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The native lace bug, Leptoypha mutica Say (Hemiptera: Tingidae), has demonstrated potential as an insect biological control agent of invasive Chinese privet (Ligustrum sinense Lour). To better evaluate its potential to establish on a new host, developmental biology on Chinese privet was studied at temperatures of 20°C, 24°C, 28°C, and 32°C. The complete duration of development of L. mutica from egg deposition through five instars on this previously unreported host ranged from 24.4 to 57.1 d. Estimated threshold temperatures and calculated thermal unit requirements for egg development were 11.0°C and 211.9 degree-days (DD); for nymphal development, 9.9°C and 326.8 DD; and for complete development, 10.5°C and 527.4 DD. Results of this study indicate that L. mutica will oviposit and can develop successfully on Chinese privet over a range of temperatures suggesting the potential for multiple generations to occur in a single season.

Exotic lace bugs (Hemiptera: Tingidae) have previously been evaluated for potential biocontrol of pervasive, exotic Chinese privet, Ligustrum sinense Lour. This study was conducted to determine if a native lace bug, Leptoypha mutica Say, could utilize Chinese privet and to determine the lace bug's preferred host plant. A no-choice test determined the lace bug's acceptance and utilization of three plant hosts: fringe tree (Chionanthus virginicus L.), swamp privet (Foresteria acuminata Michx), and Chinese privet, based on frass production, oviposition, and survival of lace bugs. Choice tests in the laboratory and the field evaluated lace bug preference among swamp privet, Chinese privet, and green ash (Fraxinus pennsylvanica Marsh). All plant hosts supported the lace bugs in laboratory assays, but fewer eggs were produced on Chinese privet. Green ash was the most preferred while Chinese and swamp privet were equally preferred. These laboratory results were consistent with a field choice test and f...

Twenty-one taxa of the warm-season perennial grass, Paspalum spp., were evaluated for response to the fall armyworm, Spodoptera frugiperda (J. E. Smith), an important pest of turfgrass. In studies using excised grass clippings conducted in a growth chamber and on whole plants in a greenhouse, the most resistant taxon was P. ionanthum Chase (PI 404,449) as measured by larval and pupal weights, days to develop to pupal stage, and survival. Paspalum notatum Fluegge var. saurae Parodi (PI 422,024), P. notatum Fluegge (PI 310,146), P. thunbergii Kunth ex Steud. (PI 286,486) and P. macrophyllum Kunth. (PI 282,807) showed moderate resistance, whereas the turf-type P. vaginatum Swartz taxa were highly susceptible. Identifying resistant Paspalum taxa can inform plant breeding programs in development of pest-resistant grasses, a foundational integrated pest management strategy.

Pesticides commonly used in commercial greenhouse management were evaluated for compatibility with two biological control agents: a leafminer parasitoid (Diglyphus isaea [Walker]), and a predatory mite (Neoseiulus californicus [McGregor]). These natural enemies were exposed to miticides, fungicides, and insecticides targeting leafminers, thrips, and whiteflies, according to label directions in laboratory vial assays, after which mortality at 12, 24, and 48 h was recorded. Greater mortality of predatory mites than leafminer parasitoids was observed overall, illustrating that fewer pesticides were compatible with predatory mites compared with the parasitoid. However, some commonly used pesticides were found to cause high mortality to both the leafminer parasitoid and predatory mites. Twospotted spider mite (Tetranychus urticae Koch) infestations often disrupt leafminer (Liriomyza trifolii [Burgess]) biocontrol programs. Therefore, potentially compatible miticides (bifenazate, hexythiazox, spiromesifen, acequinocyl, etoxazole, and clofentezine) identified in laboratory trials were also evaluated in a greenhouse study and found to be compatible with leafminer biocontrol.

The squash bug, Anasa tristis (DeGeer) (Hemiptera: Coreidae), is an indigenous pest of squash and other cucurbits. Pesticides can control squash bug populations although many small-scale growers in the Southeast seek alternative methods of management. Cultural control methods, including varying the planting date and farmscaping, are not well understood under southeastern conditions. The goal of farmscaping is to increase natural ecosystem functions to aid in the control of pest populations. In the summers of 2014 and 2015, field plots of squash, separated by a minimum of 150 m were organized in a split-split plot design, with floral resources at the whole-plot level and varied planting date at the subplot level. Data were collected on squash bug abundance and fruit yield (kg), and abundance of potential natural enemies of A. tristis. Plots with added floral resources had fewer squash bug adults than plots without added floral resources in four of eight possible year × site × planting date combinations. Furthermore, the site in 2014 which had a reduction in squash bug adult abundance also had an increase in the abundance of potential enemies, including spiders, ground beetles, and predaceous Hemiptera. There were additional instances when potential natural enemy abundance was greater in resource-enhanced plots, but they were not associated with sites that had a reduction in yield loss or squash bug abundance. The use of floral resources to attract natural enemies and beneficial insects merits further investigation.

The lace bug, Leptodictya plana Heidemann, was sampled in the field on Pennisetum purpureum Schumach. from May through late October during 2008 and 2009. Highest population levels occurred in late August, which corresponded to the warmest temperatures of the season. Adults overwintered in ground litter/mulch and contributed eggs to as many as 4 overlapping generations in central Georgia, USA. Damage ratings on P. purpureum ornamental grasses averaged 20% for the entire 2008 and 2009 summer seasons, although individual plants expressed injury as high as 90% during midseason. When 2 ornamental grass standards were compared with each other, ‘Princess’ was more heavily damaged than ‘Prince’ during both sampling years. Decreased abundance observed in 2009 may have resulted from an increase in the amount of precipitation at the site. Mean duration of development ranged from 23.3 days at 30°C to 40.5 days at 25°C. Eggs hatched at 20, 25, 30 and 35°C, but not at 10 or 15°C. Complete development (egg to a...

We studied the distribution of hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), within hemlock trees for three summer (progrediens) and two winter (sistens) generations in northern Georgia. Eastern hemlock, Tsuga canadensis (L.) Carrière, trees were treated with 0, 10, or 25% of 1.5 g of imidacloprid per 2.5 cm of tree diameter at breast height and fertilized or not in a factorial design. Adelgid ovisacs per centimeter of branch were more abundant from June 2007 to June 2008 in the upper tree crown of insecticide untreated trees and when all trees were combined and that was the general trend for most comparisons. However, ovisacs were more abundant in the lower crown of insecticide treated trees in June 2008. More sistens nymphs settled on the upper crown branches than on the lower branches in summers 2007 and 2008. Higher eggs per ovisac were observed in the upper crown in February 2008 and in both the winter and summer 2009. In contrast, adelgids were more fecund in the lower crown in June 2008. On fertilized trees, eggs laid per adult were higher in the upper crown in February 2008. In summer 2008, eggs per ovisac were higher in the lower crown, but this reversed again to the upper crown by summer 2009. New growth of branches also varied among sample dates. These data demonstrate the variable distribution of adelgid and hemlock growth within trees over time and suggest that sampling only one crown area will not provide accurate estimates of adelgid densities.

Leptodictya plana Heidemann is an emerging pest on ornamental grasses in the southern United States. Thirty-two selections of commercially available ornamental grasses and sedges and five trial accessions of Pennisetum purpureum were evaluated for susceptibility to L. plana feeding and oviposition. No-choice studies were conducted in a greenhouse by securing four lace bugs to leaf blades of each plant using clip cages. Lace bugs stayed attached for five days. Damage and number eggs were recorded. Choice studies were conducted in the laboratory by placing leaf blades from each genus of plant species into a large petri dish in a spoke pattern. There were no plants tested that consistently received zero percent damage in either trial. Plants that sustained the least damage included Acorus spp., Cordyline spp., and Panicum spp. Pennisetum spp. entries exhibited the highest overall percent damage and were the only genera of plants that supported oviposition.

Predatory potential and performance of the predaceous heteropterans, Geocoris punctipes (Say), G. uliginosus (Say) (Geocoridae), and Onus insidiosus (Say) (Anthocoridae), were evaluated using fall army worm, Spodoptera frugiperda (J. E. Smith), as prey on different turfgrass taxa (resistant zoysiagrasses, ‘Cavalier’ and ‘Palisades’; moderately resistant Bermuda grass, ‘TifSport’; and susceptible seashore paspalum, ‘Sea Isle 1’) through laboratory and field studies. When background mortality was taken into account, in small arena trials in the laboratory, the greatest mortality by predators occurred on TifSport. The predator impact on TifSport by O. insidiosus was 92.6% above the mortality in the no-predator treatment on that grass. Predator induced mortality was rarely significant on the highly resistant zoysiagrass cultivar Cavalier because mortality, even in the absence of predators, was so high. Survival of larvae on TifSport Bermuda grass was significantly reduced by the addition of just two ...

The effect of taxa [common Bermuda grass, Cynodon dactylon (L.); centipedegrass, Eremochloa ophiuroides Munro Hack; St. Augustinegrass, Stenotaphrum secundatum [Walt.] Kuntze; and zoysiagrass, Zoysia spp.], density, height, and weed density on abundance of natural enemies, and their potential prey were evaluated in residential turf. Total predatory Heteroptera were most abundant in St. Augustinegrass and zoysiagrass and included Anthocoridae, Lasiochilidae, Geocoridae, and Miridae. Anthocoridae and Lasiochilidae were most common in St. Augustinegrass, and their abundance correlated positively with species of Blissidae and Delphacidae. Chinch bugs were present in all turf taxa, but were 23-47 times more abundant in St. Augustinegrass. Anthocorids/lasiochilids were more numerous on taller grasses, as were Blissidae, Delphacidae, Cicadellidae, and Cercopidae. Geocoridae and Miridae were most common in zoysiagrass and were collected in higher numbers with increasing weed density. However, no predatory Heteroptera were affected by grass density. Other beneficial insects such as staphylinids and parasitic Hymenoptera were captured most often in St. Augustinegrass and zoysiagrass. These differences in abundance could be in response to primary or alternate prey, or reflect the influence of turf microenvironmental characteristics. In this study, Simpson's diversity index for predatory Heteroptera showed the greatest diversity and evenness in centipedegrass, whereas the herbivores and detritivores were most diverse in St. Augustinegrass lawns. These results demonstrate the complex role of plant taxa in structuring arthropod communities in turf. An increased understanding of how turf species and cultivars help shape pest and beneficial arthropod communities will enhance predictive abilities and further pest management objectives.

Columbine, Aquilegia spp., are regularly attacked by agromyzid leafminers, Phytomyza spp. Effects of columbine species and cultivars on infestation by the leafminer Phytomyza aquilegivora Spencer, and subsequent parasitism by hymenopterous parasitoids was evaluated in two-year field trials at four locations in central and north Georgia. Among 20 columbine taxa planted in non-irrigated, wooded sites in central and north Georgia, two selections (A. flabellata and A. caerulea ‘Dwarf Fantasy Mix’) were comparable to the moderately resistant native species A. canadensis. In irrigated sites in central and north Georgia, all cultivars were equally infested by the leaf miner. The most heavily attacked selections among all sites were A. alpina, A. chrysantha ‘Yellow Star’, A. caerulea, A. caerulea ‘McKana mix’, A. caerulea ‘Music hybrid’, A. skinneri, and A. x hybrida ‘Ruby Port’. The variegated selection, A. vervaeneana ‘Woodside’, sustained intermediate infestation levels as did A. vulgaris ‘Winkie Blue & White’. Cultivar influences on parasitism of leafminers was quantified at two sites. Eleven species of hymenopteran parasitoids representing three families were recovered. Leafminers infesting A. chrysantha ‘Yellow Star’ were most heavily parasitized at both locations. Chrysocharis pentheus Walker was the most abundant parasitoid, representing 41% of all parasitoids collected and 48.4% of the species reared from leafminers in central Georgia. Seladerma sp. was the only parasitoid reared from leafminers collected in north Georgia and represented 22.1% of all parasitoids obtained.

Interactions between host plant resistance and biological control may beneÞt or hinder pest management efforts. Turfgrass cultivars have rarely been tested for extrinsic resistance charac- teristics such as occurrence and performance of beneÞcial arthropods on plant genotypes with resistance to known turf pests. Parasitism of fall armyworm,Spodopterafrugiperda (J.E. Smith), among six turfgrass genotypes was evaluated. The six grasses tested (Sea Isle-1 and 561-79 seashore paspalum, Paspalum vaginatum Swartz; TifSport and TifEagle hybrid Bermuda grass, Cynodon dactylon (L.) C.transvaalensis (Burtt-Davy); and Cavalier and Palisades zoysiagrass,Zoysiajaponica von Steudel and Z. matrella (L.) Merrill, respectively) represented a range in resistance to S. frugiperda. Differential recovery of larvae released as Þrst instars resected this gradient in resistance of Cavalier Palisades TifSport TifEagle 561- Sea Isle-1 Larval recovery (percentage of initial number released) was greatest in May, less in July and August, and least in October, probably resecting the increase in activity of on-site predators and disease pressure. Parasitism of the fall armyworm by the braconid Aleiodes laphygmae Viereck varied among turfgrass genotypes. Parasitism was greatest during July. In total, 20,400 Þrst instars were placed in the Þeld; 2,368 were recovered; 468 parasitoids were subsequently reared; 92.2% were A. laphygmae. In the Þeld, the greatest percentage of reduction in S. frugiperda larvae by A. laphygmae occurred on the armyworm-susceptible seashore paspalums (51.9% on Sea Isle-1 in July). Cotesia marginiventris Cresson and Meteorus sp. also were reared from collected larvae. No parasitoids were reared from larvae collected from resistant Cavalier zoysiagrass.A.laphygmae and C. marginiventris were reared from larvae collected from the other Þve grass cultivars. No parasitoids of older larvae or pupae were observed.

Interactions between host plant resistance and biological control may be advantageous or disadvantageous for pest management. Turfgrass cultivars have rarely been tested for extrinsic resistance characteristics such as occurrence and performance of beneÞcial arthropods on plants with resistance to known turf pests. Among six turfgrass cultivars tested, the bigeyed bug, Geocorisuliginosus (Say) nymphs varied in ability to reduce numbers of fall armyworm, Spodoptera frugiperda (J. E. Smith), larvae. The six grasses tested (Sea Isle 1 and 561-79 seashore paspalum, Paspalum vaginatum Swartz; TifSport and TifEagle bermudagrass, Cynodon dactylon (L.) x C. transvaalensis (Burtt-Davy); and Cavalier and Palisades zoysiagrass Zoysia japonica von Steudel and Z. matrella (L.) Merrill) represented a range in resistance to S. frugiperda. In the laboratory, the greatest reduction in S. frugiperda larvae by a low density of G. uliginosus occurred on the resistant Cavalier zoysiagrass. A 7-fold difference in weight of 10-d-old larvae between those feeding on susceptible versus resistant grasses suggested that on the resistant grass larvae remained for a longer period in a size range susceptible to predation. Results of laboratory studies were not directly translated to the Þeld, in which a diverse predatory arthropod community varied in composition depending on turfgras cultivar. In the Þeld, the greatest reduction in S. frugiperda larvae by a low density of G. uliginosus occurred on Sea Isle 1 and 561-79 seashore paspalum grass. In the Þeld, vacuum samples indicated that predaceous Heteroptera were most abundant in paspalum grasses and bermudagrasses, while Carabidae, Staphylinidae, and Araneae were more common in zoysiagrasses. In contrast, pitfall traps indicated that carabids were more common in bermudagrasses, Araneae and Staphylinids were similar among grass taxa, and Cicindellidae were most common in paspalum grasses and bermudagrasses. Predation was never signiÞcantly decreased on resistant turfgrass cultivars in any of the experiments described in this work, indicating no negative tritrophic interactions.

The effects of azalea lace bug, Stephanitis pyrioides (Scott), feeding injury on azalea growth and development were investigated using 'Girard's Rose' azaleas during a 2-yr field study in Georgia Low, medium, and high injury treatments, which corresponded to 6, 8, and 14% maximum canopy area injury, were compared with control azaleas that received no lace bug infestation. Flower number, whole-shrub leaf and stem dry mass, and dry mass and size of new growth tissues were unaffected by treatments. In contrast, growth index measurements, a general measure of variability frequently used for horticultural differentiation, showed significant reductions for all treatments in comparison to control azaleas after 20 wk. Though not directly quantified, this apparent discrepancy may be explained as an artifact of lace bug feeding-induced leaf abscission. Growth index measurements had considerable variability and may not be the most reliable measurement of size. In July 1998, plant canopy densities among azaleas maintained in the high injury treatments were approximately 15% less full than the canopies of control shrubs. Predaceous insects had a significant negative association with azalea lace bug number during the 2-yr study. Flower and new tissue production, measured destructively during two growing seasons, revealed azalea tolerance to 14% of maximum canopy area lace bug feeding-injury levels.

Bermudagrass (Cynodon sp.) and paspalum (Paspalum vaginatum) genotypes were evaluated in laboratory, greenhouse, and field experiments for potential resistance to the common turfgrass pests, tawny mole cricket (Scapteriscus vicinus Scudder) and southern mole cricket (Scapteriscus borellii Giglio-tos). Potential resistance among 21 seashore paspalums to both insects in an environmental chamber at 27 °C, 85% relative humidity, and 15 hours light/9 hours dark) revealed that Glenn Oaks `Adalayd' was least tolerant of cricket injury, while 561-79, HI-1, and `Excalibur' were most tolerant. Nymphal survival was not influenced by turfgrass type. Plant selections that maintained the highest percentage of their normal growth after 4 weeks of feeding by tawny mole crickets over three separate greenhouse trials were 561-79, HI-1, HI-2, PI-509018, `Excalibur', SIPV-1 paspalums, and `Tifeagle' and `Tifsport' bermudagrasses. Although none of the tested genotypes was highly resistant to tawny mole cricket injury, `TifSport' bermudagrass and 561-79 (Argentine) seashore paspalum were most tolerant.

Feeding injury caused by nymphs, males and females of the azalea lace bug, Stephanitis pyrioides (Scott), reduced rates of photosynthesis and transpiration in ‘Delaware Valley White’ azalea, Rhododendron mucronatum leaves. Females caused substantially more leaf feeding injury than males or nymphs. S. pyrioides was observed to insert stylets through stomata on the lower leaf surface and to feed almost entirely on upper palisade parenchyma tissue by piercing and removing cell contents. Lace bug feeding increased leaf stomatal resistance which indicated that gas exchange was restricted by stomatal closure. Feeding injury also reduced leaf chlorophyll content and photosynthetic capacity of remaining chlorophyll, but did not consistently affect chlorophyll a:b or specific leaf weight. Net leaf photosynthesis was negatively correlated with stomatal resistance and positively correlated with both chlorophyll content per unit leaf area and photosynthetic rate of remaining chlorophyll. These results indicated that S. pyrioides reduced leaf photosynthesis in azalea by damaging palisade parenchyma which restricted gas exchange through stomata and reduced leaf chlorophyll content and photosynthetic capacity of remaining chlorophyll.

Thrips inhabiting leaf galls on noncultivated Vaccinium species were surveyed throughout Georgia. Frankliniella caudiseta Sakimura & O'Neill was present on V. tenellum Aiton, and V. myrsinites Lam. Blueberry thrips, Frankliniella vaccinii Morgan, was only collected from V. arboreum Marsh. Catinathrips similis Nakahara occurred on V. tenellum and V. myrsinites . However, C. vaccinicola Nakahara was collected only on V. arboreum. Haplothrips rectipennis Hood, a predaceous species, was found on all Vacciniurn species. F. vaccinii and C. vaccinicola were both capable of initiating gall formation on plants in the spring. Both species may coexist in the same gall and are univoltine on mature growth during a season. However, in cutover areas where new plant growth was generated during the summer, 1 additional generation was produced. Adult terebrantians became active during April. Larvae were abundant during May and June. On 2nd-growth plants, larvae were abundant during July and August and adults were collected in October. The predator H. rectipennis colonized galls during May. Larvae of this species became abundant during May and June. One generation was produced. Adults remained in the galls until leaves dropped from the plants, usually in October. Thrips significantly reduced shootlength, bud formation, and fruit production of both V. arboreurn and V. myrsinites . These observations have implications for blueberry plant improvement efforts.

Healthy hemlock trees, Tsuga canadensis (L.) Carriere, and hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), populations should favor retention and population growth of adelgid predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and Sasajiscymnus tsugae (Sasaji & McClure) (Coleoptera: Coccinellidae). Eastern hemlock trees between 15 and 38 cm diameter at breast height (dbh) were treated with 0, 10, or 25% of 1.5 g imidacloprid (Merit 75 WP) per 2.5 cm dbh and were either fertilized or not, in a 3 by 2 factorial design. After 2 yr, imidacloprid reduced the numbers of ovisacs and eggs found on trees in a dosage-dependent manner, while enhancing tree growth parameters such as new shoots or needles and the length of new shoots. Fertilized trees had greater adelgid fecundity, which was positively correlated with total foliar N in both winter generations. In February 2009 (27 mo after imidacloprid treatment), higher imidacloprid dosages to unfertilized trees resulted in reduced adelgid fecundity. Concentrations of N, P, and K were higher in the foliage of trees treated with insecticide, whereas foliar aluminum concentrations were consistently lower in trees with higher insecticide dosages. Trees treated with low rates of imidacloprid were healthier than untreated trees, but only trees treated with the 0.1× dosage had sufficient adelgids to possibly sustain predators over extended periods.

Understanding how fertilization affects host resistance to hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is important because fertilizers are often used to grow resistant selections to a suitable size for testing. We evaluated four hemlock species (Tsuga) under three different fertilizer regimes to assess whether fertility affected resistance to the adelgid and to determine whether it affected feeding preferences of the adelgid predators Laricobius nigrinus Fender and Sasajiscymnus tsugae (Sasaji & McClure). Treatments were long-term fertilization (from June 2008 to June 2009), short-term fertilization (from March to June 2009), and no fertilizer. Fertilizer was applied biweekly with 240 ppm N by using water-soluble fertilizer (N-P-K, 20:20:20). Plants (>1 yr old) were artificially infested with adelgids on 31 March 2009. Among unfertilized hemlocks (n=10 per species), foliar N was highest in Tsuga mertensiana (Bong.) CarriBre and lowest in T. chinensis (Franch.) E. Pritz. Significantly more progredien ovisacs or sisten eggs were present on T. mertensiana than on the other hemlock species with none on unfertilized T. chinensis. A. tsugae adults on T. heterophylla (Raf.) Sarg. were unaffected by fertility, but densities of developing A. tsugae nymphs were higher on unfertilized T. heterophylla plants than on fertilized T. heterophylla plants regardless of fertilizer treatment. Both L. nigrinus and S. tsugae consumed more adelgid eggs that developed on fertilized T. canadensis than from unfertilized plants. The predators did not exhibit this preference for adelgid eggs from females that developed on T. heterophylla or T. mertensiana.

Turfgrass selections including 21 paspalums (Paspalum vaginatum Swartz) and 12 zoysiagrasses (Zoysia sp.) were compared with susceptible `KY31' tall fescue (Festuca arundinacea Schreb.) and more resistant common bermudagrass (Cynodon dactylon Pers.) and common centipedegrass [Eremochloa ophiuroides (Munro.) Hack] for potential resistance to fall armyworm [Spodoptera frugiperda (J.E. Smith)], an occasionally serious pest of managed turf. Turfgrass and pasture grasses annually suffer sporadic damage by this pest, often severe in the Gulf Coast states. Resistant grasses offer an alternative management tool for the fall armyworm, reducing the need for pesticide use. Laboratory evaluations assessed the degree of antibiosis and nonpreference present among more than 30 turfgrass genotypes to first and third instar fall armyworms, respectively. Zoysiagrasses exhibiting high levels of antibiosis included `Cavalier', `Emerald', DALZ8501, DALZ8508, `Royal', and `Palisades'. Paspalum selections demonstrating reduced larval or pupal weights or prolonged development times of fall armyworm included 561-79, Temple-2, PI-509021, and PI-509022.

Cotesia marginiventris (Cresson), Diolcogaster facetosa (Weed), and Rogas nolophanae Ashmead, which respectively parasitize progressively older green cloverworm, Plathypena scabra (F.) larvae, produced (x ± SE) 362.7 ± 24.1, 83.2 ± 11.4, 66.3 ± 6.1 offspring, respectively, during their lifetimes. Adult female longevity at 24°C averaged lS.l ± O.S, ~3.0 ± 0.9, and 29.9 ± 2.7 d for these species, respectively. Numbers of mature eggs from dissections of 2-d-old females were 105 ± 7.1,57 ± 5.9, and 5.2 ± 0.9. Primary braconid and tachinid parasitoids of the green cloverworm exhibited decreasing observed or estimated fecundities with respect to increasing age of host larvae attacked. Decreasing fecundities of these parasitoid species may reflect increasing potential for survival until time of parasitoid emergence of the progressively older host larvae which these species attack. Other factors suggested as influencing fecundity are breadth of host range and complexity of host location, capture, and oviposition behaviors.

The critical photoperiod for diapause induction was determined in the laboratory and validated in the field for Diolcogaster facetosa (Weed), a parasite of the green cloverworm. In the laboratory at constant 24°C, as well as in the field under natural conditions, the critical photoperiod for diapause induction is between 13:11 and 14:10 (L:D). Second instars are sensitive to diapause-inducing photoperiods, and diapause occurs in the final instar after it has emerged from the host and spun a cocoon. Study of diapausing individuals from the field during autumn and winter indicated that photoperiod has only a minor role, if any, in diapause maintenance or termination. The date of diapause termination was not determined, but the combination of diapause development and postdiapause development had not been completed in the field by the spring equinox.

The seasonal abundance and phenology of three Nabis species and their parasitoids were studied in alfalfa (Medicago sativa L.) and soybean (Glycine max (L.) Merrill). Although all three species were present in both crops, differences were noted in composition of the Nabis complex between the two systems. Nabis americoferus (Carayon) was numerically dominant in alfalfa, a crop in which this species produced three generations per year in central Kentucky. In soybean. where one generation is produced, N. roseipennis Reuter rather than N. americo/eros or N. rufusculus Reuter produced the greatest number of nymphs for the three consecutive years of study. Sweep sampling recovered fewer nymphal nabids in comparison with suction or shake sampling and, thus, was less satisfactory in assessing population trends. Parasitoids reared from nabids that had been collected as adults or nymphs in alfalfa or soybean included the tachinid Leucostoma simplex (Fallen) and the braconid Wesmaelia pendula Foerster. Parasitism by the mymarid egg parasitoid Polynema boreum Girault was much higher in alfalfa than in soybean (50% versus 5%).

Potential resistance to the twolined spittlebug, Prosapia bicincta (Say), was evaluated among 56 turfgrass genotypes. Greenhouse, laboratory, and field bioassays identified differences in spittlebug survival and development, host preference and damage levels, and turfgrass tolerance to and ability to recover from pest induced injury. All centipede grasses demonstrated high levels of susceptibility, followed by bermudagrasses, seashore paspalums, and zoysiagrasses. Average nymphal survival to the adult stage ranged from 1.5 to 78.1%. Development required 38.1–62.0 d under greenhouse conditions, depending on plant taxa. Among seashore paspalums, nymphal survival to the adult stage was lowest and duration of development was longest on HI-1, ‘Sea Isle 2000’, 561-79, and ‘Mauna Kea’. Reduced spittlebug survival and increased developmental times were also observed on the bermudagrasses BERPC 91–15 and ‘Tifway’. Although zoysiagrasses supported spittlebug development and survival to the adult stage, developmental times were extended on the zoysiagrass cultivars ‘Emerald’ and ‘El Toro’. Spittlebug preference varied with generation evaluated. First-generation spittlebugs inflicted the greatest damage on TC201 (centipede grass), ‘Primavera’ (bermudagrass), and ‘Emerald’ (zoysiagrass) in choice tests. In the fall, second-generation spittlebugs damaged TC201 (centipedegrass) and ‘Sea Isle 1’ (paspalum) most severely, whereas 561-79 (paspalum) and ‘Emerald’(zoysiagrass) were less severely affected. Among taxa included in field trials, HI-1, ‘Mauna Kea’, ‘Sea Isle 2000’,and AP-14 paspalums, ‘Tifway’ bermudagrass, and ‘Emerald’ zoysiagrass were most tolerant (demonstrated the best regrowth potential following twolined spittlebug feeding).

Grass selections including 10 zoysiagrasses, 18 paspalums, 34 Bermuda grasses, tall fescue, creeping redfescue, andperennial ryegrasses with andwithout endophyte were evaluatedfor potential resistance to fall armyworm, Spodoptera frugiperda (J. E. Smith), larvae. Laboratory eval- uations assessedthe degree of antibiosis among 70 grass lines to Þrst-instar fall armyworms. When all parameters measured were considered, the trend in resistance to fall armyworm among endophyte- infected(E ) andendophyte-free (E-) cool season grasses from greatest to least was: ODawsonO E APR 1234 ODawsonO E- ORosalinO E Lp 5425, ORosalinO E-, ATF 480 OTulsaO or: E slender creeping redfescue E turf- type perennial ryegrass E- slender creeping red fescue E forage-type perennial ryegrass E- forage-type perennial ryegrasses, andE tall fescue E- turf-type tall fescue. Among warm season grasses larval weight gain was reduced on all zoysiagrasses. Larval weight gain also was lower on the Bermuda grasses OTifsportO, OTifgreenO, 97Ð 4, 97Ð14, 97Ð22, 97Ð28, 97Ð39, 97Ð 40, 97Ð54, 98 Ð15, 98 Ð30, and98 Ð 45 than when larvae were fedOTulsaO tall fescue or the diet control. Only APR1234 andODawsonO creeping redfescue reducedlarval survival to the same extent that was observedfor zoysiagrasses. Survival on Bermud a grasses was least on 97Ð 8. Seashore paspalums were only rarely less susceptible to fall armyworm than tall fescue, although pupal weights were consistently lower on OTemple 1O andOSea Isle 1O paspalums than that on OTulsaO tall fescue. Genetic resistance to key grass pests can reduce insecticide use and simplify management of these cultivars.

Whole-plant gas exchange was measured continuously for 24 h on rooted cuttings of Girard's 'Pleasant White' azaleas. Azalea treatments were azalea lace bug, Stephanitis pyrioides (Scott), feeding injury levels that averaged 6, 13, or 31% leaf-area injury throughout the plant canopies. Gas exchange parameters, including net photosynthesis, dark respiration, carbon use efficiency, and growth, were compared with undamaged control plants. Responses of Girard's 'Pleasant White' azaleas suggested that azaleas were tolerant of lace bug feeding injury levels above the aesthetic threshold. Azalea tolerance can be incorporated into an integrated management plan to reduce chemical inputs into the urban landscape.

Azalea lace bug, Stephanitis pyrioides (Scott), is a major pest on azalea. Adults and nymphs feed and oviposit on the underside of the leaves, causing a stippled appearance when viewed from above. Previous field and laboratory screenings of 17 taxa of deciduous azalea, including representatives of 11 species, have identified a range of resistance to lace bug. One of the most resistant plants observed was of the species R. canescens. The interveinal region on the underside of the leaves of this plant is highly pubescent. This plant was crossed to a susceptible plant of R. viscosum (formerly R. serrulatum), which was glabrous on the lower leaf surface. The resulting seeds were planted in 1996, and the seedlings were transplanted to the field in 1998. In Sept. 1999, a laboratory bioassay was conducted to determine the resistance levels of these progeny. Five cuttings, each with two leaves, were collected from each plant, including the parental genotypes. Two female lace bugs were transferred onto the leaves of each cutting and the leaves were enclosed in a plastic cup with mesh for ventilation. After 5 days, the number of live bugs and number of eggs per cutting were counted. The percent damage from feeding was estimated. To determine whether pubescence was correlated with lace bug resistance, two terminal leaves were collected from each plant, and interveinal leaf hair density was calculated. Results from the laboratory bioassays revealed a high degree of susceptiblity to lace bug among these seedlings. Most of the progeny were pubescent, indicating no relationship between leaf hair density and resistance.

Azalea lace bug (Stephanitis pyrioides) is the most serious pest on azalea. Both evergreen and deciduous azaleas are susceptible, though more resistance has been observed in the deciduous. To identify genes for resistance, fourteen deciduous azalea species, three deciduous azalea cultivars derived from complex hybrids, and one evergreen cultivar were planted in a randomized complete-block design under mixed deciduous trees in the fall of 1994. Each block was replicated 12 times. In the spring and summer of 1995, azalea lace bugs were introduced onto branches of six plants of each of the taxa. One month later, and again in the fall of 1996, the percentage of infected shoots per plant was measured. Very little damage from azalea lace bug was observed on the R. canescens, R. periclymenoides, and R. prunifolium plants, while `Buttercup', `My Mary', R. japonicum, and R. oblongifolium had the greatest damage. The cranberry rootworm, Rhadopterus picipes, damages many woody ornamentals, including some azalea species. The injury appears as elongated cuts on the leaves, and is most severe on plants growing under dense canopies. The cranberry rootworm has been observed in this azalea field plot. Plants were evaluated for damage in June 1995 and 1996. Cranberry rootworm damage was most severe on `Buttercup', R. japonicum, R. prinophyllum, and R. calendulaceum, while the evergreen azalea `Delaware Valley White' was the most resistant.

Azalea lace bug is the most serious pest of cultivated azalea. Though deciduous azaleas are generally considered to be more resistant to lace bug than are evergreen azaleas, some variation in resistance has been reported. The identification of the genetic and physiological basis of resistance is important to eventual development of resistant cultivars of both the deciduous and evergreen azaleas. The first step in this program is to evaluate a wide range of deciduous azaleas for level of resistance. Laboratory evaluations were conducted on nine species and two hybrid cultivars of deciduous azalea and a known susceptible cultivar of evergreen azalea, `Delaware Valley White'. Oviposition rate, rate of egg hatch, number of nymphs surviving, and percent damaged leaf area were evaluated for each of the tested genotypes. Results indicated a wide range of susceptibility, with R. canescens and R. periclymenoides plants highly resistant to infection, while R. atlanticum and R. viscosum were highly susceptible.

Reduction in growth by tawny mole crickets, Scapteriscus vicinus Scudder, at densities equivalent to 15 adults per 0.09 m2 varied among nine experimental and three commercially available zoysiagrass (Zoysia Willd.) cultivars. Reductions in root dry weights after a four week infestation period were similar among all cultivars, and averaged 27.1% less than non-infested controls. Shoot dry weight reduction was most severe for DALZ 8516, DALZ 9006, and Meyer zoysia. The cultivars that retained the highest percentage of their normal growth were DALZ 8502, DALZ 8514, DALZ 8701, and Emerald zoysia. Crickets fed on cultivars that were least damaged usually produced the least number of eggs. However, when the most severely injured selection (DALZ 8516) served as the host, a similarly low number of eggs was observed. Crickets fed on Meyer zoysia and DALZ 8508 produced the greatest number of eggs.

The within-plant distributions of Nabis americoferus (Carayon), N. roseipennis Reuter, and N. rufusculus Reuter differ in soybean. N. americoferus adults are located in the upper canopy, whereas adults of the other two species are located lower in the plant canopy. Early-instar nymphs of all three species are vertically separated from their respective adult stages. Nabids were observed to feed on a wide variety of arthropods including pest, beneficial, and innocuous species. The seasonal abundance of nymphal N. roseipennis and the within-plant overlap of its distribution with early instars of the green cloverworm suggested that it may be an effective predator on this pest species. N. roseipennis nymphs were successful in reducing numbers of green cloverworm larvae in the field in the presence of other predators and alternative prey under minimally modified conditions. Starting densities of 20–25 third instars per 0.9-m plot resulted in up to 50% reduction in subsequent green cloverworm populations.