Phylogenetic Placement of Pentatomid Stink Bug Gut Symbionts

Insect bacterial symbionts are ubiquitous, however, only a few groups of host families have been well studied in relation to their associations with microbes. The determination of the phylogenetic relationships among bacteria associated with different species within an insect family can provide insights into the biology and evolution of these interactions. We studied the phylogenetic placement of vertically transmitted bacterial symbionts associated with the posterior midgut (crypt-bearing) region of pentatomid stink bugs (Hemiptera, Pentatomidae). Our results demonstrate that different host species carried one major bacterium in their midgut. Phylogenetic analyses of the 16S rRNA gene sequences obtained from the midgut of stink bugs placed all symbionts in a clade with Erwinia and Pantoea species, both plant-associated bacteria. Results indicate that symbiont monophyly occurs among recently diverged taxa (e.g., within a genus) but does not occur in the Pentatomidae. Results suggest that these vertically transmitted symbionts are occasionally replaced by other taxonomically similar bacteria over evolutionary time. Our findings highlight how the evolutionary history of hemipteran symbionts in unexplored host families may have unpredictable levels of complexity.     

Horizontal Transfer of Bacterial Symbionts: Heritability and Fitness Effects in a Novel Aphid Host

Members of several bacterial lineages are known only as symbionts of insects and move among hosts through maternal transmission. Such vertical transfer promotes strong fidelity within these associations, favoring the evolution of microbially mediated effects that improve host fitness. However, phylogenetic evidence indicates occasional horizontal transfer among different insect species, suggesting that some microbial symbionts retain a generalized ability to infect multiple hosts. Here we examine the abilities of three vertically transmitted bacteria from the Gammaproteobacteria to infect and spread within a novel host species, the pea aphid, Acyrthosiphon pisum. Using microinjection, we transferred symbionts from three species of natural aphid hosts into a common host background, comparing transmission efficiencies between novel symbionts and those naturally infecting A. pisum. We also examined the fitness effects of two novel symbionts to determine whether they should persist under natural selection acting at the host level. Our results reveal that these heritable bacteria vary in their capacities to utilize A. pisum as a host. One of three novel symbionts failed to undergo efficient maternal transmission in A. pisum, and one of the two efficiently transmitted bacteria depressed aphid growth rates. Although these findings reveal that negative fitness effects and low transmission efficiency can prevent the establishment of a new infection following horizontal transmission, they also indicate that some symbionts can overcome these obstacles, accounting for their widespread distributions across aphids and related insects.     

Semiochemical Production and Laboratory Behavior Response of the Brown Marmorated Stink Bug,Halyomorpha Halys

Background

The brown marmorated stink bug (BMSB) is an exotic insect pest that was first recognized in the United States in 2001. As of today, it has been found in more than 42 states. BMSB has a very broad host plant range and damage to crops in mid-Atlantic States has reached a critical level. A reliable and accurate tool for infestation detection and population monitoring is urgently needed to provide better and more timely interventions. Pheromones produced by male BMSB have been previously identified and are currently used in BMSB infestation detection. However, the conditions affecting BMSB production of these pheromones were unknown.

Methodology/Principal Findings

In this study, we collected headspace volatiles from male BMSB under laboratory conditions, measured the temporal patterns of release of these pheromones, and assayed the attractiveness to conspecifics. In addition to the pheromone components, tridecane (C13) and E-2-decenal (an alarm compound) were observed in headspace collections of males, as well as in females and nymphs. Exposure of pheromone-emitting adult males to synthetic C13 greatly reduced pheromone emission.

Conclusions/Significance

This information should lead to a better understanding of the biology, physiology, and chemical ecology of BMSB, which will help scientists and growers develop more efficient strategies based on natural products to manage BMSB population, therefore, reducing pesticide usage and protecting the crops from BMSB damage.     

Nosema maddoxi sp. nov. (Microsporidia,Nosematidae), a Widespread Pathogen of the Green Stink Bug Chinavia hilaris (Say) and the Brown Marmorated Stink Bug Halyomorpha halys (Stål)

We describe a unique microsporidian species that infects the green stink bug, Chinavia hilaris; the brown marmorated stink bug, Halyomorpha halys; the brown stink bug, Euschistus servus; and the dusky stink bug, Euschistus tristigmus. All life stages are unikaryotic, but analysis of the consensus small subunit region of the ribosomal gene places this microsporidium in the genus Nosema, which historically has been characterized by diplokaryotic life stages. It is also characterized by having the reversed arrangement of the ribosomal gene (LSU –ITS‐ SSU) found in species within the “true Nosema” clade. This microsporidium is apparently Holarctic in distribution. It is present in H. halys both where it is native in Asia and where it is invasive in North America, as well as in samples of North American native C. hilaris collected prior to the introduction of H. halys from Asia. Prevalence in H. halys from mid‐Atlantic, North America in 2015–2016 ranged from 0.0% to 28.3%, while prevalence in C. hilaris collected in Illinois in 1970–1972 ranged from 14.3% to 58.8%. Oral infectivity and pathogenicity were confirmed in H. halys and C. hilaris. Morphological, ultrastructural, and ecological features of the microsporidium, together with a molecular phylogeny, establish a new species named Nosema maddoxi sp. nov.     

Electropenetrography (EPG): a Breakthrough Tool Unveiling Stink Bug (Pentatomidae) Feeding on Plants

In this article, we review and discuss the potential use of EPG (electropenetrography) as a powerful tool to unveil the feeding process of phytophagous stink bugs (pentatomids). These bugs are relatively big and vigorous, which presents a problem during wiring (i.e., attachment of the gold wire on the bug’s pronotum) for use in EPG. Once this challenge was overcome, using the sand paper-and-wire technique, several species have been studied using EPG, yielding waveforms that, coupled with histological studies, revealed the ingestion sites on different host plants. These sites include vascular tissues (xylem and phloem), parenchyma tissue, and seed endosperm. Stink bugs usually feed by secreting a gelling saliva to create a salivary sheath that surrounds the stylets and anchors/supports/lubricates them. However, using the cell rupture feeding strategy and the tactic of combined laceration (mechanical movements of the stylets) and maceration (action of chemical enzymes) breaks the plant cells enabling ingestion. The number of ingestion events and their duration is variable according to the feeding site. Waveforms generated have typical patterns according to the feeding site. Recent studies with several species of stink bugs have started to demonstrate the potential of EPG as a tool to unveil their feeding behavior. This may also be useful in the applied field of stink bug management, such as the development and screening of resistant genotypes and the action of chemical insecticides affecting their feeding and survivorship.     

Green Stink Bug (Hemiptera: Pentatomidae) Recorded as a New Pest of Olive in India

During the survey of olive orchards in Jammu and Kashmir, various insect pests were recorded infesting olive which include, olive psylla, olive black scale, scarab beetle and green stink bug. Among these greenstinkbug, Nezara virudula (L.) [Hemiptera: Pentatomidae] has been recorded for the first time in India.     

Evidence of Environmental and Vertical Transmission of Burkholderia Symbionts in the Oriental Chinch Bug,Cavelerius saccharivorus (Heteroptera: Blissidae)

The vertical transmission of symbiotic microorganisms is omnipresent in insects, while the evolutionary process remains totally unclear. The oriental chinch bug, Cavelerius saccharivorus (Heteroptera: Blissidae), is a serious sugarcane pest, in which symbiotic bacteria densely populate the lumen of the numerous tubule-like midgut crypts that the chinch bug develops. Cloning and sequence analyses of the 16S rRNA genes revealed that the crypts were dominated by a specific group of bacteria belonging to the genus Burkholderia of the Betaproteobacteria. The Burkholderia sequences were distributed into three distinct clades: the Burkholderia cepacia complex (BCC), the plant-associated beneficial and environmental (PBE) group, and the stinkbug-associated beneficial and environmental group (SBE). Diagnostic PCR revealed that only one of the three groups of Burkholderia was present in ∼89% of the chinch bug field populations tested, while infections with multiple Burkholderia groups within one insect were observed in only ∼10%. Deep sequencing of the 16S rRNA gene confirmed that the Burkholderia bacteria specifically colonized the crypts and were dominated by one of three Burkholderia groups. The lack of phylogenetic congruence between the symbiont and the host population strongly suggested host-symbiont promiscuity, which is probably caused by environmental acquisition of the symbionts by some hosts. Meanwhile, inspections of eggs and hatchlings by diagnostic PCR and egg surface sterilization demonstrated that almost 30% of the hatchlings vertically acquire symbiotic Burkholderia via symbiont-contaminated egg surfaces. The mixed strategy of symbiont transmission found in the oriental chinch bug might be an intermediate stage in evolution from environmental acquisition to strict vertical transmission in insects.     

Characterization of Overwintering Sites of the Invasive Brown Marmorated Stink Bug in Natural Landscapes Using Human Surveyors and Detector Canines

Halyomorpha halys is an invasive species from Asia causing major economic losses in agricultural production in the mid-Atlantic region of the United States. Unlike other crop pests, H. halys is also well-known for nuisance problems in urban, suburban, and rural areas, as massive numbers of adults often invade human-made structures to overwinter inside protected environments. Research efforts have focused on populations in human-made structures while overwintering ecology of H. halys in natural landscapes is virtually unknown. We explored forested landscapes in the mid-Atlantic region to locate and characterize natural overwintering structures used by H. halys. We also evaluated the use of detector canines to locate overwintering H. halys to enhance the accuracy and efficiency of surveys. From these studies, we indentified shared characteristics of overwintering sites used by H. halys in natural landscapes. Overwintering H. halys were recovered from dry crevices in dead, standing trees with thick bark, particularly oak (Quercus spp.) and locust (Robinia spp.); these characteristics were shared by 11.8% of all dead trees in surveyed landscapes. For trees with favorable characteristics, we sampled ∼20% of the total above-ground tree area and recovered 5.9 adults per tree from the trees with H. halys present. Two detector canines were successfully trained to recognize and detect the odor of adult H. halys yielding >84% accuracy in laboratory and semi-field trials. Detector canines also found overwintering H. halys under field conditions. In particular, overwintering H. halys were recovered only from dead trees that yielded positive indications from the canines and shared key tree characteristics established by human surveyors. The identified characteristics of natural overwintering sites of H. halys will serve as baseline information to establish crop economic risk levels posed by overwintering populations, and accordingly develop sustainable management programs.     

Comparison of Substrate-Borne Vibrational Signals of Two Congeneric Stink Bug Species, Thyanta pallidovirens and T. custator accerra (Heteroptera: Pentatomidae)

Vibrational signals (songs) were recorded and compared for two stink bug species, Thyanta pallidovirens and T. custator accerra. Females of both species produced two songs. Male T. pallidovirens also produced two songs, whereas male T. c. accerra produced four. Songs emitted by females of both species were comparable in structure and function, as was one of the male-produced songs. During the courtship phase of mating behavior, males of both species emitted a song with similar function but different temporal and spectral properties. Basic properties of songs, such as the dominant frequencies, were similar to those of songs of other pentatomid species, but the extensive use of frequency modulation and overlapping duets were novel. Differences in songs, combined with differences in male-produced pheromones, may play a role in the reproductive isolation of these congeners.     

Adjacent Habitat Influence on Stink Bug (Hemiptera: Pentatomidae) Densities and the Associated Damage at Field Corn and Soybean Edges

The local dispersal of polyphagous, mobile insects within agricultural systems impacts pest management. In the mid-Atlantic region of the United States, stink bugs, especially the invasive Halyomorpha halys (Stål 1855), contribute to economic losses across a range of cropping systems. Here, we characterized the density of stink bugs along the field edges of field corn and soybean at different study sites. Specifically, we examined the influence of adjacent managed and natural habitats on the density of stink bugs in corn and soybean fields at different distances along transects from the field edge. We also quantified damage to corn grain, and to soybean pods and seeds, and measured yield in relation to the observed stink bug densities at different distances from field edge. Highest density of stink bugs was limited to the edge of both corn and soybean fields. Fields adjacent to wooded, crop and building habitats harbored higher densities of stink bugs than those adjacent to open habitats. Damage to corn kernels and to soybean pods and seeds increased with stink bug density in plots and was highest at the field edges. Stink bug density was also negatively associated with yield per plant in soybean. The spatial pattern of stink bugs in both corn and soybeans, with significant edge effects, suggests the use of pest management strategies for crop placement in the landscape, as well as spatially targeted pest suppression within fields.     

Impact of Light and Temperature on the Uptake of Algal Symbionts by Coral Juveniles

The effects of temperature and light on the breakdown of the coral-Symbiodinium symbiosis are well documented but current understanding of their roles during initial uptake and establishment of symbiosis is limited. In this study, we investigate how temperature and light affect the uptake of the algal symbionts, ITS1 types C1 and D, by juveniles of the broadcast-spawning corals Acropora tenuis and A. millepora. Elevated temperatures had a strong negative effect on Symbiodinium uptake in both coral species, with corals at 31°C showing as little as 8% uptake compared to 87% at 28°C. Juveniles in high light treatments (390 µmol photons m⁻² s⁻¹) had lower cell counts across all temperatures, emphasizing the importance of the light environment during the initial uptake phase. The proportions of the two Symbiodinium types taken up, as quantified by a real time PCR assay using clade C- and D-specific primers, were also influenced by temperature, although variation in uptake dynamics between the two coral species indicates a host effect. At 28°C, A. tenuis juveniles were dominated by C1 Symbiodinium, and while the number of D Symbiodinium cells increased at 31°C, they never exceeded the number of C1 cells. In contrast, juveniles of A. millepora had approximately equal numbers of C1 and D cells at 28°C, but were dominated by D at 30°C and 31°C. This study highlights the significant role that environmental factors play in the establishment of coral-Symbiodinium symbiosis and provides insights into how potentially competing Symbiodinium types take up residence in coral juveniles.     

Biology of a Neotropical Harlequin Stink Bug, <Emphasis Type="Italic">Runibia perspicua</Emphasis> (F.)

Laboratory and field studies were conducted with nymphs and adults of the Neotropical stink bug Runibia perspicua (F.) to evaluate their biology on plants. Total nymph mortality was ca. 13% on immature fruits of Brunfelsia australis Benth. (IFBA) and 90% on raw shelled peanuts, Arachis hypogaea L. (RSP); no nymphs survived on immature pods of green bean, Phaseolus vulgaris L., or on immature fruits of privet, Ligustrum lucidum Ait. Nymph developmental time was ca. 36 on IFBA and 55 days on RSP. Body weight was significantly greater when nymphs were raised isolated compared to those raised in groups. Adult feeding activity was greater than third instars on IFBA. Adult longevity on IFBA + cherry tomato, Solanum lycopersicum L. fruit, reached ca. 150 days. On IFBA, fecundity was 2.5 egg masses/female and 48.3 eggs/female; 25.6% of the eggs hatched. Adults did not reproduce on tomato. Body weight gain did not increase significantly for both sexes during the first four weeks of adult life on IFBA. In the field, plants of B. australis were surveyed in Passo Fundo, RS (28°15′S; 52°24′W). The majority of egg masses were deposited on the lower (abaxial) surface of leaves. Nymphs aggregated on immature fruits, and adults were seldom found on the plants. These are the first data on the performance of R. perspicua on B. australis indicating that this plant species is suitable to the bug’s biology.     

Beneficial Effect of Verminephrobacter Nephridial Symbionts on the Fitness of the Earthworm Aporrectodea tuberculata

Almost all lumbricid earthworms (Oligochaeta: Lumbricidae) harbor species-specific Verminephrobacter (Betaproteobacteria) symbionts in their nephridia (excretory organs). The function of the symbiosis, and whether the symbionts have a beneficial effect on their earthworm host, is unknown; however, the symbionts have been hypothesized to enhance nitrogen retention in earthworms. The effect of Verminephrobacter on the life history traits of the earthworm Aporrectodea tuberculata (Eisen) was investigated by comparing the growth, development, and fecundity of worms with and without symbionts given high (cow dung)- and low (straw)-nutrient diets. There were no differences in worm growth or the number of cocoons produced by symbiotic and aposymbiotic worms. Worms with Verminephrobacter symbionts reached sexual maturity earlier and had higher cocoon hatching success than worms cured of their symbionts when grown on the low-nutrient diet. Thus, Verminephrobacter nephridial symbionts do have a beneficial effect on their earthworm host. Cocoons with and without symbionts did not significantly differ in total organic carbon, total nitrogen, or total hydrolyzable amino acid content, which strongly questions the hypothesized role of the symbionts in nitrogen recycling for the host.Symbiosis has long been recognized as a source of evolutionary innovation (24), and the acquisition of symbionts can enable animal hosts to exploit previously inaccessible niches (3). The phylum Annelida is no exception to this; chemosynthetic symbionts in marine annelids (e.g., the giant tubeworm Riftia sp. and other gutless marine oligochaetes [9]) gain energy from the oxidation of reduced sulfur compounds and fix CO₂ and supply their animal host with fixed carbon. A more obscure partnership is known from the bone-eating annelid Osedax sp., where endosymbionts help degrade the bones of whale carcasses, the only known habitat of the worms (33). The medicinal leech Hirudo sp., like other blood-feeding animals (3, 7), has symbionts that are thought to produce essential vitamins missing from a blood meal (13). In addition, leeches have a number of symbionts of unknown function in their nephridia (excretory organs) (18). Earthworms (Oligochaeta: Lumbricidae) have also long been known to harbor symbiotic bacteria in their nephridia (19, 36). The function of this symbiosis, however, is still not known, but the stability of the symbiosis over evolutionary time (23) suggests that the symbionts benefit the host.The earthworm symbionts reside in the nephridia and have therefore been proposed to be involved in internal recycling of nitrogen in the host (29). The earthworm nephridia play an important role in both nitrogenous waste excretion and osmoregulation (20). The nephridia are found in pairs in each segment of the worm and consist of a coiled tube leading from the coelom to the exterior (Fig. ​(Fig.1).1). The tube forms three loops, and the symbiotic bacteria are situated in the ampulla in the second loop, where they form a dense population lining the lumen wall (19, 36).Open in a separate windowFIG. 1.The nephridia are found as paired organs in each segment of the worm. The nephridostome (the inlet to the nephridia) protrudes into the previous segment. The nephridial tube forms three loops and finally empties out through the body wall via the nephridopore. The symbionts (black) reside in the ampulla in the second loop. (Modified from reference 23 with permission.)The symbionts form the monophyletic genus Verminephrobacter (Betaproteobacteria) (30, 36); they are species specific and present in almost all lumbricid earthworms (23). The Verminephrobacter symbionts are transmitted vertically via the cocoon, where they are deposited along with eggs and sperm (5). During embryogenesis, the symbionts migrate into the developing nephridia, and after the worm hatches, the symbionts can no longer infect (5, 6). By taking advantage of the vertical transmission mode, it has been possible to establish symbiont-free earthworm cultures in the laboratory through controlled antibiotic treatment of newly deposited cocoons (5; this study). Separation of the symbiotic partners allows studies of the effect of the symbionts on their earthworm hosts.Pandazis (29) hypothesized that the symbionts enhance earthworm nitrogen retention by excreting proteolytic enzymes that will degrade peptides and proteins lost in urine; this would allow the earthworm to reabsorb the resulting amino acids. As a consequence, earthworms cured of their symbionts should have a lower fitness level than control worms when grown under nitrogen-limiting conditions. To test this hypothesis, growth, development, fecundity, and cocoon hatching success were compared for symbiotic and aposymbiotic earthworms of the species Aporrectodea tuberculata (Eisen) under high and low nutrient availability conditions.     

Biochemical Aspects of the Soybean Response to Herbivory Injury by the Brown Stink Bug Euschistus heros (Hemiptera: Pentatomidae)

Plant defense response is an elaborate biochemical process shown to depend on the plant genetic background and on the biological stressor. This work evaluated the soybean biochemical foliar response to brown stink bug herbivory injury through an analysis of redox metabolism and proteomic 2DE profiles of susceptible (BRS Silvania RR) and resistant (IAC-100) varieties. The activity of lipoxygenase-3, guaiacol peroxidase, catalase and ascorbate peroxidase was monitored every 24 h up to 96 h. In the susceptible variety, injury caused an increase in the activities of lipoxygenase 3 and guaiacol peroxidase, no change in ascorbate peroxidase, and a decrease in catalase. In the resistant variety, injury did not cause an alteration of any of these enzymes. The proteomic profiles were evaluated after 24 h of injury and revealed to have a similar proportion (4–5%) of differential protein expression in both varieties. The differential proteins, identified by mass spectrometry, in the susceptible variety were related to general stress responses, to plant defense, and to fungal infections. However, in the resistant variety, the identified change in protein profile was related to Calvin cycle enzymes. While the susceptible variety showed adaptive changes in redox metabolism and expression of stress-responsive proteins, the resistant showed a defense response to circumvent the biological stressor.     

Male Courtship Behavior and Weapon Trait as Indicators of Indirect Benefit in the Bean Bug,Riptortus pedestris

Females prefer male traits that are associated with direct and/or indirect benefits to themselves. Male–male competition also drives evolution of male traits that represent competitive ability. Because female choice and male–male competition rarely act independently, exploring how these two mechanisms interact is necessary for integrative understanding of the evolution of sexually selected traits. Here, we focused on direct and indirect benefits to females from male attractiveness, courtship, and weapon characters in the armed bug Riptortus pedestris. The males use their hind legs to fight other males over territory and perform courtship displays for successful copulation. Females of R. pedestris receive no direct benefit from mating with attractive males. On the other hand, we found that male attractiveness, courtship rate, and weapon size were significantly heritable and that male attractiveness had positive genetic covariances with both courtship rate and weapon traits. Thus, females obtain indirect benefits from mating with attractive males by producing sons with high courtship success rates and high competitive ability. Moreover, it is evident that courtship rate and hind leg length act as evaluative cues of female choice. Therefore, female mate choice and male–male competition may facilitate each other in R. pedestris. This is consistent with current basic concepts of sexual selection.     

孵化温度对王锦蛇胚胎代谢和幼体适合度的影响

孵化温度所驱动的爬行动物的表型变异是生理生态学研究的热点。本研究以王锦蛇(Elaphe carinata)为实验动物,检验了24℃和28℃孵化温度对王锦蛇胚胎代谢速率、孵化过程中的卵重量、孵出幼体代谢和行为的影响。研究结果显示:卵重和胚胎的呼吸代谢均与孵化时间呈正相关;28℃下胚胎代谢速率大于24℃;幼蛇孵出15 d内体重随着生长时间的延长而减小,24℃孵出幼体的代谢速率大于28℃孵出幼体,两温度下孵出幼体的呼吸代谢速率和生长时间无显著关系;28℃孵出幼体的疾游速和吐信频次均大于24℃;两孵化温度孵出幼体的选择体温无显著差异,但在消耗完体内的剩余卵黄后28℃孵出幼体有60%的个体摄食,而24℃孵出幼体无摄食个体。总体而言,王锦蛇28℃孵出幼体适合度优于24℃孵出幼体。     

Contrasting Role of Temperature in Structuring Regional Patterns of Invasive and Native Pestilential Stink Bugs

Objectives

Assessment and identification of spatial structures in the distribution and abundance of invasive species is important for unraveling the underlying ecological processes. The invasive agricultural insect pest Halyomorpha halys that causes severe economic losses in the United States is currently expanding both within United States and across Europe. We examined the drivers of H. halys invasion by characterizing the distribution and abundance patterns of H. halys and native stink bugs (Chinavia hilaris and Euschistus servus) across eight different spatial scales. We then quantified the interactive and individual influences of temperature, and measures of resource availability and distance from source populations, and their relevant spatial scales. We used Moran’s Eigenvector Maps based on Gabriel graph framework to quantify spatial relationships among the soybean fields in mid-Atlantic Unites States surveyed for stink bugs.

Findings

Results from the multi-spatial scale, multivariate analyses showed that temperature and its interaction with resource availability and distance from source populations structures the patterns in H. halys at very broad spatial scale. H. halys abundance decreased with increasing average June temperature and distance from source population. H. halys were not recorded at fields with average June temperature higher than 23.5°C. In parts with suitable climate, high H. halys abundance was positively associated with percentage developed open area and percentage deciduous forests at 250m scale. Broad scale patterns in native stink bugs were positively associated with increasing forest cover and, in contrast to the invasive H. halys, increasing mean July temperature. Our results identify the contrasting role of temperature in structuring regional patterns in H. halys and native stink bugs, while demonstrating its interaction with resource availability and distance from source populations for structuring H. halys patterns.

Conclusion

These results help predicting the pest potential of H. halys and vulnerability of agricultural systems at various regions, given the climatic conditions, and its interaction with resource availability and distance from source populations. Monitoring and control efforts within parts of the United States and Europe with more suitable climate could focus in areas of peri-urban developments with deciduous forests and other host plants, along with efforts to reduce propagule pressure.     

Landscape Factors Facilitating the Invasive Dynamics and Distribution of the Brown Marmorated Stink Bug,Halyomorpha halys (Hemiptera: Pentatomidae), after Arrival in the United States

The brown marmorated stink bug, Halyomorpha halys, a native of Asia, has become a serious invasive pest in the USA. H. halys was first detected in the USA in the mid 1990s, dispersing to over 41 other states. Since 1998, H. halys has spread throughout New Jersey, becoming an important pest of agriculture, and a major nuisance in urban developments. In this study, we used spatial analysis, geostatistics, and Bayesian linear regression to investigate the invasion dynamics and colonization processes of this pest in New Jersey. We present the results of monitoring H. halys from 51 to 71 black light traps that were placed on farms throughout New Jersey from 2004 to 2011 and examined relationships between total yearly densities of H. halys and square hectares of 48 landscape/land use variables derived from urban, wetland, forest, and agriculture metadata, as well as distances to nearest highways. From these analyses we propose the following hypotheses: (1) H. halys density is strongly associated with urban developments and railroads during its initial establishment and dispersal from 2004 to 2006; (2) H. halys overwintering in multiple habitats and feeding on a variety of plants may have reduced the Allee effect, thus facilitating movement into the southernmost regions of the state by railroads from 2005 to 2008; (3) density of H. halys contracted in 2009 possibly from invading wetlands or sampling artifact; (4) subsequent invasion of H. halys from the northwest to the south in 2010 may conform to a stratified-dispersal model marked by rapid long-distance movement, from railroads and wetland rights-of-way; and (5) high densities of H. halys may be associated with agriculture in southern New Jersey in 2011. These landscape features associated with the invasion of H. halys in New Jersey may predict its potential rate of invasion across the USA and worldwide.