss the suite of available integrated pest management practices for stink bugs and suggest areas for developing improved strategies in the future.

This study aims to determine the pattern of planting points, and effect of weed control with pre-emergence herbicides on the growth and production of maize. This studies became conducted from November 2019 to the end of February 2020 in Sendang Rejo Village, Binjai District, Langkat Regency. The design of this research used factorial split-plot design: Factor I: The planting point pattern (P)- P1 = Single row cropping point pattern (70 cm x 20 cm), P2 = Two row planting point pattern (20 cm x 20 cm, the next row spacing is 70 cm), P3 = Triangular planting point pattern (20 cm x 20 cm, distance with the next row of triangles 70 cm). Factor II: Herbicide Application (H)- H1 = No herbicide application (control), H2 = Weed free (manual control), H3 = applied with dimethenamide-P + saflufenacil 3 days before planting, H4 = applied with dimethenamide-P + saflufenacil at planting, H5 = applied with dimethenamide-P + saflufenacil aged 3 DAP H6 = applied with topramezone + atrazine at 14 DAP, H7 = applied with topramezone + atrazine at 21 DAP. The type of sampel in this study were plant height, amount of leaf chlorophyll and production. The results showed that the pattern of planting points had a completely huge effect on plant heigh at the age of 6 and 8 WAP and total chlorophyll and corn production (Zea mays L.). Weed control with pre-emergence and post-growth herbicides had no huge impact on plant height, total chlorophyll and maize production (Zea mays L.). However, from this study it was found that the best herbicide application was at H7 (Toppramezone + atrazine at 21 days after planting). While the use of planting point patterns and weed control with pre-emergence and post-growth herbicides interacted significantly with the observation of total chlorophyll, while there was no huge impact on the observation of plant height and maize production (Zea mays L.).

Impatiens necrotic spot virus (INSV), family Bunyaviridae, genus Tospovirus, is an emerging virus found mostly in ornamentals under greenhouse production. INSV has been detected in peanut (Arachis hypogaea L.) in Georgia and Texas (3) and recently in tobacco (Nicotiana tabacum L.) in the southeastern United States (2) but little is known about INSV distribution and impact on these crops. Noncrop plant hosts are likely to contribute to disease spread by serving as reservoirs for the virus and reproductive hosts for thrips (Frankliniella occidentalis Pergande), which transmit the virus. Yellow nutsedge, a native of North America, and purple nutsedge introduced from Eurasia, are considered serious weed problems in the southeastern United States. To date, there are no reports of natural INSV infections in these weeds. A survey was conducted at two research farms in Tift County, Georgia to determine if yellow and purple nutsedge plants were naturally infected with Tomato spotted wilt virus (TSWV) and INSV. The first field at the Black Shank Farm had been planted with flue-cured tobacco K-326 earlier in the year and fallow at the time of sampling. The second field at the Ponder Farm was planted at the time of sampling with yellow squash (Cucurbita pepo L.) and cabbage (Brassica oleracea L.). In early October 2002, 90 nutsedge plants were taken at random from each site. Leaf and root tissues of each of the nutsedge plants were tested for TSWV and INSV using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) alkaline phosphatase antisera kits (Agdia Inc., Elkhart, IN). No visible symptoms of INSV or TSWV were observed. Samples from the field at the Black Shank Farm resulted in 2 of 26 positive for INSV in purple nutsedge plants and 6 of 64 in yellow nutsedge plants. At the Ponder Farm, 3 of 12 were positive for INSV in purple nutsedge plants and 14 of 78 in yellow nutsedge plants. None of the samples in either site tested positive for TSWV. The DAS-ELISA positive samples were verified for INSV using reverse transcription-polymerase chain reaction (RT-PCR) as previously described by Dewey et al. (1). Total RNA extracts were obtained from the DAS-ELISA positive nutsedge samples using RNeasy extraction kits (Qiagen Inc., Valencia, CA). The RT-PCR was carried out with primer 1F: 5'-TCAAG(C/T) CTTC(G/T)GAA(A/G)GTGAT 3' (1) and primer 2R: 5'-ATGAACAAAGCAAAGATTACC 3' specific to the 3' end of the INSV N gene open reading frame (GenBank Accession No. NC003624). DAS-ELISA negative tissues of Cyperus esculentus L. and Emilia sonchifolia (L.) DC and an E. sonchifolia DAS-ELISA positive for INSV were included in the reactions as controls. All of the DAS-ELISA positive nutsedge samples yielded an amplification product with the expected size of 298 bp when PCR products were resolved by agarose (0.7%) gel electrophoresis. The relatively high occurrence of INSV found in the sampled fields may explain the recent increase in incidence of INSV in susceptible field crops. Although yellow nutsedge is more common than purple nutsedge in North America, the potential for dispersal of INSV in both species could be significant because of the nature of nutsedge tuber survival and spreading capabilities.

Yellow and purple nutsedge are common in the southeastern United States, and both perennial species are difficult to control in organic crop-production systems. Tubers are generally confined to the upper portions of the soil profile and are vulnerable to desiccation when brought to the soil surface. A peanut digger is a common implement found in the coastal plain region of the southeastern United States and has shown promise controlling perennial nutsedges in fallow sites. The peanut digger undercuts perennial nutsedges, deposits weeds on the soil surface, and exposes weeds to desiccation. However, rainfall after tillage with the peanut digger allows displaced nutsedges to survive. As part of a senior-level class project, undergraduate mechanical engineering students from Auburn University designed and constructed a cart attached to a peanut digger that collected nutsedges. Key features included a custom hitch that allowed the correct plane of movement and a hydraulic conveyor system that discarded the perennial nutsedges off-site, away from the field. The prototype was tested in a fallow location in the summer of 2014 with a yellow nutsedge infestation averaging 148 plants m−2. One week after the initial field test, tillage using the peanut digger with specialized cart reduced yellow nutsedge densities in the tilled area by > 99%.

Euschistus servus (Say), Nezara viridula (L.), and Chinavia hilaris (Say) (Hemiptera: Pentatomidae) are economic pests of cotton in the coastal plain of the southeastern United States. The objective of this 2-yr study was to determine the ability of trap cropping systems, pheromone-baited stink bug traps, and a synthetic physical barrier at the peanut-to-cotton interface to manage stink bugs in cotton. The physical barrier was the most effective management tactic. Stink bug density in cotton was lowest for this treatment. In 2010, boll injury was lower for the physical barrier compared to the other treatments except for soybean with stink bug traps. In 2011, boll injury was lower for this treatment compared to the control. Soybean was an effective trap crop, reducing both stink bug density in cotton and boll injury regardless if used alone or in combination with either stink bug traps or buckwheat. Incorporation of buckwheat in soybean enhanced parasitism of E. servus egg masses by Telenomus podisi Ashmead in cotton. The insertion of eyelets in the lid of the insect-collecting device of a stink bug trap allowed adult stink bug parasitoids, but not E. servus, to escape. Stand-alone stink bug traps were not very effective in deterring colonization of cotton by stink bugs or reducing boll injury. The paucity of effective alternative control measures available for stink bug management justifies further full-scale evaluations into these management tactics for control of these pests in crops.

CO2 emission and soil carbon sequestration from spring- and fall-applied poultry litter in corn production as simulated with RZWQM2

The host specificity of the European flea‐beetle Longitarsus quadriguttatus was investigated between 1991 and 1993 as a potential agent for the biological control of hound's‐tongue (Cynoglossum officinale), a weed of European origin that has become naturalized in North America. Life‐history studies showed a good synchronization of the univoltine flea‐beetle with its host plant. Adults feed on leaves and deposit eggs on host plant rosettes. The larvae develop inside the roots. Host specificity screening tests comprising adult feeding‐, oviposition‐ and larval development tests were carried out with 49 European plant species. Adults or larvae exclusively attacked plants in the family Boraginaceae. The 18 test plant species in nine other families remained free from feeding and oviposition and supported no larval development. Adults nibbled on most of the 31 Boraginaceae species tested. Normal adult feeding was mainly found on plants in the tribe Cynoglosseae, which were preferrably attacked in oviposition tests. Larvae developed mainly in roots of Cynoglosseae species. Occasional attack of other Boraginoideae species in laboratory tests could not be verified under field conditions. Host acceptance tests showed normal feeding, oviposition and development on the North American biotype of hound's‐tongue. L. quadriguttatus has a narrow host range and a good potential for controlling the target plant in North America.

Core Ideas Living mulch cover crops help stabilize erosive soils when used with row crops.White clover living mulch systems use water in the surface 15 cm of soil.Supplemental irrigation is necessary to support a living mulch corn production system.Canopy closure induces soil moisture equilibration due to shading of the clover.Water use efficiency is less in the living mulch system, especially during drought. Corn (Zea mays L.) comprises 95% of the feed grain production in the United States. The area dedicated to corn production in the southeastern United States has increased over the past decade, raising concerns about environmental degradation, and creating a need for more sustainable productions systems. One production system that addresses these concerns is the white clover (Trifolium repens L.) living mulch (LM). Previous research defined a sustainable LM system for corn production, but questions regarding water use efficiency (WUE) of the system remain. In this experiment, soil moisture was monitored in the top 30 cm of the soil, from 0 to 15 and 15 to 30 cm, during the corn growing season in a LM, crimson clover (CC) (Trifolium incarnatum L.), and cereal rye (CR) (Secale cereale L.) cover crops. We found that soil volumetric water content (VWC) was greater in the CR treatment than in the LM throughout the growing season, whereas CC and LM were similar 60 days after planting (DAP). The VWC between corn rows was greater in the CR and CC treatments than the LM in both years of the study. The CC and CR treatments had greater WUE than the LM treatment in both years of the study. The WUE was reduced in cover crop treatments in 2016 compared with 2015, likely due to drought conditions in 2016. These results suggest the LM system may be best suited to regions with high rainfall, soils with high water holding capacity, and/or supplemental irrigation.

Seventy‐five alfalfa varieties, synthetics, and ecotypes were evaluated in a study designed to: (1) evaluate the effectiveness of mass screening alfalfa in the cotyledon stage for isolating resistance to the adult and larval stages of the alfalfa weevil, (2) study possible relationships among plant reactions in laboratory [or adult feeding and larval development, and (3) search for sources of resistance to adult and larval feeding. Plants selected by a cotyledon feeding test were compared with unselected checks for resistance to adult leaf feeding and larval development. Plants selected by the cotyledon test had significantly less adult feeding and smaller larvae than did unselected plants of the same variety. Differences, however, were small. Some varietal differences were noted, but no entry had a high degree of resistance. Plants with some resistance were isolated in low frequency from most varieties.

Information on long-term glyphosate- and glufosinate-resistant corn (Zea mays L.) production on weed control and rotation benefits is lacking. A six-year field study was conducted from 2004 to 2009 at Stoneville, MS, to examine the effects of rotating glyphosate-resistant and glufosinate-resistant corn under reduced tillage conditions on weed control, soil weed seedbanks, and yield. The four rotation systems were glyphosate-resistant and glufosinate-resistant corn grown continuously and in rotation with two herbicide programs, post-emergence-only herbicides (POST) and preemergence herbicides followed by POST (PRE + POST). Control of 13 predominant weed species in glyphosate-resistant and glufosinate-resistant corn was >95%, regardless of herbicide program, with the exception of johnsongrass and yellow nutsedge, both perennial weeds. Johnsongrass and yellow nutsedge control was lower in the continuous glufosinate-resistant corn system compared with other rotation systems. Yellow nutsedge control was higher with the PRE + POST (89% to 99%) compared with the POST-only (72% to 86%) treatment. Corn yields were similar regardless of rotation when a corn cultivar stacked with both glyphosate-resistant and glufosinate-resistant traits was used. The PRE + POST program gave 5% to 10% higher yield than the POST-only program in four of six years. The seedbank for yellow nutsedge and predominant grass and broadleaf weeds was not significant among the four rotation systems. Seedbanks for grasses and yellow nutsedge were higher in the POST-only program (20.5 and 1.8 per core of 678 cm3, respectively) compared with the PRE + POST program (9.5 and 0.4 per core, respectively). These results indicate that johnsongrass and yellow nutsedge control could be reduced in continuous glufosinate-resistant corn and could be mitigated by rotating with glyphosate-resistant corn.

Many corn (Zea mays L.) producers in New York harvest fields for either silage or grain, depending upon growing conditions, storage space, and grain prices. Corn producers, who plant corn for dual purposes require more information on silage and grain yield responses of modern hybrids to plant density. Silage and grain yield responses of seven commercial hybrids were evaluated at harvest densities from 12 000 to 36 000 plants/acre on a well-drained soil in a wet (1992) and dry (1993) year to compare optimum plant densities among hybrids with recommendations by seed companies and Cornell Cooperative Extension. When averaged across hybrids, optimum densities for corn silage exceeded 36 000 plants/acre in 1992 and averaged 35 231 in 1993. When averaged across hybrids, optimum densities for grain exceeded 36 000 plants/acre in 1992 and averaged 30 452 in 1993. Apparently, plant densities should average about 7.5% higher for silage than for grain on well-drained soils in New York. Hybrid responses to plant density varied most in the dry year when optimum silage and grain densities ranged from about 27 500 to above 36 000 plants/acre. Optimum silage and grain yield densities did not vary much among hybrids with fixed, flex, and semi-prolific ear types. Optimum grain densities in this study exceeded the 1992 recommendations of seed companies and Cornell Cooperative Extension by more than 6000 plants/acre. Seed companies and Cooperative Extension should periodically evaluate plant density responses of newly released hybrids in specific growing regions to accurately adjust plant density recommendations.

Maize (Zea mays L.) cultivation under the shifting cultivation system of Yucatán, Mexico, is normally limited to 2–3 years due to nutrient depletion and weed pressure. This study was undertaken to evaluate the effect of manure application and weed control on partial nutrient budgets for maize, and assess the effect of grain-only or whole-plant harvest on nutrient removal. Two farms were selected near Mérida, Mexico, each including two cultivation years. Maize grain, stem, and leaf fractions were harvested and analyzed for N, P, and K concentrations, and compared to quantities added through manure, to generate partial nutrient budgets. Multiple years of cultivation did not change soil organic matter content while extractable P was reduced (53–62%) at both farms and extractable K was lower (22%) for farm 1. Plant fractions contained similar amounts of N, while P accumulated in grain, and stem and leaf contained the largest K pools. Applied treatments affected crop nutrient removal predominantly through crop yield. Partial nutrient budgets suggested that with stover removal, the lower rate of manure may be sufficient to maintain P, but not N or K; whereas with the higher rate of manure all partial budgets were positive, suggesting nutrient accumulation over time.

Production of watermelon (Citrullus lanatus L.) is a highly profitable crop in the Southeastern United States; however, adequate weed management is lacking due to the limited number of registered herbicides. Field studies were conducted in the summer of 2011 and 2012 in Auburn, Alabama, to evaluate the efficacy of selected preemergence (pre) and postemergence (post) herbicides in combination with a winter rye cover crop for controlling yellow nutsedge and smooth and redroot pigweed. Herbicide treatments included all combinations of two levels of ethalfluralin applied pre (none and 1900 g·ha−1) along with 4 levels of post-applied herbicides. The four post herbicides included halosulfuron (54 g·ha−1), glufosinate (340 g·ha−1), carfentrazone (35 g·ha−1), and none. The treatment consisting of no pre or post herbicides is referenced as cover crop only (CCO). Pigweed density was reduced by all herbicide treatments in comparison to the CCO treatment. Ethalfluralin applied pre followed by glufosinate post provided the greatest control of pigweed and was similar to ethalfluralin pre followed by either halosulfuron or carfentrazone post as well as glufosinate post (no pre). In comparison to the CCO treatment, yellow nutsedge density was significantly reduced by both treatments containing halosulfuron (ethalfluralin pre plus halosulfuron post; halosulfuron post) in addition to plots treated with glufosinate post. Watermelon yield and subsequent crop value was highest in plots receiving ethalfluralin pre followed by glufosinate post and was similar to the treatment of ethalfluralin pre followed by carfentrazone post. Use of pre- and post-applied herbicides along with a rye cover crop could improve control of pigweed species and yellow nutsedge and led to an increase in watermelon yield and subsequent crop value.