Dramatic expansion of the range of the invasive ash pest,buprestid beetle Agrilus planipennis Fairmaire, 1888 (Coleoptera,Buprestidae) in European Russia

The emerald ash borer (Agrilus planipennis Fairmaire, 1888) is a dangerous invasive pest of ashes. It was previously believed that in European Russia it occurs only in Moscow, Moscow Province, and in the eastern regions of Smolensk Province. An examination of ash trees in 12 cities of European Russia has revealed a much wider area of the emerald ash borer invasion. The pest was found in Konakovo (Tver Province), Tula, Kaluga, Orel, and Voronezh. We have found that A. planipennis damages not only Fraxinus pennsylvanica (an American species which is commonly planted in cities), but also the aborigine European ash Fraxinus excelsior. Ashes in the European forests and in the protective forest belts are badly endangered.     

Impacts of the emerald ash borer (Agrilus planipennis Fairmaire) induced ash (Fraxinus spp.) mortality on forest carbon cycling and successional dynamics in the eastern United States

Invasive species are widely recognized as altering species and community dynamics, but their impacts on biogeochemical cycling and ecosystem processes are less understood. The emerald ash borer (Agrilus planipennis Fairmaire) is a phloem feeding beetle that was inadvertently introduced to the US in the 1990s and relies solely on ash trees (Fraxinus spp.) to complete its life cycle. Ash trees have a wide geographic distribution and are an important component of many different forest types in the US. The larval feeding behavior of the emerald ash borer (EAB) effectively girdles the tree’s phloem tissue resulting in tree mortality in as little as 2 years and stand mortality in as little as 5 years. Using the forest inventory and analysis database, we found that forest lands in the lower 48 states hold approximately 8.7 billion ash trees and saplings, which represent ~2.5 % of the aboveground forest carbon mass. Furthermore, we measured tree growth in 7 EAB impacted and 5 non-EAB impacted temperate forests in the Midwestern United States to quantify the impacts of EAB induced tree mortality on tree growth. We hypothesized that the initial C lost would be partly compensated for by the enhanced non-ash tree growth in EAB-impacted regions relative to non-EAB impacted regions. The EAB disturbance enhanced growth of non-ash trees in the EAB impacted region relative to the non-EAB impacted region. Results also indicate that in EAB impacted areas, growth of trees from the genera Acer and Ulmus responded most positively. Finally, we quantified annual biometric net primary productivity of the EAB impacted forests and compared these quantities to modeled growth of these forests in the absence of EAB and found that large scale ash tree mortality has reduced short term regional forest productivity. The loss of ash biometric net primary productivity is, in part compensated by enhanced growth of non-ash species. As expected, EAB disturbance severity was greater in forests with higher basal areas of ash. This study illustrates the ecosystem and regional scale impacts of invasive pest-induced disturbance on biogeochemical cycling and forest species composition.     

A decade of emerald ash borer effects on regional woodpecker and nuthatch populations

The emerald ash borer (EAB) Agrilus planipennis, first detected in 2002 in the vicinity of Detroit, Michigan, USA, has spread throughout much of eastern and midwestern North America as of 2016, resulting in widespread mortality of ash trees in the genus Fraxinus. We investigated the effects of this newly available, exotic food source on populations of six species of largely resident insectivorous birds, including five species of woodpeckers and white-breasted nuthatch (Sitta canadensis), using North American Breeding Bird Survey data for breeding season estimates and Audubon Christmas Bird Counts for winter season estimates. We found evidence for relatively modest and variable effects of EAB invasion on the populations of these birds during the breeding season, but highly significant numerical increases during the winter that in several cases appeared to be increasing as the EAB invasion has progressed. Our results confirm that the EAB invasion is resulting in increased populations of several insectivorous birds, primarily during the winter. They also suggest that the numerical response of woodpeckers to EAB may be such that avian predation, which represents a significant, and possibly the largest, morality factor affecting some EAB populations, may continue to increase and help control the EAB epidemic as the invasion continues.     

Critical rearing parameters of Tetrastichus planipennisi (Hymenoptera: Eulophidae) as affected by host plant substrate and host-parasitoid group structure

In laboratory assays, we evaluated the potential impact of host plant substrate types, host-parasitoid group sizes (densities), and parasitoid-to-host ratios on select fitness parameters of the larval endoparasitoid Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae), newly introduced for biological control of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in the United States. Results from our study showed that offspring production and critical fitness parameters (body size and sex ratio) of T. planipennisi from parasitized emerald ash borer larvae are significantly influenced by host plant substrate type, host-parasitoid group size, parasitoid-to-host ratio, or a combination in the primary exposure assay. The number of both female and male T. planipennisi progeny was significantly greater when emerald ash borer larvae were inserted into tropical ash [Fraxinus uhdei (Wenz.) Lingelsh.] logs rather than green ash (Fraxinus pensylvanica Marshall). When maintained at a constant 1:1 parasitoid-to-host ratio, assays with larger host-parasitoid group sizes (3:3-12:12) produced significantly greater numbers of both male and female offspring per parental wasp compared with those with the single host-parasitoid (1:1) group treatment. As the parasitoid-to-host ratio increased from 1:1 to 8:1 in the assay, the average brood size (number of offspring per parasitized emerald ash borer larva) increased significantly, whereas the average brood sex ratio (female to male) changed from being female-biased (6:1) to male-biased (1:2); body size of female offspring as measured by the length of ovipositor and left hind tibia also was reduced significantly. Based on these findings, we suggest that the current method of rearing T. planipennisi with artificially infested-emerald ash borer larvae use the tropical ash logs for emerald ash borer insertion, a larger (> or = 3:3) host-parasitoid group size and 1:1 parasitoid-to-host ratio in the primary parasitoid exposure assays.     

Potential Species Replacements for Black Ash (<Emphasis Type="Italic">Fraxinus nigra</Emphasis>) at the Confluence of Two Threats: Emerald Ash Borer and a Changing Climate

The emerald ash borer (Agrilus planipennis; EAB) is causing widespread mortality of ash (Fraxinus spp.) and climate change is altering habitats of tree species throughout large portions of North America. Black ash (F. nigra), a moist-soil species common in the Northwoods of Minnesota, Wisconsin, and Michigan, USA, is under a double threat of losing habitat from climate change and near annihilation from EAB. Because black ash often occurs in nearly pure stands, planting non-ash species is a management strategy already underway or being planned for thousands of acres. Tools are needed to assist managers in prioritizing sites for early treatment and to select potential species to replace black ash. This study explores the implications of threats to black ash ecosystems using analyses of field data and models to assess both the threats to, and potential replacement species for, black ash in Minnesota. For our analysis we (1) assessed the status of ashes and co-occurring species in forest inventory plots throughout Minnesota; (2) modeled the risk of EAB attack for multiple years in Minnesota; (3) modeled potential impacts of climate change on tree species with current or potential future habitat in Minnesota; (4) evaluated species co-occurring with black ash in plots in Ohio and Michigan, southeast of Minnesota; and (5) synthesized these results to provide a classification for candidate replacement species, both from within Minnesota and from points farther south. Though this process is demonstrated for black ash in Minnesota, the elements to be considered and modeled would be similar for any other location with a pest or pathogen threat for a species which simultaneously faces a changing climate.     

Occurrence of emerald ash borer (Coleoptera: Buprestidae) and biotic factors affecting its immature stages in the Russian Far East

Field surveys were conducted from 2008 to 2011 in the Khabarovsk and Vladivostok regions of Russia to investigate the occurrence of emerald ash borer, Agrilus planipennis Fairmaire, and mortality factors affecting its immature stages. We found emerald ash borer infesting both introduced North American green ash (Fraxinus pennsylvanica Marshall) and native oriental ashes (F. mandshurica Rupr. and F. rhynchophylla Hance) in both regions. Emerald ash borer densities (larvae/m(2) of phloem area) were markedly higher on green ash (11.3-76.7 in the Khabarovsk area and 77-245 in the Vladivostok area) than on artificially stressed Manchurian ash (2.2) or Oriental ash (10-59). Mortality of emerald ash borer larvae caused by different biotic factors (woodpecker predation, host plant resistance and/or undetermined diseases, and parasitism) varied with date, site, and ash species. In general, predation of emerald ash borer larvae by woodpeckers was low. While low rates (3-27%) of emerald ash borer larval mortality were caused by undetermined biotic factors on green ash between 2009 and 2011, higher rates (26-95%) of emerald ash borer larval mortality were caused by putative plant resistance in Oriental ash species in both regions. Little (<1%) parasitism of emerald ash borer larvae was observed in Khabarovsk; however, three hymenopteran parasitoids (Spathius sp., Atanycolus nigriventris Vojnovskaja-Krieger, and Tetrastichus planipennisi Yang) were observed attacking third - fourth instars of emerald ash borer in the Vladivostok area, parasitizing 0-8.3% of emerald ash borer larvae infesting Oriental ash trees and 7.3-62.7% of those on green ash trees (primarily by Spathius sp.) in two of the three study sites. Relevance of these findings to the classical biological control of emerald ash borer in newly invaded regions is discussed.     

Progression of ash canopy thinning and dieback outward from the initial infestation of emerald ash borer (Coleoptera: Buprestidae) in southeastern Michigan

Our objective was to characterize the rate at which ash (Fraxinus spp.) trees decline in areas adjacent to the leading edge of visible ash canopy thinning due to emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). Trees in southeastern Michigan were surveyed from 2003 to 2006 for canopy thinning and dieback by comparing survey trees with a set of 11 standard photographs. Freeways stemming from Detroit in all directions were used as survey transects. Between 750 and 1,100 trees were surveyed each year. A rapid method of sampling populations of emerald ash borer was developed by counting emerald ash borer emergence holes with binoculars and then felling trees to validate binocular counts. Approximately 25% of the trees surveyed for canopy thinning in 2005 and 2006 also were sampled for emerald ash borer emergence holes using binoculars. Regression analysis indicates that 41-53% of the variation in ash canopy thinning can be explained by the number of emerald ash borer emergence holes per tree. Emerald ash borer emergence holes were found at every site where ash canopy thinning averaged > 40%. In 2003, ash canopy thinning averaged 40% at a distance of 19.3 km from the epicenter of the emerald ash borer infestation in Canton. By 2006, the point at which ash trees averaged 40% canopy thinning had increased to a distance of 51.2 km away from Canton. Therefore, the point at which ash trees averaged 40% canopy thinning, a state of decline clearly visible to the average person, moved outward at a rate of 10.6 km/yr during this period.     

Efficacy of multifunnel traps for capturing emerald ash borer (Coleoptera: Buprestidae): effect of color, glue, and other trap coatings

Tens of thousands of adhesive-coated purple prism traps are deployed annually in the United States to survey for the invasive emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). A reusable, more user-friendly trap is desired by program managers, surveyors, and researchers. Field assays were conducted in southeastern Michigan to ascertain the feasibility of using nonsticky traps as survey and detection tools for emerald ash borer. Three nonsticky trap designs, including multifunnel (Lindgren), modified intercept panel, and drainpipe (all painted purple) were compared with the standard purple prism trap; no statistical differences in capture of emerald ash borer adults were detected between the multifunnel design and the prism. In subsequent color comparison assays, both green- and purple-painted multifunnel traps (and later, plastic versions of these colors) performed as well or better than the prism traps. Multifunnel traps coated with spray-on adhesive caught more beetles than untreated traps. The increased catch, however, occurred in the traps' collection cups and not on the trap surface. In a separate assay, there was no significant difference detected between glue-coated traps and Rain-X (normally a glass treatment)-coated traps, but both caught significantly more A. planipennis adults than untreated traps.     

Measuring the impact of biotic factors on populations of immature emerald ash borers (Coleoptera: Buprestidae)

Cohorts of emerald ash borer larvae, Agrilus planipennis Fairmaire, were experimentally established in July of 2008 on healthy green ash (Fraxinus pennsylvanica) trees in two wooded plots at each of three sites near Lansing, MI, by caging gravid emerald ash borer females or placing laboratory-reared eggs on trunks (0.5-2 m above the ground) of selected trees. One plot at each site was randomly chosen for release of two introduced larval parasitoids, Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) and Spathius agrili Yang (Hymenoptera: Braconidae), whereas the other served as the control. Stage-specific mortality factors and rates were measured for all experimentally established cohorts and for associated wild (i.e., naturally occurring) emerald ash borer immature stages via destructive sampling of 2.5 m (above the ground) trunk sections of cohort-bearing trees in the spring and fall of 2009. Host tree defense was the most important mortality factor, causing 32.0 to 41.1% mortality in the experimental cohorts and 17.5 to 21.5% in wild emerald ash borer stages by spring 2009, and 16.1 to 29% for the remaining experimental cohorts, and 9.9 to 11.8% for wild immature emerald ash borer stages by fall 2009. Woodpecker predation was the second most important factor, inflicting no mortality in the experimental cohorts but causing 5.0 to 5.6% mortality to associated wild emerald ash borer stages by spring 2009 and 9.2 to 12.8% and 3.2 to 17.7%, respectively, for experimental cohorts and wild emerald ash borer stages by fall 2009. Mortality from disease in both the experimental and wild cohorts was low (<3%) in both the spring and fall sample periods. In the fall 2009 samples, ≈ 1.5% of experimental cohorts and 0.8% of the wild emerald ash borer stages were parasitized by T. planipennisi. While there were no significant differences in mortality rates because of parasitism between parasitoid-release and control plots, T. planipennisi was detected in each of the three release sites by the end of the study but was not detected in the experimental cohorts or associated wild larvae in any of the three control plots.     

Ashes in Europe are in danger: the invasive range of Agrilus planipennis in European Russia is expanding

The emerald ash borer, Agrilus planipennis (Coleoptera, Buprestidae), is a pest of ash native to Asia. This major stem borer has killed millions of ash trees in North America. It was first found in Europe in 2003 in the city of Moscow. Now it is rapidly spreading in European Russia. In 2012 A. planipennis was found in the Tula, Kaluga, and Smolensk regions. A survey of green plantations in 22 localities in 2013 has revealed that A. planipennis occurs also in the Tver, Orel, Voronezh, Tambov, and Yaroslavl regions. It occurs 230 km northeast, 350 km southeast, and 460 km south from Moscow. Most ashes in the Moscow region, both alien American Fraxinus pennsylvanica and the indiginous European ash Fraxinus excelsior, are dying or already dead. Thousands of trees in other regions are seriously damaged. The pest will cross the western border of Russia soon. It represents a serious threat for ashes in other European countries.     

Factors influencing the dispersal of a native parasitoid, <Emphasis Type="Italic">Phasgonophora sulcata</Emphasis>, attacking the emerald ash borer: implications for biological control

High parasitism by a native parasitoid, Phasgonophora sulcata Westwood (Hymenoptera: Chalcididae), has been reported on emerald ash borer (hereafter EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), in North America. Use of this parasitoid in an augmentative biological control program has been proposed to slow the spread of EAB, yet information is lacking on key aspects of this parasitoid’s dispersal. We document the flight capacity and walking activity of P. sulcata, its potential fecundity, and describe how age, body size, temperature, and time of day affect these parameters. Wasp flight capacity, measured using flight mills, increased with temperature and decreased with age. Unexpectedly, age and body size did not affect wasp walking activity, and we saw no relationship between walking activity and flight capacity. Older wasps had lower potential fecundity than younger wasps. These results suggest that P. sulcata should be released as pupae near EAB-infested ash trees to improve efficacy and potential biological control success.     

Biology and damage traits of emerald ash borer planipennis Fairmaire）in China

Emerald ash borer （Agrilus planipennis Fairmaire） （Coleoptera： Buprestidae） is a major stem borer of ash （Fraxinus spp.）. It is univoltine in Tianjin, while it is semivoltine in Heilongjiang Province, and both univoltine and semivoltine in Changchun, Jilin Province, where the majority is univoltine. The longevity of emerald ash borer adults is 17.2 ± 4.6 days （n = 45）, eggs 9.0 5：1.1 days （n = 103）, univoltine larvae 308 days, semivoltine larvae 673 days, and pupae 61.2 ± 1.6 days （n = 45）. It takes about 100 days from the time larvae bore into the phloem to when they complete the pupal cell. In a 10-year-old velvet ash （Fraxinus velutina Tort.） plantation in Tianjin, emerald ash borer preferred to oviposit on the regions of boles from 50-150 cm above ground, accounting for 76.7% of the total girdling. Girdling on the south side of the tree boles accounted for 43.40% of the total girdling. The emerald ash borer population density is higher at the edge of the plantation compared with the center.     

Physiology of Hibernating Larvae of the Pistachio Twig Borer, <Emphasis Type="Italic">Kermania pistaciella</Emphasis> Amsel (Lepidoptera: Tineidae), Collected from Akbari Cultivar of <Emphasis Type="Italic">Pistacia vera</Emphasis> L.

The pistachio twig borer, Kermania pistaciella Amsel (Lepidoptera: Tineidae), a key pest of pistachio trees, is a monovoltine pest living inside the feeding tunnel of pistachio twigs for almost 10 months in a year and overwinters there as last instar larvae. In this study, we measured some physiological parameters of overwintering field collected larvae of the pest. There were no changes in trehalose, glucose, and myo-inositol contents, but there were differences in the levels of total simple sugar and glycogen during overwintering. Total sugar content at the beginning of overwintering (October) was at the lowest level (24.13 mg/g body weight) and reached to the highest level (55.22 mg/g fresh body weight) in November whereas glycogen content was at the highest level (44.05 mg/g fresh body weight) in October and decreased to 18.42 mg/g fresh body weight in November. Decrease in lipid content during the overwintering period was not significant. The highest and lowest levels of protein content were recorded in January and February, respectively. Supercooling points (SCP) of the overwintering larvae were stable and low (ranged between ?17.80 and ?25.10°C) throughout the cold season and no larva survived after SCP determination. The lowest cold hardiness (60 and 0.0% survival following exposure to ?10 and ?20°C/24 h, respectively) was observed for in November-collected larvae. Overwintering larvae of the pistachio twig borer rely mostly on maintaining the high supercooling capacity throughout the overwintering to avoid freezing of their body fluid.     

Long-term monitoring of the introduced emerald ash borer (Coleoptera: Buprestidae) egg parasitoid,Oobius agrili (Hymenoptera: Encyrtidae), in Michigan,USA and evaluation of a newly developed monitoring technique

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of ash trees (Fraxinus spp.) in North America from China. The egg parasitoid Oobius agrili Zhang and Huang (Hymenoptera: Encyrtidae) was introduced from China as a biological control agent for this pest in Michigan and throughout the infested area of the United States. A critical component of any biological control program is post-release monitoring and evaluation; however, because of the small size and cryptic nature of O. agrili, evaluation of its impact is difficult. We compared two methods for measuring parasitism of emerald ash borer eggs: (1) timed visual searches of bark on standing ash trees and (2) bark collection, sifting, and sorting. Both methods were carried out in paired parasitoid-release and control plots, the visual search method over a six-year period (2008–2013) and the more recently developed bark-collection and sifting method for 2 years (2012–2013). The visual search method found parasitism in release plots remained low (0.7–4.2%) in samples taken from 2008 to 2012 and reached 10.6% in 2013. In comparison, the bark-sifting method found that rates of egg parasitism were considerably higher in release plots, 21.8% and 18.9% for samples taken in 2012 and 2013, respectively. These findings indicate that the population-level impact of O. agrili is increasing and may be an important source of mortality for EAB populations. We recommend the bark-collection and sifting method as the more effective method to recover parasitoids and estimate parasitism rates of O. agrili.     

Detectability of the emerald ash borer (Coleoptera: Buprestidae) in asymptomatic urban trees by using branch samples

The emerald ash borer, Agrilus planipennis Fairmaire, is an exotic invasive insect causing extensive mortality to ash trees, Fraxinus spp., in Canada and the United States. Detection of incipient populations of this pest is difficult because of its cryptic life stages and a multiyear time lag between initial attack and the appearance of signs or symptoms of infestation. We sampled branches from open-grown urban ash trees to develop a sample unit suitable for detecting low density A. planipennis infestation before any signs or symptoms are evident. The sample unit that maximized detection rates consisted of one 50-cm-long piece from the base of a branch ≥6 cm diameter in the midcrown. The optimal sample size was two such branches per tree. This sampling method detected ≈75% of asymptomatic trees known to be infested by using more intensive sampling and ≈3 times more trees than sampling one-fourth of the circumference of the trunk at breast height. The method is less conspicuous and esthetically damaging to a tree than the removal of bark from the main stem or the use of trap trees, and could be incorporated into routine sanitation or maintenance of city-owned trees to identify and delineate infested areas. This research indicates that branch sampling greatly reduces false negatives associated with visual surveys and window sampling at breast height. Detection of A. planipennis-infested asymptomatic trees through branch sampling in urban centers would provide landowners and urban foresters with more time to develop and implement management tactics.     

Relationship between temperature and development rate of <Emphasis Type="Italic">Copitarsia incommoda</Emphasis> (Lepidoptera: Noctuidae) in the Bolivian Andes

The relationship between temperature and development rate of Copitarsia incommoda Walker (Lepidoptera: Noctuidae), a major pest of the quinoa crop in the Andes, was investigated using eight constant temperatures from 5.1 to 34.6 °C, on an artificial diet under laboratory conditions. We used a Gauss model to fit the survival rate, and the Holling type III, the Wang, and the Sharpe and DeMichele models to fit the different development rates for each life stage, among 25 models investigated and compared. Optimum temperatures for survival were between 13.2 and 27.1 °C, and optimum temperatures for development were between 19.1 and 31.9 °C. We used the development rate models with a large-scale temperature database to predict and map the risk of outbreaks once C. incommoda invades, using the number of generations per year, revealing that the pest was univoltine or bivoltine in most Bolivian regions of quinoa production. While temperatures from this database underestimate the temperatures experienced by the pest, this study provides a new insight into C. incommoda physiology, which should be a key factor in designing integrated pest management strategies.     

Effects of rearing conditions on reproduction of Spathius agrili (Hymenoptera: Braconidae), a parasitoid of the emerald ash borer (Coleoptera: Buprestidae)

Spathius agrili Yang (Hymenoptera: Braconidae) can be successfully reared on emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), larvae feeding in chambers drilled in small ash twigs that are wrapped with floral tape. Females maintained in groups with males for one week can receive enough sperm for production of female progeny throughout their lives. Volatiles released by emerald ash borer adults feeding on ash foliage increased parasitoid fecundity over ash foliage alone or no stimulus. The temperature at which the parasitoids were reared ranged from 20 to 25 degrees C in a daily cycle; however, raising the daily maximum temperature to 28 degrees C did not affect parasitoid longevity or fecundity. Adult females lived between 12 and 127 d, with an average of 60.8 +/- 4.5 d. Males lived slightly longer, with an average of 66 +/- 4.5 d. The first clutch of eggs was laid when the female was between 2 and 42 d old, with the average preoviposition period lasting 11.4 +/- 1.4 or 19.5 +/- 2.0 d in 2007 and 2009 trials, respectively. A higher proportion of the emerald ash borer larvae were feeding and thus attractive to parasitoids in the 2009 trial, and female S. agrili laid an average of 9.5 +/- 1.0 clutches containing 5.4 +/- 0.2 eggs, for an average of 51.2 eggs per female. Approximately three quarters of the progeny were female. The number of eggs per clutch was significantly greater when deposited on larger emerald ash borer larvae, further highlighting the need for quality larvae in rearing. Chilling S. agrili pupae at 10 degrees C to stockpile them for summer release was not successful; chilling resulted in lower survival and lower fecundity of emerging progeny. Female S. agrili proved capable of attacking emerald ash borer larvae through even the thickest bark of an ash tree that was 30-cm diameter at breast height. Even emerald ash borer larvae that were creating overwintering chambers in the outer sapwood of the tree were successfully attacked, suggesting that S. agrili could be reared on field collected logs infested with emerald ash borer.     

Impact of Chemical,Organic and Bio-Fertilizers Application on Bell Pepper, <Emphasis Type="Italic">Capsicum annuum</Emphasis> L. and Biological Parameters of <Emphasis Type="Italic">Myzus persicae</Emphasis> (Sulzer) (Hem.: Aphididae)

Myzus persicae (Sulzer) is a polyphagous aphid that causes chlorosis, necrosis, stunting, and reduce growth rate of the host plants. In this research, the effects of Zinc sulfate and vermicompost (30%), Bacillus subtilis, Pseudomonas fluorescens, Glomus intraradices, G. intraradices × B. subtilis, and G. intraradices × P. fluorescens compared to control was investigated on the growth characters of Capsicum annuum L. and biological parameters of M. persicae. Different fertilizers caused a significant effect on growth characters of C. annuum and biological parameters of M. persicae. The highest plant growth was observed on Zinc sulfate and B. subtilis treated plants, and the lowest was on control. Increase in the amount of specific leaf area (SLA) (0.502 mm² mg^?1) was significantly higher in the B. subtilis than other fertilizer treatments. The longest (10.3 days) and the shortest (5.3 days) developmental times of M. persicae nymphs were observed on 30% vermicompost and Zinc sulfate treatments, respectively. The lowest adult longevity periods of M. persicae (11.2 and 11.3 days) were observed on G. intraradices × B. subtilis and 30% vermicompost treatments, respectively, and the longest ones (16.4 days) on Zinc sulfate. The highest rate of nymphal mortality and the lowest amount of nymphal growth index (NGI) were recorded on 30% vermicompost. The nymphs reared on Zinc sulfate treatment had the lowest rate of nymphal mortality and the highest amount of NGI. Thus, amending the soil with 30% vermicompost had a significantly negative effect on the biological parameters of M. persicae that can be used as an ecological control tactic for this pest.     

Role of emerald ash borer (Coleoptera: Buprestidae) larval vibrations in host-quality assessment by Tetrastichus planipennisi (Hymenoptera: Eulophidae)

The biological control agent Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) is a gregarious larval endoparasitoid of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive cambium-feeding species responsible for recent, widespread mortality of ash (Fraxinus spp.) in North America. T. planipennisi is known to prefer late-instar emerald ash borer, but the cues used to assess host size by this species and most other parasitoids of concealed hosts remain unknown. We sought to test whether vibrations produced by feeding emerald ash borer vary with larval size and whether there are any correlations between these cues and T. planipennisi progeny number (i.e., brood size) and sex ratio. The amplitudes and rates of 3-30-ms vibrational impulses produced by emerald ash borer larvae of various sizes were measured in the laboratory before presenting the larvae to T. planipennisi. Impulse-rate did not vary with emerald ash borer size, but vibration amplitude was significantly higher for large larvae than for small larvae. T. planipennisi produced a significantly higher proportion of female offspring from large hosts than small hosts and was shown in previous work to produce more offspring overall from large hosts. There were no significant correlations, however, between the T. planipennisi progeny data and the emerald ash borer sound data. Because vibration amplitude varied significantly with host size, however, we are unable to entirely reject the hypothesis that T. planipennisi and possibly other parasitoids of concealed hosts use vibrational cues to assess host quality, particularly given the low explanatory potential of other external cues. Internal chemical cues also may be important.