Changing Abundance of Hexagenia Mayfly Nymphs in Western Lake Erie of the Laurentian Great Lakes: Impediments to Assessment of Lake Recovery?

After an absence of 40 years, mayfly nymphs of the genus Hexagenia were found in sediments of western Lake Erie of the Laurentian Great Lakes in 1993 and, by 1997, were abundant enough to meet a mayfly‐density management goal (ca. 350 nymphs m^—2) based on pollution‐abatement programs. We sampled nymphs in western Lake Erie and Lake St. Clair, located upstream of western Lake Erie, to determine the importance of seasonal abundance and life‐history characteristics of nymphs (e.g., emergence and recruitment) on density estimates relative to the mayfly‐density management goal. Two types of density patterns were observed: (1) densities were relatively high in spring and gradually decreased through late summer (observed in Lake Erie and Lake St. Clair in 1997 and Lake St. Clair in 1999) and (2) densities were relatively high in spring, gradually decreased to mid summer, abruptly decreased in mid summer, and then increased between summer and late fall (Lake Erie and Lake St. Clair in 1998 and Lake Erie in 1999). Length‐frequency distributions of nymphs and observations of adults indicate that the primary cause for the two density patterns was attributed to failed (first pattern) and successful (second pattern) reproduction and emergence of nymphs into adults in mid summer. Gradual declines in densities were attributed to mortality of nymphs. Our results indicate that caution should be used when evaluating progress of pollution‐abatement programs based on mayfly densities because recruitment success is variable both between and within years. Additionally, the interpretation of progress toward management goals, relative to the restoration of Hexagenia populations in the Great Lakes and possibly other water bodies throughout the world, is influenced by the number of years in which consequtive collections are made.     

Transmission of Xylella fastidiosa to grapevines by Homalodisca coagulata (Hemiptera: Cicadellidae)

Pierce's disease (PD) of grapevines is caused by a xylem-limited bacterium Xylella fastidiosa (Wells, Raju, Hung, Weisburg, Mandelco-Paul, and Brenner) that is transmitted to plants by xylem sap-feeding insects. The introduction of the sharpshooter leafhopper Homalodisca coagulata (Say) into California has initiated new PD epidemics in southern California. In laboratory experiments, the major characteristics of H. coagulata's transmission of X. fastidiosa to grapevines were the same as reported for other vectors: short or absent latent period; nymphs transmitted but lost infectivity after molting and regained infectivity after feeding on infected plants; and infectivity persisted in adults. Adult H. coagulata acquired and inoculated X. fastidiosa in <1 h of access time on a plant. Inoculation rates increased with access time, but acquisition efficiency (20% per individual) did not increase significantly beyond 6-h access. Estimated inoculation efficiency per individual per day was 19.6, 17.9, and 10.3% for experiments where plant access was 1, 2, and 4 d, respectively. Freshly molted adults and nymphs acquired and transmitted X. fastidiosa more efficiently than did older, field-collected insects. H. coagulata transmitted X. fastidiosa to 2-yr-old woody tissues of grapevines as efficiently as to green shoots. H. coagulata transmitted X. fastidiosa 3.5 mo after acquisition, demonstrating persistence of infectivity in adults. About half (14/29) of the H. coagulata from which we failed to culture X. fostidiosa from homogenized heads (with a detection threshold of 265 CFU/head) transmitted the pathogen to grape, and 17 of 24 from which we cultured X. fastidiosa transmitted.     

Feasibility of tracking within-field movements of Homalodisca coagulata (Hemiptera: Cicadellidae) and estimating its densities using fluorescent dusts in mark-release-recapture experiments

A mark-release-recapture technique was developed and tested for use in tracking the field movements of adult glassy-winged sharpshooters, Homalodisca coagulata (Say) (Hemiptera: Cicadellidae), in various agricultural and urban plantings. Greenhouse experiments in which adult H. coagulata were marked with one of five colored fluorescent dusts (Aurora Pink-All, Horizon Blue-A19, Blaze Orange-A15N, Saturn Yellow-A17, and Corona Magenta-A21) and released into cages with citrus seedlings showed that their mortality rates during a 30-d period were statistically similar to that of the undusted controls. Adults marked with a sixth dust color (Signal Green-A18N) suffered higher rates of mortality than did the undusted controls and thus were eliminated from further consideration. Adult H. coagulata marked with one of the five accepted colors of fluorescent dust were able to fly beyond 100 m in a field devoid of vegetation within minutes of their release, and the marking did not affect overall flight behavior significantly compared with that of the undusted controls. However, at wind speeds above 5 m/s, percentage recapture was significantly reduced, which indicates that both dusted and undusted adults were unable to orient their flight. In total, 41,124 marked and unmarked adults were released in the three field experiments in southern California (Riverside and Kern counties) during 2000 and 2001 to evaluate flight dispersal and estimate densities of H. coagulata. The mark-release-recapture and feral data obtained during the June, July, and August 2001 studies, when coupled with the Lincoln index, yielded estimates of adult H. coagulata of 1.2 and 2.2 million per ha, respectively, at a San Joaquin Valley (Kern Co.) and a southern California (Riverside Co.) citrus grove. The use of colored dusts to mark H. coagulata proved to be reliable, cost-effective, and time-efficient for mark-release-recapture studies with this insect within a citrus grove, but they are less likely to be useful for studies of adult H. coagulata movements among plantings.     

Dispersion of Homalodisca coagulata (Hemiptera: Cicadellidae), a vector of Xylella fastidiosa, into vineyards in southern California

Recent epidemics of Pierce's disease of grapevine in California vectored by Homalodisca coagulata (Say), an invasive vector species, have characteristics that differ from epidemics involving native vectors. Among these differences are the longer distances and greater speed that the disease is spread by H. coagulata. In this investigation, we used yellow sticky traps to study the seasonal dispersion activity of H. coagulata in a southern California grape-growing area in which an epidemic of Pierce's disease has caused large losses. For 21 mo, we monitored adult H. coagulata at the edges of vineyards bordering citrus, an important crop host, natural coastal sage scrub vegetation, and natural riparian vegetation. We also monitored H. coagulata dispersion from 0 to 40 m into vineyards. Finally, we examined the vertical dispersion of H. coagulata adults into grapevines through a season. This investigation showed that H. coagulata is associated with citrus, from where it disperses deep into vineyards, and not just the vineyard edge as with Pierce's disease vectors that are native to California. Peak dispersion into vineyards occurred in the summer. Another period of H. coagulata activity occurred in the winter in vineyards bordering citrus. Through the period of peak flight activity, 97% of all H. coagulata adults trapped between 1 and 7 m were caught at an altitude of 5 m or lower, suggesting the potential of a barrier as a management tactic to keep H. coagulata out of vineyards.     

Stage-specific population dynamics of cottony cushion scale,Icerya purchasi (Hemiptera: Monophlebidae), in citrus orchards in Jeju,Korea

The cottony cushion scale, Icerya purchasi Maskell (Hemiptera: Monophlebidae), is a polyphagous, cosmopolitan and destructive pest of citrus. This study was conducted to obtain the stage-specific phenology of I. purchasi for seasonal management strategies in the field. Movement of crawlers (hatched nymphs) in egg sacs of overwintered females started in late May, peaked in early to mid-June, and was completed by late June. Generally, the 1st generation occurred from late May until late September and the overlapping second generation occurred from early September. The 1st nymphs in the 1st generation peaked in mid June. The 2nd nymphs showed peak activity in late July. The 3rd nymphs showed peak population in early September. The 1st generation adults peaked in mid September. In the 2nd generation, the 1st nymphs peaked in early October, the 2nd nymphs showed peak activity in late October, and the 3rd nymphs reached a plateau after mid October. The 2nd generation adults occurred from late October. Consequently, two life cycles were competed in the Jeju area. The average fertilities of I. purchasi were 623 and 247 crawlers per female in overwintered and summer generations, respectively. An average of 20.7% of all citrus orchards was infested with I. purchasi, with a mean of 3.9% infested trees in Jeju. These results should be useful in establishing management strategies for I. purchasi in citrus orchards.     

Ecophysiological attributes of adult overwintering in insects: insights from a field study of the nut weevil,Curculio nucum

Abstract Diapausing insect species have evolved a great diversity of life cycles, although overwintering occurs at a single development stage within most species. Understanding why diapause has evolved towards a given life stage requires investigation of both the ecological and physiological attributes. Notably, it is suggested that adult overwintering is more energy‐demanding than larval overwintering but it brings fitness gains by allowing adults to be synchronized with their seasonal requisites through an early spring emergence. This hypothesis is tested in field conditions in the nut weevil Curculio nucum, whose life cycle comprises an obligate 2‐year, nonfeeding underground phase, including a larval, followed by an adult, overwintering. In this species, adult wintering leads to an early spring emergence; at first glance, however, this does not enhance synchronization between weevils and their host because adults emerge more than 1 month before starting to breed. It is suggested that adult overwintering ultimately evolved in response to the phenology of the host, by allowing females to oviposit in nuts before their full sclerotinization. Adult overwintering appears to be costly because adults postpone reproduction for 1 year, incur a significant weight loss and require feeding before egg laying. Surprisingly, lipids are unaffected during diapause, lipogenesis even being likely in the summer metamorphosis. These results suggest that the lipids involved in egg production may entirely come from the larval stages, whereas the other nutrients are acquired through adult feeding but this remains to be tested.     

大猿叶虫生活史的研究

大猿叶虫Colaphellus bowringi是江西山区十字花科蔬菜上的重要食叶害虫,以成虫在土中越夏和越冬。由于成虫滞育期的差异,该虫的化性显示了明显的种内变异。有些个体隔年繁殖;有些个体是一化性的,仅在春季或秋季繁殖1代;有些个体是二化性的,春季和秋季各繁殖1代;有些个体是多化性的,春季1代,秋季2～3代。因此,大猿叶虫在田间一年可发生4代。在春季,滞育成虫于2月底至4月初陆续出土繁殖;在秋季,滞育成虫于8月中旬至10月初陆续出土繁殖。春季羽化的成虫于4月底至6月上旬陆续入土越夏,秋季羽化的成虫于9月中旬至12月底陆续入土越冬。大猿叶虫一生能交配多次,大多数雌虫的产卵期超过1个月,最长达67天。平均每雌产卵量：春季世代为644粒,秋季世代为963粒,最高达1.950粒。各虫态的发育历期：在15～30℃间,卵为13.78～3.14天,幼虫为22.83～6.95天,蛹为12.10～3.18天。发育阈值温度：卵为10.7℃,幼虫为8.8℃,蛹为9.6℃。非滞育成虫的寿命约为1～2个月,滞育成虫的寿命为5～38个月。滞育成虫均入土蛰伏,在土中的蛰伏深度为9～31 cm 。     

Phenology of Lygus lineolaris (Hemiptera: Miridae) in Minnesota June-bearing strawberries: comparison of sampling methods and habitats

Field studies were conducted in southeastern Minnesota from 2000 to 2002 to determine the phenology of Lygus lineolaris in various habitats and to compare yellow and white sticky traps as a sampling method for adult L. lineolaris. Strawberry fields were sampled for L. lineolaris adults using yellow sticky traps, and nymphs were sampled using the standard white pan beat method. Adult L. lineolaris abundance in alfalfa, an adjacent fence-row, and a wooded habitat were also compared. The nonlinear relationship between cumulative trap catch and cumulative degree-days was modeled with a two-parameter cumulative Weibull function to predict early-season adult capture using yellow sticky traps. Adult L. lineolaris were detected in bearing-year strawberries at the onset of vegetative growth in all years. Yellow sticky traps caught significantly higher densities of adult L. lineolaris than white sticky traps. The Weibull model predicted 50% capture at 10 DD (>12.4 degrees C), which corresponds to the vegetative strawberry growth stage. L. lineolaris nymphs were not detected until the blossom stage. Alfalfa harbored significantly higher densities of L. lineolaris than other habitats during early-season sampling (i.e., March-June). Late-season sampling (July-September) revealed significantly higher densities in bearing-year strawberries. These results suggest that monitoring at the onset of vegetative growth, using yellow sticky traps, will be an efficient method for detecting early L. lineolaris adult activity.     

Seasonal abundance and activity of the tick Dermacentor silvarum in northern China

Studies on the seasonal abundance and activity of larvae, nymphs and adults of Dermacentor silvarum (Ixodida: Ixodidae), both on and off the host, were carried out over a 2-year period from February 2008 to January 2010 in northern China. During the study period, feeding ticks were removed weekly from domestic sheep and free-living ticks were collected weekly by flag-dragging in four different habitat types. Rodents were captured and inspected for immature ticks from June to September 2008. The results of this study suggest that the ticks mainly reside in shrubs and complete only one generation per year with sequential seasonal distribution and little overlap between the activity of the larvae and nymphs. Adults were most prevalent from late February to late May and peaked in number in mid-April. Larvae were found from early June to early September and peaked in number in mid-July. Nymphs were mainly distributed from late June to late September and peaked in mid-August. Adult and nymphal D. silvarum were found primarily on the ears of sheep, but no larvae were found on sheep. Additionally, an overwintering male adult population was detected on sheep after October, but no free-living adults were found by dragging.     

黑刺粉虱及其天敌的研究

黑刺粉虱Aleurucamhus spiniferus Quaint．是柑桔、茶树等经济作物的重要害虫。福建一年发生4-5代,闽北、闽中发生4代,世代重叠。主要以若虫在柑桔等叶背越冬,越冬若虫于翌年2月间开始化蛹(伪蛹),4月间成虫羽化并产卵。各世代若虫发生期为第一代4月上旬至6月上旬;第二代6月中旬至7月下旬;第三代7月中旬至9月上旬;第四代9月中旬至翌年3月,11月进入越冬期。一年中以6-9月为发生为害高峰期。黑刺粉虱的寄生性天敌和捕食性天敌资源丰富,蛹期被寄生率甚高,对该虫的综合治理可以生物防治为主要措施。     

Olfactory and visual stimuli affecting host plant detection in Homalodisca coagulata (Hemiptera: Cicadellidae)

The relative effects of visual and olfactory stimuli on host plant detection in immature and adult Homalodisca coagulata Say (Homoptera: Cicadellidae) were studied using a novel olfactometer and factorial experimental designs. Colored, gray, and white cards were used as visual targets. Each card was attached to a glass thistle tube from which host-plant odor (from Vigna unguiculata L.) or blank, humidified air was dispensed. Visual + odor stimuli combinations were presented in no-choice tests. Nymphs were released onto a perch stick downwind from the target. Nymph response to color + odor treatments was measured by the duration of orientation behavior, residence time on the perch, and percentage of individuals that jumped to the target. The assay was modified so that adults crawled from the perch onto the target. Adult response was measured by the duration of individual behaviors (e.g., foraging) and by their position and residence time on the target. Both main effects and interactive effects of the stimuli were observed. Nymphs showed a decrease in orientation and residence times in the colored target + host odor treatments and increased jumping response in the gray + host odor treatment. When adults were exposed to host odor, the duration of foraging behavior increased, whereas crawling and phototactic behaviors decreased. Although nymphs and adults responded to visual stimuli + blank air treatments, host odor enhanced their responses. The primary effect of host odor on host detection behavior may be to enhance H. coagulata responsiveness to visual cues.     

Seasonal activity patterns of Ixodes pacificus nymphs in relation to climatic conditions

Abstract In western North America, the tick Ixodes pacificus Cooley & Kohls (Acari: Ixodidae) is the primary vector to humans and domestic animals of the disease agents causing Lyme disease and granulocytic ehrlichiosis. We examined the seasonal activity patterns of I. pacificus nymphs over a 4‐year period, including the wet and cold El Niño winter/spring of 1998, in a dry oak/madrone woodland, and for one year in a cooler and moister redwood/tanoak woodland in Mendocino County, California. Linear regressions were used to estimate when nymphal densities first exceeded and then fell below 25, 50 and 75% of the recorded yearly peak densities. In oak/madrone woodland, nymphs typically were active by mid‐March, reached 50% of their yearly peak densities in early to mid‐April, peaked by early May, fell below 50% of their peak densities by early to mid‐June, and were absent by late July to mid‐August. The lengths of the periods with nymphal densities exceeding 50 and 75% of the recorded yearly peaks in oak/madrone woodland were associated positively with rainfall and negatively with maximum air temperatures during April–May. Moreover, nymphal numbers typically reached 50% of their peak 10–15 days later, remained at levels above 50% of the peak 1.3–1.5 times longer, and started declining 4–6 weeks later under cooler, moister climatic conditions (oak/madrone woodland in 1998 and redwood/tanoak woodland in 2000) relative to warmer, drier conditions (oak/madrone woodland in 2000–2001). In oak/madrone woodland, nymphal densities typically started to decline when mean maximum daily air temperatures exceeded 23°C. Nymphal densities were higher in dry oak/madrone relative to moist redwood/tanoak woodland from mid‐March to late May 2000, similar in both habitat types in early June, but higher in redwood/tanoak woodland from late June onwards. We conclude that large‐scale studies of the density of I. pacificus nymphs in California need to consider spatial variation in the length of nymphal activity periods and select temporal sampling regimens that yield representative data for all included habitat types.     

Seasonal activity and spatial distribution of host-seeking adults of the tick Dermacentor variabilis

The seasonal temporal and spatial distribution and emergence of overwintering and summer cohorts of host-seeking American dog tick, Dermacentor variabilis (Say) (Acari: Ixodidae), adults were examined for 5 years in the Bluegrass region of Kentucky. Weekly drag cloth sampling was conducted from early March until late September 1992-1995 and early March until the end of May 1996. Overwintering adult cohorts became active in early to mid-April followed by bimodal host-seeking activity each year, with the duration and intensity of the first activity period being related to the previous year's summer cohort activity. The first activity peak extended from mid-April through late May and the second activity peak occurred in July. All host-seeking activity ceased by early August, except in 1995, when activity ended on 22 August. Laboratory survival of adults, collected weekly during 1993-1996, was used to estimate the emergence of summer adult cohorts. Summer adult cohorts became active in late May or early June and overlapped with overwintering adult host-seeking activity. The termination of host-seeking activity in overwintering adults could not be determined using the methods employed in this study and is most likely to have continued for the entire season. Host-seeking adults displayed contagious distribution patterns along trails bordering ecotone habitats, as determined by fitting a negative binomial frequency distribution to weekly sampling data. These patterns did not vary from year to year. In addition, the location of D. variabilis activity did not change from year to year, which suggests that microhabitats within apparently homogeneous environments enhance adult survival and lead to 'hot spots' of tick activity despite the ability of vertebrate hosts to disperse D. variabilis populations more widely. These data better define our understanding of D. variabilis adult seasonal and spatial host-seeking activity, estimate for the first time the intensity of summer cohort host-seeking activity, and relate summer cohort activity with spring activity the following year.     

Overwintering survival and spring emergence of Helicoverpa armigera (Lepidoptera: Noctuidae) in northern Greece

Overwintering survival of Helicoverpa armigera (Hübner) was studied under field conditions during the winter of 2004-2005 and 2005-2006 to clarify whether a local population of this insect is established in northern Greece. Additionally, the postdiapause eclosion times of the overwintering generation was compared with adult male dynamics using pheromone traps. Our study supplies strong evidence that part, if not all, of the late-season generation of H. armigera overwinters as diapausing pupa in northern Greece, suggesting that a local population exists in this area. Pupae enter diapause during September and October in response to declining temperatures and photoperiod. A limited number of degree-days in autumn prevented part of the population from developing to the diapausing pupal stage. Larvae of H. armigera that were placed in field conditions late in October were not able to pupate and died. The termination of diapause and the eclosion of adults in the following spring were determined by the local soil temperatures. Diapause terminated between mid-April and early May, and adult emergence occurred within a 4- to 6-wk period from late April to early June. Females emerged slightly earlier than the males. The emergence of 10, 25, 50, 75, and 90% of adults required 153, 199, 252, 303, and 347 DD, respectively. Differences in timing and degree of overlap between adult emergence from the experimental population and pheromone trap catches suggests that the spring population of this species also includes immigrants.     

Effect of seasonal variation in host-plant quality on the rice leaf bug, Trigonotylus caelestialium

The rice leaf bug, Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae), is an important insect pest, causing pecky-rice damage in Japan. This bug has a multivoltine life cycle and feeds on various species of the Poaceae. The phenology of the host-plants differs between species and the plant quality of a single host species may change with the seasons. The fitness of the bug may be affected by these seasonal changes in host-plant quality. In the current study, the effects of such quality changes on adult and nymphal performance were examined using a population of bugs collected in Joetsu, Niigata, Japan. Rearing of newly emerged adults collected from spring to autumn from Italian rye grass, Lolium multiflorum Lam., and southern crabgrass, Digitaria ciliaris (Retz.), showed that body size and performance of adults differed between collection seasons and plant species, indicating that nymphal conditions including host-plant quality have crucial effects on their fitness. Rearing nymphs from hatching to adult emergence on various field-collected grasses under laboratory conditions showed that the performance of nymphs depends on the plant species and varies greatly with the season, within a given species. In general, nymphs performed more poorly on most of the plants collected late in the season, but they performed well on some plants unavailable early in the season. Therefore, in T. caelestialium , seasonal and spatial variations are important factors that affect fitness of nymphs and adults, and this suggests that oviposition of diapause eggs in summer is an adaptation to deteriorating food conditions.     

Spatial and temporal dynamics of overwintering Homalodisca coagulata (Hemiptera: Cicadellidae)

A 4-yr landscape-scale study was conducted to investigate spatial and temporal dynamics of overwintering Homalodisca coagulata (Say) (Hemiptera: Cicadellidae) in the lower San Joaquin Valley, California. Spatial structures of H. coagulata distributions were characterized with Moran's I index, and spatial associations between H. coagulata and the surrounding environment were investigated with a geographic information system. H. coagulata was caught consistently with sticky traps throughout the winter, and trap catches formed a distinctive peak in December or January, indicating active flight of H. coagulata during the winter. In 2000-2001, the mean +/-SE trap count was 4.8 +/- 1.21 per trap per wk, and H. coagulata trap catches were spatially autocorrelated within approximately 1.3 km. Approximately 49% of H. coagulata were caught in citrus, 23% in stone fruit, and 11% in grape. After a control program began in spring 2001, the mean trap count was considerably lower (0.041 +/- 0.0004 per trap per wk), and no spatial autocorrelations were detected in 2001-2004. H. coagulata trap catch-crop associations also changed after initiation of the control program. Between 25 and 38% of H. coagulata trap catches were from citrus, between 8 and 20% were from stone fruit, and between 11 and 25% were from grape. Potential for winter-season spread and management of Xylella fastidiosa Wells et al., a pathogen causing Pierce's disease, are discussed.     

橄榄星室木虱的生活史和种群消长动态的研究

本研究了莆田市延寿村的橄榄星室木虱的生活史和种群消长动态。结果表明,橄榄星室木虱在莆田地区一年发生8代,世代重叠。卵、若虫(1—5龄)、成虫在1年中有6个发生高峰期,以秋梢期为全年雌成虫产卵、若虫发生最高峰,夏梢期是成虫羽化全年最高峰。其田间种群数量消长与橄榄抽梢期有着极为密切的关系,每一次抽梢期都带来一个产卵高峰期和低龄若虫发生高峰期,每一次抽梢都使虫口数量急尉上升,并出现高峰,其间也带来一个很高的种群增长率,待到新梢定型老化(枝梢生长后期)又使种群数量明显下降,而低龄若虫的发生和高峰期的出现,一般比产卵滞后5—10d。     

The bimodal adult activity of Monochamus alternatus (Coleoptera: Cerambycidae) caught in pheromone traps in Jeju can be explained by the competitive attractiveness of dying pine trees

The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae), is known to be the primary vector of pinewood nematode Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle that causes pine wilt disease. Adult activity of M. alternatus caught in a pheromone trap on Jeju Island of Korea showed a bimodal form with the first peak in mid to late June and the second peak in mid to late September. The two peaks were separated between mid and late August, showing a valley. Accumulated degree‐days predicted that the emergence of the second generation adults could be possible just before the second peak. But actually no adults of the second generation occurred in the field development experiments of M. alternatus in 2016 and 2017. Pine trees without oleoresin flow (namely dying trees by the infection of pinewood nematode) were abundant during early July to early August. The bimodal adult activity pattern of M. alternatus could be partially explained by the competitive attractiveness of dying trees against pheromone traps, when we accepted the assumption that dying pine trees attract strongly M. alternatus.     

Characterizing spring emergence of adult Halyomorpha halys using experimental overwintering shelters and commercial pheromone traps

To improve our understanding of adult Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) overwintering biology and to better inform models of its population dynamics, its temporal pattern of spring emergence was investigated using experimental overwintering shelters in screened cages within protective structures. In 2012, plastic shelters containing 100 adults were deployed in unheated, unlighted buildings, and adjacent woodlots in Virginia, USA. In 2013 and 2014, wooden shelters containing 300 paint‐marked adults were deployed in pairs in six woodlots across Virginia, West Virginia, and Maryland, USA; one in a closed cage and one in a cage with the top removed, enabling emerged adults to be counted or to disperse, respectively. In 2013 and 2014, pheromone‐baited and non‐baited pyramid traps encircled the shelters at each site. Regular counts of adults that emerged into the closed cage and of marked and ‘wild’ (unmarked) adults captured in traps were conducted from February or March through early July. In 2012, emergence patterns from shelters in buildings and woodlots were very similar and matched those recorded from woodlots in 2013 and 2014. In all years, a small peak of emergence occurred in about mid‐April, a larger and more prolonged peak was observed between mid‐May and early June, and emergence ended by early July. Of the 449 H. halys adults captured in traps between 2013 and 2014, only three were marked individuals from shelters in the open cage, suggesting that adults emerging from overwintering sites may require a dispersal flight before responding to pheromone‐baited traps. In 2013 and 2014, respectively, 98 and 93% of captures were in pheromone‐baited traps, but there was no correlation between the weekly number of adults that emerged from shelters in the closed cages and captures in traps.     

Life history and spatial distribution of Oriental beetle (Coleoptera: Scarabaeidae) in golf courses in Korea

Larval and adult activity of the oriental beetle Exomala orientalis (Waterhouse), a pest of turfgrass in Korea, was investigated at four golf clubs in Pusan, Korea, from 1995 to 1999. Adult emergence was first observed on the greens in late May with peak activity occurring 2 wk later. During the day, E. orientalis adults were most active between 1800 and 2200 hours. First instars were found mostly in early July, second instars mostly in late July, and third instars from August to April. The density of larvae in fixed plots decreased steadily from the time of egg laying to pupation: 667/m3 on 26 July, 267/m3 on 29 August, and 122/m3 on 2 October 1997. All the observed E. orientalis completed one generation per year. Adult females were observed feeding on flowers of a late-blooming variety of Japanese chestnut (Castanea crenata Sieb & Zucc). E. orientalis larval densities were higher in greens with Japanese chestnut nearby, and where magpie, Pica pica sericea (Gould), feeding was observed. More E. orientalis adults emerged from the right, left, and back of greens than from the front or middle. The intensity of emergence was inversely proportional to the amount of golfer traffic on various parts of the green. Counting emergence holes may be a way that golf course superintendents can predict which greens and tees are most likely to be damaged from E. orientalis larvae without destructive sampling.