BIOLOGICAL CONTROL Influence of Commercially Available Wildflower Mixes on Beneficial Abundance and Predation in Turfgrass

1 S. K. BRAMAN, A. F. PENDLEY, AND W. CORLEY

Department of Entomology, University of Georgia, College of Agricultural andEnvironmental Sciences, GrifÞn, GA 30223

Environ. Entomol. 31(3): 564Ð572 (2002) ABSTRACT Conservation andaugmentation of indigenousnatural enemies are promising strategies for biologically basedpest management in outdoorurban environments. This research sought to determine whether the addition of wildßower plantings would enhance the occurrence, abundance and impact of beneÞcial in the landscape, and to determine the potential compatibility of pest-resistant turfgrass andnatural control of Japanese , Popillia japonica Newman, andfall armyworm, Spodoptera frugiperda (J.E. Smith). A bermudagrass cultivar (susceptible to fall army- worm), a zoysiagrass cultivar (resistant to fall armyworm), andtwo differentcommercially available wildßower mixes all harbored a diverse array of beneÞcial arthropods in both large and small plot evaluations. A wildßower mix containing 15 of ßowers provided signiÞcant, season-long increases in foliar-dwelling spiders and bigeyed bugs during 1-yr of a 2-yr study in large (1,512 m2) plots. Ground-dwelling spiders were more abundant in bermudagrass turfgrass than in wildßowers both years, whereas were not signiÞcantly affectedby cover type. Each wildßowermix evaluated in a separate 2-yr small plot study increased the abundance of some, but not all beneÞcial arthropod taxa sampled. This increased abundance was only occasionally also observed in adjacent turfgrass areas. However, fall armyworm eggs andlarvae, andJapanese beetle eggs were consistently andheavily preyed upon in small plots regardless of turfgrass species in the plot or surrounding border of ßowers or mulch. Most beneÞcial taxa, even Geocoris uliginosus, which was more common in turfgrass, were representedin ßowers, suggesting that these ßoral plantings may be useful in providingrefugia for beneÞcials when insecticide applications are required to suppress turfgrass pests.

KEY WORDS turfgrass, ornamentals, wildßowers, predators, parasitoids, conservation biological control

BENEFICIAL ARTHROPODS ARE well representedin man- 1993) but relatively little impact occurredwhen a agedturfgrass habitats (e.g., CockÞeldandPotter chloronicotinyl or an ecdysteroid agonist were ap- 1983, 1985; Braman andPendley1993; Heng-Moss et plied (Kunkel et al. 1999). Insecticide-induced sup- al. 1998; Braman et al. 2000b). Predators, including pression of predator populations reduces predation on groundbeetles (Carabidae),rove (Staphylini- such common turfgrass pests as , Po- dae), spiders (Araneae), bigeyed bugs (Geocoris pillia japonica Newman, fall armyworm, Spodoptera spp.), andants (Formicidae),are particularly well frugiperda (J.E. Smith), andsodwebworms (Pyrali- documented. Hymenopterous parasitoids have also dae)(CockÞeldandPotter 1984, Terry et al. 1993). been surveyed, demonstrating the occurrence of the Our hypothesis is that a diverse, adjacent, nonturf families Mymaridae, Trichogrammatidae, Encyrtidae, refugia wouldsupport beneÞcial arthropodsand andScelionidaein buffalograss (Heng-Moss et al. speedthe recolonization process when natural con- 1998). Undoubtedly, indigenous parasitoids and pred- trols in turf are disrupted, thereby reducing the length ators assist in limiting or preventing outbreaks of po- of disruption by application of turf insecticides. tential pests in turfgrass (Potter 1993). Structurally complex landscapes offer greater di- Short-term, but signiÞcant, reductions of certain versity that may attract andretain parasitoidsand taxa have been documented in response to organo- especially generalist predators that can enable better phosphate or carbamate insecticide applications such regulation of ornamental plant pests (Shrewsbury and as those made during regular lawn care or landscape Raupp 2000, Tooker andHanks 2000). Marking studies management programs have effected(CockÞeldand demonstrated that lady beetles (Coccinellidae), Potter 1984, Braman andPendley1993, Terry et al. lacewings (Chrysopidae, Hemerobiidae), syrphid ßies (Syrphidae), and parasitic wasps (Hypoaster sp., Tri- 1 E-mail: [email protected]Þn.peachnet.edu. chogramma sp., and Macrocentrus sp.) fedon nectar or

0046-225X/02/0564Ð0572$02.00/0 ᭧ 2002 Entomological Society of America June 2002 BRAMAN ET AL.: WILDFLOWER MIXES ON ARTHROPOD ABUNDANCE AND PREDATION 565 pollen provided by borders of ßowering plants around Pendley (1993). The contents were collected weekly farms, with many subsequently moving at least andthe six traps per plot were combinedfor each of 76 m into adjacent Þeld crops (Freeman-Long et al. the six plots per treatment type. Sweep net samples 1998). The relative attractiveness of individual land- using a standard beating net (40 per plot) were col- scape ßowering plants andpotential insectary plants lected along the diagonal weekly in each plot during to beneÞcial insects has been explored(e.g., Al- 1993 and1994. Samples were returnedto the labora- Doghairi andCranshaw 1999, Colley andLuna 2000) tory where foliar dwelling spiders and bigeyed bugs and results suggest that the addition of ßowering (Lygaeidae)were extractedandcounted.Pitfall sam- plants in landscape settings may enhance natural pest pling was conducted during 1993 from 22 March control. The objective of this study was to evaluate the through 16 December. Samples during 1994 were col- potential for commercially available wildßower mixes, lectedfrom 13 January through 15 December. Sweep including those advertised as offering pest control samples were collectedfrom 16 June through 9 De- beneÞts, to increase abundance of beneÞcial insects in cember 1993 andfrom 4 May through 19 October 1994. the landscape and enhance pest suppression in adja- Effects of Flower Mix and Turf Type on Beneficial cent turfgrasses. Arthropod Occurrence in Small Plots. Experimental plots were establishedduring1997 at the Georgia Station Research and Education Garden in Spalding Methods and Materials County, GA, in an area of tall fescue (Festuca arundi- Effects of Cover Type on Beneficial Arthropod Oc- nacea Schreber). Each plot contained122 m 2 turf area currence: Large Plot Study. During 1992, a 2.0-ha Þeld surrounded on three sides by a 3-m border of either in Pike County, GA, was divided into areas that were ÔBorder PatrolÕ pest control wildßower mix (Clyde 55 by 27.5 m with 3 m separating each area. Each area Robbins Seed, Castro Valley, CA), or a Smith Mix was then divided in half so that plots (27.5 by 27.5 m) wildßower mix for optimum southeastern color as de- couldbe plantedwith one of three combinations of scribedpreviously, or bare cultivatedsoil with wheat plant material: common Bermuda grass, Cynodon dac- straw mulch. Border Patrol wildßower mix contained tylon (L.) Person, adjacent to a ÔSmith MixÕ custom- the ßowers Achillea millefolium L., Ammi majus L., ized wildßower mix recommended by University of Angelica atropurpurea L., Fagopyrum esculentum Georgia Horticulture Extension specialists for opti- Moench, Helichrysum bracteatum (Ventenant) An- mum southeastern urban color (Corley 1992), or ber- drews, Iberis sp., Nasturtium sp., Nemophila menziesii mudagrass adjacent to bermudagrass or wildßowers- Hook & Arnott, Oenothera biennis L., Rudbeckia hirta adjacent to wildßowers. Plots were arranged in a L. Turfgrass interiors were equally divided between randomized complete block design with six replica- ÔTifwayÕ bermudagrass (Cynodon dactylon x C. trans- tions. Wildßowers bloomed continuously from spring vaalensis) andÔEmeraldÔ zoysiagrass ( Zoysia japonica to fall. Species containedin the mix were Achillea x Zoysia tenuifolia), which hadpreviously demon- millefolium L., Centaurea cyanus L., Cassia fasiculata stratedpotential for resistance or tolerance to fall Michaux, Consalida ambigua (L.) P.W. Ball & Hey- armyworm, twolinedspittlebug [ Prosapia bicincta wood, Coreopsis lanceolata L., Coreopsis tinctoria Nut- (Say)] andtawny mole cricket ( Scapteriscus vicinus tall, Eschscholzia californica Chamisso, Gaillardia Scudder) (Braman et al. 1994, 2000a, 2000b). Three aristata Pursh, Gaillardia pulchella Fougeroux de replications of the three treatment blocks (turf sur- Bondaroy, Monarda citriodora Cervantes ex Lagaska y rounded by mulch alone, turf surrounded by Border Seguera., Nemophila menziesii Hook & Walker-Arnott, Patrol ßower mix, or turf surrounded by ÔSmithÕ ßower Oenothera speciosa Nuttall, Papaver rhoeas L., Rud- mix) were establishedwith a minimum of 30.5 m beckia hirta L., and Salvia farinacea Bentham. between plots to minimize potential movement of Arthropodoccurrence andabundancewere com- arthropods between plots. pared among bermudagrass plots adjacent to ber- Arthropodtaxa were sampledin the turfgrass andin mudagrass, bermudagrass adjacent to wildßowers, and the surrounding border using pitfall traps (Morrill wildßowers alone. Bermudagrass was planted in June 1975) anda Vortis vacuum sampler (BurkardManu- 1992 andsuppliedwith overheadirrigation until well facturing County, Herferdshire, England) during 1998 established. Wildßowers were seeded in November and1999. Nine, 120-ml pitfall traps per plot were 1992 andmulchedwith wheat straw. Bordersbetween emptiedweekly from the beginning of June to the end plots were maintainedvegetation free with spot ap- of August. Ten vacuum samples of 10-s duration each plications of 41% glyphosate appliedat 4.7 liter/ha. No were collected along a diagonal on the same dates that additional herbicides, insecticides, or fungicides were pitfall traps were emptied. Specimens were identiÞed applied. Plots were fertilized with ammonium nitrate using appropriate keys andreference collections at 37 kg/ha in August 1992 and1993. Wildßowerplots maintainedin the museum at the GrifÞn campus and were reseeded in November 1993. Turfgrass was the Athens campus of the University of Georgia. mowedweekly at 5 cm. Voucher specimens are retainedin the collection at Carabidae, Formicidae, and ground dwelling Ara- the GrifÞn campus. neae were sampledusing 120 ml (6 cm diameterby 7 Effects of Surrounding Flower Mix or Mulch on cm high) pitfall traps (Morrill 1975). Six pitfall traps Predation on Fall Armyworm Eggs and Larvae and on per plot spacedat 3-m intervals in the center of each japanese Beetle Eggs in Turf in Small Plots. During plot were maintainedas describedinBraman and July andAugust of 1998 and1999, turf in the interior 566 ENVIRONMENTAL ENTOMOLOGY Vol. 31, no. 3 of each plot was artiÞcially infestedwith fall army- (GLM) procedure in SAS (SAS Institute 1985). Mean worm eggs andlarvae, andwith Japanese beetle eggs separation among treatments was accomplishedusing during 1999. Nine “exposure periods” during the 2 yr TukeyÕs studentized range test when ANOVA for a were monitoredto evaluate the potential differences variable was signiÞcant. in predation in turfgrass among plots surrounded with Effects of Flower Mix and Turf Type on Beneficial different cover types. Arthropod Occurrence in Small Plots. Arthropodabun- Fall Armyworm Eggs. On 7 July 1998 and20 July dance among the borders containing either one of the 1999, fall armyworm eggs deposited on paper towels two ßower mixes (Border Patrol and Smith Mix) or were countedandtransferredto the turf plots. Paper bare soil with wheat straw mulch andthe interior plot aroundthe egg masses was trimmedso that only a with two turf types (bermudagrass and zoysiagrass) small triangle of paper remainedaroundeach egg were subjectedto ANOVA using the GLM procedure mass. Each egg mass on paper was retainednext to the in SAS (SAS Institute 1985) as before. Orthogonal thatch surface with an pin. Eggs on the paper contrasts were usedto examine inßuence of cover towel triangles were allowedto remain in the turf for type on arthropods within the borders and on adjacent 23 h. Following the exposure period, paper towel tri- turfgrass areas. Contrasts examinedwere BorderPa- angles anchoredwith insect pins were relocatedand trol versus Smith Mix, bermudagrass versus zoysia- returnedto the laboratory to count the eggs. On 28 grass, grasses surrounded by Border Patrol versus July 1998, fall armyworm eggs were exposedin each grasses surroundedbySmith Mix, ßowers andgrass Þeld plot as described, except that the exposure period versus mulch, grasses surrounded by ßowers versus was only 2 h from 1300 1500 hours. Weather conditions grasses surroundedbymulch, andßowers versus were sunny andwarm (29.4 ЊC) following a morning grasses. rain. Effects of Surrounding Flower Mix or Mulch on Pre- Fall Armyworm Larvae. Fifty neonate larvae were dation on Fall Armyworm Eggs and Larvae and Japa- releasedinto the center of each turf plot on 5 August nese Beetle Eggs in Turf in Small Plots. Percent survival 1998. Vacuum samples were taken 24 h later. Fifteen data of fall armyworm and Japanese beetle eggs or second-instar fall armyworms were introduced within relative larval recovery with vacuum samples basedon a 15-cm-diameter polyvinyl chloride (PVC) cage in- initial release numbers were transformedusing an serted5 cm into the soil in each turf plot on 3 August arcsine square root of the proportion before being 1998. Surviving larvae were collectedon 7 August by subjectedto ANOVA. thoroughly vacuuming the area enclosedusing the Vortis vacuum sampler. During 1999, 1,900 neonate Results and Discussion larvae were releasedinto the center of each turf plot on 30 June. Samples were collectedfrom each plot 24 h Effects of Cover Type on Beneficial Arthropod Oc- later by vacuuming the turf was in ever-widening currence: Large Plot Study. Carabidspecies assem- circles to a diameter of 3 m. Larvae (820 per plot) were blages collectedin this portion of the studywere also releasedon 20 July for a 24-h exposure period. similar to those collectedin centipedegrassin a pre- Japanese Beetle Eggs. Japanese beetle eggs were vious study (Braman and Pendley 1993). Abacdicus obtainedby collecting adultfemales in pheromone permundus Say, Agonum punctiforme Say, Amara sp., traps, placing them in transparent plastic rearing con- Calathus opaculus LeConte, Calosoma sayi Dejean, tainers (14 cm high by 38 cm l by 24 cm wide) with Cratacanthus dubuis Beauvois, Harpalus pennsylvani- topsoil andcrape myrtle ( Lagerstroemia spp.) leaves cus DeGeer, and Scarites subterraneus F. represented andallowing the beetles to oviposit. Eggs were placed 98% of the total carabids captured in pitfall traps in the in 5.5-cm-diameter plastic petri dishes lined with current study. Previously, in centipedegrass, A. punc- moistenedÞlter paper. Dishes containing eggs were tiforme, H. pennsylvanicus, S. subterraneus, Notophilus then placedwithout lidsbeneath the turfgrass surface novemstriatus LeConte, Anisodactylus furvus Le- in the Þeld plots by opening a wedge 5 cm deep using Conte, Amara aena DeGeer, and A. permundus rep- an adz (a cutting tool with a thin arched blade set at resented93 and87% of carabidscollectedat two lo- right angles to the handle). Dishes containing eggs cations in centipedegrass in a 3-yr study. Morrill were carefully insertedinto the opening andthe sod (1992) determinedthatÞve carabidspecies repre- resettledover the opening. The location of each dish sented94% of the total pitfall trap catch in Georgia was markedwith a ßag so they couldbe relocated24 h grasslands during 1975 and 1976. Abacidus sculptus later. Dishes were collected, covered, marked, and (LeConte), H. pennsylvanicus, Evarthrus unicolor returnedto the laboratory to determinetheir con- (Say), S. subterraneus quadriceps Chadoir, and S. sub- tents. Japanese beetle eggs were placedin the Þeldon terraneus subterraneus F. were the most abundant spe- 30 June (three eggs per dish, two dishes per plot) and cies in that study. Ants were most active during the 20 July (seven eggs per dish, two dishes per plot). summer months but were capturedyear round.Spe- Statistical Analysis. The Effects of Cover Type on cies identiÞed included Solenopsis invicta (Buren), Beneficial Arthropod Occurrence, Large Plot Study. Ar- (Say), Iridomyrmex humilis (Mayr), thropod abundance data from pitfall traps and sweep Formica schaufussi Mayr, and Ponera pennsylvanica samples in wildßowers, turf adjacent to wildßowers Buckley. Spider families captured in pitfalls included andturf adjacentto turf were subjectedto analysis of Erigonidae, Thomisidae, Hahniidae, Lycosidae, Gna- variance (ANOVA) using the general linear models phosidae, Salticidae, Tetragnathidae, Agelenidae, Clu- June 2002 BRAMAN ET AL.: WILDFLOWER MIXES ON ARTHROPOD ABUNDANCE AND PREDATION 567

Fig. 1. Season-long abundance of ground-dwelling spi- Fig. 2. Season-long abundance of foliar spiders captured ders captured in pitfall traps in Bermuda grass turf adjacent in sweep samples in Bermuda grass turf adjacent to turf to turf (T/T), turf adjacent to wildßowers (T/WF), or wild- ϭ (T/T), turf adjacent to wildßowers (T/WF), or wildßowers ßowers alone (WF) in large plots, n 6 blocks. alone (WF) in large plots, n ϭ 6 blocks. bionidae, Ctenizidae, and Linyphiidae. Spiders were ants demonstrated considerable plot to plot variability abundant throughout the year; immatures were most in abundance among the six blocks. common duringlate June andearly July andagain in Bigeyedbugs (Fig. 5) collectedin sweep samples September. during 1993 were primarily Geocoris punctipes. This As measured by pitfall traps, ground-dwelling spi- species was most numerous in wildßowers during 1993 ders were most abundant in turfgrass adjacent to turf- (F ϭ 11.1; df ϭ 5, 2; P Ͻ 0.003). Fewer bigeyedbugs grass and turfgrass adjacent to wildßowers compared were collectedduring1994, anda larger proportion with wildßower stands alone during both years (Fig. were Geocoris uliginosus (Say). Similar numbers were 1). During 1993, spiders were more than twice as collectedamong cover type in sweep samples during common in turfgrass alone than in wildßowers alone 1994 (F ϭ 0.6; df ϭ 5, 2; P Ͼ 0.05). The wildßower mix (F ϭ 25.7; df ϭ 5, 2; P Ͻ 0.0001), whereas turf adjacent used in this portion of the study provided signiÞcant, to wildßower stands supported an intermediate num- season-long increases in foliar-dwelling spiders and ber of spiders. During 1994, spider numbers were bigeyed bugs during 1993, but not 1994. Ground- statistically similar in both turf treatments, but spiders dwelling spiders were more abundant in turfgrass than were signiÞcantly more numerous in turf than in wild- in wildßowers both years, while ants appeared not to ßowers alone (F ϭ 7.5; df ϭ 5, 2; P Ͻ 0.01). Foliar be signiÞcantly affectedby cover type. spiders, however, were more common in the wild- Effects of Flower Mix and Turf Type on Beneficial ßowers during 1993 (Fig. 2) (F ϭ 87.6; df ϭ 5, 2; P Ͻ Arthropod Occurrence in Small Plots. Taxa captured 0.0001). Similar numbers of spiders were captured in in vacuum samples that were signiÞcantly inßuenced sweep net samples in all three cover types during 1994 by substrate (ßower type, turf type, mulch, surround- (F ϭ 2.4; df ϭ 5, 2; P Ͼ 0.05). ing border type) included Berytidae, Geocoris spp., Groundbeetle abundance(Fig. 3), exhibiteda Formicidae, parasitic and Staphylinidae trendtowardincreasedabundancein wildßowerplots (Tables 1 and2). Damsel bugs (Nabidae)andspiders andturf surroundedbywildßowersboth years, but in vacuum samples were statistically similar in all plots was not signiÞcantly different among these three during both years. Berytids were more abundant in cover types (F ϭ 2.2; df ϭ 5, 2; P Ͼ 0.05 in 1993; F ϭ Border Patrol ßowers than in Smith Mix during 1998, 0.4; df ϭ 5, 2; P Ͼ 0.05 in 1994). Ants (Fig. 4) were but equally abundant in both mixes during 1999. They present in similar numbers in all three cover types were more likely to be capturedin bermudagrassthan each year (F ϭ 0.3; df ϭ 5, 2; P Ͼ 0.05 in 1993; F ϭ 0.8; in zoysiagrass both years, but were also more likely to df ϭ 5, 2; P Ͼ 0.05 in 1994). Both groundbeetles and be capturedin ßowers than in grasses both years 568 ENVIRONMENTAL ENTOMOLOGY Vol. 31, no. 3

Fig. 3. Season-long abundance of carabids captured in pitfall traps in bermudagrass turf adjacent to turf (T/T), turf Fig. 4. Season-long abundance of ants captured in pitfall adjacent to wildßowers (T/WF), or wildßowers alone (WF) ϭ traps in bermudagrass turf adjacent to turf (T/T), turf ad- in large plots, n 6 blocks. jacent to wildßowers (T/WF), or wildßowers alone (WF) in large plots, n ϭ 6 blocks. (Table 2). The bigeyedbugs in these samples were 98% Geocoris uliginosus. Bigeyedbugs were equally common during 1998 in all plots, but were most abun- common in Border Patrol and Smith Mix ßowers. dant during 1999 in Bermuda grass or zoysiagrass bor- These predators were more commonly captured in dered by Border Patrol. Bermuda grass than zoysiagrass both years, where Effects of Surrounding Flower Mix or Mulch on they were equally or more abundant than in adjacent Predation on Fall Armyworm Eggs and Larvae and ßowers. Further, G. uliginosus was less numerous in Japanese Beetle Eggs in Small Turf Plots. Survival of turfgrass bordered by ßowers than turf plots sur- fall armyworm eggs exposedfor 23 h in turf during roundedbystraw mulch (Tables 1 and2). 1998 and1999 averaged Ͻ2% of the Ͼ9,000 eggs per Formicidae and parasitic Hymenoptera were more exposure periodfor both years. Eggs were similarly common in ßowers than in grasses during both years preyedupon in all plots ( P Ͼ 0.05). When fall army- of the study, and Staphylinidae were more common in worm eggs were exposedin the Þeldfo r2hduring ßowers during 1998 only. Formicidae were more 1998, survival averaged59% in zoysiagrass surrounded abundant in the Border Patrol mix during 1998, and by mulch; 48% in zoysiagrass surrounded by Border parasitic Hymenoptera andStaphylinidaewere better Patrol; 36% in bermudagrass surrounded by Border representedin the Smith Mix. However, staphylinids Patrol; 33% in bermudagrass surrounded by mulch; were more common in turf bordered by straw mulch 32% in Bermuda grass surrounded by Smith Mix and than turf surrounded by ßowers during 1998. 10% in zoysiagrass surrounded by Smith Mix. These Carabids captured in pitfall traps were most com- differences, however, were not signiÞcant (F ϭ 0.32; mon in the Border Patrol ßower mix during 1998 and df ϭ 2, 5; P Ͼ 0.05). Fall armyworm larvae also were equally abundant in all cover types during 1999 (Ta- heavily preyedupon both years regardlessof turf or bles 3 and4). Tiger beetles, primarily Megacephala border type. During 1998, recovery of neonate larvae carolina carolina L. with some M. virginica L., were from vacuum samples was 1.4% in bermudagrass sur- most abundant in the bare soil with wheat straw mulch rounded by Smith Mix, 1.3% in bermudagrass sur- comparedwith ßowers andgrasses duringboth 1998 rounded by mulch, 0.8% in zoysiagrass surrounded by and1999. Although there were no differencesin other Smith Mix, 0.5% in zoysiagrass surrounded by mulch, Formicidae among substrate types in the pitfall traps, 0.4% in bermudagrass surrounded by Border Patrol the redimportedÞre , Solenopsis invicta (Buren), and0.3% in zoysiagrass surroundedbyBorderPatrol tended to be more common in ßowers than in grasses (F ϭ 1.03; df ϭ 2, 5; P Ͼ 0.05). Secondinstars which andmost common in the Smith Mix andin turfgrasses hadbeen conÞnedin tubes in the plots (left open to surrounded with Smith Mix. Earwigs were equally allow entry of predators) also survived similarly June 2002 BRAMAN ET AL.: WILDFLOWER MIXES ON ARTHROPOD ABUNDANCE AND PREDATION 569

1900 neonate larvae releasedwas 1.1% in bermuda- grass surrounded by mulch, 2.4% in zoysiagrass sur- rounded by mulch, 2.6% in bermudagrass surrounded by Smith Mix, 2.0% in zoysiagrass surrounded by Smith Mix, 0.7% in bermudagrass surrounded by Border Pa- trol and1.3% in zoysiagrass surroundedbyBorder Patrol after 24 h (F ϭ 0.72; df ϭ 2, 5; P Ͼ 0.05). Too few (Ͻ0.04%) neonate larvae releasedon 20 July were recoveredin vacuum samples on 21 July to permit statistical analysis. Using our method(without a pred- ator exclusion control) it was not possible to deter- mine what proportion of the larvae that were not recovered was due to predation and what proportion was an artifact of the sampling technique. Average Japanese beetle egg survival on one and28 July 1999 respectively was 72.1 and28.5% in bermudagrasssur- roundedbymulch, 44.5 and33.3% in zoysiagrass sur- roundedbymulch, 22.2 and42.8% in bermudagrass surroundedbySmith Mix, 55.7 and26.1% in zoysia- grass surroundedbySmith Mix, 55.7 and30.8% in bermudagrass surrounded by Border Patrol and 66.6 and23.8% in zoysiagrass surroundedbyBorderPatrol after 24 h (F ϭ 0.23; df ϭ 2, 6; F ϭ 0.72; df ϭ 2, 5; P Ͼ 0.05). Turfgrass andwildßowermixes all harboreda di- verse array of beneÞcial arthropods in both large plot Fig. 5. Season-long abundance of bigeyed bugs captured and small plot studies. Each wildßower mix increased in sweep samples in bermudagrass turf adjacent to turf (T/ the abundance of some, but not all beneÞcial arthro- T), turf adjacent to wildßowers (T/WF), or wildßowers ϭ podspecies sampled.This increasedabundancewas alone (WF) in large plots, n 6 blocks. only occasionally observedin adjacentturfgrass areas. Ground-inhabiting spiders were more numerous in among plots andaveraged20% in turf surroundedby turf, foliar spiders were more abundant in ßowers, Border Patrol, 18% in turf surrounded by mulch and groundbeetles were only rarely signiÞcantly more 13% in turf surrounded by Smith Mix (F ϭ 0.18; df ϭ abundant in wildßowers than turf. Fall armyworm 2, 2; P Ͼ 0.05). During 1999, average recovery of the eggs andlarvae andJapanese beetle eggs were heavily

Table 1. Mean number of beneficials per vacuum sample per date in flower mixes (Smith Mix or Border Patrol) or wheat straw mulch or in bermudagrass or zoysiagrass bordered by either Smith Mix (SM) Border Patrol (BP) or mulch

Contrast Berytidae Nabidae Geocoris Formicidae Araneae Parasitic Hymenoptera Staphylinidae 1998 Smith Mix 0.26 0.22 0.92 9.89 3.17 7.67 2.17 Border Patrol 1.04 0.11 0.93 13.59 3.17 4.67 0.33 Mulch 0.07 0.07 0.11 2.48 1 0.5 0 Bermudagrass w/SM 0.67 0.11 0.93 4.44 5.33 0.83 0 Bermudagrass w/BP 0.52 0.11 0.59 5.44 2.33 0.67 0 Bermudagrass w/Mulch 0.33 0.07 0.93 3.22 5.33 1.17 0.33 Zoysiagrass w/SM 0.11 0 0.18 4.04 5.17 0.83 0.17 Zoysiagrass w/BP 0.22 0.04 0.3 3.81 18.17 2 0 Zoysiagrass w/Mulch 0.11 0 0.18 2.48 7.83 0.17 0.5 F(2.8) 2.25 1.56 5.2 6.74 0.89 9.03 3.9 P 0.02 0.14 0.0001 0.0001 0.53 0.0001 0.002 1999 Smith Mix 0.22 0.12 1.38 10.36 4.26 0.86 0.69 Border Patrol 0.14 0.48 1.07 14.24 8.31 0.86 0.57 Mulch 0.02 0.48 1.12 5.86 2.24 0.21 0.26 Bermudagrass w/SM 0.07 0.02 3.59 7.07 2.76 0.48 0.5 Bermudagrass w/BP 0.07 0.07 2.45 7.53 3.9 0.8 0.8 Bermudagrass w/Mulch 0.22 0.07 4.02 7.51 2.66 0.56 0.7 Zoysiagrass w/SM 0 0.02 1.12 4.35 3.3 0.15 0.79 Zoysiagrass w/BP 0.07 0 1.45 8.98 3.83 0.43 0.79 Zoysiagrass w/Mulch 0.05 0.05 1.83 5.5 3.95 0.38 0.71 F(2.8) 1.87 0.86 5.57 2.62 1.13 1.63 1.32 P 0.06 0.55 0.0001 0.009 0.34 0.11 0.23 570 ENVIRONMENTAL ENTOMOLOGY Vol. 31, no. 3

Table 2. Comparison of beneficial arthropod densities in vacuum samples as influenced by turfgrass species or surrounding border of either Border Patrol (BP) or Smith Mix (SM) wildflowers or bare soil with wheat straw mulch

Contrast Berytidae Nabidae Geocoris Formicidae Araneae Parasitic Hymenoptera Staphylinidae 1998 BP vs SM ** NS NS * NS ** *** Bermudagrass vs ** * *** NS NS NS NS Zoysiagrass Grass w/BP vs Grass NS NS NS NS NS NS ** w/SM Flowers andGrass vs ** NS ** *** NS *** NS Mulch Grass w/Flowers vs NS NS NS NS NS NS NS Grass w/Mulch Flowers vs Grasses * ** *** *** NS *** *** 1999 BP vs SM NS NS NS NS * NS NS Bermudagrass vs * NS *** NS NS * NS Zoysiagrass Grass w/BP vs Grass NS NS NS ** NS NS NS w/SM Flowers andGrass vs NS NS NS * NS NS NS Mulch Grass w/Flowers vs NS NS **NS NS NS Grass w/Mulch Flowers vs Grasses ** NS ** *** ** ** NS

NS, non signiÞcant. *, P Ͻ 0.10; **, P Ͻ 0.05; ***, P Ͻ 0.001. preyedupon in small plots regardlessof turfgrass spe- Most predators were equally well represented in cies or surrounding border of ßowers or mulch. bermudagrass and zoysiagrass, suggesting that the Lo´pez andPotter (2000) have demonstratedthat more pest resistant zoysiagrass may be compatible indigenous ants may be an important buffer against with biological control by natural enemies. The pest outbreaks on lawns andgolf courses. Ants were greater number of bigeyedbugs observedin bermuda- among the most abundant predators in each of the grass may reßect larger numbers of alternative prey experiments describedhere,andwere frequently ob- such as leafhoppers associatedwith this grass (datanot servedpreying on fall armyworm eggs andlarvae, as presented). While parasitism of turfgrass pests was not were Geocoris uliginosus andthe staphylinids Copro- evaluatedhere, the increase in parasitic Hymenoptera porus laevis LeConte andan unidentiÞedAleocharine present in the ßower mixes usedin these studiessug- species. gests their potential in attracting beneÞcial parasitoid

Table 3. Mean number of beneficials arthropods per pitfall sample per date in flower mixes (Smith Mix or Border Patrol) or wheat straw mulch or in bermudagrass or zoysiagrass bordered by either Smith Mix, Border Patrol or mulch

Contrast Carabidae Staphylinidae Cicindellidae Formicidae Solenopsis Araneae Dermaptera 1998 Smith Mix 9.67 5.01 0.31 17.81 8.24 10.28 0.36 Border Patrol 15.02 4.19 0.26 27.04 6.52 10.8 0.19 Mulch 6.07 3.09 0.59 38.26 4.36 12.14 0.21 Bermudagrass w/SM 9.45 4.35 0.14 22.07 6.95 12.37 0.52 Bermudagrass w/BP 7.71 3.64 0.12 24.42 5.86 12.24 0.52 Bermudagrass w/Mulch 6.07 4.43 0.14 21.24 5.97 20.21 0.64 Zoysiagrass w/SM 8 5.01 0.07 17.62 9.07 11.33 0.51 Zoysiagrass w/BP 7.24 5.52 0.09 27.01 5.98 11.47 0.54 Zoysiagrass w/Mulch 5.24 4.38 0.12 17.67 9.07 15.04 0.45 F(2.8) 2.47 1.04 3.16 1.08 1.87 0.96 1.15 P 0.01 0.4 0.002 0.38 0.06 0.47 0.33 1999 Smith Mix 3.79 2.96 0.32 20.59 19.07 13.4 0.45 Border Patrol 4.15 4.44 0.27 30.98 7.49 22.11 0.71 Mulch 3.34 2.41 1.36 104.07 6.02 10.11 0.18 Bermudagrass w/SM 4.89 4.29 0.09 23.59 7.84 25.16 1.27 Bermudagrass w/BP 4.09 4.91 0.08 28.16 5.38 21.84 1.56 Bermudagrass w/Mulch 4.09 3.87 0.07 30.6 6.87 21.8 0.91 Zoysiagrass w/SM 5.02 4.62 0.02 20.78 8.71 25.02 1.11 Zoysiagrass w/BP 5.04 4.38 0.09 25.09 5.64 23.11 1.61 Zoysiagrass w/Mulch 4.78 4.11 0.22 16.87 6.82 17.96 0.93 F(2.8) 0.79 1.29 6.58 2.12 2.45 2.63 3.09 P 0.61 0.25 0.0001 0.03 0.01 0.008 0.002 June 2002 BRAMAN ET AL.: WILDFLOWER MIXES ON ARTHROPOD ABUNDANCE AND PREDATION 571

Table 4. Comparison of beneficial arthropod densities in pitfall samples as influenced by turfgrass species or surrounding border of either Border Patrol (BP) or Smith Mix (SM) wildflowers or bare soil with wheat straw mulch

Contrast Carabidae Staphylinidae Cicindellidae Formicidae Solenopsis Invicta Araneae Dermaptera 1998 BP vs SM ** NS NS NS NS NS NS Bermudagrass vs NS NS NS NS NS NS NS Zoysiagrass Grass w/BP vs Grass NS NS NS NS ** NS NS w/SM Flowers andGrass vs *** NS * NS ** ** NS Mulch Grass w/Flowers vs NS NS NS NS NS ** NS Grass w/Mulch Flowers vs Grasses *** NS NS NS NS NS ** 1999 BP vs SM NS NS NS NS ** * NS Bermudagrass vs NS NS NS NS NS NS NS Zoysiagrass Grass w/BP vs Grass NS NS NS NS ** NS NS w/SM Flowers andGrass vs NS NS *** * NS ** ** Mulch Grass w/Flowers vs NS NS NS NS NS NS ** Grass w/Mulch Flowers vs Grasses NS NS NS NS ** * ***

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