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Public interest in ecological landscaping and gardening is fueling a robust market for native plants. Most plants available to consumers through the horticulture trade are cultivated forms that have been selected for modified flowers or foliage, compactness, or other ornamental characteristics. Depending on their traits, some native plant cultivars seem to support pollinators, specialist insect folivores, and insect-based vertebrate food webs as effectively as native plant species, whereas others do not. There is particular need for information on whether native cultivars can be as effective as true or “wild-type” native species for supporting specialist native insects of conservation concern. Herein we compared the suitability of native milkweed species and their cultivars for attracting and supporting one such insect, the iconic monarch butterfly (Danaus plexippus L.), as well as native bees in urban pollinator gardens. Wild-type Asclepias incarnata L. (swamp milkweed) and Asclepias tuberosa L. (butterfly milkweed) and three additional cultivars of each that vary in stature, floral display, and foliage color were grown in a replicated common garden experiment at a public arboretum. We monitored the plants for colonization by wild monarchs, assessed their suitability for supporting monarch larvae in greenhouse trials, measured their defensive characteristics (leaf trichome density, latex, and cardenolide levels), and compared the proportionate abundance and diversity of bee families and genera visiting their blooms. Significantly more monarch eggs and larvae were found on A. incarnata than A. tuberosa in both years, but within each milkweed group, cultivars were colonized to the same extent as wild types. Despite some differences in defense allocation, all cultivars were as suitable as wild-type milkweeds in supporting monarch larval growth. Five bee families and 17 genera were represented amongst the 2,436 total bees sampled from blooms of wild-type milkweeds and their cultivars in the replicated gardens. Bee assemblages of A. incarnata were dominated by Apidae (Bombus, Xylocopa spp., and Apis mellifera), whereas A. tuberosa attracted relatively more Halictidae (especially Lasioglossum spp.) and Megachilidae. Proportionate abundance of bee families and genera was generally similar for cultivars and their respective wild types. This study suggests that, at least in small urban gardens, milkweed cultivars can be as suitable as their parental species for supporting monarch butterflies and native bees.

Susceptibility of the armyworm, Mythimna unipuncta (Haworth), to infection by a baculovirus (NPV) isolated from a Kentucky armyworm population was compared on two suspected progenitors of tall fescue, Festuca mairei and Festuca arundinacea subsp. fenas , with spiny leaf margins intact or removed to test whether leaf spines abrade or puncture the peritrophic matrix (PM) and facilitate passage of virions to infection sites in midgut tissue. PCR amplification and sequencing of selected genes from the virus and phylogenetic inference from aligned sequences were carried out to identify and classify the virus. Edge spines had no effect on percentage infection or days to death of newly molted 5th instars fed spiny- or smooth-edged F. mairei leaf blades for 24 h before and after droplet feeding doses of 10 8 or 10 9 OBs ml −1 . Fifth instars fed spiny- or smooth-edged grass blades had similarly undamaged PMs when viewed by scanning electron microscope. Fourth instars fed virus-treated F. arundinacea subsp. fenas leaf blades with spiny edges intact or removed did not differ in proportion infected or days to death. The food bolus moves in a liquid medium within the PM, and frass dissections showed that edge spines were often located inside a food bolus separated from the PM by non-spiny plant material rather than contiguous with the PM; therefore, friction of edge spines with the PM may have been low. These results suggest that armyworms will not be less susceptible to baculovirus infection when feeding on tall fescue cultivars with smooth leaf edges planted for improved livestock performance compared with those feeding on standard spiny-edged cultivars. We believe this to be the first study to investigate the effects of a natural physical structure on disruption of the PM and infection by a baculovirus.

Plant secondary chemicals can alter herbivore suitability for parasitoids by weakening or stunting the host, delaying its development, or when larval parasitoids encounter ingested phytotoxins in the body of their host. Experiments with different parasitoids that exploit the same host species feeding on the same plant may provide insight about how parasitoid life history affects the strength of such interactions. The encyrtid wasp Copidosoma bakeri, a slow-developing polyembryonic egg-larval parasitoid, and the tachinid fly Linnaemya comta, a fast-developing solitary species, both parasitize Agrotis ipsilon, a generalist noctuid. We tested the hypothesis that of the two parasitoid species, the encyrtid, because of its more prolonged developmental association with the host, would suffer greater fitness costs when A. ipsilon feeds on perennial ryegrass containing an alkaloid-producing fungal endophyte. Indeed, fewer parasitized cutworms yielded C. bakeri broods, and those host mummies were smaller, formed more slowly, and contained fewer adults when the hosts fed on endophytic as opposed to endophyte-free grass. In contrast, L. comta fitness parameters were similar regardless of the type of grass upon which their host fed. Our results highlight that the outcome of endophyte-mediated tritrophic interactions may differ for different parasitoid species. Implications for integrating the use of endophytic grasses and biological control are discussed.

Ontogenetic changes in feeding behavior of armyworms, Pseudaletia unipucta (Haworth), were compared on tall fescue [Schedonorus arundinaceus (Schreb.) Dumort] cultivars with spiny-, intermediate-, or smooth-edged leaf blades to clarify whether the edge spines deter caterpillars, in which case release of modified, smooth-edged forage grasses for improved livestock performance might aggravate armyworm damage to pastures. Edge biting, success initiating edge-feeding, and propensity to window- or edge-feed were observed for individual 2nd, 3rd, or 4th instars on grass leaf blades with intact margins. Early second instars bit smooth and spiny leaf edges with equal frequency but were unable to initiate edge-feeding. They fed on leaf edges after margins were cut away, but not when leaf juice was applied to intact edges, indicating the leaf margin is a barrier. Third and 4th instars mostly edge-fed on smooth leaves, but on the grasses with spiny margins they compensated for the difficulty of edge-feeding by prolonging their window-feeding. There was no developmental cost to window-feeding by 3rd instars, but 4th instars suffered reduced weight gain on spiny grass apparently because, unlike earlier instars, their mandibles are too large and not well shaped for efficient window-feeding between the parallel vascular bundles. Armyworms display behavioral plasticity in feeding mode in response to spiny- versus smooth-edged grasses. Greater use of smooth-bladed pasture grasses may result in proportionately more edge-feeding by armyworms but is unlikely to result in markedly greater pasture losses because this grass-feeding specialist so effectively exploits conventional tall fescue despite its structural characteristics.

Root-feeding grubs (Coleoptera: Scarabaeidae) were sampled from damaged areas of 61 irrigated roughs on 32 Kentucky golf courses to determine species composition and natural enemy incidence, the first such survey in the United States' transitional turfgrass climatic zone. Masked chafers (Cyclocephala lurida Bland and C. borealis Arrow) and Japanese beetle (Popillia japonica Newman) accounted for ≈73 and 26% of grubs found in an autumn survey, with Cyclocephala spp. predominating at most sites, although mixed infestations were common. Only a few Phyllophaga spp., and no exotic species other than P. japonica were found. Cyclocephala spp. also predominated in seasonal and statewide surveys regardless of whether a course had cool- or warm-season grass fairways. Pathogenic bacteria, Paenibacillus and Serratia spp., and the autumn-active parasitoid Tiphia pygidialis Allen were the main enemies associated with Cyclocephala spp. Predominant enemies of P. japonica were Paenibacillus, Serratia, and Metarhizium spp. in autumn, and eugregarines, Stictospora sp. (probably S. villani Hays and Clopton) and Tiphia vernalis Rohwer in spring. Entomopathogenic nematodes and the microsporidian Ovavesicula popilliae Andreadis & Hanula were nearly absent in our samples. No predictive relationships were found between soil parameters and proportionate abundance of Cyclocephala or P. japonica, or with natural enemy incidence at particular sites. Although incidence of individual enemies was generally low (

Twenty genotypes of landscape-suitable Dutch elm disease-resistant elms (Ulmus spp.) were evaluated in a replicated field study for resistance to multiple insect pests in Lexington, Kentucky, U.S. The European elm flea weevil (EEFW), Orchestes alni, a recentlyintroduced pest that disfigures elms by leaf-mining and adult feeding, was found as a new state record so its feeding preferences and life history were monitored. U. parvifolia and U. propinqua, originally from Japan, were relatively resistant to Japanese beetles, and U. americana was generally less susceptible than most hybrids. Agromyza aristata, a serpentine leaf-mining fly, favored American elms, whereas Kaliofenusa ulmi a blotch-mining sawfly, and aphid (Tetraneura nigriabdominalis) pouch galls were uncommon on American and Asian elms but abundant on certain hybrids. EEFW infested all elms but at highest densities, (>20 mines per 30 cm shoot and >85 adult feeding holes per leaf), on certain hybrids. American elms, especially ‘Jefferson’, were somewhat less susceptible. EEFW laid eggs in expanding leaves; mines were initiated in late April and completed by mid- to late- May. Newly-emerged adults extensively damaged leaves in late May and June but nearly disappeared from tree canopies by mid-July. Implications for re-introduction of elms into urban landscapes are discussed.

Invasive species' facilitation, or benefiting, of native species is rarely considered in biological invasion literature but could have serious economic consequences should a non-native herbivore facilitate injury by a native pest of high-value crops. Japanese beetle (JB),Popillia japonica, a polyphagous scarab, facilitates feeding by the obligate fruit-feeding native green June beetle (GJB),Cotinis nitida, by biting into intact grape berries that GJB, which has blunt spatulate mandibles, is otherwise unable to exploit. Here, we show JB further facilitates GJB by contaminating fruits with yeasts, and by creating infection courts for yeasts associated with GJB, that elicit volatiles exploited as aggregation kairomones by GJB. Traps baited with combinations of grapes and beetles were used to show that fruits injured by JB alone, or in combination with GJB, become highly attractive to both sexes of GJB. Such grapes emit high amounts of fermentation compounds compared with intact grapes. Beetle feeding on grape mash induced the same volatiles as addition of winemaker's yeast, and similar attraction of GJB in the field. Eight yeast species were isolated and identified from JB collected from grapevine foliage. Establishment and spread of JB throughout fruit-growing regions of the United States is likely to elevate the pest status of GJB and other pests of ripening fruits in vineyards and orchards.

The Japanese beetle, Popillia japonica Newman, has an unusually broad host range among deciduous woody plants, yet it feeds only sparingly, or not at all, on certain species in the field. We evaluated beetles' preference, survival over time and fecundity on eight woody plant species historically rated as susceptible or resistant and, after verifying those ratings, tested whether resistance is correlated with so-called quantitative defense traits including leaf toughness, low nutrient content (water, nitrogen, and sugars), and relatively high amounts of tannins or saponins, traditionally associated with such plants. We further tested whether species unsuitable for Japanese beetles are also rejected by fall webworms, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), the expected outcome if the aforementioned traits serve as broad-based defenses against generalists. Choice tests supported historical resistance ratings for the selected species: tuliptree, lilac, dogwood, and Bradford callery pear were rejected by Japanese beetles, whereas sassafras, cherry plum, Virginia creeper, and littleleaf linden were readily eaten. Rejected species also were unsuitable for survival over time, or egg-laying, indicating beetles' inability to overcome the resistance factors through habituation, compensatory feeding, or detoxification. None of the aforementioned leaf traits was consistently higher or lower in the resistant or susceptible plants, and plant species rejected by Japanese beetles often were not rejected by fall webworms. Specialized secondary chemistry, not quantitative defenses, likely determines the Japanese beetle's dietary range among deciduous woody plant species it may encounter.

BACKGROUND:Proteoteras aesculana (Riley), a caterpillar that causes tip dieback and kills the central leader of maples, is an important nursery pest. The authors sought to develop a pheromone lure, use it to clarify the pest's seasonal biology, determine when and where infestations originate and extend the management window. RESULTS: Gas chromatography, electroantennographic detection and trapping showed that (Z)-dodec-8-en-1-ol (Z8-12:OH) is the major sex pheromone component. Flight began in March, peaking in early spring. Larvae developed during April and May, giving rise to moths active in late May and June. No additional larvae were found in maples following that flight. Sporadic moth captures occurred into November, suggesting that adults overwinter. Three parasitoid species, all new host records, were documented. A different tortricid, Episimus tyrius Heinrich, caused leaf-tying damage in late summer. Maples shipped from Oregon were free of shoot borers, refuting speculation that larvae overwinter in buds. One bifenthrin spray applied from just before bud break at onset of moth flight to just after peak flight when shoots had two pairs of leaves reduced infestation by 96–100%. CONCLUSION: Maples are infested soon after planting in Kentucky nurseries via eggs laid in early spring. The temporal window for preventive control is broader than previously thought. Copyright © 2008 Society of Chemical Industry

Neotyphodium and Epichloe species (Ascomycota: Clavicipitaceae) are fungal symbionts (endophytes) of grasses. Many of these endophytes produce alkaloids that enhance their hosts' resistance to insects or are toxic to grazing mammals. The goals of eliminating from forage grasses factors such as ergot alkaloids that are responsible for livestock disorders, while retaining pasture sustainability, and of developing resistant turf grasses, require better understanding of how particular alkaloids affect insect herbivores. We used perennial ryegrass Lolium perenne L. (Poaceae) symbiotic with Neotyphodium lolii x Epichloe typhina isolate Lp1 (a natural interspecific hybrid), as well as with genetically modified strains of Lp1 with altered ergot alkaloid profiles, to test effects of ergot alkaloids on feeding, growth, and survival of the black cutworm, Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae), a generalist grass-feeding caterpillar. Neonates or late instars were provided clippings from glasshouse-grown plants in choice and rearing trials. Wild-type endophytic grass showed strong antixenosis and antibiosis, especially to neonates. Plant-endophyte symbiota from which complex ergot alkaloids (ergovaline and lysergic acid amides such as ergine) or all ergot alkaloids were eliminated by endophyte gene knockout retained significant resistance against neonates. However, this activity was reduced compared to that of wild-type Lp1, providing the first direct genetic evidence that ergot alkaloids contribute to insect resistance of endophytic grasses. Similarity of larval response to the two mutants suggested that ergovaline and/or ergine account for the somewhat greater potency of wild-type Lp1 compared to the knockouts, whereas simpler ergot alkaloids contribute little to that added resistance. All of the endophyte strains also produced peramine, which was probably their primary resistance component. This study suggests that ergot alkaloids can be eliminated from an endophyte of perennial ryegrass while retaining significant insect resistance.

We investigated the biology of Tiphia pygidialis Allen, a previously unstudied native parasitoid of masked chafer, Cyclocephala spp. grubs, in central Kentucky and the seasonal dynamics of Tiphia vernalis Rohwer, an introduced parasitoid of Japanese beetle, Popillia japonica Newman. T. pygidialis was active from mid-August to early October, parasitizing third-instar masked chafers, whereas T. vernalis attacked overwintered third-instar P. japonica from mid-April to early June. Adult T. vernalis were attracted to modified Japanese beetle traps and yellow pan traps and to 10% sugar water sprayed on tree foliage. Spraying sugar water directly on turf most effectively monitored T. pygidialis wasps. Parasitism rates as high as 33 and 58% were observed for T. pygidialis and T. vernalis, respectively. In the laboratory, T. pygidialis larvae progressed through five instars to cocoon formation in ≈22 d. They overwinter as prepupae. Field-collected female wasps lived 32 ± 4 d, parasitizing 22 ± 6 grubs. In...

We examined the effects of supplemental food sources on parasitism of turf-infesting white grubs (Coleoptera: Scarabaeidae) by tiphiid wasps (Hymenoptera: Tiphiidae). Survival of spring active Tiphia vernalis Rohwer and late summer active Tiphia pygidialis Allen, parasitoids of Japanese beetle, Popillia japonica Newman, and masked chafer, Cyclocephala spp., grubs, respectively, was significantly increased when wasps were provided with 10% sugar water in the laboratory. Presence of a grub for host feeding did not affect wasp longevity. Sugar sprays applied directly to turf were examined as a method for increasing grub parasitism rates. Large numbers of T. pygidialis visited turf sprayed with sugar water to feed. Parasitism of Cyclocephala spp. grubs by T. pygidialis was reduced in sugar-sprayed turf, but higher in turf plots located near sugar-sprayed turf. T. vernalis, which feeds on homopteran honeydew secretions, was never observed feeding on sugar-sprayed turf, nor did such treatments affect i...

The events leading to oviposition by Tiphia pygidialis Allen and Tiphia vernalis Rohwer on their host Cyclocephala spp. and Popillia japonica Newman grubs, respectively, were compared and quantiÞed using videotaped recordings. Mean (SE) duration of the oviposition process was 49.3 2.9 min for T. pygidialis and 31.5 2.2 min for T. vernalis. Behaviors included stinging, moving soil from around grubs, host kneading, host examination, host feeding, and scraping of the grubOs cuticle. Sequence of behavioral events was translated into a Þrst-order (Markovian) contingency table to construct sow charts of the oviposition process for both species. T. pygidialis spent more time kneading and scraping the cuticle of grubs than did T. vernalis, whereas T. vernalis performed more stinging and soil-moving events. These behaviors most likely serve to move the grubs into a suitable position for oviposition. Scraping of the hostOs cuticle where an egg was to be laid took more time than any other behavior. Compared with nonparasitized grubs, cuticle from parasitized grubs contained numerous grooves Þlled with cement used to anchor the parasitoid egg. Scanning electron microscopy revealed peg-like structures, similar in size to the grooves made in the cuticle of parasitized grubs, on the ovipositor sheath of female wasps. These structures are thought to be used in making the grooves in the cuticle, whose postulated function is to increase the surface area of the host cuticle to facilitate egg attachment. This is the Þrst study to implicate such use of the ovipositor sheath by a parasitoid.

The Japanese beetle, Popillia japonica Newman, feeds on the flowers and foliage of roses. Rosa x hybrida. Beetles attracted to roses land almost exclusively on the flowers. This study evaluated characteristics of rose flowers including color, size, petal count and fragrance, as well as height of plants and blooms within plant as factors in attractiveness to Japanese beetles. Artificial flowers that had been painted to match the spectral reflectance of real blooms were attached to potted nonflowering rose plants in the field and the number of beetles that landed on each model was recorded. More beetles landed on the yellow- and white-colored flower models than on the five other bloom colors that were tested. Large (15 cm diameter) yellow flower models attracted more beetles than did smaller (8 cm diameter) yellow models. There was no difference in beetle response to yellow flower models of the same size that differed in bloom complexity (i.e., number of petals). Experiments in which blooming rose plants were elevated above controls, or in which flower models were placed at different heights within plant canopies, failed to support the hypothesis that height per se accounts for beetles' attraction to flowers over leaves. Attractiveness of selected rose cultivars that varied in fragrance and flower color also was evaluated in the field. Yellow-flowered cultivars were more susceptible than those with red flowers, regardless of fragrance intensity as rated by breeders. Growing cultivars of roses that have relatively dark and small-sized blooms may have some benefit in reducing Japanese beetles' attraction to roses.

An equine disease now known as mare reproductive loss syndrome (MRLS) struck the Ohio Valley in 2001-2002 causing thousands of foal abortions and enormous economic loss. Evidence that pregnant mares' exposure to Eastern tent caterpillars Malacosoma americanum (F) induces MRLS created an urgent call for control measures suitable for use on horse farms. We surveyed egg mass distribution and monitored emergence in wild cherry trees, and evaluated reduced-risk treatment strategies including foliage sprays, trunk injections, winter egg mass treatments and barrier sprays to intercept larvae entering pastures. Egg masses were concentrated in the lower canopy, on exposed sides of trees. Larval emergence began in mid-March. Emergence was prolonged (3-4 weeks) in 2002, a typically cool spring, but more synchronized in warmer 2003. Winter treatment of egg masses with bifenthrin or permethrin in a penetrating solvent prevented emergence, but 3% horticultural oil was ineffective for that purpose. Insecticidal soap or oil sprayed directly on neonates gave relatively poor control. Bifenthrin and spinosad were effective as foliage sprays against all instars, their field-weathered residues active for at least 7 days. Bacillus thuringiensis Berliner var kurstaki controlled neonates within 3 days but was less active against late instars, with shorter residual action than bifenthrin or spinosad. Larvae did not avoid insecticide-treated leaves. Trunk microinjection of cherry trees with dicrotophos was effective against all instars, whereas microinjection with milbemectin or abamectin gave poor or inconsistent control. Trunk injection with emamectin benzoate also was effective. Dry permethrin residues controlled late instars crawling in pasture grass for at least 7 days. Factors complicating M americanum management on horse farms are discussed.

The Japanese beetle (Popillia japonica Newman), a polyphagous scarab, feeds on certain palatable plants that are toxic, or reputedly toxic. Paralysis of the beetle after consumption of flowers of zonal geranium (Pelargonium × hortorum L. H. Bailey) has been documented, but factors affecting expression and range of this phenomenon are poorly known. Published anecdotes regarding toxicity of two other hosts, larkspur (Delphinium sp.) and bottlebrush buckeye (Aesculus parviflora Walt.), have not been empirically tested. For zonal geraniums, we compared toxicity with P. japonica of flowers versus leaves, sun-grown and shaded plants, and different-colored flowers. The progression of paralysis and recovery, as well as survival of paralyzed beetles under laboratory and field conditions, also were evaluated. Beetles became paralyzed after feeding on flowers of zonal geranium, but not by consuming leaves, suggesting the active compound is unique to flowers. Shaded or sun-grown flowers, and red-, white-, or...

We studied effects of parasitism by two Tiphia species (Hymenoptera: Tiphiidae) on burrowing behavior of their respective scarabaeid hosts and tested the hypothesis that parasitoid alteration of host hormones accounts for the observed behavioral change. In turf field-plots, third-instar masked chafer grubs, Cyclocephala sp., parasitized by native Tiphia pygidialis Allen burrowed to depths of 12-16 cm within 21 d, whereas nonparasitized grubs remained in the upper 4 cm of soil. Grubs bearing an egg or early-instar Tiphia larva were found relatively close to the surface, whereas those with a fourth- or fifth-instar parasitoid were deeper. Experiments in soil-filled, vertical observation chambers confirmed downward movement by parasitized Cyclocephala, and similar response in third-instar Japanese beetle, Popillia japonica Newman, parasitized by Tiphia vernalis Rohwer. Removal of the Tiphia egg from masked chafers was followed by initial downward movement of grubs and then a gradual ascent, suggesting that host behavior is affected both by the venomous sting and feeding by the wasp larva. Significant but inconsistent differences were found in juvenile hormone-III (JH III) titers in hemolymph taken from nonparasitized grubs or grubs parasitized for 1 or 14 d. Topical application of JH III and methoprene acid resulted in grubs moving deeper into the soil, whereas injection of 20-hydroxyecdysone did not affect grub behavior. Failure to dig deeply enough in soil when sampling for parasitized scarab grubs or Tiphia cocoons likely will result in underestimation of parasitism rates.

Effectiveness of companion planting, and use of nonhost masking odors were evaluated under field conditions for protecting roses against the Japanese beetle, Popillia japonica Newman. Three reputedly effective companion species, rue (Ruta graveolens L.), zonal geranium (Pelargonium x hortorum Bailey), and garlic chives (Allium scheonparum L.) were interplanted with roses in replicated garden plots. Numbers of beetles on these roses were compared with rose-only control plots on 6 d during beetle flight. The masking odor hypothesis was tested by hanging mesh bags of aromatic herbs or other sources of reputedly repellent nonhost volatiles around potted roses in the field. Treatments included crushed red pepper (Capsicum frutescens L.), fennel seeds (Foeniculm vulgare Miller), crushed spearmint (Mentha picata L.), cedar shavings (Juniperus sp.), osage orange fruits (Maclura pomifera (Raif) Schneid.), and fleshy gingko seeds (Gingko biloba L.). No treatment significantly reduced numbers of beetles relative to the controls. Interplanting with geraniums significantly increased numbers of Japanese beetles on roses. Similarly, roses surrounded by sachets with fennel seeds, cedar shavings, crushed red pepper, or osage orange fruits had significantly more beetles than the control plants on two or more sample dates. Our results suggest that the use of companion or reputedly repellent plants or plant odors probably will be ineffective for protecting roses or other highly-susceptible ornamentals from P. japonica. Use of such tactics in an effort to discourage other garden pests might even increase Japanese beetle damage in those plantings.

Insecticides used on turf are sometimes applied to areas with flowering weeds that attract honey bees and native pollinators. We tested residual effects of such treatments on colony vitality and behavior of the bumble bees Bombus impatiens Cresson foraging on turf containing white clover, Trifolium repens L. Imidacloprid, a systemic chloronicotinyl used for preventive control of root-feeding grubs, was applied as granules, followed by irrigation, or sprayed as a wettable powder, with or without irrigation. Hives were confined on the plots in large field cages after residues had dried and colony vitality (i.e., numbers of brood, workers, and honey pots, and weights of queens, workers, and whole colonies with hives) was evaluated after 28–30 d. Workers’ foraging activity and defensive response to an aggressive stimulus also were evaluated. In another test, weedy turf was sprayed with chlorpyrifos, carbaryl, or cyfluthrin at labeled rates for surface-feeding pests. Bee colonies were confined on the plots after residues had dried, with effects on colony vitality evaluated after 14 d. Finally, foraging activity of wild bumble bees was monitored on open plots to determine if insecticide-treated areas were avoided. Imidacloprid granules, and imidacloprid sprays applied with posttreatment irrigation, had no effect on colony vitality or workers’ behavior, suggesting that such treatments pose little systemic or residual hazard to bumble bees. In contrast, exposure to dry nonirrigated residues of all of the aforementioned insecticides had severe impact on colony vitality. Foraging workers did not avoid insecticide-treated areas. Means by which turf managers can reduce hazards of insecticide applications to pollinators are discussed.

Twenty-six purple- or green-leaved cultivars representing 12 species of woody landscape plants were evaluated in the field for defoliation by Japanese beetles (Popillia japonica Newman) over three growing seasons. We further evaluated the hypothesis that, within closely-related plants, purple cultivars generally are preferred over green ones by comparing beetles' consumption of foliage in laboratory choice tests and their orientation to painted silk tree models baited with Japanese beetle lures. Cultivars of Prunus cerasifera Ehrh. and hybrids of that species [e.g., Prunus ×cistena (Hansen) Koehne, Prunus ×blireiana André] were more heavily damaged than nearly all other plants tested. Among maples, Acer palmatum Thunb. `Bloodgood' and A. platanoides L. `Deborah' and `Fairview' were especially susceptible. None of the cultivars of Berberis thunbergii DC, Cercis canadensis L., Cotinus coggygria Scop., or Fagus sylvatica L. were heavily damaged, regardless of foliage color. In the choice tests, purple Norway maples were preferred over green ones in three of four comparisons, but preference varied within the other plant genera. In fact, more beetles oriented to green-leaved tree models than to purple ones. Our results indicate that within a genus, purple-leaved plants do not necessarily sustain more damage than green-leaved ones. Widespread use of certain purple-leaved cultivars of generally susceptible plant species probably contributes to the perception that purpleleaved plants, overall, are preferred. Purple-leaved cultivars of redbud, European beech, smoketree, and barberry, or the purple-leaved Prunus virginiana L. `Canada Red' or Malus ×hybrida Lemoine `Jomarie' may be suitable substitutes for more susceptible purple-leaved plants in landscapes where Japanese beetles are a concern.

Cues used in below-ground host-searching behaviour and host discrimination were examined for Tiphia vernalis Rohwer and Tiphia pygidialis Allen (Hymenoptera: Tiphiidae), ecto-parasitoids of root-feeding larvae of the Japanese beetle, Popillia japonica Newman, and masked chafers, Cyclocephala spp. (Coleoptera: Scarabaeidae), respectively. Response to potential stimuli was compared in dual choice tests in an observation chamber filled with soil. Each wasp showed species-specific, directed movement along residual body odor trails made by dragging its respective host through the soil. Presence of a grub was not necessary for wasps to follow such trails. Frass from either host- or non-host grubs elicited trail-following, but each Tiphia species followed frass trails from its respective host when a choice was presented. Frass trails elicited stronger responses than body odor trails. The combination of host frass and body odor elicited the strongest trail-following responses. Our results suggest that once in the soil, Tiphia spp. locate their hosts using contact kairomones present in grub body odor trails and frass.

We tested the potential for the Japanese beetle, Popillia japonica Newman, to habituate to a neem-based feeding deterrent applied to foliage of linden, Tilia cordata L., a preferred host for the adults. Female beetles' consumption of control foliage versus foliage treated with either a low or high rate of neem insecticide, corresponding to 9 or 39 pm azadirachtin, respectively, was tested in a series of 4-h choice or no-choice tests over four successive days. In another experiment, females were conditioned for 22 h with either control foliage, leaves treated with the low rate, or a mixture of both treated and untreated leaves. Deterrence of either the low or high rate of neem to these beetles was then evaluated in choice tests with control foliage, as before. In choice tests, mean consumption of control foliage was always greater than for treated foliage, regardless of rate. There was, however, proportionately more feeding on foliage treated with the high rate upon successive exposures. In no-choice tests, beetles initially deterred by the low rate were not significantly deterred by that rate by the third and fourth days of the experiment. Finally, beetles conditioned by exposure to leaves treated with the low rate were not deterred by that rate in a subsequent choice test, although they were deterred by the higher rate. Despite these trends, we suggest that Japanese beetles' polyphagy and mobility probably would reduce the likelihood for habituation to neem-based feeding deterrents in the field.

Incidental transport of arthropods on plant material can be a significant mode of pest entry into greenhouses. We evaluated the use of controlled atmosphere treatments as a potential way to eliminate arthropod pests on plant propagules (i.e., cuttings or small rooted plants). Lethal exposures to CO2 or N2 were determined for common greenhouse pests including fungus gnat larvae, Bradysia sp.; green peach aphid, Myzus persicae (Sulzer); sweetpotato whitefly, Bemisia sp.; twospotted spider mite, Tetranychus urticae Koch; and western flower thrips, Frankliniella occidentalis (Pergande). We also studied the effect of pest species, life stage, and presence or absence of plants on efficacy of modified atmosphere treatments. Finally, effects of modified atmospheres on plant quality were evaluated for several bedding plant species including begonia, Begonia semperflorens-cultorum Hort. ‘Cocktail Series’, chrysanthemum, Dendranthema grandiflora Tzvelev., geranium, Pelargonium × hortorum L.H. Bailey, and impatiens, Impatiens wallerana Hook f., and among cultivars of geranium and chrysanthemum. Exposure for 12–18 h to >99% N2 or CO2 caused complete mortality of aphids, mites, thrips, and whiteflies. Fungus gnat larvae were more tolerant of hypoxic conditions. Adult mites and eggs were equally susceptible. For most pests, there was no difference in response to atmospheres modified by CO2 or N2. However, there was variation in response among plant species and cultivars, with effects ranging from delayed flowering to mortality. Despite the possibility of adverse effects on some plants, this work indicates that use of modified atmospheres has potential to eliminate arthropod pests on plant propagules before they are introduced into greenhouses.

Patterns of feeding by Japanese beetles, Popillia japonica Newman, were studied in relation to time of day or night and to ambient temperature (Ta). We also measured beetles’ thoracic temperatures (Tth) at rest, during preflight warm up, and during flight, and observed their within-plant distributions in relation to sunlight or shade to gain insight regarding whether their in-field behavior involves physiological and behavioral thermoregulation. Finally, we studied startle response as affected by Ta and time of morning. Japanese beetles fed most extensively within trees from midmorning until late afternoon, but also substantially in evening (1800–2200 hours) and sparingly throughout the night so long as Ta was >15°C. Beetles in the field were capable of endothermy, maintaining elevated Tth independent of basking. At low to moderate Ta (19–32°C), nonflying beetles in shade or direct sunlight had Tth as much as 3.75 or 5.5°C higher, respectively, than Ta. Thoracic temperature was elevated during fl...

Callirhytis cornigera (Osten Sacken) is a gall wasp that has alternating agamic and sexual generations that develop in large, woody stem galls and small, blister-like leaf galls, respectively, on pin oak, Quercus palustris Muenchhausen. We assessed the spatial distribution of the leaf galls within leaves, shoots, canopy levels, and whole trees, and examined the relationship between leaf gall density and various tree parameters. Within leaves, proportionately more galls were located on primary lateral veins (59.5%) or midveins (38.1%), as compared with the petioles (2.0%) or secondary lateral veins (0.4%). As many as 18 galls occurred on individual leaves, but most leaves contained 0–4 galls. Some current-year shoots contained as many as 132 leaf galls, but most shoots had

Published anecdotal reports suggest that Japanese beetles, Popillia japonica Newman, feed more heavily on host plants growing in full sun than on shaded plants. We studied the effects of shading on foliar characteristics of roses (Rosa variety floribunda ‘Class Act’) and determined preference and fecundity of beetles provided with sun- or shade-conditioned leaves. Defoliation by P. japonica also was compared between sun-grown and experimentally shaded roses in the field. Leaves from plants grown in full sun were smaller and thicker than ones from shaded plants, with slightly higher tannins. Leaf toughness and nitrogen levels were not affected by shading, but leaves from sun-grown plants had relatively higher sugar content. Beetles consistently consumed more foliage from sun-grown plants than from shade-grown plants in laboratory preference tests. However, beetles fed continuously for 2 wk on leaves from sun- or shade-grown plants had similar fecundity. In the field, beetles fed somewhat more heav...

Populations of Callirhytis cornigera (Osten Sacken) and its associated community of natural enemies and inquilines were monitored on pin oak, Quercus palustris Muenchhausen, in Lexington, KY, from 1997 to 1999. The gall wasp has alternating agamic and sexual generations that differ morphologically and develop in multichambered galls on branches and single-chambered galls on leaves, respectively. There was a strong association between maximum gall diameter and the number of total stem gall inhabitants, such that proportionately more C. cornigera survived and fewer were parasitized as stem gall diameter increased. The most abundant natural enemies of the agamic generation included the hymenopteran parasitoids Sycophila spp. (Eurytomidae) and Ormyrus labotus Walker (Ormyridae), and the clerid predator Phyllobaenus verticalis (Say). The most abundant inquilines in stem galls were the cynipids Synergus sp. near lignicola and Ceroptres sp., and the dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae). In leaf galls, Aprostocetus sp. was the most abundant parasitoid, and Ceroptres sp. was the only inquiline. The unique aspects of the C. cornigera gall system are discussed, including the relative abundance, emergence phenology, and host relationships of C. cornigera and its associated natural enemies and inquilines.

Pin oak, Quercus palustris Muenchhausen, is the primary host for the gall wasp Callirhytis cornigera (Osten Sacken). Woody stem galls formed by C. cornigera may be infested by the dogwood borer, Synanthedon scitula (Harris), an important pest of flowering dogwood, Cornus florida L. Previous research has shown that S. scitula has a bimodal seasonal flight pattern, with peaks in late spring and midsummer. We tested the hypothesis that moths emerging from dogwoods largely account for the first flight pulse, whereas emergence from stem galls contributes disproportionately to the second pulse. Seasonal flight activity of S. scitula was monitored with pheromone traps baited with Z,Z-3,13-octadecadien-1-ol acetate. Traps were hung near plantings of dogwoods in suburban landscapes or near heavily galled pin oaks. Borer emergence from dogwood was monitored by sampling infested trees for pupal exuviae, and from galls that were collected and held in outdoor rearing cages. The impact of S. scitula on C. cornigera larvae was assessed by weighing, measuring, and dissecting galls. Flight activity of S. scitula began on 5 May and ended on 13 October 1999, with peaks in late May and in late July to early August. The flight pattern was similar for the two types of trapping sites, and moths emerged from both hosts during both flight periods. Proportionately more moths emerged from dogwoods during the first flight pulse than during the second, but emergence from galls was nearly evenly divided between the two flight peaks. We therefore reject the hypothesis that emergence of borers from galls contributes disproportionately to the second flight period. Approximately 12-15% of stem galls (2-3 yr old) contained S. scitula larvae. Feeding and tunneling by borers contributed to gall desiccation and reduced horn development, but rarely killed C. cornigera larvae. This study has implications for management of S. scitula because borers emerging from horned oak galls may represent a threat to dogwood.

The ant Lasius neoniger Emery can be a serious pest when its nesting and mound-building activities occur on golf putting greens and tees. Controlling turf-infesting ants is difficult because conventional insecticides usually fail to eliminate the subterranean queen. We compared the attractiveness of commercial and experimental ant baits to L. neoniger workers, and we evaluated baits containing novel, delayed-action toxicants for selective control of L. neoniger on creeping bentgrass, Agrostis stolonifera L., golf tees. Efficacy of nonbait granular fipronil, a new phenyl pyrazole insecticide, also was evaluated. In choice tests, protein-based baits were more readily taken than baits containing sugar- or oil-based attractants. Abamectin-, hydramethylnon-, or spinosad-based baits significantly reduced numbers of ant mounds and nests when applied either as spot or broadcast treatments. Two commercial baits, Advance Granular Carpenter Ant Bait, containing 0.011% abamectin B 1 , and Maxforce Ant Killer Granular Bait, containing 0.9% hydramethylnon, were especially effective. Spot-treatment with either of these baits, using 1 g of bait per mound, eliminated 88 to 97% of the mounds within 3 d. Broadcast application of fipronil (0.028 kg a.i. ha -1 ) on heavily infested, sand-based creeping bentgrass putting green turf in May provided 80% reduction of ant mounds at 7 d after treatment and 86% reduction at 60 d.

It is commonly held that food-aversion learning should be more prevalent in polyphagous herbivores than in specialists. We tested the ability of Popillia japonica, a polyphagous scarab, to learn avoidance of a palatable but illness-inducing plant. Beetles that feed on flowers of geranium, Pelargonium × hortorum, became paralyzed, although most recovered within 24 h. In choice tests, naive beetles strongly preferred geranium petals over leaves of linden, Tilia cordata, a highly suitable host. Experienced beetles maintained this preference although it resulted in repeated bouts of paralysis. Fecundity was >10 times higher for beetles fed linden foliage for 2 wk than for those fed only geranium. Nevertheless, when a surplus of both foods was provided, the beetles fed mainly on geranium, resulting in greatly reduced fecundity. These results contradict the view that generalists should show propensity for food-aversion learning. Indeed, in this case, P. japonica continued to prefer the toxic plant, compromising its fitness.

The basis for resistance of Bradford callery pear, Pyrus calleryana Decaisne ‘Bradford,’ [Rosaceae] to the Japanese beetle, Popillia japonica Newman, was investigated. Chloroform-dipping rendered leaves palatable, initially suggesting that deterrent waxes had been removed. However, extracts containing surface waxes were not deterrent. Subsequent experiments showed that increased palatability of solvent-dipped leaves is associated with enzymatic tissue browning, characteristic of polyphenol oxidases, rather than simply release of phagostimulants from surface disruption of damaged leaves. Frozen and thawed leaves showed similar browning, becoming increasingly palatable for several hours after thawing. Palatability changes were temperature- and aerobic-sensitive, further evidence that oxidizing enzymes are involved. Juice from leaves that had been frozen and thawed stimulated feeding on glass fiber disks, whereas fresh leaf juice did not. Survival and fecundity were much higher for beetles fed frozen and thawed or chloroform-dipped Bradford pear leaves than for beetles fed normal leaves. We hypothesize that decompartmentalization of deterrent compounds, possibly phenolics, followed by enzymatic oxidation and altered leaf chemistry may explain the increased palatability of chloroform-dipped or frozen and thawed Bradford pear tissue to P. japonica. This approach may be helpful in identifying specific compounds responsible for resistance of woody plants to generalist insects.

Attraction of Japanese beetles, Popillia japonica Newman, to 17 compounds typical of those released by undamaged and insect-damaged angiosperm leaves was compared in replicated field trials. Eight compounds attracted significantly more beetles than did an unbaited trap; however, the 2 most attractive single compounds, phenylacetonitrile and ( Z )-jasmone, were only ≍10% as effective as geraniol, a component of commercial lures. Progressive pairwise addition of less attractive volatiles to a blend of phenylacetonitrile and ( Z )-jasmone resulted in increasing beetle capture. The relative attractiveness of blends of conifer/eucalyptus, fruit-like, and floral odors, plus a complete mixture of these, also was tested. Although the floral, fruit-like, and complete mixtures captured more beetles than did the conifer/eucalyptus blend or phenylacetonitrile alone, our results suggest that this polyphagous insect is likely to be attracted to many naturally occurring plant volatiles, and that as the number of components in a volatile blend increases, so will its attractiveness. The complete mixture of volatile compounds also attracted more green June beetles, Cotinis nitida (L)., than did the fruit-like, floral, or conifer/eucalyptus blends.

The volatile compounds liberated by Japanese beetle ( Popillia japonica Newman) feeding on grape leaves ( Vitis labrusca L.) were studied. Ten consecutive collections of 3 hr duration were performed on live vines starting at 09:00 and continuing until 15:00 the following day. Release of most compounds followed a diurnal pattern, with the period of peak emission from 12:00 to 15:00 and the period of least emission from 00:00 to 03:00. Nineteen compounds were identified from the beetle-damaged vines, most of which were aliphatic aldehydes, alcohols and esters as well as terpene hydrocarbons. During periods of peak emission, volatile production from beetle-damaged vines was about 50-times higher than that of undamaged vines. © 1997 Elsevier Science Ltd. All rights reserved

We studied the close range olfactory response of Japanese beetles, Popillia japonica Newman, to constitutive or feeding-induced volatiles from leaves of 4 maple species differing in susceptibility to defoliation. In pitfall arenas, intact leaves of susceptible species, Acer palmatum Thunberg and A. platanoides L., were not significantly more attractive than those of resistant maples, A. rubrum L. and A. saccharinum L. Consistent with these results, the compounds emitted by intact maple leaves were generally similar across resistance groupings. For each maple species, leaves that had been damaged overnight by Japanese beetles attracted significantly more beetles than did undamaged leaves. Beetles did not discriminate between damaged leaves of susceptible and resistant maple species. Significant differences were noted, however, in the types of feeding-induced compounds emitted by susceptible and resistant maple leaves. Specifically, leaves of susceptible species emitted relatively higher amounts of esters with fruit-like odors and the floral fragrance compound linalool, whereas leaves of resistant maples emitted more terpene hydrocarbons. Possible roles of volatile compounds as attractants and feeding stimulants, or as feeding deterrents, for the Japanese beetle are discussed.

The hypothesis that feeding-induced plant volatiles are responsible for aggregation of Japanese beetles, Popillia japonica Newman, on leaves was tested using clonal grape plants, Vitis Labrusca L. The attractiveness of undamaged vines, undamaged vines with nonfeeding beetles, vines with fresh feeding damage, and vines with overnight feeding damage was compared in replicated field trials by placing the treatments in the field in the morning and counting the number of beetles that landed on the plants throughout the day. Many more beetles were recruited to vines with overnight feeding damage than to any of the other treatments, indicating attraction to feeding-induced volatiles. Furthermore, the low number of beetles attracted to vines with nonfeeding beetles or freshly damaged vines provided evidence against the existence of a putative aggregation pheromone. Subsequently, we examined the emission of volatiles from grape vines in situ. During the period of peak emission (1200–1500 hours), emission from vines with overnight feeding damage was almost 65 times higher than from undamaged vines. Aliphatic compounds and terpenoids were the major classes of compounds emitted by the beetle-damaged vines. The implications of feeding-induced volatiles in host-finding and mate location by this polyphagous insect are discussed.

The volatile compounds emitted by leaves of four crabapple cultivars susceptible to damage by Japanese beetles and four relatively resistant cultivars were examined. Twelve compounds, mostly terpene hydrocarbons, were identified from intact leaves. The terpenes (E)-β-ocimene, caryophylene, germacrene D and (E,E)-α-farnesene occurred in significantly higher levels in susceptible cultivars, whereas resistant cultivars produced greater amounts of (E)-4,8-dimethyl 1,3,7-nonatriene and linalool. The relative attractiveness of the cultivars as determined in a pitfall bioassay, however, was not related to their susceptibility to the Japanese beetle as previously determined by defoliation sustained in the field. The attractiveness of individual cultivars was found to be positiviely correlated with linalool as a percent of the total volatile blend emitted by leaves. This study and previous work suggest that variation in susceptibility of crabapple cultivars to defoliation by Japanese beetles is not due to the attractiveness of the individual cultivars but rather to nonvolatile components of susceptibility and/or resistance. A scenario for host location by the Japanese beetle is presented.

Cultural practices were manipulated before or during seasonal flights of Japanese beetle, Popillia japonica Newman, and masked chafers, Cyclocephala spp., to study effects on grub densities in tall fescue or Kentucky bluegrass turf. Masked chafer grubs were consistently smaller and less abundant in turf that had been treated with aluminum sulfate to reduce soil pH and in high-mown turf. High mowing or application of aluminum sulfate before beetle flights reduced total biomass of white grubs in tall fescue by as much as 55 and 77%, respectively. However, where spatial gradients in soil moisture occur, the positive response of grub populations to moisture may override effects of those treatments. Grub densities were not affected by spring applications of lime or urea or by aerification of plots before beetle flights. Plots that were irrigated during beetle flights incurred significantly higher densities of both P. japonica and Cyclocephala spp. grubs than did nonirrigated turf. The use of a 2,247- kg roller to compact the soil before beetle flights did not affect subsequent grub populations, and the roller was not effective for remedial control of 3rd instars in the fall. Application of organic fertilizers (composted cow manure or activated sewage sludge) resulted in significant increases in grubs of green June beetle, Cotinis nitida L., in 1 of 2 yr. Cultural practices may have general or species-specific effects on densities of white grubs. This study suggests that witllolding irrigation during peak flight of beetles, raising cutting height, and light application of aluminum sulfate in spring may help to reduce the severity of subsequent grub infestations.

Root-feeding white grubs (Coleoptera : Scarabaeidae) are among the most injurious insect pests of cool-season turfgrasses ; however, little is known about the influence of common lawn weeds on white grub populations. Greenhouse studies were conducted to evaluate the suitability of six weed species and one turfgrass including white clover (Trifolium repens L.), red clover (T. pratense L.), large crabgrass [Digitaria sanguinalis (L.) Scop.], annual bluegrass (Poa annua L.), buckhorn plantain (Plantago lanceolata L.), dandelion (Taraxacum officinale Weber), and Kentucky bluegrass (Poa pratensis L.) as food for grubs of the Japanese beetle (Popillia japonica Newman) and southern masked chafer (Cyclocephala lurida Bland). Third instars of both species fed upon and reduced root biomass of all weeds tested, and in some cases, reduced foliage yields as well. Survival of both grub species was as high, or higher, on most weeds as on Kentucky bluegrass. Dandelion and white clover appear to be particularly poor hosts for P. japonica and C. lurida, respectively.

Adult females of the southern masked chafer, Cyclocephala lurida Bland, produce a volatile sex pheromone that attracts conspecific males. Previously we documented that extracts of 3rd-instar Cyclocephala spp. grubs contain one or more compounds that attract males and stimulate copulatory attempts when these males arrive at the source of the odor. Attraction of males to larvae appears to be undocumented for any other insect species. We examined developmental expression of the production of this attractant within Cyclocephala spp., and evaluated hexane extracts of other species of scarabaeid grubs for attractiveness to C. lurida or conspecifics. We found that the attractant is not limited to the postoverwintering last instar, but rather is present in all larval stages and in male and female pupae. Extracts of Cyclocephala spp. grubs also attracted males of the northern masked chafer, Cyclocephala borealis Arrow. Hexane extracts of 3rd instars of Japanese beetles, Popillia japonica Newman, and green June beetles, Cotinis nitida L., were not attractive to male C. lurida , indicating that there is some phylogenetic specificity to this unusual production of a sex-specific attractant. Third instars of C. nitida do not attract conspecific males. Studies of male attraction to conspecific immature stages in Cyclocephala spp. and other Scarabaeidae may provide insights into the evolutionary origins of chemical communication systems.

Flowering crabapples, Malus spp., are important small landscape trees in much of the United States and southern Canada. We evaluated 42 cultivars of Malus spp. for resistance to defoliation by Japanese beetles, Popillia japonica Newman, for 2 growing seasons and found marked and consistent variation in resistance. Defoliation caused by beetles ranged from 100 to

Use of Bacillus popilliae Dutky, causal agent of milky disease in Japanese beetle grubs, has been limited because of its inability to produce infective spores in vitro. Recently, putative milky disease products produced by a patented in vitro process were marketed. We evaluated in vivo- and putatively in vitro-produced commercial spore formulations for efficacy against Japanese beetle grubs in laboratory and field trials. In soil confinement assays, infectivity by feeding (per os) was greater for the traditional spore powder made by maceration of diseased grubs than for the putative in vitro formulation. However, in multi-year field trials on 2 golf courses, neither product was effective in inducing higher levels of milky disease or in reducing grub populations. Application of a full dose (2 g) of spore powder, the amount normally applied every 1.2 m in a grid pattern, within 0.1-m 2 field enclosures failed to induce milky disease in grub populations in soil directly beneath the treated turf. Laboratory-infected 3rd instars in late phases of milky disease continued to feed on grass roots. Putatively in vitro-produced formulations were recalled from the market in 1991 because of questions about the identity of the bacterial spores they contained. We challenge the evidence that commercially available spore powder, applied according to conventional methods, is effective for suppressing localized grub populations in turfgrass, and suggest that standard recommended practices for use of milky disease bacteria should be reevaluated.

The endophytic fungus Acremonium coenophialum Morgan-Jones & Gams conveys resistance to herbivory in tall fescue, Festuca arundinacea Schreber. In contrast, nitrogen fertilization generally enhances plant quality for herbivores. We studied the main effects and interaction of A. coenophialum and fertilization on plant-feeding, predatory, and soil-dwelling invertebrates in tall fescue turf. Fall armyworms, Spodoptera frugiperda (J. E. Smith), developed faster when reared on foliage from plots treated with medium or high rates of urea than on unfertilized tall fescue, but development rates were not affected by A. coenophialum. Greenbugs, Schizaphis graminum Rondani, preferred fertilized, endophyte-free fescue over nonfertilized, endophyte-free grass. Similarly, bird cherry-oat aphids, Rhopalosiphum padi (L.), developed fastest on fertilized, endophyte-free tall fescue. Fertilization, however, did not override the strong, adverse effects of A. coenophialum on both aphid species. In field plots, densities of leafhoppers, flea beetles, and Staphylinidae were generally higher in fertilized than in nonfertilized turf. Flea beetles and two of the five most abundant species of leafhoppers were less numerous in endophyte-infected plots. Predatory arthropods, earthworms, oribatid mites, and Japanese beetle grubs were equally abundant in endophyte-infected and endophyte-free plots. Fertilization did not affect the densities of oribatids or P. japonica, but earthworms were more abundant in fertilized plots on some dates. Results showed variable main effects, and an absence of interactive effects of A. coenophialum and fertilization on invertebrates in tall fescue. Fertilization of tall fescue probably will not nullify the benefits of endophyte-enhanced resistance

Maintaining bee-friendly habitats in cities and suburbs can help conserve the vital pollination services of declining bee populations. Despite label precautions not to apply them to blooming plants, neonicotinoids and other residual systemic insecticides may be applied for preventive control of lawn insect pests when spring-flowering weeds are present. Dietary exposure to neonicotinoids adversely affects bees, but the extent of hazard from field usage is controversial. We exposed colonies of the bumble bee Bombus impatiens to turf with blooming white clover that had been treated with clothianidin, a neonicotinoid, or with chlorantraniliprole, the first anthranilic diamide labeled for use on lawns. The sprays were applied at label rate and lightly irrigated. After residues had dried, colonies were confined to forage for six days, and then moved to a non-treated rural site to openly forage and develop. Colonies exposed to clothianidin-treated weedy turf had delayed weight gain and produced no new queens whereas those exposed to chlorantraniliprole-treated plots developed normally compared with controls. Neither bumble bees nor honey bees avoided foraging on treated white clover in open plots. Nectar from clover blooms directly contaminated by spray residues contained 171±44 ppb clothianidin. Notably, neither insecticide adversely impacted bee colonies confined on the treated turf after it had been mown to remove clover blooms present at the time of treatment, and new blooms had formed. Our results validate EPA label precautionary statements not to apply neonicotinoids to blooming nectar-producing plants if bees may visit the treatment area. Whatever systemic hazard through lawn weeds they may pose appears transitory, however, and direct hazard can be mitigated by adhering to label precautions, or if blooms inadvertently are contaminated, by mowing to remove them. Chlorantraniliprole usage on lawns appears non-hazardous to bumble bees.

Ant-exclusion to facilitate biocontrol by endemic natural enemies was investigated for suppressing infestations of two coccids, calico scale, Eulecanium cerasorum (Cockerell), and magnolia scale, Neolecanium cornuparvum (Thro), in landscape settings. Application of sticky bands combined with basal trunk sprays resulted in 92-100% reduction in counts of honeydew-seeking ants, mainly Formica subsericea Say, ascending large, scale-infested sugar maple (Acer saccharum Marshall) trees. Ant-exclusion was associated with increased numbers of green lacewing, mainly Chrysoperla rufilabris (Burmeister), larvae and spiders on multiple sample dates, and 54 and 69% fewer surviving scale nymphs after the first and second growing seasons. Foliar sooty mold accumulation was also significantly reduced where ants were excluded. In feeding trials, C. rufilabris larvae collected from the tree canopies consumed large numbers of settled scale nymphs. On another site, ant-exclusion led to 82% reduction in magnolia scale densities on Magnolia stellata (Siebold & Zuccarini) Maximowicz, compared with controls, after 1 yr. Nine and 10 ant species were found tending calico and magnolia scales, respectively, at landscape sites in central Kentucky, and in situ observation trials showed that many of them aggressively attack approaching lacewing larvae. Our results suggest that where ants are closely associated with soft scales on woody landscape plants, ant-exclusion has potential as a sustainable pest management strategy.

Relative suitability of 23 cultivars of juniper (Juniperus spp.) for growth and survival of the bagworm, Thyridopteryx ephemeraeformis (Haworth) was evaluated in laboratory and field experiments. Weight gain, developmental rate, and survival of bagworms differed significantly among groups of larvae fed foliage from different cultivars. By these criteria, cultivars ‘Expansa’ and ‘Hibemica’ were most unsuitable for survival and development of bagworms, whereas ‘Broadmoor’ and ‘Emerald Isle’ were consistently among the most suitable cultivars. This study suggests that use of certain juniper cultivars may be useful in managing this perennial insect pest in urban landscapes.

Seasonal phenology and control of the potato leafhopper (Empoasca fabae (Harris)) on red maples (Acer rubrum L.) were studied for three years in nurseries in central Kentucky. Migratory adult leafhoppers were first captured on yellow sticky traps in early May. Peak population density ranged from late May to late June. The second flush of leaves was most heavily damaged in each year. Foliar sprays of cyfluthrin (Tempo 2), a synthetic pyrethroid, beginning 1 to 2 weeks after first capture of leathoppers and repeated at biweekly intervals during May and June, greatly reduced symptoms of injury. Acephate (Orthene) was less effective than cyfluthrin, whereas treatment of the soil with disulfoton (Di-syston) was ineffective. Oviposition and development of the leafhopper on red maple were confirmed. Field evaluations of selected cultivars showed that red maples were more severely damaged than sugar (A. saccharum L.) or Norway (A. platanoides L.) maples. ‘Autumn Blaze’, an A. rubrum × saccharinum hybrid, was relatively resistant.

BACKGROUND: Earthworm casts are a worldwide problem on golf courses and sports fields when they disrupt the playability, aesthetics and maintenance of closely mowed playing surfaces. Currently, no pesticides are labeled for earthworms in the United States. Tea seed pellets (TSPs), a saponin-rich byproduct of Camellia oleifera Abel oil manufacture, were tested for expelling earthworms and reducing casts on creeping bentgrass turf. The fate of expelled worms, methods for removing them and impacts on pest and beneficial arthropods were also evaluated. RESULTS: Application of TSPs at 2.93 kg 100 m−2, followed by irrigation, quickly expelled earthworms from the soil. A single application reduced casts by 80–95% for at least 5 weeks. Mowing or sweeping removed expelled earthworms from putting green surfaces. Most expelled earthworms burrowed down when transferred to untreated turf, but few survived. Bioassay-guided fractionation confirmed the vermicidal activity results from a mix of saponins. TSPs did not reduce the abundance of beneficial soil arthropods, nor did they control black cutworms or white grubs in treated turf. CONCLUSION: TSPs are an effective botanical vermicide that could be useful for selectively managing earthworm casts on closely mowed turfgrass. They might also be used to suppress earthworms in grassy strips alongside runways to reduce bird strike hazard at airports. Copyright © 2009 Society of Chemical Industry

We tested the response of wood and phloem boring Coleoptera to traps baited with ethanol alone, and to ethanol baits augmented with oak logs. The logs provided a source of natural oak volatiles, and we hypothesized that these volatiles would increase attraction of borers to ethanol. Ethanol baited traps augmented with oak logs attracted 2.3 times more cerambycid adults than ethanol alone, and 4.9 times more cerambycids than logs alone. Logs alone were not attractive to Scolytidae, nor did they enhance attractiveness of ethanol alone to scolytids. Although many saprophagous wood and phloem feeding Coleoptera are attracted to ethanol, these results suggest that for some groups of borers, other tree emitted volatiles may also aid host location.