Jeremy D. Allison

Effect of Aerosol Surface Lubricants on the Abundance and Richness of Selected Forest Insects Captured in Multiple-Funnel and Panel Traps

ABSTRACT Survey and detection programs for native and exotic forest insects frequently rely on traps baited with odorants, which mediate the orientation of target taxa (e.g., the southern pine beetle, Dendroctonus frontalis Zimmermann) toward a resource (e.g., host material, mates). The influence of trap design on the capture efficiency of baited traps has received far less empirical attention than odorants, despite concerns that intercept traps currently used operationally have poor capture efficiencies for some target taxa (e.g., large woodborers). Several studies have recently demonstrated that treating traps with a surface lubricant to make them “slippery” can increase their capture efficiency; however, previously tested products can be expensive and their application time-consuming. The purpose of this study was to evaluate the effect of alternate, easier to apply aerosol lubricants on trap capture efficiency of selected forest insects. Aerosol formulations of Teflon and silicone lubricants increased both panel and multiple-funnel trap capture efficiencies. Multiple-funnel traps treated with either aerosol lubricant captured significantly more Monochamus spp. and Acanthocinus obsoletus (Olivier) than untreated traps. Similarly, treated panel traps captured significantly more Xylotrechus sagittatus (Germar), Ips calligraphus (Germar), Pissodes nemorensis (Germar), Monochamus spp., A. obsoletus, Thanasimus dubius (F.), and Ibalia leucospoides (Hochenwarth) than untreated traps. This study demonstrates that treating multiple-funnel and panel traps with an aerosol dry film lubricant can increase their capture efficiencies for large woodborers (e.g., Cerambycidae) as well as bark beetles, a weevil, a woodwasp parasitoid and a bark beetle natural enemy (Coleoptera: Cleridae).

The Impact of Trap Type and Design Features on Survey and Detection of Bark and Woodboring Beetles and Their Associates: A Review and Meta-Analysis*

A large literature on the survey and detection of forest Coleoptera and their associates exists. Identification of patterns in the effect of trap types and design features among guilds and families of forest insects would facilitate the optimization and development of intercept traps for use in management programs. We reviewed the literature on trapping bark and woodboring beetles and their associates and conducted meta-analyses to examine patterns in effects across guilds and families; we observed the following general patterns: (a) Panel traps were superior to multiple-funnel traps, (b) bark beetles and woodborers were captured in higher numbers in traps treated with a surface treatment to make them slippery than untreated traps,

Considering species richness and rarity when selecting optimal survey traps: comparisons of semiochemical baited flight intercept traps for Cerambycidae in eastern North America

We compared standard multiple‐funnel, modified multiple‐funnel, intercept panel and canopy malaise (SLAM) traps with top and bottom collecting cups for their effectiveness (species richness, rarity, abundance) at capturing Cerambycidae in eastern North America. Experiments were conducted in New York, Louisiana, Massachusetts and Georgia in 2011 and 2012. A combination of pheromones and host volatiles chosen to match local forest types were used as lures. Species richness tended to be higher in SLAM and modified funnel traps than standard funnel and intercept panel traps. SLAM traps also captured the highest number of species, unique species, rare (species accounting for ≤ 1% of total cerambycids at a site) and singleton species at each site. Individual‐based rarefaction and sample‐based species accumulation curves suggested that SLAM traps are more effective for capturing cerambycid species. For many estimates, modified funnel and funnel traps were lower than SLAM traps but greater than intercept panel traps for describing cerambycid communities. Modified funnel and SLAM traps generally captured the highest abundance of cerambycids but the response of the individual subfamily and species varied by trap type. SLAM traps should be considered as a strong tool to describe cerambycid communities when used in conjunction with pheromones and host volatiles.

Considering species richness and rarity when selecting optimal survey traps: comparison of semiochecmial baited flight intercept traps for Cerambycidae in eastern North America

We compared standard multiple‐funnel, modified multiple‐funnel, intercept panel and canopy malaise (SLAM) traps with top and bottom collecting cups for their effectiveness (species richness, rarity, abundance) at capturing Cerambycidae in eastern North America. Experiments were conducted in New York, Louisiana, Massachusetts and Georgia in 2011 and 2012. A combination of pheromones and host volatiles chosen to match local forest types were used as lures. Species richness tended to be higher in SLAM and modified funnel traps than standard funnel and intercept panel traps. SLAM traps also captured the highest number of species, unique species, rare (species accounting for ≤ 1% of total cerambycids at a site) and singleton species at each site. Individual‐based rarefaction and sample‐based species accumulation curves suggested that SLAM traps are more effective for capturing cerambycid species. For many estimates, modified funnel and funnel traps were lower than SLAM traps but greater than intercept panel traps for describing cerambycid communities. Modified funnel and SLAM traps generally captured the highest abundance of cerambycids but the response of the individual subfamily and species varied by trap type. SLAM traps should be considered as a strong tool to describe cerambycid communities when used in conjunction with pheromones and host volatiles.

Predicting Sirex noctilio and S. nigricornis emergence using degree days

The study of temporal interactions between native insects and alien invaders can be facilitated by the ability to forecast adult emergence. We used field‐collected adult emergence data of Sirex noctilio Fabricius (Hymenoptera: Siricidae), a woodwasp native of Eurasia that has recently invaded northeastern North America, and Sirex nigricornis Fabricius, a woodwasp native to North America, to develop and test cumulative degree‐day (CDD) models. Five data sets were collected each in Ontario, Canada (S. noctilio) and Louisiana, USA (S. nigricornis) over 4 years; three data sets were used to develop models and two were used to test them. Males and females of each species were modelled separately. After testing several potential temperatures, chosen thresholds for CDD were 0 °C lower threshold and 25 °C upper threshold for both Sirex spp. We used a three‐parameter Gompertz growth function to model Sirex spp. emergence against CDD. Models predicted 10% emergence of S. noctilio in Ontario after 1 239 and 1 280 CDD, for males (start date = 1 April; R2 = 0.91) and females (start date = 1 April; R2 = 0.86), respectively. Models predicted 10% emergence of S. nigricornis in Louisiana after 3 980 and 5 016 CDD, for males (start date = 1 May; R2 = 0.83) and females (start date = 1 March; R2 = 0.73), respectively. Cumulative degree‐day models predicted 10 and 90% emergence of woodwasp populations with less error (1–13%) than they did 50% emergence (5–27%). For both Sirex spp., male emergence began a few days before and concluded at about the same time as that of females. In southern Ontario, models predict that S. noctilio adults will be in flight between 1 015 and 2 430 CDD (1 April start date for CDD; from early‐July until mid‐September). In Louisiana, models predict that S. nigricornis adults will be in flight between 3 854 and 4 700 CDD (1 May start date for CDD; from early‐October until late‐November).

Do Native Insects and Associated Fungi Limit Non-Native Woodwasp, Sirex noctilio, Survival in a Newly Invaded Environment?

Sirex noctilio F. (Hymenoptera: Siricidae) is an introduced pest of pines (Pinus spp.) in several countries in the Southern Hemisphere. Although S. noctilio is established in North America (first discovered in 2004), it has not been a destructive pest there so far, where forest communities more closely resemble those in its native Eurasian range—where it is not a pest. To investigate the influence of the existing community of associated insects (competitors + natural enemies) and fungi (vectored by insects) on S. noctilio survival in North America, we examined stage-specific mortality factors and their relative importance, generating life tables drawn from experimentally-manipulated and natural cohorts of Sirex spp. (mostly S. noctilio, but some native S. nigricornis F.). For both natural and experimentally-manipulated cohorts, factors which acted during the earliest Sirex life stages, most likely tree resistance and/or competition among fungal associates, were paramount in dictating woodwasp survival. Experimentally-manipulated life tables revealed that protection from the community of associates resulted in a significantly, and substantially larger (>15x) S. noctilio F1 generation than exposure to it. Seventy percent of generation mortality in the exposed cohort was due to tree resistance or unknown causes early in larval development, which could have included competition among other bark- or wood-inhabiting insects and/or their fungal associates. Only 46% of generation mortality in the protected cohort was due to tree resistance and/or unknown causes. Parasitoids, particularly endoparasitoids (Ibalia spp.), showed limited ability to control S. noctilio, and reduced the experimentally-established cohort by only 11%, and natural cohorts an average of 3.4%. The relative importance of tree resistance vs. competition with bark- and wood-borers in reducing S. noctilio survival remains unclear. Tree resistance and/or competition likely contribute more than natural enemies in maintaining the S. noctilio population in North America below damaging levels.

Detection and Identification of Amylostereum areolatum (Russulales: Amylostereaceae) in the Mycangia of Sirex nigricornis (Hymenoptera: Siricidae) in Central Louisiana

ABSTRACT The woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) has become established in North America.Aprimary tactic for the management of S. noctilio in the southern hemisphere has been the development of a biological control agent, Deladenus siricidicola Bedding. This nematode has a bicyclic life cycle including a mycetophagous free-living and parasitic cycle. During oviposition, female Sirex woodwasps inject a symbiotic fungus. Because D. siricidicola only develops well on Amylostereum areolatum (Chaillet ex Fries) Boidin (Russulales: Amylostereaceae) and North American woodwasps were thought to all have Amylostereum chailletii (Persoon) Boidin as their fungal symbiont, the risk of unintended impacts from D. siricidicola in North America was considered low. Specific polymerase chain reaction primers were designed to amplify the intergenic spacer region of Amylostereum symbionts in a population of the native woodwasp Sirex nigricornis F. located in central Louisiana (i.e., well outside the known distribution of S. noctilio); identity of the symbiont was confirmed by phylogenetic analyses. Overall, 95 out of 100 fungal isolates obtained from the mycangia of S. nigricornis were identified as Amylostereum species. Contrary to expectations, 60% were identified as A. chailletii (N = 60), while 35% were identified as A. areolatum (N = 35). The remaining 5% of these isolates (N = 5) were identified as Bipolaris papendorfii (Aa) Alcorn, Alternaria alternata (Fr.) Keissl, Penicillium marneffei Segretain, Scytalidium cuboideum (Sacc. & Ellis) Sigler & Kang, and Hyphopichia heimii (Pignal) Kurtzman based on sequencing of the internal transcribed spacer (ITS) region. The five non-Amylostereum isolates were likely contaminants during mycangia-spore extraction process. This study confirms the presence of A. areolatum in a population of the native woodwasp S. nigricornis well outside the known distribution of S. noctilio.

Role of Ipsdienol, Ipsenol, and cis-Verbenol in Chemical Ecology of Ips avulsus, Ips calligraphus, and Ips grandicollis (Coleoptera: Curculionidae: Scolytinae)

ABSTRACT Stressed or damaged pine (Pinus sp.) trees in the southeastern United States are often colonized simultaneously by three southern Ips species (Coleoptera: Curculionidae: Scolytinae): small southern pine engraver, Ips avulsus (Eichhoff); sixspined ips, Ips calligraphus (Germar); and eastern fivespined ips, Ips grandicollis (Eichhoff). All three species mediate colonization of host material with volatile pheromones. All of the southern Ips produce cis-verbenol, and either ipsdienol or ipsenol, and electrophysiological studies have demonstrated that all three southern Ips are able to detect all three compounds. This study examined the role of ipsdienol, ipsenol, and cis-verbenol in the chemical ecology of the southern Ips in Georgia and Louisiana. The most attractive blends of pheromones, with the fewest number of components, were ipsdienol plus ipsenol for I. avulsus, cis-verbenol plus ipsdienol for I. calligraphus, and either cis-verbenol plus ipsenol or ipsdienol plus ipsenol for I. grandicollis. Cross-attraction of I. grandicollis to the pheromone blend most attractive to I. avulsus was observed. Although the presence of heterospecific pheromone reduced the catches of all three species (i.e., the tertiary blend captured fewer beetles than the most attractive binary blends) in both states (significantly in two cases), high numbers of all three species were still captured in traps baited with all three compounds. These results suggest that the pheromones cis-verbenol, ipsdienol, and ipsenol can be combined for monitoring all three species of the southern Ips simultaneously.

Nonlethal Effects of Nematode Infection on Sirex noctilio and Sirex nigricornis (Hymenoptera: Siricidae)

Abstract A nonnative woodwasp, Sirex noctilio F., has established in pine forests in eastern North America. To facilitate prediction of the full range of impacts S. noctilio could have as it continues to spread in North American forest ecosystems, we studied the effects of infection by a nonsterilizing parasitic nematode on S. noctilio size, fecundity, and flight capacity and on the native woodwasp, S. nigricornis, size and fecundity. We also developed predictive models relating size to fecundity for both species. On average, S. noctilio (3.18 ± 0.05mm) were larger than S. nigricornis (2.19 ± 0.04 mm). For wasps of similar size, S. nigricornis was more fecund. Nematode infection negatively affected potential fecundity by a mean difference of 36 and 49 eggs in S. noctilio and S. nigricornis, respectively. Nematode-infected males of S. noctilio, however, were larger than uninfected individuals. Nematode infection showed inconsistent results on mean speed and total distance flown by S. noctilio males and females. Nematode infection did not affect total distance flown by females, and so is unlikley to have a direct, or strong influence on S. noctilio flight capacity. Models developed to predict fecundity of Sirex spp. from body size, based on the close relationship between pronotum width and potential fecundity for both species (R2 ≥ 0.69), had low measures of error when compared with true values of fecundity (± 25–26 eggs).

A Tetraene Aldehyde as the Major Sex Pheromone Component of the Promethea Moth (Callosamia promethea (Drury))

The promethea moth Callosamia promethea is one of three species of silkmoths from the genus Callosamia that occur in North America. Cross attraction of males to heterospecific calling females has been observed in the field, and hybrid progeny have been produced by pairing heterospecifics in captivity. These observations suggest that all three species share or have considerable overlap in the sex attractant pheromones produced by females, so that other prezygotic isolating mechanisms, such as diel differences in reproductive activity, limit hybridization in the field. Coupled gas chromatography-electroantennogram detection and gas chromatography- mass-spectrometry analyses of extracts of volatiles collected from female promethea moths supported the identification of (4E,6E,11Z,13Z)-hexadeca-4,6,11,13-tetraenal [(4E,6E,11Z,13Z)-16:Ald] as the compound in extracts that elicited the largest responses from antennae of males. The identification was confirmed by non-selective synthesis of several isomers as analytical standards, and stereoselective synthesis of (4E,6E,11Z,13Z)-16:Ald for testing in field trials. Male moths were strongly attracted to synthetic (4E,6E,11Z,13Z)-16:Ald, suggesting that this compound is the major and possibly the only component of the sex pheromone of these large saturniid moths. Based on the cross-attraction of heterospecifics, it is likely that this is also a major pheromone component of the other two North American Callosamia species as well.