Megacopta Cribraria Research Articles

A fortuitous find: a unique haplotype of Ooencyrtus nezarae Ishii (Encyrtidae: Encyrtinae) discovered in Florida.

The adventive arrival of biological control agents circumvents the regulatory process by introducing exotic species to control invasive pests and is generally followed by post hoc risk evaluation. The bean plataspid, Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), is an invasive pest of leguminous crops in the south-eastern United States that was eventually followed by two parasitoid wasps from its range in the eastern hemisphere, Paratelenomus saccharalis (Dodd) (Scelionidae) and Ooencyrtus nezarae Ishii (Encyrtidae). In North Central Florida, sentinel egg masses, intended to capture Paratelenomus saccharalis, instead yielded Ooencyrtus nezarae, which was previously known only from Alabama (Ademokoya et al. 2018). Two generations of O. nezarae were subsequently reared in the laboratory. COI sequences from the Florida population of O. nezarae differed by 1.3% from the Alabama population and the presence of a different haplotype suggests the possibility of a separate introduction. Laboratory parasitism rates, sex ratios, morphology, molecular diagnosis and implications for agriculture are discussed.

Soybean Host Plant Resistance to Megacopta cribraria (Hemiptera: Plataspidae) and the Potential Role of Leaf Trichome Density.

Megacopta cribraria (F.) (Hemiptera: Plataspidae) is an invasive pest of soybean that has spread across the southeastern United States since its initial discovery in 2009 in Georgia. Previous studies in the southeastern states have documented both the population dynamics of this pest and host plant resistance (HPR) among soybean varieties, although the specific mechanisms of HPR remain unknown. The objectives of this study were, therefore, to 1) quantify field resistance to M. cribraria in multiple soybean varieties in two states previously affected by severe M. cribraria infestations, North Carolina (NC) and South Carolina (SC); and 2) study the role of soybean trichome density in imparting resistance against M. cribraria. Soybean variety 'Camp' was least attractive to M. cribraria, through time and locations, suggesting consistent resistance. Other varieties showed variable performance among the locations and sampling dates. A significant difference in trichome density was evident. However, there was no correlation between trichome density and M. cribraria infestation. Compared to a previously published study in the same location, when M. cribraria adults emerging from overwintering dispersed into soybeans, in our study only first-generation adults dispersed into soybeans. Considering the current trend of significantly lower M. cribraria infestation rates in North and South Carolina, this pest may be finally succumbing to indigenous natural enemies and should be managed by incorporating integrated pest management tactics, such as HPR, that help conserve natural enemy populations.

Paratelenomus anu Rajmohana, Sachin & Talamas (Hymenoptera, Scelionidae): description and biology of a new species of phoretic egg parasitoid of Megacopta cribraria (Fab.) (Hemiptera, Plataspidae)

Paratelenomus anuRajmohana, Sachin & Talamas,sp. nov.(Hymenoptera: Scelionidae) is an egg parasitoid of the kudzu bug,Megacopta cribraria(Fab.) (Hemiptera: Plataspidae). It is morphologically and genetically distinct fromP. saccharalis(Dodd), a well-known egg parasitoid of the same host.Paratelenomus anuis here described from India and diagnosed from other species ofParatelenomusDodd. This parasitoid can be reared easily, has high rates of parasitism, and thus may be significant for the biological control ofM. cribraria.Phoresy is documented inP. anuand provides the first known example of this behavior inParatelenomus.Paratelenomus longus(Kozlov & Lê)syn. nov.andP. mangrovusRajmohana & Narendran,syn. nov.are treated as junior synonyms ofP. tetartus(Crawford), andP. obtusus(Lê)syn. nov.is treated as a junior synonym ofP. saccharalis.

Flight capacity increases then declines from the core to the margins of an invasive species' range.

Individuals that disperse farther than other individuals are more likely to be on the frontlines of spreading populations and may be more likely to mate with one another as a consequence of their spatial proximity. Over generations, this process-known as spatial sorting-can produce patterns of increasing dispersal ability from a population's core towards the spreading front. By contrast, when the spread of a population is limited by the availability of suitable habitat, theory predicts that range boundaries can select against more dispersive phenotypes and produce patterns of decreasing dispersal capacity towards population margins. In a common garden study of invasive kudzu bugs (Megacopta cribraria)-which are limited by the availability of hostplants in their southern and western margins-I show that midrange individuals fly 49% farther than individuals in the core and 37% farther than individuals at margins. This result highlights that other processes, such as maternal effects or selection at range boundaries, may create more complicated patterns of dispersal ability across landscapes than predicted by models of spatial sorting alone.

Comparative phylogeography of two hemipteran species (Geisha distinctissima and Megacopta cribraria) in the Zhoushan Archipelago of China reveals contrasting genetic structures despite concordant historical demographies.

Continental islands are useful models to explore the roles of shared historical factors in the evolution of sympatric species. However, China's largest continental group of islands, the Zhoushan Archipelago, was neglected by most studies focusing on biodiversity hotspots. Here we investigated the phylogeographic patterns and the historical demography of two sympatric hemipteran insects (Geisha distinctissima and Megacopta cribraria), which shared historical factors in the Zhoushan Archipelago. The results based on mtDNA (COX1, COX2-COX3, and CYTB) and nDNA (28S and ITS2) showed that G. distinctissima diverged into three genetic lineages (L1-L3) ~8.9-13.7 thousand years ago (kya), which coincided with the period of island isolation. However, the three lineages exhibit no clear phylogeographic patterns for frequent asymmetrical gene flow (starting around 5 kya) from the mainland and adjacent islands to other distant islands due to subsequent human activities. In contrast, only one genetic lineage exists for M. cribraria, without any phylogeographic structures. The ancestral range in the mainland as well as in neighboring islands, together with the frequent asymmetrical gene flow of M. cribraria (from the mainland and neighboring islands to more distant islands) within the last 5000 years suggests that human activities may have lead to the colonization of this species in the Zhoushan Archipelago. The contrasting genetic structures indicate shared historical factors but independent evolutionary histories for the two sympatric species in the Zhoushan Archipelago. Our demographic analysis clearly showed that both species underwent population expansion before 5 kya during the post-LGM (Last Glacial Maximum), which indicates that the two species shared concordant historical demographies. This result suggests that the population size of the two species was affected similarly by the climatic oscillations of post-LGM in Eastern China. Together, our findings reveal that the two insect species in the Zhoushan Archipelago exhibit contrasting genetic structures despite concordant historical demographies, which provides an important framework for the exploration of the evolution patterns of sympatric species in the continental island.

Even obligate symbioses show signs of ecological contingency: Impacts of symbiosis for an invasive stinkbug are mediated by host plant context.

Many species interactions are dependent on environmental context, yet the benefits of obligate, mutualistic microbial symbioses to their hosts are typically assumed to be universal across environments. We directly tested this assumption, focusing on the symbiosis between the sap‐feeding insect Megacopta cribraria and its primary bacterial symbiont Candidatus Ishikawaella capsulata. We assessed host development time, survival, and body size in the presence and absence of the symbiont on two alternative host plants and in the insects' new invasive range. We found that association with the symbiont was critical for host survival to adulthood when reared on either host plant, with few individuals surviving in the absence of symbiosis. Developmental differences between hosts with and without microbial symbionts, however, were mediated by the host plants on which the insects were reared. Our results support the hypothesis that benefits associated with this host–microbe interaction are environmentally contingent, though given that few individuals survive to adulthood without their symbionts, this may have minimal impact on ecological dynamics and current evolutionary trajectories of these partners.OPEN RESEARCH BADGES This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://doi.org/10.5061/dryad.kg4bc56

Parasitism declines with distance from the site of introduction for the kudzu bug, Megacopta cribraria (F.), and depends on host density at different spatial scales

Individuals at the frontlines of expanding populations tend to experience less parasitism than those in the core of their range. This reduction in parasitism may contribute to the rapid spread of invasive species because parasites could otherwise reduce host population growth. To better understand patterns of parasitism in the invasive population of the kudzu bug, Megacopta cribraria (F.), we examined how both the proportion of eggs parasitized and the incidence of parasitism—presence or absence of parasitism within a clutch of eggs—varied with distance from the kudzu bug’s site of introduction and with their density at two different spatial scales: at the level of sites (10–20 m2) and the level of the egg clutch (number of eggs in a clutch). Egg clutches were collected from populations along an east–west and a south-north transect of the U.S. invasion. We found that both metrics of parasitism declined with increasing host-density at the site level, which may be a general trend for the wind-dispersed parasites of invasive species. We also found that both metrics of parasitism declined with increasing distance from the site of introduction. However, since kudzu bug density tended to decrease across their invasion gradient and parasitism rates increased with decreasing kudzu bug density, the reductions in parasitism with increasing distance from site of introduction were not discernible if the effect of site-level density was not accounted for; leaving site-level density out of our models made it seem as though there was no distance effect. This finding complicates models that exhibit a “honeymoon phase”, where vanguard populations of the host suffer from little or no parasitism. In addition, we observed a small effect of clutch size on the incidence of parasitism, but no interaction among the spatial scales of density investigated. Our results underscore the importance of considering host density at different scales when seeking to understand trends in parasitism across a host’s invasive range.

Electrophysiological and Behavioral Responses of the Kudzu Bug, Megacopta cribraria (Hemiptera: Plataspidae), to Volatile Compounds from Kudzu and Soybean Plants.

The kudzu bug, Megacopta cribraria, is a key pest of soybean in the United States. Electrophysiological and behavioral responses of adult M. cribraria to kudzu and soybean volatile compounds were examined to identify semiochemicals used for host location. Headspace volatiles collected from undamaged potted plants were analyzed by gas chromatography with electroantennographic detection (GC-EAD). Subsequently, six GC-EAD-active compounds were identified by gas chromatography-mass spectrometry (GC-MS). These six compounds, along with some previously reported insect attractants, were selected for electroantennogram (EAG) assays. The four chemicals that elicited the strongest EAG responses, 1-octen-3-ol, nonanal, benzaldehyde, and ocimene, were selected for evaluation in olfactometer bioassays. Both benzaldehyde and 1-octen-3-ol exhibited dose-dependent responses at higher concentration. Our results provide insight into host location compounds used by adult M. cribraria. These results may be evaluated in future field tests and ultimately useful to develop a semiochemical-based monitoring technique and integrated pest management program for M. cribraria.

Determining Spread Rate of Kudzu Bug (Hemiptera: Plataspidae) and Its Associations With Environmental Factors in a Heterogeneous Landscape.

By the end of 2017, kudzu bug was reported in 652 counties in the United States since it was first observed in Georgia in 2009. Modeling its invasion dynamics is valuable to guide management through early detection and prevention of further invasion. Herein, we initially estimated the spread rate of kudzu bug with county-level invasion records and then determined important spatial factors affecting its spread during years 2010-2016. As kudzu bug infests a large heterogeneous area and shows asymmetric spread, we first utilized spatially constrained clustering (SCC), an unsupervised machine learning method, to divide the infested area into eight spatially contiguous and environmentally homogenous neighborhoods. We then used distance regression and boundary displacement methods to estimate the spread rates in all neighborhoods. Finally, we applied multiple regression to determine spatial factors influencing the spread of kudzu bug. The average spread rate reached 76 km/yr by boundary displacement method; however, the rate varied largely among eight neighborhoods (45-144 km/yr). In the southern region of the infested area, host plant density and wind speed were positively associated with the spread rate, whereas mean annual temperature, precipitation in the fall, and elevation had inverse relationships. In the northern region, January minimum temperature, wind speed, and human population density showed positive relationships. This study increases the knowledge on the spread dynamics of kudzu bug. Our research highlights the utility of SCC to determine natural clustering in a large heterogeneous region for better modeling of local spread patterns and determining important factors affecting the invasions.

The effect of pseudo-absence selection method on transferability of species distribution models in the context of non-adaptive niche shift

Transferability of species distribution models (SDMs) is key to predicting invasion patterns and can be challenged if niche shift occurs in the invaded range. When using native occurrences to estimate potential invasions with presence-only modeling methods, it is important to constrain the pseudo-absence (PA) sampling to the species’ native range. However, some studies including highly cited ones, do not follow this approach to selecting PA samples. In this research, we addressed two questions using an invasive species in the United States (U.S.), kudzu bug (Megacopta cribraria): 1) is model transferability challenged by a non-adaptive niche shift? and 2) is model performance affected by use of PA samples from outside the native range of the species? Kudzu bug is native to Asia, with recently observed non-adaptive niche shift in the U.S. To answer the first question, we quantified the environmental space anisotropy and non-adaptive niche change, and then evaluated the performances of seven SDMs. To answer the second question, we further compared the interpolation and transferability of seven SDMs trained with PAs from the native range and from both native and invaded ranges. We confirmed that the environmental space anisotropy (P = 0.01) and non-adaptive niche change (P = 0.01) are both statistically significant. Of the seven SDMs used, four models had transferability indices higher than 0.9. Boosted regression tree and random forests both had good interpolation and transferability (AUC>0.80 and kappa>0.60), whereas three other models showed good interpolation and fair transferability (AUC>0.70 and kappa>0.40). Inclusion of pseudo-absences from the invaded range significantly increased the interpolation (P < 0.001) but decreased the transferability (P < 0.01) of almost all models. Our findings suggest that SDMs can show good transferability with non-adaptive niche shift, thus native occurrence information should be used in similar situation. We confirmed that it is crucial to constrain the PAs to the same spatial range as presences to accurately model potential invasions.

First Report of Soybean Vein Necrosis Virus Infecting Kudzu (Pueraria montana) in the United States of America

Soybean vein necrosis virus (SVNV) is a virus originally discovered in Arkansas and Tennessee and is currently present in all major soybean-producing states in the United States and Canada (Zhou and Tzanetakis 2013). Studies were carried out to investigate the role of kudzu (Pueraria montana) in SVNV epidemiology. Kudzu is present in millions of acres in the southeastern United States and is known to host at least another soybean-infecting virus, tobacco ringspot virus (TRSV) (Aboughanem-Sabanadzovic et al. 2014; Khankum et al. 2013). Eighty-five samples collected from 15 Mississippi counties during September 2015 were tested for SVNV infections using DAS-ELISA (Agdia Inc, U.S.A.) and three were infected by the virus. Two of the samples displayed mild deformation of young leaves, whereas the third was symptomless. In order to verify the results, virus-specific RT-PCR tests were performed on nucleic acid extracts from all ELISA-positive samples along with three SVNV-free kudzu plants and controls, represented by SVNV-infected and healthy soybeans. A DNA band of 236 bp corresponding to the NSs gene (Zhou and Tzanetakis 2013) was amplified only from the three ELISA-positive kudzu samples and positive controls. The products were directly sequenced in both directions and confirmed to be SVNV-specific as they shared 96 to 99% nt identity with corresponding region of the SVNV reference isolate (GenBank accession no. GU722319). In a greenhouse-based study, first instar larvae of soybean thrips (Neohydatothrips variabilis Beach) were fed on symptomatic soybean for virus acquisition and transferred to eight SVNV-free kudzu seedlings as described (Zhou and Tzanetakis 2013). Leaf and root tissues were randomly collected from virus-inoculated and mock-inoculated kudzu, respectively, at 6 weeks post inoculation. Total nucleic acids were isolated and RT-PCR was performed using primer set SdetF/SdetR (Zhou et al. 2011). Amplification products corresponding to the complete NP gene (834 bp) were obtained in both leaf and root tissues from five inoculated plants and shared 97 to 99% identity with the reference isolate (GenBank accession no. GU722319), whereas there was no amplification from mock-inoculated controls. Those results were further confirmed by dot blot immunoassay with infected plants remaining asymptomatic for at least a month post inoculation. Our findings represent the first report of SVNV infections of kudzu in the U.S.A. and the world. Kudzu is likely to play a role in the epidemiology of virus and disease. Furthermore, our results expand the range of pathogens (Asian soybean rust, TRSV) and insects (kudzu bug) that kudzu can sustain, indicating its ecological impact as an invasive species.

Predicting the potential invasion of kudzu bug, Megacopta cribraria (Heteroptera: Plataspidae), in North and South America and determining its climatic preference

Biological invasions have long placed challenges on ecosystems, agricultural production, and human health. Modeling potential invasion of an introduced organism becomes a critical tool for early management of damaging species, such as kudzu bug, Megacopta cribraria (F.) (Hemiptera:Heteroptera:Plataspidae). Since it was first found in the United States in 2009, kudzu bug has spread rapidly, economically impacted agricultural production, and became a household pest. To better predict the potential invasion of kudzu bug in North and South America, we used the species distribution models Genetic Algorithm for Rule-set Production (GARP) and Maximum Entropy (Maxent). We used the D metric to test for niche equivalency and similarity between native and invaded populations of kudzu bug. We found that kudzu bugs currently occupied unequal environmental space between the two ranges. Therefore, distribution models using GARP and Maxent were constructed using occurrences in both native and invaded ranges. Area under the curve (AUC), true skill statistics (TSS), and omission rate (OR) were used to evaluate and compare the models. Results indicated both models had good performance, but Maxent (AUC = 0.971, TSS = 0.946, OR = 0.019) performed better than GARP (AUC = 0.922, TSS = 0.860, OR = 0.037). This research confirmed the effectiveness of using occurrence data in both ranges to predict potential invasions. Kudzu bugs prefer warm (annual mean temperature around 15 °C) and humid (annual mean precipitation around 1300 mm) regions. Distribution models generated by both methods indicated similar regions with high invasion risk. Management programs that include quarantine and prevention measures are suggested for these regions to avoid outbreaks of kudzu bug.

Degree Day Requirements for Kudzu Bug (Hemiptera: Plataspidae), a Pest of Soybeans.

Understanding the phenology of a new potential pest is fundamental for the development of a management program. Megacopta cribraria Fabricius (Hemiptera: Plataspidae), kudzu bug, is a pest of soybeans first detected in the United States in 2009 and in Maryland in 2013. We observed the phenology of kudzu bug life stages in Maryland, created a Celsius degree-day (CDD) model for development, and characterized the difference between microhabitat and ambient temperatures of both kudzu, Pueraria montana (Lour.) Merr. (Fabales: Fabaceae) and soybeans, Glycine max (L.) Merrill (Fabales: Fabaceae). In 2014, low population numbers yielded limited resolution from field phenology observations. We observed kudzu bug populations persisting within Maryland; but between 2013 and 2016, populations were low compared to populations in the southeastern United States. Based on the degree-day model, kudzu bug eggs require 80 CDD at a minimum temperature of 14°C to hatch. Nymphs require 545 CDD with a minimum temperature of 16°C for development. The CDD model matches field observations when factoring a biofix date of April 1 and a minimum preoviposition period of 17 d. The model suggests two full generations per year in Maryland. Standard air temperature monitors do not affect model predictions for pest management, as microhabitat temperature differences did not show a clear trend between kudzu and soybeans. Ultimately, producers can predict the timing of kudzu bug life stages with the CDD model for the use of timing management plans in soybean fields.

The First Record of Ooencyrtus nezarae (Hymenoptera: Encyrtidae) on Kudzu Bug (Hemiptera: Plataspidae) in North America

The kudzu bug, Megacopta cribraria (F.) (Heteroptera: Plataspidae), is an invasive insect pest introduced from Asia in 2009 that poses a threat to soybeans (Glycine max [L.] Merr. [Fabales: Fabaceae]) and other legume crops in the United States. Initially discovered in Georgia, M. cribraria rapidly expanded across the southeast until 2014 when a significant decline in its population was observed across many locations. This notable decline in M. cribraria populations is attributed to the emergence of new parasitoids and pathogens in its new invasive range. So far, only a single egg parasitoid, Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae), is known to parasitize the eggs of M. cribraria in the United States. Here, we report a new egg parasitoid of M. cribraria identified as Ooencyrtus nezarae Ishii, 1928 (Hymenoptera: Encyrtidae), recovered from egg masses of M. cribraria collected from soybean in Alabama. O. nezarae is reported to parasitize eggs from a variety of heteropteran families and has been observed parasitizing M. cribraria in China. To the best of our knowledge, this is the first report of O. nezarae in North America. The potentials of O. nezarae for biological control of M. cribraria in the United States and the direction of future studies are discussed.

Identification of the Compounds Released by Megacopta cribraria (Heteroptera: Plataspidae)1

Identification of the Compounds Released by <i>Megacopta cribraria</i> (Heteroptera: Plataspidae)¹

Diel flight pattern and size‐dependent flight speed of kudzu bug, Megacopta cribraria (Fabricius)

AbstractKudzu bug, Megacopta cribraria (Fabricius) (Hemiptera: Plataspidae), was introduced to North America in 2009 and has since spread across the eastern and south‐eastern United States, where it poses an economic threat to leguminous crop production, especially soya bean. However, we still lack an understanding of many basic aspects of their flight‐related biology, including descriptions of their pattern of diel flight activity, their dispersal capacity and the determinants of each. Using cross‐vane bucket traps and flight mills, we found that kudzu bug exhibits a diel flight activity pattern in the field that is well characterized by temperature and a quadratic relationship with time of day. In general, the number of adults collected in the cross‐vane bucket traps rose from 07:30 and declined from 17:30 to 19:30. No kudzu bugs were collected before 07:30 or after 19:30 during any of the replicates. We also demonstrate on flight mills that females fly faster than males, and that this difference is due to differences in their size. These basic biological findings may help to inform management decisions and improve our understanding of the invasion dynamics of M. cribraria.

Spatial Distribution of Megacopta cribraria (Hemiptera: Plataspidae) Adults, Eggs and Parasitism by Paratelenomus saccharalis (Hymenoptera: Platygastridae) in Soybean.

Since 2014, populations of the kudzu bug, Megacopta cribraria (F.) (Hemiptera: Plataspidae), have declined in the southeastern United States and seldom require treatment. This decline follows the discovery of Paratelenomus saccharalis (Dodd; Hymenoptera: Platygastridae), a non-native egg parasitoid. The objective of this project was to observe the temporal and spatial dynamics of P. saccharalis parasitism of kudzu bug egg masses in commercial soybean fields. Four fields were sampled weekly for kudzu bugs and egg masses at a density of one sample per 0.6 ha. Sampling commenced when soybean reached the R2 maturity stage and continued until no more egg masses were present. Responses including kudzu bugs, egg masses, and parasitism rates were analyzed using ANOVA, Spatial Analysis by Distance Indices (SADIE), and SaTScan spatial analysis software. Egg masses were collected from the field, held in the lab and monitored for emergence of kudzu bug nymphs or P. saccharalis. Kudzu bug populations were generally lower than previously reported in the literature and spatial aggregation was not consistently observed. Egg parasitism was first detected in early July and increased to nearly 40% in mid-August. Significant spatial patterns in parasitism were observed with spatio-temporal clusters being loosely associated with clusters of egg masses. There were no significant differences in parasitism rates between field margins and interiors, suggesting that P. saccharalis is an effective parasitoid of kudzu bug egg masses on a whole-field scale.

Diversity of mung bean insect pests and their natural enemies in farmers’ fields in East Java, Indonesia

Indiati SW, Bejo, Rahayu M. 2017. Diversity of mung bean insect pests and their natural enemies in farmers’ fields in East Java, Indonesia. Biodiversitas 18: 1300-1307. A survey was conducted from June to September in 2016 in mung bean fields in East Java. The objectives of this survey were to identify the mung bean pests that were present, and to identify potential natural enemies of these pests at each location. Insect pests recorded in low numbers in all fields surveyed were bean fly (Ophiomyia phaseoli), thrips and grasshoppers. Pod sucking bugs (Nezara viridula, Piezodorus hybneri, and Riptortus linearis) were found in all fields in all months. The population densities of pod sucking bugs were relatively high, and represent a major threat to mung beans in Indonesia.White flies (Bemicia tabaci) and leafhoppers (Empoasca spp.) were found in low numbers in all fields surveyed during the August-September period. Several new pests of mung bean were recorded in this survey: the leaf beetle (Megacopta cribraria) was recorded in fields in the villages of Pungkurlawas, Brondong, Lamongan; and pod boring weevils (Apion clavipes, Curculionoidae) were found in high numbers in Madiun and Nganjuk, resulting in significant damage to mung bean pods. Natural enemies of insect pests recorded during the survey were spiders, dragonflies, Hymenoptera (Braconidae and Trichogrammatidae), Diptera (Tachinidae and Syrphidae), and Coleoptera (Coccinellidae and Paederus fuscipes). Natural enemies - spider and Coccinella predators - were present in low numbers in all fields surveyed, although Coccinella predators were not present in Lamongan.

Diel Flight Activity and Intra-Plant Distribution ofMegacopta cribraria(Hemiptera: Plataspidae) Adults in Soybean

Abstract Megacopta cribraria (F.) (Hemiptera: Plataspidae), the kudzu bug, is a soybean pest in the southeastern United States. Accidentally introduced into Georgia in 2009 from Asia, kudzu bug can reduce up to 60% of soybean yield when left uncontrolled. There is limited information on the life history of this invasive pest in soybean. The main goals of this research were to investigate the daily flight activity pattern and intra-plant distribution of kudzu bug adults in soybean. This was accomplished through experiments in two locations in North Carolina during 2013 in which dispersing adult kudzu bugs captured on white sticky cards between 0900–1700 h were counted hourly, and adults on plants were visually sampled between 0900–1200 h from soybean maturity group IV to VII plants. Adult captures on sticky cards were higher from 1300 to 1500 h across sampling dates, suggesting that dispersal or flight activity peaks during this interval. When soybean plants were visually inspected, most of the adults form...

Attraction ofParatelenomus saccharalis(Hymenoptera: Platygastridae), an Egg Parasitoid ofMegacopta cribraria(Hemiptera: Plataspidae), to Host-Associated Olfactory Cues

Abstract Paratelenomus saccharalis (Dodd) (Hymenoptera: Platygastridae) is an egg parasitoid of Megacopta cribraria (F.) (Hemiptera: Plataspidae). Although the parasitoid has been previously reported in parts of Africa, Europe, Asia, and Australia, it was first reported in North America in 2013 on M. cribraria that was introduced from Asia into North America in 2009. Field observations showed that P. saccharalis females readily parasitize eggs of M. cribraria. However, the cues used by the parasitoid for host location have not been investigated. It was hypothesized that P. saccharalis uses olfactory cues to locate M. cribraria. The objective of this study was to test the attraction of P. saccharalis to host-associated cues in Y-tube olfactometer bioassays. Compared to the control of no host plant or eggs, female P. saccharalis showed significantly greater attraction to M. cribraria-damaged soybean, M. cribraria eggs only, and damaged soybean plus M. cribraria eggs, in separate bioassays. However, the para...