Pest Management Efforts Research Articles

Collective Motion and Cannibalism in Locust Migratory Bands

Plagues of mass migrating insects such as locusts are estimated to affect the livelihood of one in ten people on the planet [1]. Identification of generalities in the mechanisms underlying these mass movements will enhance our understanding of animal migration and collective behavior while potentially contributing to pest-management efforts. We provide evidence that coordinated mass migration in juvenile desert locusts (Schistocerca gregaria) is influenced strongly by cannibalistic interactions. Individuals in marching bands tend to bite others but risk being bitten themselves. Reduction of individuals' capacity to detect the approach of others from behind through abdominal denervation (1) decreases their probability to start moving, (2) dramatically reduces the mean proportion of moving individuals in groups, and (3) significantly increases cannibalism. Similarly, occlusion of the rear visual field inhibits individuals' propensity to march. Abdomen denervation did not influence the behavior of isolated locusts. When within groups, abdominal biting and the sight of others approaching from behind triggers movement, creating an autocatalytic feedback that results in directed mass migration. This "forced march" driven by cannibalistic interactions suggests that we need to reassess our view of both the selection pressure and mechanism that can result in the coordinated motion of such large insect groups.

Analyzing NEXRAD doppler radar images to assess nightly dispersal patterns and population trends in Brazilian free-tailed bats (Tadarida brasiliensis)

Operators of early weather-surveillance radars often observed echoes on their displays that did not behave like weather pattern, including expanding ring-like shapes they called angels. These echoes were caused by high-flying insects, migrating birds, and large colonies of bats emerging from roosts to feed. Modern weather-surveillance radar stations in the United States (NEXt-generation RADar or NEXRAD) provide detailed images that clearly show evening bat emergences from large colonies. These images can be used to investigate the flight behavior of groups of bats and population trends in large colonies of Brazilian free-tailed bats (Tadarida brasiliensis) in south-central Texas which are clearly imaged by local NEXRAD radar stations. In this study, we used radar reflectivity data from the New Braunfels, Texas NEXRAD station to examine relative colony size, direction of movement, speed of dispersion, and altitude gradients of bats from these colonies following evening emergence. Base reflectivity clear-air-mode Level-II images were geo-referenced and compiled in a GIS along with locations of colonies and features on the landscape. Temporal sequences of images were filtered for the activity of bats, and from this, the relative size of bat colonies, and the speed and heading of bat emergences were calculated. Our results indicate cyclical changes in colony size from year to year and that initial headings taken by bats during emergence flights are highly directional. We found that NEXRAD data can be an effective tool for monitoring the nightly behavior and seasonal changes in these large colonies. Understanding the distribution of a large regional bat population on a landscape scale has important implications for agricultural pest management and conservation efforts.

Effects of Orchard Host Plants (Apple and Peach) on Development of Oriental Fruit Moth (Lepidoptera: Tortricidae)

Studies were designed to examine the effects of host plants (apple, Malus domestica Borkh., and peach, Prunus persica L.) on the development of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Oriental fruit moth larvae developed faster on peach than on apple, both on fruit as well as on growing terminal shoots. On fruit, these differences were shown to cause significant changes in both the rate (≈ap;20–ndash;60 degree-days earlier emergence on peach than on apple) and patterns of adult emergence among several cultivars of peaches and apples. Slopes of female emergence plots varied by host in 2003, with emergence occurring over a longer period on peach cultivars than on apple cultivars (with one exception). Slopes of male emergence curves did not differ by cultivar in 2003. These host-driven effects could impact the efficacy of traditional pest management approaches and probably complicate efforts to predictively model G. molesta populations in mixed cultivar orchards. Such developmental effects may help to explain previously observed differences in patterns of pheromone trap captures in peach versus apple orchards. Host-associated effects should be incorporated into future models to develop more realistic predictive tools and thus improve integrated pest management efforts.

Effects of Orchard Host Plants (Apple and Peach) on Development of Oriental Fruit Moth (Lepidoptera: Tortricidae)

Studies were designed to examine the effects of host plants (apple, Malus domestica Borkh., and peach, Prunus persica L.) on the development of oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae). Oriental fruit moth larvae developed faster on peach than on apple, both on fruit as well as on growing terminal shoots. On fruit, these differences were shown to cause significant changes in both the rate (approximately 20-60 degree-days earlier emergence on peach than on apple) and patterns of adult emergence among several cultivars of peaches and apples. Slopes of female emergence plots varied by host in 2003, with emergence occurring over a longer period on peach cultivars than on apple cultivars (with one exception). Slopes of male emergence curves did not differ by cultivar in 2003. These host-driven effects could impact the efficacy of traditional pest management approaches and probably complicate efforts to predictively model G. molesta populations in mixed cultivar orchards. Such developmental effects may help to explain previously observed differences in patterns of pheromone trap captures in peach versus apple orchards. Host-associated effects should be incorporated into future models to develop more realistic predictive tools and thus improve integrated pest management efforts.

Efficacy of Integrated Pest Management in Reducing Cockroach Allergen Concentrations in Urban Public Housing

The efficacy of residential interventions to reduce cockroach allergens in public housing developments was evaluated over months of follow-up. Repeated measurements were collected from 39 apartments, with longitudinal analyses used to evaluate changes over time. Bla g 1 kitchen concentrations were reduced 71% and bed concentrations 53% (86% and 70% for Bla g 2, respectively) by 6 months post-intervention, after which concentrations began to increase. Apartments with higher concentrations were usually in poorer condition and benefited most from pest management efforts. Intensive interventions can significantly reduce the allergen burden in public housing apartments, but intervention efforts must be sustained.

Effects of Orchard Host Plants on the Oviposition Preference of the Oriental Fruit Moth (Lepidoptera: Tortricidae)

Recently, the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), has emerged as a major problem on apples (Malus spp.) grown in the mid-Atlantic and midwestern United States, despite its historically important and frequent occurrence as a peach (Prunus spp.) pest. It is possible that host-driven biological phenomena may be contributing to changes in G. molesta population dynamics resulting in outbreaks in apple. Studies were designed to examine the effects of host plants on oviposition behavior, in an effort to clarify the host association status of eastern U.S. populations and also to gain insight into how pest modeling and management efforts may be altered to take into account various host-associated effects. G. molesta adults exhibited ovipositional preference for nonbearing peach trees over nonbearing apple trees in close-range choice tests conducted in the field, regardless of the larval host origin. A significant preference for peach shoots over apple shoots was observed on six of 12 sampling dates with a wild G. molesta population at the interface of adjacent peach and apple blocks. Numbers of eggs found on apple fruit were higher after peach fruit were harvested and apple fruit began to approach maturity (during the flight period for third and fourth brood adults). Possible implications for population modeling and integrated management of G. molesta are discussed.

Effects of Orchard Host Plants on the Oviposition Preference of the Oriental Fruit Moth (Lepidoptera: Tortricidae)

Recently, the oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), has emerged as a major problem on apples (Malus spp.) grown in the mid-Atlantic and midwestern United States, despite its historically important and frequent occurrence as a peach (Prunus spp.) pest. It is possible that host-driven biological phenomena may be contributing to changes in G. molesta population dynamics resulting in outbreaks in apple. Studies were designed to examine the effects of host plants on oviposition behavior, in an effort to clarify the host association status of eastern U.S. populations and also to gain insight into how pest modeling and management efforts may be altered to take into account various host-associated effects. G. molesta adults exhibited ovipositional preference for nonbearing peach trees over nonbearing apple trees in close-range choice tests conducted in the field, regardless of the larval host origin. A significant preference for peach shoots over apple shoots was observed on six of 12 sampling dates with a wild G. molesta population at the interface of adjacent peach and apple blocks. Numbers of eggs found on apple fruit were higher after peach fruit were harvested and apple fruit began to approach maturity (during the flight period for third and fourth brood adults). Possible implications for population modeling and integrated management of G. molesta are discussed.

A community-based participatory research study of multifaceted in-home environmental interventions for pediatric asthmatics in public housing

Pest infestation is a major problem in urban, low-income housing and may contribute to elevated asthma prevalence and exacerbation rates in such communities. However, there is poor understanding of the effectiveness of integrated pest management (IPM) efforts in controlling pediatric asthma, or of the interactions among various interventions and risk factors in these settings. As part of the Boston-based Healthy Public Housing Initiative, we conducted a longitudinal, single-cohort community-based participatory research intervention study. Fifty asthmatic children aged 4–17 from three public housing developments in Boston, Massachusetts, USA successfully completed interventions and detailed environmental, medical, social, and health outcome data collection. Interventions primarily consisted of IPM and related cleaning and educational efforts, but also included limited case management and support from trained community health advocates. In pre-post analyses, we found significant reductions in a 2-week recall respiratory symptom score (from 2.6 to 1.5 on an 8-point scale, p = 0.0002 ) and in the frequency of wheeze/cough, slowing down or stopping play, and waking at night. Longitudinal analyses of asthma-related quality of life similarly document significant improvements, with a suggestion of some improvements prior to environmental interventions with an increased rate of improvement subsequent to pest management activities. Analyses of potential explanatory factors demonstrated significant between-development differences in symptom improvements and suggested some potential contributions of allergen reductions, increased peak flow meter usage, and improved social support, but not medication changes. In spite of limitations with pre-post comparisons, our results are consistent with aggressive pest management and other allergen reduction efforts having a positive impact on clinical health outcomes associated with asthma. Our findings reinforce the multifactorial nature of urban asthma and suggest a need for further study of the relative contributions of and possible synergies between environmental and social factors in asthma intervention programs.

Turfgrass Species and Cultivar Influences on Survival and Parasitism of Fall Armyworm

Interactions between host plant resistance and biological control may benefit or hinder pest management efforts. Turfgrass cultivars have rarely been tested for extrinsic resistance characteristics such as occurrence and performance of beneficial arthropods on plant genotypes with resistance to known turf pests. Parasitism of fall armyworm, Spodoptera frugiperda (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.) x C. transvaalensis (Burtt-Davy); and Cavalier and Palisades zoysiagrass, Zoysia japonica von Steudel and Z. matrella (L.) Merrill, respectively] represented a range in resistance to S. frugiperda. Differential recovery of larvae released as first instars reflected this gradient in resistance of Cavalier > or = Palisades > or = TifSport = TifEagle > or = 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 reflecting 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 first instars were placed in the field; 2,368 were recovered; 468 parasitoids were subsequently reared; 92.2% were A. laphygmae. In the field, 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 five grass cultivars. No parasitoids of older larvae or pupae were observed.

Turfgrass Species and Cultivar Influences on Survival and Parasitism of Fall Armyworm

Interactions between host plant resistance and biological control may benefit or hinder pest management efforts. Turfgrass cultivars have rarely been tested for extrinsic resistance characteristics such as occurrence and performance of beneficial arthropods on plant genotypes with resistance to known turf pests. Parasitism of fall armyworm, Spodoptera frugiperda (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, Zoysia japonica von Steudel and Z. matrella (L.) Merrill, respectively] represented a range in resistance to S. frugiperda. Differential recovery of larvae released as first instars reflected 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 reflecting 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 first instars were placed in the field; 2,368 were recovered; 468 parasitoids were subsequently reared; 92.2% were A. laphygmae. In the field, 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 five grass cultivars. No parasitoids of older larvae or pupae were observed.

Seasonal abundance of aphids (Homoptera: Aphididae) in wheat and their role as barley yellow dwarf virus vectors in the South Carolina coastal plain.

Aphid (Homoptera: Aphididae) seasonal flight activity and abundance in wheat, Triticum aestivum L., and the significance of aphid species as vectors of barley yellow dwarf virus were studied over a nine-year period in the South Carolina coastal plain. Four aphid species colonized wheat in a consistent seasonal pattern. Greenbug, Schizaphis graminum (Rondani), and rice root aphid, Rhopalosiphum rufiabdominalis (Sasaki), colonized seedlingwheat immediately after crop emergence, with apterous colonies usually peaking in December or January and then declining for the remainder of the season. These two aphid species are unlikely to cause economic loss on wheat in South Carolina, thus crop managers should not have to sample for the subterranean R. rufiabdominalis colonies. Bird cherry-oat aphid, Rhopalosiphum padi (L.), was the second most abundant species and the most economically important. Rhopalosiphum padi colonies usually remained below 10/row-meter until peaking in February or March. Barley yellow dwarf incidence and wheat yield loss were significantly correlated with R. padi peak abundance and aphid-day accumulation on the crop. Based on transmission assays, R. padi was primarily responsible for vectoring the predominant virus serotype (PAV) we found in wheat. Pest management efforts should focus on sampling for and suppressing this aphid species. December planting reduced aphid-day accumulation and barley yellow dwarf incidence, but delayed planting is not a practical management option. English grain aphid, Sitobion avenae (F.), was the last species to colonize wheat each season, and the most abundant. Sitobion avenae was responsible for late-season virus transmission and caused direct yield loss by feeding on heads and flag leaves during an outbreak year.

Sustainability of Siberia and Far East Russia's Forest Resource

The objective of this study is to project the sustainability of Siberia and Far East Russia's forest resource. This projection involves using empirical data to evaluate the impact of increased ecological protection and increased management activities, such as fire prevention, pest management, and regeneration efforts. As a result of these projections, we quantify a biologically sustainable harvesting level. In 1988, there were an estimated 551.6 million hectares of forested area in Siberia and Far East Russia in the major forest types. Of this total, about 55 percent are nonexploitable forests which are protected from harvesting due to ecological limitations. Exploitable forests contained an estimated total growing-stock volume of 29.8 billion cubic meters and nonexploitable forests contained 30.7 billion cubic meters. Projections based on implementation of selected management actions on exploitable forests show a potential to maintain a sustainable harvest level of almost 260 million cubic meters by 2028, and more than 275 million cubic meters by 2068.

Preference of Twolined Spittlebug for Ilex Species, Hybrids and Cultivars

Abstract Preference of twolined spittlebug, Prosapia bicincta (Say), for holly species and cultivars was evaluated in the laboratory using detached leaf assays. Field evaluations of spittlebug preference confirmed the high level of susceptibility of holly taxa with Ilex cassine L. or I. opaca Ait. parentage. Taxa observed in the field were rated as highly preferred (10 taxa), moderately (15 taxa), slightly (49), or not preferred (63) based on number of spittlebugs found infesting plants and degree of damage apparent during the two-year study. Increased production and use of pest-resistant plant material reduces the need for pesticide use and provides a good foundation for integrated pest management efforts.

Immigrant arthropod pests: Ke Chung Kim gives a new perspective

Immigrant arthropod pests, namely insects and mites, constitute a major economic threat to the preduction of foods, fibre and other renewable natural resources throughout the world. In North America, 1683 immigrant species were recorded by 1983, of which 235 species are important pests and an additional 630 species are pests of lesser importance. The important pest species of foreign origin constitute approximately 40% of the 600 serious arthropod pests which warrant control measures (Sailer, 1983), and they cause as much as 50% of the total economic losses by pest species which are estimated to be more than 10 000 species (Schwartz and Klassen, 1981). The most notorious pests, such as boll weevil ( Anthonomus grandis grandis Boheman), European corn borer [ Ostrinia nubilalis (Hübner)], gypsy moth [ Lymantria dispar (Linnaeus)], Japanese beetle ( Popillia japonica Newman), and codling moth [ Laspeyresia pomonella (Linnaeus)], are immigrants. For the last 50 years, major pest management efforts have been directed to these and other immigrant pests.

Control of the Golden Nematode in the United States*

The golden nematode is considered the most serious pest threatening the potato industry of the United States. Since its discovery on Long Island, New York, federal, state, and local governments have joined forces to eliminate the threat of the golden nematode to the potato industry of the United States. This effort has involved the close cooperation of research, regulatory, and extension personnel as well as potato growers. The resulting program is one of the largest pest-management efforts ever attempted. This article is an account of the golden nematode control program from its inception in the 1940s until the present.