Impact of Location, Cropping History, Tillage, and ... - Oxford Journals

COMMUNITY AND ECOSYSTEM ECOLOGY

Impact of Location, Cropping History, Tillage, and Chlorpyrifos on Soil Arthropods in Peanut YASMIN J. CARDOZA,1,2 WENDY L. DRAKE,3 DAVID L. JORDAN,3 MICHELLE S. SCHROEDER-MORENO,3 CONSUELO ARELLANO,4 AND RICK L. BRANDENBURG1

Environ. Entomol. 44(4): 951–959 (2015); DOI: 10.1093/ee/nvv074

ABSTRACT Demand for agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems, and grass and pasture rotations have been investigated to help maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. However, documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticides, on pest damage and soil arthropod activity in peanut production for the Mid-Atlantic US region is still limited. Therefore, this project was implemented to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effects of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soil-dwelling organisms were also evaluated. Soil arthropod populations were assessed by deploying pitfall traps containing 50% ethanol in each of the sampled plots. Results from the present study provide evidence that location significantly impacts pest damage and soil arthropod diversity in peanut fields. Cropping history also influenced arthropod diversity, with higher diversity in fescue compared with cash crop fields. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others. Cropping history (fescue vs. cash crop) did not have an effect on rootworm damage, but increased numbers of hymenopterans, acarina, heteropterans, and collembolans in fescue compared with cash crop fields. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with nontreated controls. KEY WORDS mite, springtail, Diabrotica, Arachis hypogaea, fescue

The need to develop and implement agricultural production systems that are both economically viable and environmentally conscious continues to increase. In recent years, reduced tillage systems have been investigated in peanut, Arachis hypogaea L., production systems to maintain or improve soil quality, increase crop yield, and decrease labor requirements for production. Tillage can directly impact incidence of soil pest populations through mechanical damage and exposure to natural enemies (reviewed in Willis et al. 2010). In addition to reduced tillage, nontraditional rotation systems with perennial grasses including bahiagrass, Paspalum notatum Fluegge´ (Katsvairo et al. 2007a), and tall fescue, Festuca arundinaceae Schreb.(Hively and Cox 2001, Drake et al. 2010), are of interest and have potential to be a good source of forage or hay, which can provide an alternative income source for peanut producers in the mid-Atlantic United States, and suppress certain pests (Katsvairo et al. 2006, 1 Department of Entomology, North Carolina State University, Raleigh, NC 27695-7613. 2 Corresponding author, e-mail: [email protected]. 3 Department of Crop Science, North Carolina State University, Raleigh, NC 27695-7620. 4 Department of Statistics, North Carolina State University, Raleigh, NC 27695-8203.

2007b; Russelle et al. 2007; Russelle and Frazluebbers 2007; Weeks, 2008; Drake et al. 2010). In a previous study, we reported the impacts of crop history and tillage treatments on crop response and incidence of diseases and nematode pests in peanut (Drake et al. 2010). Soil parasitic nematode populations were generally lower following tall fescue compared with rotations of corn, Zea mays L., or cotton, Gossypium hirsutum L. However, lower incidence of plant parasitic nematodes did not translate into increased peanut yield (Drake et al. 2010). Documentation of the effects of reduced tillage, fescue rotation systems as well as other management practices, including pesticide applications, on pest damage and soil arthropod activity in peanut production for the region is limited. Soil arthropod groups (i.e., mites, springtails) are important because they have high reproductive rates, due to their short generation times. These soil arthropods are also highly responsive to environmental changes, making their populations an excellent tool to assess environmental consequences of agricultural management practices (Moldenke et al. 2000), such as those considered in the present study. Chlorpyrifos is an important insecticide in peanut production systems where it is applied to the soil to manage root and pod feeders, such as the southern corn rootworm, Diabrotica undecimpunctata L. However, the

C The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. V

All rights reserved. For Permissions, please email: [email protected]

ENVIRONMENTAL ENTOMOLOGY

952

effectiveness and nontarget impacts of this pesticide for peanut production remain poorly understood. These are topics that merit scrutiny because of the broad spectrum and high toxicity against insects attributed to chlorpyrifos (Cruz 1997). In addition, tillage practices have also been shown to impact arthropod populations in agroecosystems (Sapkota et al. 2012), but need to be further explored in peanut cropping systems in the region. This project, therefore, was undertaken to assess impacts of fescue-based rotation systems on pests and other soil organisms when compared with cash crop rotation systems over four locations in eastern North Carolina. In addition, the effect of tillage (strip vs. conventional) and soil chlorpyrifos application on pod damage and soildwelling organisms was also evaluated. Arthropod populations are sensitive to soil moisture, humidity, temperature, prey availability, fertilizers, pesticides, plant cover, and other factors (Sapkota et al. 2012). Materials and Methods The experiment was conducted at four locations in eastern North Carolina: Lewiston-Woodville, Edenton, Rocky Mount, and Rocky Hock. From 2004–2008, treatments consisted of a tall fescue-based sod compared with reduced tillage production of cotton, field corn, or sweet corn depending upon location and year (Drake et al. 2010). Corn, cotton, peanut, and soybean were planted following both cropping systems during 2009. The focus of the current paper is discussion of results found in peanut in the four locations relative to arthropod populations. Soil at the Peanut Belt Research Station located near Lewiston-Woodville was Norfolk loamy sand (fine-loamy, kaolinitic, thermic typic Kandiudults). At the Upper Coastal Plain Research Station located near Rocky Mount, soil consisted of a mix of Rains loamy sand (fine-loamy, siliceous, semiactive, thermic Typic Paleaquults) and Goldsboro loamy sand (fineloamy siliceous, subactive thermic aquic, paleudults), and soil near Edenton was Perquimans silt loam (finesilty, mixed, semiactive, thermic Typic Endoaquults). Soil near Rocky Hock was Valhalla fine sand (loamy, siliceous, semiactive, thermic Arenic Hapludults). These locations are found in the predominant peanut production regions of North Carolina and represent the range of soil characteristics associated with peanut production systems. Plot size at all locations was at least 16 rows wide (91-cm spacing) by 23 to 32 m long. Tall fescue ‘Kentucky 31’ (endophyte-free) was seeded in fall (October) of 2004 and allowed to grow until peanut cultivar ‘Phillips’ (Isleib et al. 2006) was planted in May 2009. Tall fescue was established in four randomly assigned plots at Edenton, Rocky Hock, and Rocky Mount and in three plots at Lewiston-Woodville. The same number of plots at each location was planted to combinations of cotton, sweet corn, or peanut from 2004–2008 (Drake et al. 2010) preceding the peanut used in this study. Except for tillage operations, all pest management and production practices for peanut were based on Cooperative Extension recommendations (Brandenburg 2013; Jordan, 2013a,b; Shew 2013). Conventional tillage

Vol. 44, no. 4

consisted of disking twice followed by field cultivation and in-row subsoiling and bedding. Reduced tillage consisted of a 40-cm-wide tilled area on 91-cm rows into residue from the previous crop using strip tillage implements consisting of two sets of coulters and basket attachments following in-row subsoiling (KMC Manufacturing, Tifton, GA). Depth of subsoiling was 30–40 cm with peanut planted within 1 wk following reduced tillage or bedding. Seeding rates for each cultivar were designed to obtain a final in-row population of 13 plants m-1 for each cultivar. Chlorpyrifos (Lorsban 15G Insecticide, Dow AgroSciences, Indianapolis, IN) was applied in a 20-cm band centered over the row of peanut at 2.2 kg ai ha1 at the R3 stage of peanut growth (Barbour and Brandenburg 1995) to control corn rootworms (Diabrotica spp.) for the majority of each plot excluding a 3-m section in one row of each plot. This section was maintained as a no-chlorpyrifos control. A rainfall event of 7 to 15 cm occurred within 11 d after application of chlorpyrifos at each location, which helped activate the insecticide. Soil arthropod populations were assessed by deploying three pitfall traps containing 50% ethanol in each of the plots 2 wk after chlorpyrifos was applied. Pitfall trapping provides an efficient, commonly used mechanism for monitoring soil arthropods activity, including responses to chlorpyrifos applications to peanut fields (Mack 1992, Skokova´ Habusˇtova´ et al. 2015). Traps consisted of a SOLO plastic cup (473.17 ml, Quill Linconshire, Inc., Palatine, IL) half-filled with the ethanol solution. Each trap was covered with a 10-cm2 plasticcovered corrugated cardboard shelter to protect it from flooding in the event of rain. Traps were left in the field for 48 h and contents from the three traps in each plot were pooled. Trap position was randomized and positioned between rows within each plot. Contents from pitfall traps were stored in 75% ethanol and transported to the laboratory for classification and counting. Organisms within individual samples were classified to order and the numbers of individuals within each order were recorded. A sample of 150 pods from each plot was removed within 2 wk prior to harvest in late September to quantify pod scarring and pod penetration as a result of feeding by corn rootworms (Brandenburg and Herbert 1991, Barbour and Brandenburg 1995). The experimental design was a split-split plot. The previous cropping history, either fescue or cash crops, served as whole plot units. Within each whole plot unit, sections were divided at random and subjected to either conventional tillage or strip tillage. These plots served as the first split in the experimental design. Within each tillage system, sections treated with either chlorpyrifos or left untreated were established at random. The chlorpyrifos treatments served as the second split in the experimental design. Combinations of previous cropping system, tillage system, and chlorpyrifos treatment were replicated three times at LewistonWoodville and four times at the remaining locations. Data for pod penetration and scarring by corn rootworms, as well as total of arthropods (total abundance) and observed abundance per order collected from pitfall traps were subjected to analysis of variance

August 2015

CARDOZA ET AL.: IMPACT OF LOCATION ON SOIL ARTHROPODS IN PEANUT

(ANOVA; Proc Mixed, SAS Institute, Cary NC, 2012) testing the effect of four locations (Edenton, LewistonWoodville, Rocky Hock, and Rocky Mount), two cropping histories (tall fescue vs. corn and cotton rotations), two tillage regimes (strip vs. conventional), and two insecticide treatments (no insecticide vs. chlorpyrifos), as well as their interactions. Location was considered as a random effect while cropping history, tillage regime, and chlorpyrifos were considered fixed effects. Means for significant main effects and interactions were separated using Tukey’s mean separation test at P 0.05. Data for population of arthropods collected from pitfall traps were subjected to diversity and ordination analysis with the statistical software R (R Core Team, (2014). Diversity analysis for arthropod order at each location was performed with R package vegan (v 2.2-0; Oksanen et. al. 2015). The Shannon–Wiener index of diversity was calculated for arthropod orders present at each location. Ordination analysis of community abundance data was carried on with nonmetric multidimensional scaling (NMDS), using the function metaMDS() (R package Vegan). Euclidean distances (dissimilarities) between sites, were calculated after the Herlinger transformation was applied to the “max 1” relative abundances for each of the orders (Legendre and Birks 2012). Mapping of the observed dissimilarities onto an ordination space allowed for a graphical representation. Further nonmetric dimensional analysis included an environmental regression fitting, using the function envfit () (R package Vegan). Crop history, tillage, and chlorpyrifos were used as environmental factors impacting abundance of arthropod orders. Mean values for these factors were regressed onto ordination axes, which yielded centroid estimates for each factor. Significance tests for these analyses were based on 999 random permutations of data, testing the null hypothesis of no relationship between the environmental factors of interest and ordination axes. Location was used as strata (analysis option in R) to allow for permutations done within each location thereby controlling for location effect, equivalent to a blocking factor in ANOVA.

953

Table 1. P > F for pod scarring and pod penetration in early September as a result of rootworm feeding Source

df

Pod scarring ________

Fixed effects Location Cropping history Tillage Cropping history Tillage Chlorpyrifos Cropping history Chlorpyrifos Tillage Chlorpyrifos Random effects Location Cropping history Location Tillage Location Chlorpyrifos Location Cropping history Tillage Location Tillage Chlorpyrifos Cropping history Tillage Chlorpyrifos Location Cropping history Tillage Chlorpyrifos

Pod penetration ________ P-value

3 1 1 1 1 1 1

F of impact of cropping history, chlorpyrifos application, tillage, location, and their interaction on soil arthropod densities at the order level found in pitfall traps within peanut fields Source Fixed effects Cropping history (Crop) Tillage (Till) Crop Till Chlorpyrifos (Chlor) Crop Chlor Till Chlor Crop Till Chlor Random effects Location (Loc) Loc Crop Loc Till Loc Chlor Loc Crop Till Loc Till Chlor Loc Crop Till Chlor

df

Aranea

Acarina

Coleoptera

Diptera Hymenoptera Miriapoda Thysanoptera P-values___________________________________________________

1 1 1 1 1 1 1

– – – – – – –

– – – – – – –

– – – – – – –

– – – 0.0357 – – –

0.0464 – – – – – –

– – – – – – –

0.01 – – – – – –

3 3 3 3 3 3 3

0.0143 – – – – – –

0.0324 0.0466 – – – – –

0.01 – – – – – –

– 0.0001 – – – – –

– – – – – – –

0.0256 – – – – – –

0.0261 0.0381 – – – – –

___________________________________________________

10

Mean number of arthropods per plot

a

a

9 8

a 7 6 5

b

4 3 2 1 0 Edenton

Lewiston

Rocky Hock

Rocky Mount

Fig. 1. Overall mean arthropod number collected from peanut fields at four different locations across North Carolina. Values represent means 6 SE and bars headed by the same letter are not significantly different (Tukey’s mean separation test, P 0.05).

applied at Edenton and Rocky Hock while populations were lower following chlorpyrifos application at Rocky Mount (Table 3; Fig. 3). Arthropods representing 10 orders were captured across all locations (Table 4). The number of spiders (Araneae) were overall low, but were affected by location (Table 3) with the highest number noted at Rocky Mount and lowest number at Lewiston-Woodville (Table 4). Beetles (Coleoptera) were significantly affected by location and the interaction of location and chlorpyrifos application (Table 3). Beetle numbers were almost twice as high in Lewiston-Woodville and Rocky Mount compared with the other two sites (Table 4). Moreover, numbers of this insect group were higher on insecticide-treated plots in three of the locations (Edenton, Lewiston-Woodville, and Rocky Hock), but not at Rocky Mount. Springtails (Collembola)

counts were statistically comparable with slightly higher numbers at Rocky Hock, intermediate at LewistonWoodville and Rocky Mount, and lowest at Edenton (Table 4). Mean numbers of flies (Diptera) were comparable across locations; but were higher following cash crops at Edenton and Rocky Hock and higher following tall fescue at the other two locations (Table 4). Numbers of thrips (Thysanoptera) were higher following tall fescue at Lewiston-Woodville and Rocky Hock and were not affected by cropping history at Edenton or Rocky Hock. Hymenoptera (ants and wasps) were only affected by cropping history (Table 3). Mites (Acarina) numbers were lowest at Edenton, intermediate at Lewiston-Woodville and Rocky Mount, and highest at Rocky Mount. Orthopterans (grasshoppers and crickets) were high at Edenton and relatively low in all other locations (Table 4).

August 2015


955

14 Crop

Fescue


12

* 10

8

6

4

2

0 Edenton

Lewiston

Rocky Hock

Rocky Mount

Fig. 2. Effect of cropping history on soil arthropod at four different locations across North Carolina. Values represent means 6 SE and bars headed by asterisk are significantly different within location. 12 Chlorpyrifos

Control

*


10

8

6

*

*

4

2

0 Edenton

Lewiston

Rocky Hock

Rocky Mount

Fig. 3. Effect of chlorpyrifos application on soil arthropod activity at four different locations across North Carolina. Values represent means 6 SE and bars headed by asterisks are significantly different within location.

Shannon diversity indices indicate significant impacts on arthropod communities based on location (Fig. 4A), with diversity indices among locations ranging from 0.62–1.76 for Edenton, 0.59–1.95 for LewistonWoodville, 0.46–1.96 for Rocky Mount, and 0.46–1.94 for Rocky Hock; and based on cropping history (Fig. 4B), ranging from 0.46 to 1.94 for cash crops, and from 0.46 to 1.96 for fescue fields. There was a clear tendency for fescue fields, median equal 1.50, to host more arthropod orders compared with cash crop fields,

median 1.46 (Fig. 4B). Results of the ordination analysis yielded a bidimensional graphical representation of locations and orders (Fig. 5). The goodness of fit obtained on NMDS analysis was 0.20, indicating large variability in arthropod order abundance among locations. In the graphical two-dimensional representation of distances between sites, orders are represented as vectors, with the arrow pointing the direction of abundance for orders and the angle of the vectors representing the correlation of abundance among orders (Fig. 5).

956


Environmental fit and position of the location centroids within the two-dimensional plane allows visualization of how locations (r2 ¼ 0.24; P ¼ 0.0002) impact arthropod abundance for each order (Fig. 5A). Heteroptera, Hymenoptera, Aranea, Acarina, and Collembola were predominantly associated with Rocky Mount and Rocky Hock, whereas Edenton and Lewiston-Woodville showed higher incidence of Orthoptera, Coleptera, and Diptera (Fig. 5A). Environmental regression for cropping history after NMDS analysis also showed that differences in arthropod order incidence due to cropping history were only significant at a ¼ 0.10 (r2 ¼ 0.01; P ¼ 0.092; Fig. 5B), with higher representation of Heteroptera, Hymenoptera, Aranea, Acari, and Collembolla in fescue fields and higher representation of Orthoptera in cash crop fields (Fig. 5B). A 95% ellipse is presented

Table 4. Soil arthropod composition of pitfall trap samples (mean numbers per sample) obtained from peanut fields across four locations in North Carolina Group

Edenton

LewistonWoodville

Rocky Hock

Rocky Mount

Aranea Coleoptera Collembola Diptera Hemiptera Hymenoptera Miriapoda Acarina Orthoptera Thysanoptera

1.0a 5.6a 7.5a 9.2a 0.2a 2.4a 0.4a 3.7a 10.6a 0.01a

0.7a 12.6c 12.8a 6.4a 1.2a 21.1a 0.0b 14.5b 4.3b 0.6b

0.9a 5.4a 25.4a 5.4a 1.6a 12.4a 0.0b 10.5b 0.88c 1.42c

2.0b 9.2bc 15.4a 6.9a 1.0a 21.0a 0.0b 21.0c 3.2b 0.3ab

Row means (within an order) followed by the same letter are not statistically different according to Tukey’s test at 0.05.

Vol. 44, no. 4

for each location and cropping history, their centroids is marked as circles within the ellipses. Ellipses show high overlap, indicating little differentiation in arthropod order incidence among locations (Fig. 5A) or cropping history (Fig. 5B). The environment modeling using the function envfit for each of these factors yielded no significant differences among any of the remaining factors (P ¼ 0.20 for tillage P ¼ 0.42 for insecticide) tested. Discussion Results from the present study provide evidence that location, likely due to differences in soil characteristics and local weather conditions, is a main factor impacting pest damage and soil arthropod diversity in peanut fields. Cropping history also appears to influence arthropod diversity, with higher diversity in fescue compared with cash crop fields; however, these effects were not as clearly demarked as those due to location. Corn rootworm damage to pods was higher at one of our locations (Rocky Mount) compared with all others, and numbers of soil organisms in 7 out of 12 orders identified from these fields were impacted by location. We also found a higher number of order diversity in Rocky Hock and Rocky Mount compared with Edenton and Lewiston-Woodville. Cropping history (fescue vs. cash crops) did not have an effect on rootworm damage, but differentially affected numbers of Hymenoptera (predominantly ants), Acarina, Heteroptera, and Collembola being favored in fescue compared with cash crop fields. Soil texture and organic matter content have been found to affect oviposition (Brust and House 1990) preference and survival in Diabrotica spp. Surface

Fig. 4. Shannon–Wiener diversity indices indicate significant impacts on arthropod order abundance based on: location (A), ranging from 0.62–1.76 for Edenton, 0.59–1.95 for Lewiston-Woodville, 0.46–1.96 for Rocky Mount, and 0.46–1.94 for Rocky Hock; cropping history (B), ranging from 0.46–1.94 for cash crops, and 0.46–1.96 for fescue fields. Boxplots represent arthropod order abundance, based on Shannon indices for each location, with the central 50% of data points within the range of the upper and lower limit of the box and the median value for Shannon index (1.31, 1.54, 1.58, and 1.45) represented by the bold line within the box. The upper and lower 25% of observed values are represented by the whiskers of the box, while ouliers are represented by circles.

August 2015


characteristics of soil at Lewiston-Woodville and Rocky Hock are coarser in nature than soils at Edenton and Rocky Mount and therefore are less conducive to survival of southern corn rootworm egg and larvae survival (Brandenburg and Herbert 1991), which may help explain differences in pod damage by this pest in our study. Soil disturbance due to tillage practices can directly impact water content, temperature, crop residue decomposition, and thereby, affect the community assemblage and abundance of soil invertebrates. Yet, in our study reduced tillage was found to increase rootworm damage to pods and do not impact incidence of other soil arthropods in the system. Although not quantified in this study, cooler temperatures are often associated with reduced tillage systems (Gray and Tollefson 1988) and would favor southern corn rootworm survival (Turpin and Peters 1971, Gray and Tollefson 1988, Brust and House 1990). This in turn would increase the likelihood of pod damage from rootworm feeding, as seen in our study. A risk index has been developed in North Carolina and Virginia to assist growers and their advisors in determining when chlorpyrifos should be applied to control southern corn rootworm (Herbert et al. 1997, 2004). Components of the index include soil texture, soil drainage, planting date, cultivar, and irrigation (Brandenburg 2013). Monitoring systems that focus on adult insects have been ineffective in predicting presence of southern corn rootworm in soil and risk of damage (Brandenburg et al. 1992). In additional to not receiving return on investment when southern corn rootworm are not present at economically damaging levels, application of chlorpyrifos can cause secondary outbreaks of two-spotted spider mites, Tetranychus urticae Koch, under some conditions which are difficult to manage and when not controlled can reduce peanut yield significantly (Brandenburg and Kennedy 1987). Tillage system and previous crop rotation are not considered in this southern corn rootworm index. Also, contrary to our expectations, chlorpyrifos application only had significant impacts on the number of flies caught but not on any of the other soil arthropod

957

orders documented here. Interestingly, there was an overall tendency for higher number of soil arthropods in traps placed in chlorpyrifos-treated plots compared with untreated controls. The reasons behind this are not known. One possibility is that insecticidal effects had disappeared by the time soil arthropod sampling took place (2 wk after application) and higher arthropod numbers are due to immigration and reproduction of recolonizing organisms. Nonetheless, our results are consistent with those of Michereff-Filho et al. (2004) who reported that foliar application of chlorpyrifos to control corn earworm, Helicoverpa zea L., impact on soil arthropods in tropical corn fields was speciesdependent but were for the most part significantly lower than was expected from such a broad-spectrum chemical. When the effects of pasture and crop rotation on soil insect communities are examined, Hooks et al. (2011) reported greater populations of spiders found on soybean, Glycine max (L.) Merr, plots previously planted to Italian ryegrass, Lolium multiflorum Lam. We did not observe greater spider populations in fescue plots, but hymenopterans and thysanopterans were differentially impacted in fescue versus cash crop plots. In our study, we found that numbers of these groups were generally higher in fescue compared with cash crop fields, which may help explain the significant results obtained in our MDS analyses. In another study evaluating the impacts of wheatgrass, Elymus trachycaulus Link., on rootworm incidence and damage and soil arthropod activity in corn, Lundgren and Fergen (2010) reported lower root damage rates in corn fields preceded by the slender wheatgrass crop compared with fields without it. These results contrast with ours in that fescue plots did not impact rootworm damage one way or another. These authors also found an increased abundance of predatory arthropods, which were negatively correlated with the abundance of third instars D. virgifera in the cover cropped fields. This is somewhat concordant with our finding of higher hymenopteran populations, which include ants and wasps, both of which can be predatory or parasitic on insect pests, including D. v. virgifera. We do not, however, have data

Fig. 5. MDS ordination of the study sites based on the arthropod abundance (stress ¼ 0.20) in response to location (A) and cropping history (B), which were found to be significant (P 0.05). In this graph, arthropod orders are represented as vectors and the four locations are presented as centroids, ED—Edenton, RH—Rocky Hock, RM—Rocky Mount, and LW—Lewiston-Woodville (A), and two cropping history C—Cash Crop, F—Fescue (B) are presented as centroids.

958


on rootworm populations, so we do not know if these predatory groups had any impact on pest numbers. Results from these experiments suggest that reduced tillage might contribute to greater presence and more damage from southern corn rootworm. However, our data are limited to one year at four locations and levels of infestation were below economic impact; thus, additional research is needed to further define the implications of tillage system on prevalence of this pest before modifications of the southern corn rootworm risk index are made. Lack of interactions among previous rotation crop (tall fescue vs. cash crops) with other treatment factors as well as previous rotation crop suggests that the risk index formula for southern rootworm does not need to be adjusted for previous rotation. While this is consistent with other studies that suggest crop rotation does not affect damage by rootworms in crops (Brust and King 1994, Lundgren and Fergen 2010), it could be argued that strip tillage and conventional tillage operations in the pegging zone are relatively similar with respect to residue of the previous crop or tall fescue. Additional research is also needed to determine if differences would be present in no till systems with sod-based rotations versus traditional agronomic crops in absence of strip tillage. Moreover, given that endophyte-infected fescue has been found to affect arthropod populations, especially those associated with foliar tissue, it would also be interesting to determine if the same effects are detectable in non-pest soil arthropod populations, such as those assessed in this study. Acknowledgments The authors are grateful to the North Carolina Peanut Grower Association, Inc, The National Peanut Board, USAID CRSP (Grant LAG-G-00-96-00-13-00) for their financial support of this research. The technical support of P. D. Johnson (NCSU Department of Crop Science) and Axel Gonzalez (NCSU Department of Entomology) is also appreciated.

References Cited Barbour, J. D., and R. L., Brandenburg 1995. Impact of type and timing of southern corn-rootworm treatments on predaceous arthropods in peanut. J. Entomol. Sci. 30: 447–462. Brandenburg, R. L. 2013. Peanut insect and mite management, pp. 81–100. In 2013 Peanut Information. North Carolina Cooperative Extension Service Publication AG-331, 160 pp. Brandenburg, R. L. and G. G. Kennedy. 1987. Ecological and agricultural considerations in the management of the twospotted spider mite. Agric. Zool. Rev. 2: 185–236. Brandenburg, R. L. and D. A. Herbert. 1991. Effect of timing on prophylactic treatments for southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae), in peanut. J. Econ. Entomol. 84: 1894–1898. Brandenburg, R. L., J. D. Barbour, and D. A. Herbert, Jr. 1992. Pheromone trapping for predicting southern corn rootworm damage in peanut. Peanut Sci. 19: 37–40. Brust, G. E., and G. J. House. 1990. Influence of soil texture, soil moisture, organic cover, and weeds on oviposition preference of southern corn rootworm (Coleoptera: Chrysomelidae). Environ. Entomol. 19: 966–971.

Vol. 44, no. 4

Brust, G. E., and L. R. King. 1994. Effects of crop-rotation and reduced chemical inputs on pests and predators in maize agroecosystems. Agric. Ecosyst. Environ. 48: 77–89. Cruz, I. 1997. Manejo de pragas na cultura de milho, pp. 18–39. In A. Fancelli and D. Dourado-Neto (eds), Tecnologia da Producao de Milho. Piracicaba, Sao Paulo, Brazil. Drake, W. L., D. L. Jordan, M. Schroeder-Moreno, P. D. Johnson, J. L. Heitman, Y. J. Cardoza, R. L. Brandenburg, B. B. Shew, T. Corbett, C. R. Bogle, et al. 2010. Crop response following a tall fescue sod and agronomic crops. Agron. J. 102: 1692–1699. Gray, M. E., and J. J. Tollefson. 1988. Emergence of the Western and Northern corn rootworms (Coleoptera: Chrysomelidae) from four tillage systems. J. Econ. Entomol. 81: 1398–1403. Herbert, Jr. D. A., W. J. Petka, and R. L. Brandenburg. 1997. A risk index for determining insecticide treatment for southern corn rootworm. Peanut Sci. 24: 128–136. Herbert, Jr. D. A., S. Malone, and R. L. Brandenburg. 2004. Evaluation of the Southern corn rootworm advisory for peanut. Peanut Sci. 31: 28–32. Hively, W. D., and W. J. Cox. 2001. Interseeding cover crops nto soybean and subsequent corn yields. Agron. J. 93: 308–313. Hooks, C.R.R., W. Koon-Hui, and M.L.F. Susan. 2011. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with emphasis on soybean cyst nematodes. J. Nematol. 43: 172–181. Isleib, T. G., P. W. Rice, R. W. Mozingo, II, S. C. Copeland, J. B. Graeber, H. E. Pattee, T. H. Sanders, R. W. Mozingo, and D. L. Coker. 2006. Registration of “Phillips” peanut. Crop Sci. 46: 2308–2309. Jordan, D. L. 2013a. Peanut production practices, pp. 15–44. In 2013 Peanut Information. North Carolina Cooperative Extension Service Publication AG-331, 160 pp. Jordan, D. L. 2013b. Peanut weed management, pp. 45–80 In 2013 Peanut Information. North Carolina Cooperative Extension Service Publication AG-331, 160 pp. Katsvairo, T. W., D. L. Wright, J. J. Marois, D. L. Hartzog, K. B. Balkcom, J. R. Rich, and P. J. Wiatrak. 2006. Sod/ livestock integration in the peanut/cotton rotation: A systems farming approach. Agron. J. 98: 1156–1171. Katsvairo, T. W., D. L. Wright, J. J. Marois, and J. R. Rich. 2007a. Transition from conventional farming to organic farming using bahiagrass. J. Sci. Food Agric., 87: 2751–2756. Katsvairo, T. W., D. L. Wright, J. J. Marois, D. L. Hartzog, K. B. Balkcom, P. J. Wiatrak, and J. R. Rich. 2007b. Performance of peanut and cotton in a bahiagrass cropping system. Agron. J. 99: 1245–1251. Lundgren, J. G., and J. K. Fergen. 2010. The effects of a winter cover crop on Diabrotica virgifera (coleoptera: chrysomelidae) populations and beneficial arthropod communities in no-till maize. Environ. Entomol. 39: 1816–1828. Mack, T. P. 1992. Effects of 5 granular insecticides on the abundance of selected pests and predators in peanut fields. J. Econ. Entomol. 85: 2459–2466. Michereff-Filho, M., R.N.C. Guedes, T.M.C. Della-Lucia, M.F.F. Michereff, and I. Cruz. 2004. Non-target impact of chlorpyrifos on soil arthropods associated with no-tillage cornfields in Brazil. Int. J. Pest Manage. 50: 91–99. Moldenke, A. R., M. Pajutee, and E. Ingham. 2000. The functional roles of forest soil arthropods: The soil is a living place, pp. 7–22. In R. F., Powers, D.L. Hauxwell, and G. M. Nakamura (eds.), Proceeding of California Forest Soils Council conference on Forest Soils Biology and Forest Management. USDA For. Serv. Gen. Tech. Rep. PSW-GTR-178, Berkeley, CA. Oksanen, J., F. Guillaume Blanchet, R. Kindt, P. Legendre, P. R. Minchin, R. B. O’Hara, G. L. Simpson, P. Solymos, M. Henry, H. Stevens, et al. 2015. Vegan: Community

August 2015


Ecology Package. R package version 2.2-1. (http://CRAN.Rproject.org/package¼vegan) R Core Team. 2014. R: A language and environment for statistical computing. R foundation for tatistical computing, Vienna, Austria. (http://www.R-project.org/) Russelle, M. P., and A. J. Franzluebbers. 2007. Introduction to Symposium: Integrated crop–livestock systems for profit and sustainability. Agron. J. 99: 323–324. Russelle, M. P., M. H. Entz, and A. J. Franzluebbers. 2007. Reconsidering integrated crop–livestock systems in North America. Agron. J. 99: 325–334. Sapkota, T. B., M. Mazzoncini, P. Barberi, D. Antichi, and N. Silvestri. 2012. Fifteen years of no till increase soil organic matter, microbial biomass and arthropod diversity in cover crop-based arable cropping systems. Agron. Sustain. Dev. 32: 853–863. Shew, B. B. 2013. Peanut disease management, pp. 101–131. In 2013 Peanut Information. North Carolina Cooperative Extension Service Publication AG-331, 160 pp.

959

Skokova´ Habusˇtova´, O., Z. Svobodova´, L. Spitzer, P. Dolezˇal, H. M. Hussein, and F. Sehnal. 2015. Communities of ground-dwelling arthropods in conventional and transgenic maize: Background data for the post-market environmental monitoring. J. Appl. Entomol. 139: 31–45. Turpin, F. T., and D. C. Peters. 1971. Survival of Southern and Western corn root worm larvae in relation to soil texture. J. Econ. Entomol. 64: 1448–1451. Weeks, Jr. J. M. 2008. Perennial grass based crop rotations in Virginia: Effects on soil quality, disease incidence, and cotton and peanut growth. Masters thesis. (http://scholar.lib.vt.edu/ theses/available/etd-10152008-150128/unrestricted/James WeeksETD.pdf) (accessed 7 August 2010). Willis, R. B., M. R. Abney, and G. J. Holmes. 2010. Influence of preceding crop on wireworm (Coleoptera: Elateridae) abundance in the coastal plain of North Carolina. J. Econ. Entomol. 103: 2087–2093. Received 18 September 2014; accepted 15 April 2015.