Drench treatments for management of larval Japanese beetle (Coleoptera: Scarabaeidae) in field-grown balled and burlapped nursery plants

Insecticide drenches were applied to postharvest field-grown nursery plants harvested as 60-cm-diameter balled and burlapped (B&B) root balls for controlling third instars of Japanese beetle, Popillia japonica Newman (Coleoptera: Scarabaeidae). Bifenthrin, chlorpyrifos, lambda-cyhalothrin, and thiamethoxam were drench-applied in fall and spring tests at volumes of runoff (1X; approximately equal 2.57 liters per drench per root ball) or twice runoff (2X). Tests also examined consecutive drenches (two, four, or six) and B&B rotation between drenches. Fall-applied drenches did not meet the Domestic Japanese Beetle Harmonization Plan (DJHP) standards of < or =1 grub and ranged from 0 to 90% control. However, most fall-applied drenches significantly reduced grub numbers relative to the untreated root balls. Spring-applied drenches were more effective than fall drenches: chlorpyrifos treatments gave 94-100% control, whereas other spring-applied treatments were less consistent, including thiamethoxam (83-100% control) and bifenthrin (61-100% control). Lambda-cyhalothrin was not effective. A higher drench volume (2X) did not significantly improve treatment efficacy; however, grub numbers decreased as the number of drenches increased for fall-applied chlorpyrifos and thiamethoxam and spring-applied bifenthrin. Rotation of root balls significantly reduced grub numbers compared with nonrotated treatments for fall-applied chlorpyrifos (six drenches) and bifenthrin (two or six drenches), but these treatments did not meet DJHP standards. The study indicates chlorpyrifos, bifenthrin, and thiamethoxam drenches can control Japanese beetle in the spring and may provide a new postharvest option to certify B&B plants for Japanese beetle.     

Potential resistance of crape myrtle cultivars to flea beetle (Coleoptera: Chrysomelidae) and Japanese beetle (Coleoptera: Scarabaeidae) damage

Field and laboratory studies were conducted to identify potential resistance among crape myrtles, Lagerstroemia spp., to Japanese beetle, Popillia japonica Newman and to flea beetles, Altica spp. Damage ratings revealed variation among cultivars in susceptibility to beetle feeding. Cultivars with Lagerstroemia fauriei Koehne in their parentage exhibited the least amount of damage in choice and no-choice experiments, with few exceptions. The data indicate that both beetle species cause more feeding damage on certain cultivars of Lagerstroemia indica L., such as 'Country Red', 'Twilight', and 'Carolina Beauty' than interspecific cultivars with L. fauriei in their parentage, such as 'Natchez', 'Tonto', and 'Muskogee'. When comparing the effect of parentage on all of the major pests of crape myrtle, L. faurei confers resistance to all pests except crape myrtle aphid. No correlation was found between leaf toughness, leaf color, and leaf nutrients in estimating flea beetle cultivar preference. With this information, growers can more effectively target scouting measures to the most susceptible cultivars. and breeders can select plants that will require the fewest chemical inputs.     

Impact of Japanese beetle (Coleoptera: Scarabaeidae) feeding on seashore paspalum

Ten cultivars of seashore paspalum, Paspalum vaginatum Swartz, were compared for their response to Japanese beetle, Popillia japonica Newman, larval root feeding. Cultivars of Bermuda grass, Cynodon sp., and zoysiagrass, Zoysia sp., also were included for comparison. Turf grown in pots in the greenhouse was infested with second and third instars in this 2-yr study. Grub survival and weight gain, foliar growth, and root loss were compared among turfgrass species and cultivars. Few species-related differences were identified. Differences in grub tolerance were, however, observed to be a function of turfgrass cultivar. Some turf types demonstrating tolerance to grub feeding had rapid root growth and high root mass in control pots, but this was not consistent for all cultivars showing enhanced ability to maintain foliar growth despite grub feeding. The paspalum cultivars that seemed most tolerant of grub feeding were '561-79', 'Sea Isle 2000', 'Durban', 'HI-10', 'Kim-1', 'Sea Dwarf', and 'Sea Spray'.     

Feeding damage of Japanese beetle (Col.: Scarabaeidae) on 16 field-grown birch (Betula L.) genotypes

Feeding damage by Japanese beetle ( Popillia japonica Newman) was evaluated on 16 field-grown birch genotypes ( Betula L.) under two irrigation regimes at Fayetteville, AR in 2003, 2004 and 2005. Percentage of total leaf area skeletonized by Japanese beetle was visually estimated, and leaf damage was rated as no damage, low damage, moderate or severe damage based on the percentage of leaf skeletonization. The average percentage of leaf skeletonization on all birch trees by Japanese beetles was 32% in 2003, 27% in 2004 and 25% in 2005. In 2005, well-watered trees had a higher percentage of leaf skeletonization than water-stressed trees. Betula utilis var. jacquemontii and Betula papyrifera 'Uenci', rated as severe damage in all 3 years, were estimated to have the highest percentage of leaf skeletonization followed by B. papyrifera , which was rated as moderate-to-severe damage. Betula maximowicziana , Betula nigra 'Cully', B. papyrifera 'Renci', and Betula platyphylla 'Fargo' were rated as low-to-moderate damage. Betula pendula 'Laciniata' had nearly no damage from Japanese beetle in all 3 years. The other birch genotypes were rated as low damage during the 3-year period.     

Field and vegetable crops as hosts of larval western spotted cucumber beetle (Coleoptera: Chrysomelidae)

The western spotted cucumber beetle, Diabrotica undecimpunctata undecimpunctata Mannerheim, is an important pest of melons (Cucurmis melo L.) in northern California. Recent observations indicate that adults are using alfalfa (Medicago sativa L.) as a feeding host and larvae may be developing on the roots. Greenhouse studies were conducted during the winters of 2009 and 2010 in which larval development was compared on the roots of six field and vegetable crops commonly grown in the southern Sacramento Valley. The growth parameters used to evaluate the hosts were larval and pupal head capsule width, body width, and body length as well as total survival percentage and survival percentage to the third instar. According to larval growth and survivorship in 2009, maize (Zea mays L.) was the best host, followed by alfalfa and tomato (Solanum lycopersicum L.) that were roughly equivalent to one another. Melon was a slightly weaker host than alfalfa and tomato; sunflower (Helianthus annuus L.) was a completely incompatible host and thus dropped from the 2010 study. In 2010, melon was the weakest host for larval development. Maize was the superior host again followed closely by alfalfa that performed slightly better than tomato and lima bean (Phaseolus lunatus L.). Data suggest that larval western spotted cucumber beetles may primarily develop outside of melon fields and the adults emigrate to melons.     

Bark-carving behavior of the Japanese horned beetle Trypoxylus dichotomus septentrionalis (Coleoptera: Scarabaeidae)

The Japanese horned beetle, Trypoxylus dichotomus septentrionalis, usually aggregates at the wounds caused by boring insects on Quercus oak trees to feed on exuding sap. Here, a unique behavior of the beetle, which enables it to independently obtain sap without any activities of other insects, is reported. Beetles carved intact bark of Fraxinus griffithii, where no sap was exuding, using clypeus. As a result of carving behavior, bark was stripped, and sap exuded from these scars temporarily, which beetles immediately began to lick. A digital video image relating to the article is available at ().     

Rainfastness and residual activity of insecticides to control Japanese beetle (Coleoptera: scarabaeidae) in Grapes

Field-based bioassays and residue profile analysis were used to determine the relative toxicity, rainfastness, and field degradation over time of five insecticides from five insecticide classes on adult Japanese beetles, Popillia japonica Newman (Coleoptera: Scarabaeidae), in grapes, Vitis labrusca L. Bioassays assessed Japanese beetle condition as alive, knockdown, or immobile when exposed for 24 h or 7-d field-aged residues of phosmet, carbaryl, bifenthrin, thiamethoxam, or indoxacarb after 0, 12.7, or 25.4 mm of rain had been simulated. We found that the two most toxic insecticides to Japanese beetle were phosmet and carbaryl, followed by bifenthrin, thiamethoxam, and then indoxacarb. The efficacy of phosmet decreased because of rainfall, but not because of field aging. The efficacy of carbaryl decreased because of rainfall and field aging. The efficacies of bifenthrin and thiamethoxam were not affected by rainfall but decreased because of field aging. The efficacy of indoxacarb was not affected by rainfall or field aging. This study will help vineyard managers make informed decisions on when reapplications of insecticides are needed with the aim of improving integrated pest management programs.     

Preference of temperate Chinese elms (Ulmus spp.) for the adult Japanese beetle (Coleoptera: Scarabaeidae)

Trees of newly acquired Ulmus species originating from the temperate regions of China and growing at The Morton Arboretum, Lisle, IL, were evaluated in no-choice and multiple-choice laboratory bioassays and cage-studies for feeding preference for adults of the Japanese beetle, Popillia japonica Newman. Ulmus lanceaefolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis were less preferred for feeding by adult Japanese beetles. No-choice, multiple-choice, and cage feeding studies revealed that Ulmus wallichiana was moderately preferred, and U. procera and U. americana were highly preferred for feeding. Dry fecal pellet weights were strongly correlated with the percent of leaf tissue removed. Feeding preference in the multiple-choice study was strongly correlated with feeding preference in the cage study and in the no-choice study. Likewise, adult feeding preference in the cage study was strongly correlated with preference in the multiple-choice and no-choice studies. The less preferred species of U. lanceafolia, U. prunifolia, U. pseudopropinqua, and U. taihangshanensis show promise for future elm breeding programs.     

Ultrastructure of pheromone-detecting sensillum placodeum of the Japanese beetle, Popillia japonica Newmann (Coleoptera: Scarabaeidae)

The pheromone-detecting sensilla placodea are significantly more numerous than other sensory structures in the antennae of the Japanese beetle, Popillia japonica (Coleoptera: Scarabaeidae). Their abundance in males is nearly twice of that in females, showing a clear sexual dimorphism. Externally, they have a tortoise shell-like round cuticular plate containing a few polygonal plates separated by narrow ridges. Internally, they house two long dendrites that branch and terminate near fine cuticular pores. They have a system of two bipolar neurons accompanied by three enveloping cells, resembling sensilla trichodea in moths. The conspicuous difference with the latter is that the sensillum-lymph cavity near the outer cuticle is funnel-shaped, into which the tormogen cell projects numerous microvilli whose tips approach the terminal branches of the dendrites.     

Carabid beetle (Coleoptera: Carabidae) conservation in New Zealand

An overview of carabid beetles in the New Zealand conservation context is provided. Processes for threatened species recovery within the New Zealand Department of Conservation are outlined, and the Department’s two major beetle-related recovery documents (The Conservation Requirements for New Zealand’s Nationally Threatened Invertebrates, and The Carabid Beetle Recovery Plan) are discussed. A subjective consideration of the merits and drawbacks of both the documents, and the systems that support them, is presented, along with an option for the way forward for threatened species conservation in New Zealand.     

Impact of four insecticides on Japanese beetle (Coleoptera: Scarabaeidae) egg predators and white grubs in turfgrass

Field experiments were conducted to measure the effects of four commonly used turfgrass insecticides (isofenphos, diazinon, imidacloprid, halofenozide) on white grubs (Coleoptera: Scarabaeidae) and ant predators of white grub eggs. Ant populations were measured over time with canned tuna, whereas predation by the ants was measured with artificially placed Japanese beetle, Popillia japonica Newman, eggs. The effectiveness of each insecticide at controlling Japanese beetle grubs, when applied at different times during the growing season, also was measured. Isofenphos and diazinon significantly reduced both ant numbers and white grub egg predation, whereas imidacloprid and one halofenozide treatment did not significantly impact either measurement. A second halofenozide treatment significantly reduced white grub egg predation. Isofenphos and diazinon were ineffective at controlling Japanese beetle grubs when applied in June but were highly efficacious when applied in August. Evidence of enhanced biodegradation was found in plots that received both June and August applications of diazinon. Both June and August applications of imidacloprid and halofenozide provided good control of white grubs.     

The first fossil Athyreini beetle (Coleoptera: Geotrupidae)

The first fossil Athyreini in the subfamily of Bolboceratinae from the family of Geotrupidae, ?Amberathyreus beuteli Bai et Zhang gen. et sp. nov., is described based on a specimen from the mid-Cretaceous Myanmar (Burmese) amber from northern Myanmar. Its external morphology (including 3D reconstruction of the head and pronotum) was analyzed and compared with all known genera of Athyreini. ?Amberathyreus’ close relationship between Athyreini and Bolboceratini is supported. ?Amberathyreus was likely active at night and lived in a lowland environment. The finding of ?Amberathyreus greatly enrich our knowledge of Athyreini.     

Size dependent predatory pressure in the Japanese horned beetle,Allomyrina dichotoma L. (Coleoptera; Scarabaeidae)

We surveyed male survival and reproductive performances associated with dimorphism in the Japanese horned beetleAllomyrina dichotoma L. in a secondary forest in 1996. Morphological comparisons between living marked and prey individuals indicated that the larger horned males suffered higher predatory pressure than the smaller ones. The dominant predators of the beetles were suspected to be 2 crow species. The small-horned males showed lower recapture rates than the large-horned ones. This suggested that the former was more sensitive to disturbance, and/or dispersed more than the latter. Fighting behavior was rarely seen because of the low population density of the beetles in the study area. These results suggested that the large-horned males suffer not only the injury risk of intrasexual competition but also more predatory risk than the small-horned ones.     

Structure in temperate predaceous diving beetle communities (Coleoptera: Dytiscidae)

Collection records of adult dytiscid beetles (Coleoptera, Dytiscidae) from 312 sites within the province of Alberta, Canada, were analyzed for patterns of similarity in species distribution. Sites compared on the basis of species occurrence (Jaccard coefficient of similarity and group average cluster analysis) separated into 12 principal clusters, interpreted as communities. However, cluster inclusion occurred at very low levels of similarity and 30% of sites were unclustered outliers. Ecological charade us tics of sites that were recognized as varying between dusters were salinity, productivity, stability, water temperature, substrate type, flow and vegetation. An index relating these qualitatively defined variables to species numbers is presented. An analysis of co-occurrence patterns of species was conducted as an alternative approach to definition of multispecies associations. Each possible combination of co-occurrence between pairs of species occurring in more than 5 collections each was tested for significance (p = 0.005) by means of Yates corrected χ² tests. Results of tests were expressed in binary terms, blank – no significance, x - significant. Species were then clustered on the basis of patterns of significant co-occurrences as above. This analysis was used as the basis for ordination of species in a symmetrical matrix with species ordered so as to maximize density of points of significant co-occurrence (x) around the principal diagonal. Areas in the matrix showing high densities of co-occurrence were interpreted as representing communities. The cluster analysis of species produced a better cluster pattern than obtained for sites but while generally similar, the species clustering pattern was less fine. The principal species groups consisted of those of saline water, alpine/subalpine lotic sites, other lotic habitats, and lentic habitats with two subgroups, species in forest areas and grassland species. The ordination, while reflecting this grouping of species, demonstrated that each group graded into others through loss of certain species and acquisition of others and thus showed the continuum nature of these communities. Restricting ordination to congeneric species indicated that these do not usually show identical patterns of co-occurrence but neither are patterns coincident with mutual exclusion. Within genera, considerable overlap in occurrence between species is the norm but species tend to occupy slightly different positions relative to one another along qualitatively defined ecological gradients. Relative position of species in these ordinations shows good correlation with patterns of geographical distribution lending support to the interpretation of ordination patterns reflecting relative ecological segregation. The dytiscid beetle fauna of north temperate regions is especially rich. Also, the large number of significant co-occurrences observed between species shows that species packing in many habitats of this region is dense. It is speculated that this species richness is possible because of the seasonality of habitats at these latitudes which reduces competition and predation from other groups and produces seasonal pulses of high productivity permitting a species rich fauna to develop because of abundant resources. It is likely that factors other than interspecific competition for resources are important in shaping dytiscid communities in habitats with strong nutrient pulses.     

Thermal death kinetics of red flour beetle (Coleoptera: Tenebrionidae)

While developing radio frequency heat treatments for dried fruits and nuts, we used a heating block system developed by Washington State University to identify the most heat-tolerant life stage of red flour beetle, Tribolium castaneum (Herbst), and to determine its thermal death kinetics. Using a heating rate of 15 degrees C/min to approximate the rapid heating of radio frequency treatments, the relative heat tolerance of red flour beetle stages was found to be older larvae > pupae and adults > eggs and younger larvae. Lethal exposure times for temperatures of 48, 50, and 52 degrees C for the most heat-tolerant larval stage were estimated using a 0.5th order kinetic model. Exposures needed for 95% mortality at 48 degrees C were too long to be practical (67 min), but increasing treatment temperatures to 50 and 52 degrees C resulted in more useful exposure times of 8 and 1.3 min, respectively. Red flour beetle was more sensitive to changes in treatment temperature than previously studied moth species, resulting in red flour beetle being the most heat-tolerant species at 48 degrees C, but navel orangeworm, Amyelois transitella (Walker), being most heat tolerant at 50 and 52 degrees C. Consequently, efficacious treatments for navel orangeworm at 50-52 degrees C also would control red flour beetle.     

Evaluating companion planting and non-host masking odors for protecting roses from the Japanese beetle (Coleoptera: Scarabaeidae)

Effectiveness of companion planting, and use of nonhost masking odors were evaluated under field conditions for protecting roses against the Japanese beetle, Popillia japonica Newman. Three reputedly effective companion species, rue (Ruta graveolens L.), zonal geranium (Pelargonium x hortorum Bailey), and garlic chives (Allium scheonparum L.) were interplanted with roses in replicated garden plots. Numbers of beetles on these roses were compared with rose-only control plots on 6 d during beetle flight. The masking odor hypothesis was tested by hanging mesh bags of aromatic herbs or other sources of reputedly repellent nonhost volatiles around potted roses in the field. Treatments included crushed red pepper (Capsicum frutescens L.), fennel seeds (Foeniculm vulgare Miller), crushed spearmint (Mentha picata L.), cedar shavings (Juniperus sp.), osage orange fruits (Maclura pomifera (Raif) Schneid.), and fleshy gingko seeds (Gingko biloba L.). No treatment significantly reduced numbers of beetles relative to the controls. Interplanting with geraniums significantly increased numbers of Japanese beetles on roses. Similarly, roses surrounded by sachets with fennel seeds, cedar shavings, crushed red pepper, or osage orange fruits had significantly more beetles than the control plants on two or more sample dates. Our results suggest that the use of companion or reputedly repellent plants or plant odors probably will be ineffective for protecting roses or other highly-susceptible ornamentals from P. japonica. Use of such tactics in an effort to discourage other garden pests might even increase Japanese beetle damage in those plantings.     

Sterol limitation in a pollen-fed omnivorous lady beetle (Coleoptera: Coccinellidae)

Nutritional constraints of non-prey foods for entomophagous arthropods are seldom investigated, yet are crucial to understanding their nutritional ecology and function within natural and managed environments. We investigated whether pollen from five maize hybrids was of variable quality for the lady beetle, Coleomegilla maculata, whether suitability of these pollens was related with their sterol profiles, and how augmenting sterols (β-sitosterol, cholesterol, or ergosterol) affected the fitness and performance of C. maculata. Preimaginal survival, development rates, the duration of the pre-oviposition period, post-mortem adult dry weight, adult hind tibial length, sex ratio, fecundity, cohort generation time (T_c), net replacement rate (R₀) and intrinsic rate of increase (r) were measured. Individual sterols in the pollens were quantified using GC-MS. Pollens were of variable suitability for C. maculata; the development rate was positively correlated with the amount of 24-methylene-cholesterol and r was positively correlated with episterol and 24-methylene-lophenol found in the pollens. Performance of C. maculata was entirely unaffected by augmenting pollen meals with sterols. This research shows that pollens clearly vary in their sterol contents intraspecifically, which affects their suitability for omnivores that rely on pollen. However, sterols appear to be only one of the limiting nutrients in pollens.     

Spermatophore expulsion in the carrion beetle Silpha perforata (Coleoptera: Silphidae)

Silphinae (Coleoptera: Silphidae) is an abundant decomposer that plays important roles in the ecosystem. However, there is little information about the life history of this taxon. We found sperm displacement behavior in carrion beetle Silpha perforata. Copulating males bit the female's antenna strongly and inserted the penis into the partner's genital organ more than once. We found a white substance on the tip of penis during copulation. We examined whether this white substance is a previous male's spermatophore, which was removed from the mating partner. When females were dissected just after mating, the same substance that often presents on the penis of mating males was found in the bursa copulatrix of females, although the bursa copulatrix of virgin females was empty. Male behavior during copulation with females of different mating history was also observed to confirm that the removal of spermatophores was observed only in copulation with females that have the spermatophores of previous males. Consequently, we estimated that S. perforata males removed spermatophores of previous males from mating partners. In addition, we dissected the males frozen during copulation, and inspected the penis morphology. This observation revealed that the apical part of the penis was usually hidden in the basal part of penis, but expanded and appeared during insertion. This apical part had many spines, which play an important role in sperm displacement and sexual conflict in some species. These results indicate that there is the sperm competition in S. perforata. This is the first report on sperm competition in Silphinae.     

Biological control agents for white grubs (Coleoptera: Scarabaeidae) in anticipation of the establishment of the Japanese beetle in California

We tested biological control agents for the control of 3rd-instar scarab turfgrass pests, both for the masked chafer Cyclocephala hirta LeConte and the Japanese beetle, Popillia japonica Newman. The former species is endemic in California whereas the latter, although not yet established, constitutes a permanent serious threat to agriculture and horticulture in California. We conducted experiments using C. hirta in California and P. japonica in New Jersey. A field trial conducted in 2 different California turfgrass sites compared the field persistence in the absence of hosts of Bacillus thuringiensis Berliner subspecies japonensis Buibui strain, the milky disease bacterium, Paenibacillus (=Bacillus) popilliae (Dutky), and the entomopathogenic nematodes Steinernema kushidai Mamiya and Heterorhabditis bacteriophora Poinar to that of the organophosphate diazinon. Soil samples taken 0-70 d after applications were bio-assayed with P. japonica. Only diazinon and the entomopathogenic nematode S. kushidai caused substantial mortality and S. kushidai activity persisted significantly longer than diazinon activity. In greenhouse experiments, combinations of entomopathogenic nematode species usually resulted in additive mortality of scarab larvae. Combinations of S. kushidai and diazinon also resulted in additive mortality. In field trials, the efficacy of H. bacteriophora and especially S. kushidai and S. glaseri, was comparable to that of diazinon over 14-18 d. However, it is likely that at least S. kushidai would have outperformed diazinon over an extended period because of its longer persistence and potential for recycling in the hosts. S. kushidai, should it become commercially available, deserves further examination as an alternative to chemical white grub control especially as a highly compatible component of sustainable turfgrass management.