Relative performance of Lindgren multiple-funnel, Intercept panel, and Colossus pipe traps in catching Cerambycidae and associated species in the southeastern United States

In 2004, we evaluated the relative performance of 8-unit Lindgren multiple-funnel (funnel), Intercept panel (panel), and Colossus pipe (pipe) traps, baited with ethanol and ac-pinene lures, in catching saproxylic beetles (Coleoptera) in pine stands in northern Florida and western South Carolina. Panel traps were as good as, if not better than, funnel and pipe traps for catching Cerambycidae. In particular, more Monochamus titillator (F.) were captured in panel traps than in pipe and funnel traps. Of three species of Buprestidae captured in our study, most Buprestis lineata F. were caught in panel traps, whereas most Acmaeodera tubulus (F.) were caught in funnel traps. Catches of Chalcophora virginiensis Drury and the root-feeding weevils Hylobius pales Herbst an dPachylobius picivorus LeConte (Curculionidae) were unaffected by trap type. Among bark beetles (Curculionidae: Scolytinae), catches of Ips grandicollis (Eichhoff) were unaffected by trap type, whereas most Dendroctonus terebrans (Olivier) were caught in panel traps, most Hylastes salebrosus Eichhoff were caught in panel and pipe traps, and most Hylastes tenuis Eichhoff were caught in funnel traps. Among ambrosia beetles (Curculionidae: Scolytinae), panel traps caught the most Xyleborinus saxesenii (Ratzeburg), whereas pipe traps caught the most Xyleborus Eichhoff spp. More Xylosandrus crassiusculus (Motschulsky) and Dryoxylon onoharaensis (Murayama) were caught in panel and funnel traps than in pipe traps. Among bark beetle predators, more Platysoma Leach spp. (Histeridae) were caught in pipe and panel traps than in funnel traps, whereas most Lasconotus Erichson spp. (Zopheridae) were caught in funnel traps. Variation among trap performance for various species suggests that managers should consider more than one type of trap in their detection programs.     

Effect of trap type, trap position, time of year, and beetle density on captures of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)

The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae: Scolytinae), and its fungal symbiont Raffaellea lauricola Harrington, Fraedrich, and Aghayeva are responsible for widespread redbay, Persea borbonia (L.) Spreng., mortality in the southern United States. Effective traps and lures are needed to monitor spread of the beetle and for early detection at ports-of-entry, so we conducted a series of experiments to find the best trap design, color, lure, and trap position for detection of X. glabratus. The best trap and lure combination was then tested at seven sites varying in beetle abundance and at one site throughout the year to see how season and beetle population affected performance. Manuka oil proved to be the most effective lure tested, particularly when considering cost and availability. Traps baited with manuka oil lures releasing 5 mg/d caught as many beetles as those baited with lures releasing 200 mg/d. Distributing manuka oil lures from the top to the bottom of eight-unit funnel traps resulted in similar numbers of X. glabratus as a single lure in the middle. Trap color had little effect on captures in sticky traps or cross-vane traps. Funnel traps caught twice as many beetles as cross-vane traps and three times as many as sticky traps but mean catch per trap was not significantly different. When comparing height, traps 1.5 m above the ground captured 85% of the beetles collected but a few were caught at each height up to 15 m. Funnel trap captures exhibited a strong linear relationship (r2 = 0.79) with X. glabratus attack density and they performed well throughout the year. Catching beetles at low densities is important to port of entry monitoring programs where early detection of infestations is essential. Our trials show that multiple funnel traps baited with a single manuka oil lure were effective for capturing X. glabratus even when no infested trees were visible in the area.     

Comparison of trap designs for use with aggregation pheromone and synthetic co-attractant in a user-friendly attract and kill system to control Carpophilus spp. (Coleoptera: Nitidulidae)

Abstract  Three field experiments were conducted in stone fruit orchards in the Goulburn Valley, northern Victoria, Australia to identify a user-friendly trap for use in attract and kill stations for control of Carpophilus spp. (Coleoptera: Nitidulidae). A funnel trap design was compared with two types of delta trap in one experiment and two types of Lucitrap in another experiment. All traps were baited with synthetic co-attractant and synthetic pheromone. The funnel trap was the most effective type of trap tested. The funnel traps caught significantly more beetles than either the delta traps with bio-attractant or delta traps wrapped with insecticide impregnated banana wrap. No difference was observed between catches in either delta trap design. Lucitraps without covers caught significantly more beetles than Lucitraps with covers but funnel traps caught significantly more beetles than either type of Lucitrap. Beetle numbers caught in the funnel traps were three to five times higher than in Lucitrap. The use of funnel traps in attract and kill stations to protect stone fruit crops by suppressing the Carpophilus spp. population gave superior control to 'grower normal practice of spraying insecticides' both in terms of Carpophilus spp. numbers and in terms of reduction in percentage of fruit damaged.     

Efficacy of traps, lures, and repellents for Xylosandrus compactus (Coleoptera: Curculionidae) and other ambrosia beetles on Coffea arabica plantations and Acacia koa nurseries in Hawaii

The black twig borer, Xylosandrus compactus (Eichhoff) (Coleoptera: Curculionidae: Scolytinae), is a pest of coffee and many endemic Hawaiian plants. Traps baited with chemical attractants commonly are used to capture ambrosia beetles for purposes of monitoring, studying population dynamics, predicting outbreaks, and mass trapping to reduce damage. The objectives of this research were to optimize trapping systems for X. compactus and other ambrosia beetles such as Xylosandrus crassiusculus (Motschulsky) and Xyleborinus saxesenii (Ratzeburg) by comparing efficacy of several attractants, repellents, and trap types. The ability of certain chemicals to act as beetle repellents and thus interfere with trap catch was tested for purposes of protecting host plants from attack. Potential attractants and application methods tested were as follows: ethyl alcohol pouch delivery system, ethyl alcohol vial delivery system, α-pinene in Eppendorf tubes, eugenol bubblecaps, ginger oil bubblecaps, manuka oil bubblecaps, phoebe oil bubblecaps, and an unbaited control. Potential repellents tested were limonene and verbenone. Ethyl alcohol vials were as attractive as ethyl alcohol sleeves, and were more effective than traps baited with eugenol and α-pinene. Japanese beetle traps were more effective for black twig borer trapping than Lindgren funnel traps, and were easier to deploy. Verbenone and limonene significantly reduced trap catch of Xylosandrus compactus and X. crassiusculus, suggesting that they may be effective for reducing attraction to host plants. These results show the importance of developing a combination of several monitoring techniques to enhance management procedures for the black twig borer.     

Lepidoptera pests collected in Eucalyptus urophylla (Myrtaceae) plantations during five years in Três Marias,State of Minas Gerais,Brazil

Lepidoptera pest species from eucalyptus were collected in Eucalyptus urophylla plantations in the region of Três Marias, State of Minas Gerais, Brazil, every 15 days from June 1989 to June 1994 with five light traps. Twelve primary and 15 secondary pest species were collected in the period with an average of 13,387 and 812 individuals per light trap, respectively. Most collected primary pest species were Stenalcidia grosica (Geometridae), Iridopsis subferaria (Geometridae), Eupseudosoma aberrans (Arctiidae) and Psorocampa denticulata (Notodontidae), totalizing for the study period an average of 5,450, 2,162, 2,436 and 1,458 individuals per light trap, respectively. Idalus admirabilis (Arctiidae) was the most collected secondary pest species, averaging 652 individuals/trap. Most primary pest species were collected during the dry season, from April to July, whereas most secondary pest species were collected during the rainy season, from January to March. These differences on seasonal occurrence between the two groups could be due to the fact that many secondary pest species of Eucalyptus in Brazil pupate in the soil, and they need humidity to complete its pupal stage.     

Test of nonhost angiosperm volatiles and verbenone to protect trap trees for Sirex noctilio (Hymenoptera: Siricidae) from attacks by bark beetles (Coleoptera: Scolytidae) in the northeastern United States

Sirex noctilio F. (Hymenoptera: Siricidae) is an invasive woodwasp, currently established in northeastern North America. In other regions of the world, stressed trap trees are used to monitor populations of S. noctilio and to provide inoculation points for the biological control nematode Deladenus siricidicola Bedding. However, the operational use of trap trees for S. noctilio in North America may be compromised by the large community of native organisms that inhabit stressed and dying pine trees. Common bark beetles such as Ips pini (Say) and Ips grandicollis (Eichhoff) (Coleoptera: Scolytidae) could potentially compete with S. noctilio and associates for resources on trap trees, possibly reducing the efficacy of trap trees as habitats for the woodwasp. In an attempt to develop a technology to mitigate this potential issue, three common semiochemical interruptants--conophthorin, green leaf volatile mix, and verbenone--were tested for effectiveness in reducing arrivals of I. pini and I. grandicollis on trap trees treated with herbicides in northeastern United States. In addition, the effects of these compounds were determined independently with pheromone-baited multiple-funnel traps. None of the interruptants reduced numbers of I. pini or I. grandicollis either arriving on trap trees or caught in pheromone-baited traps. However, verbenone increased catches of I. grandicollis in traps baited with its pheromone, ipsenol. The mix of green leaf volatiles reduced catches of a native ambrosia beetle, Gnathotrichus materiarius (Fitch), whereas verbenone reduced trap catches of an exotic ambrosia beetle, Xylosandrus germanus (Blandford). Catches of X. germanus in traps adjacent to trap trees were enhanced with conophthorin.     

Comparison of naturally and synthetically baited spruce beetle trapping systems in the central Rocky Mountains

We compared naturally baited trapping systems to synthetically baited funnel traps and fallen trap trees for suppressing preoutbreak spruce beetle, Dendroctonus rufipennis Kirby, populations. Lures for the traps were fresh spruce (Picea spp.) bolts or bark sections, augmented by adding female spruce beetles to create secondary attraction. In 2003, we compared a naturally baited system ("bolt trap") with fallen trap trees and with synthetically baited funnel traps. Trap performance was evaluated by comparing total beetle captures and spillover of attacks into nearby host trees. Overall, the trap systems did not significantly differ in spruce beetle captures, although bolt traps caught 6 to 7 times more beetles than funnel traps during the first 4 wk of testing. Funnel traps with synthetic lures had significantly more spillover than either trap trees or bolt traps. The study was repeated in 2004 with modifications including an enhanced blend synthetic lure. Again, trap captures were generally similar among naturally and synthetically baited traps, but naturally baited traps had significantly less spillover. Although relatively labor-intensive, the bolt trap could be used to suppress preoutbreak beetle populations, especially when spillover is undesirable. Our work provides additional avenues for management of spruce beetles and suggests that currently used synthetic lures can be improved.     

An effective strategy for trapping Douglas-fir beetle, Dendroctonus pseudotsugae (Col., Scolytidae) using combinations of unbaited and pheromone baited funnel traps

Experiments were conducted to confirm and quantify earlier observations that unbaited funnel traps in conjunction with pheromone baited funnel traps may substantially increase trap catches of Douglas-fir beetles, Dendroctonus pseudotsugae . In 12 replicates of one of these experiments during 1998 and 1999, the catches of a single baited control trap were compared to those of a set of four traps where the central trap was baited and a ring of three traps, 1 m from the central trap arranged in a star configuration, were unbaited. In the second experiment conducted during 1999, a ring of three unbaited traps was placed at 2 m and a second at 5 m from the central baited trap. Statistically robust results demonstrated clearly that the configuration of one central baited trap plus three unbaited satellite traps collected twice as many beetles on average over the season compared to the baited control trap. Addition of a second ring of unbaited traps increased collections by only about 20%, but this experiment indicated that trap catches dropped off exponentially with distance from the centre. The number of beetles caught in the baited traps was essentially the same in all 3 arrangements, suggesting that the additional unbaited traps captured beetles that otherwise may not have been captured.     

Optimizing ethanol-baited traps for monitoring damaging ambrosia beetles (Coleoptera: Curculionidae, Scolytinae) in ornamental nurseries

The exotic ambrosia beetles Xylosandrus crassiusculus (Motschulsky) and Xylosandrus germanus (Blandford) (Coleoptera: Curculionidae: Scolytinae) are serious pests in ornamental tree nurseries. To optimize bottle-traps as a monitoring system for X. crassiusculus and X. germanus in nurseries, we tested whether increasing the rate of commercial ethanol lures improved captures or early detection of these species. Experiments were conducted in Ohio (2008 and 2009) and Virginia (2008), two states that have experienced significant damage from X. crassiusculus, X. germanus, or both. There were four treatments: no-lure (unbaited control), 1-ethanol lure, 2-ethanol lures and 1 + 1-ethanol lures (one lure in the trap and one suspended 0.5 m above the trap). Captures of X. crassiusculus and X. germanus were higher in all ethanol treatments than unbaited controls, and were generally higher in treatments with two lures versus one. There was no difference in beetle captures between the 2-lure and 1 + 1-lure treatments. First detection of X. crassiusculus and X. germanus occurred more consistently in the treatments with two lures than one lure. Xyleborinus saxesenii (Ratzeburg), Anisandrus sayi Hopkins, Hypothenemus dissimilis Zimmermann, and Hypothenemus eruditus Westwood were also more attracted to traps baited with ethanol than unbaited controls. X. saxesenii was captured in higher numbers in the treatments with two lures than one in Virginia but not in Ohio. There was no difference in captures of the other species among ethanol treatments. The current research shows that ethanol release rates influence sensitivity of traps for detecting emergence of overwintered ambrosia beetles.     

Ambrosia beetle (Coleoptera: Curculionidae) responses to volatile emissions associated with ethanol-injected Magnolia virginiana

Xylosandrus germanus (Blandford) and other species of ambrosia beetles are key pests of ornamental nursery trees. A variety of laboratory- and field-based experiments were conducted in pursuit of improved monitoring strategies and to develop a trap tree strategy for ambrosia beetles. Traps baited with bolts prepared from Magnolia virginiana L. injected with ethanol caught five times more X. germanus than ethanol-baited traps. Basal stem injections of ethanol into M. virginiana induced more ambrosia beetle attacks than irrigating or baiting with ethanol, and no attacks occurred on water-injected trees. A positive correlation was also detected between concentration of injected ethanol and cumulative attacks. Solid phase microextraction-gas chromatography-mass spectrometry characterized bark emissions from ethanol- and water-injected M. virginiana at 1, 2, 10, and 16 d after treatment. Ethanol emission from injected trees steadily declined from 1 to 16 d after treatment, but was not emitted from water-injected trees. A variety of monoterpenes were also emitted in trace amounts from the ethanol- and water-injected trees. Antennal responses of X. germanus via gas chromatography-electroantennographic detection to volatiles from ethanol-injected M. virginiana occurred for ethanol, but not the various monoterpenes. X. germanus and other ambrosia beetles were also equally attracted to traps baited with ethanol alone compared with a synthetic mixture of ethanol plus various monoterpenes formulated to mimic ethanol-injected M. virginiana. Injecting concentrated solutions of ethanol into trees may be useful for establishing odor-based trap trees, which could aid with monitoring programs and/or potentially deflect ambrosia beetles away from valuable nursery stock.     

Temporal analysis of sesquiterpene emissions from manuka and phoebe oil lures and efficacy for attraction of Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood-borer that vectors the fungal agent (Raffaelea lauricola) responsible for laurel wilt. Laurel wilt has had severe impact on forest ecosystems in the southeastern United States, killing a large proportion of native Persea trees, particularly redbay (P. borbonia) and swampbay (P. palustris), and currently poses an economic threat to avocado (P. americana) in Florida. To control the spread of this lethal disease, effective attractants are needed for early detection of the vector. Two 12-wk field tests were conducted in Florida to evaluate efficacy and longevity of manuka and phoebe oil lures, and to relate captures of X. glabratus to release rates of putative sesquiterpene attractants. Two trap types were also evaluated, Lindgren funnel traps and sticky panel traps. To document lure emissions over time, a separate set of lures was aged outdoors for 12 wk and sampled periodically to quantify volatile sesquiterpenes using super-Q adsorbant and gas chromatography-mass spectroscopy analysis. Phoebe lures captured significantly more X. glabratus than manuka lures, and sticky traps captured more beetles than funnel traps. Phoebe lures captured X. glabratus for 10-12 wk, but field life of manuka lures was 2-3 wk. Emissions of alpha-copaene, alpha-humulene, and cadinene were consistently higher from phoebe lures, particularly during the 2-3 wk window when manuka lures lost efficacy, suggesting that these sesquiterpenes are primary kairomones used by host-seeking females. Results indicate that the current monitoring system is suboptimal for early detection of X. glabratus because of rapid depletion of sesquiterpenes from manuka lures.     

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.     

Integrating repellent and attractant semiochemicals into a push–pull strategy for ambrosia beetles (Coleoptera: Curculionidae)

Non‐native ambrosia beetles (Coleoptera: Curculionidae), especially Xylosandrus compactus (Eichhoff), Xylosandrus crassiusculus (Motschulsky) and Xylosandrus germanus (Blandford), are destructive wood‐boring pests of trees in ornamental nurseries and tree fruit orchards. Previous studies have demonstrated the adults are repelled by verbenone and strongly attracted to ethanol. We tested a “push–pull” semiochemical strategy in Ohio, Virginia and Mississippi using verbenone emitters to “push” beetles away from vulnerable trees and ethanol lures to “pull” them into annihilative traps. Container‐grown trees were flood‐stressed to induce ambrosia beetle attacks and then deployed in the presence or absence of verbenone emitters and a perimeter of ethanol‐baited interception traps to achieve the following treatment combinations: (a) untreated control, (b) verbenone only, (c) ethanol only, and (d) verbenone plus ethanol. Verbenone and ethanol did not interact to reduce attacks on the flooded trees, nor did verbenone alone reduce attacks. The ethanol‐baited traps intercepted enough beetles to reduce attacks on trees deployed in Virginia and Mississippi in 2016, but not in 2017, or in Ohio in 2016. Xylosandrus germanus, X. crassiusculus and both Hypothenemus dissimilis Zimmermann and X. crassiusculus were among the predominant species collected in ethanol‐baited traps deployed in Ohio, Virginia and Mississippi, respectively. Xylosandrus germanus and X. crassiusculus were also the predominant species dissected from trees deployed in Ohio and Virginia, respectively. While the ethanol‐baited traps showed promise for helping to protect trees by intercepting ambrosia beetles, the repellent “push” component (i.e., verbenone) and attractant “pull” component (i.e., ethanol) will need to be further optimized in order to implement a “push–pull” semiochemical strategy.     

Comparison of adult corn rootworm (Coleoptera: Chrysomelidae) sampling methods

Studies were conducted in Kansas corn and soybean fields during 1997 to compare various sampling methods, traps, and trap components for capturing three species of adult corn rootworms: western (Diabrotica virgifera virgifera Leconte), southern (D. undecimpunctata howardi Barber), and northern (D. barberi Smith & Lawrence). Lure constituents affected the species of beetle attracted to the trap. Traps with a lure containing 4-methoxycinnamaldehyde attracted more western corn rootworms, those with a lure containing eugenol were more attractive to northern corn rootworms, and those containing trans-cinnamaldehyde were most attractive to southern corn rootworms. Multigard sticky traps caught more beetles than did Pherocon AM sticky traps. In corn, a newly designed lure trap caught more beetles than did sticky traps on most occasions. Also, lure-baited sticky traps caught more beetles than did nonbaited sticky traps. Varying the color of the lure trap bottom did not affect the number caught. In soybeans, the new lure traps captured more beetles than did the nonbaited Multigard or Pherocon AM sticky traps. Results of this study suggest the new lure trap may provide a more accurate assessment of corn rootworm populations than traditional monitoring techniques and may be more esthetically pleasing to growers and consultants.     

Efficacy of Fluon conditioning for capturing cerambycid beetles in different trap designs and persistence on panel traps over time

Fluon PTFE is a fluoropolymer dispersion applied as a surface conditioner to cross-vane panel traps to enhance trap efficiency for cerambycid beetles. We describe the results of three experiments to further optimize cerambycid traps of different designs and to test the effect of Fluon over time. We tested Fluon with Lindgren funnel and panel traps fitted with either wet or dry collection cups on catches of cerambycid beetles and how the effect of Fluon on panel traps persisted. Fluon-treated funnel traps with wet collection cups captured approximately 6x more beetles than the untreated funnel traps with wet collection cups. Untreated funnel traps with dry collection cups did not capture any beetles; however, Fluon-treated funnel traps with dry collection cups captured an average of four beetles per trap. Fluon-treated panel traps with wet collection cups captured approximately 9x more beetles than untreated panel traps with wet collection cups. Fluon-treated panel traps with dry collection cups captured approximately 11x more beetles than untreated panel traps with dry collection cups. The effect of Fluon on capturing cerambycid beetles did not decline after use in one or two field seasons. There was no significant difference in the number of beetles captured in freshly treated panel traps compared with traps that had been used for 1 or 2 yr. Fluon-treated traps captured nine species that were not captured in untreated traps. Conditioning both Lindgren funnel and panel traps with Fluon enhances the efficacy and sensitivity of traps deployed to detect exotic cerambycid species, or for monitoring threatened species at low population densities.     

Optimization of traps for live trapping of Pine Wood Nematode vector Monochamus galloprovincialis

The pine sawyer beetle Monochamus galloprovincialis, a secondary pest of pines in Europe and North Africa, has become important as it was identified as the vector in Europe of Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). An effective trapping system is needed, not only for monitoring the insect vector but also for direct control of its population. Trapping may also provide key information on the nematode load carried by the beetles, allowing early detection of infections, provided that captured beetles remain alive within the trap. Highly effective attractants have been developed in recent years that are commonly used in combination with diverse standard trap designs. In this study, several trap designs were developed and compared to commercial standard models in order to determine which designs maximized the number of attracted insects actually caught and the proportion of them remaining alive. In total, 12 trap designs were evaluated in five field experiments carried out in France, Spain and Portugal. Teflon coating applied to the whole trap and extended, ventilated collecting cups resulted in a significant improvement of trap performance. These modifications led to significant increases of pine sawyer catches, up to 275%, when applied to multiple‐funnel or black cross‐vane traps, compared to standard designs. Furthermore, a significant proportion of the captured beetles remained alive within the trap. These findings have been used to develop new commercial traps (Econex Multifunnel‐12^® and Crosstrap^®; Econex, Murcia, Spain) available to forest managers. A model for insect survival within the trap was also fitted. Elapsed time between consecutive samplings, mean relative humidity and maximum radiation were the three most significant variables. Thus, traps should provide a suitable sample of live insects if sun exposure of the trap is minimized and a reasonable sampling schedule is implemented.     

Effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay ambrosia beetle and granulate ambrosia beetle (coleoptera: Curculionidae: Scolytinae)

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps baited with swampbay (Persea palustris (Rafinesque) Sargent) and camphortree (Cinnamomum camphora (L.) J. Presl), which were more attractive than avocado (Persea americana Miller), lancewood (Ocotea coriacea (Swartz) Britton), and sweetbay (Magnolia virginiana L.). These species were more attractive than loblolly bay (Gordonia lasianthus (L.) J. Ellis). X. glabratus entrance hole density and emergence from caged bolts were highest on swampbay and camphortree. In 2010, swampbay was significantly more attractive to X. glabratus than sassafras (Sassafras albidum (Nuttall) Nees), yellow poplar (Liriodendron tulipifera L.), and eastern redbud (Cercis canadensis L.). Sassafras bolts end sealed with a liquid wax-and-water emulsion were more attractive to X. glabratus than end-sealed bolts of yellow poplar and redbud. Relative to unsealed bolts, end seal decreased X. glabratus entrance hole density on swampbay and decreased granulate ambrosia beetle (Xylosandrus crassiusculus (Motschulsky)) trap catch, entrance hole density, and adult emergence from swampbay. X. crassiusculus was not attracted to sassafras, yellow poplar, and redbud and was not more attracted to manuka oil than to unbaited traps. Sassafras was more attractive to X. glabratus than previously reported and supported reproducing populations of the insect. End sealing bolts with a wax-and-water emulsion may not be optimal for attracting and rearing ambrosia beetles in small logs.     

Evaluation of funnel traps for characterizing the bark beetle (Coleoptera: Scolytidae) communities in ponderosa pine forests of north-central Arizona

Lindgren funnel traps baited with aggregation pheromones are widely used to monitor and manage populations of economically important bark beetles (Coleoptera: Scolytidae). This study was designed to advance our understanding of how funnel trap catches assess bark beetle communities and relative abundance of individual species. In the second year (2005) of a 3-yr study of the bark beetle community structure in north-central Arizona pine (Pinus spp.) forests, we collected data on stand structure, site conditions, and local bark beetle-induced tree mortality at each trap site. We also collected samples of bark from infested (brood) trees near trap sites to identify and determine the population density of bark beetles that were attacking ponderosa pine, Pinus ponderosa Douglas ex Lawson, in the area surrounding the traps. Multiple regression models indicated that the number of Dendroctonus and Ips beetles captured in 2005 was inversely related to elevation of the trap site, and positively associated with the amount of ponderosa pine in the stand surrounding the site. Traps located closer to brood trees also captured more beetles. The relationship between trap catches and host tree mortality was weak and inconsistent in forest stands surrounding the funnel traps, suggesting that trap catches do not provide a good estimate of local beetle-induced tree mortality. However, pheromone-baited funnel trap data and data from gallery identification in bark samples produced statistically similar relative abundance profiles for the five species of bark beetles that we examined, indicating that funnel trap data provided a good assessment of species presence and relative abundance.     

Ambrosia beetles (Curculionidae: Scolytinae and Platypodinae) on Fagus crenata Blume: community structure,seasonal population trends and resource utilization patterns

Ambrosia beetles (many Scolytinae and all Platypodinae) are one of the most important insect pests for forestry worldwide, but little is known about the community structure of ambrosia beetles in terms of their vertical variations and resource utilization. We clarified the community structure and seasonal population trends of ambrosia beetles on 11 living and three newly dead Fagus crenata Blume trees using individual tube traps placed up to 10 m high from May to November in 2007 and 2008. We captured seven scolytine species (Ambrosiodmus lewisi (Blandford), Euwallacea validus (Eichhoff), Trypodendron proximum (Niisima), Xyleborinus saxeseni (Ratzeburg), Xyleborus atratus Eichhoff, Xylosandrus brevis (Eichhoff) and Xylosandrus germanus (Blandford)) and three platypodine species (Crossotarsus niponicus Blandford, Platypus hamatus Blandford and Platypus severini Blandford). The ambrosia beetles were suggested to breed at species‐specific height ranges, with the equal host resource use per individual among the species. Of the three major species, C. niponicus, P. hamatus and P. severini, two (C. niponicus and P. hamatus) had male‐biased sex ratios, which is considered a reproductive strategy to increase maternal fitness. Morphological characteristics of the mandibles may play an important role in the difference of sex roles on reproduction in the three major species.     

The effectiveness of traps used currently for monitoring populations of the cabbage root fly (Delia radicum)

Six different types of traps were compared for capturing adults of Delia radicum. Cone traps caught so few flies that it seems inadvisable for them to be used for monitoring populations of this pest. All the other traps tested were suitable for monitoring D. radicum populations. When expressed on a trap for trap basis, the large 1800 cm² Canadian traps caught most flies. When expressed as the numbers of flies caughthnit area of trapping surface, most flies were caught in the water traps. Similar numbers of D. radicum, D. platura, syrphids, blowflies and a tachinid, Eriothrix rufomaculatus were caught per unit area on each of three different vertical sticky traps. Although water traps have the advantage that they catch about 5 times as many females D. radicum/unit area as the most effective vertical sticky traps of a comparable size, their disadvantage is that they catch about 10 times as many beneficial syrphids. The reasons why water traps are so effective against D. radicum are discussed, with details of how to convert water-trap data to sticky-trap equivalents, and vice versa.