Survival and Phenology of \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae) Reared on a Newly Developed Artificial Diet Free of Host Material

The final phase in the development of an artificial diet that contains no ash host material and the phenology of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Bupresidae) on that diet are documented. A diet containing powdered ash phloem exists, but host material introduces potential variability and contamination, and the cost and effort needed to collect and process it can be high. The post-embryonic development of A. planipennis was evaluated on four artificial diets lacking host material, and effects of variations in diet layer thickness and moisture content were also investigated. The best diet and rearing method resulted in 67.8% survival to pupation and 51% to adult. Larval size and development rate were comparable to published accounts for emerald ash borer larvae developing on susceptible host plants. Important advances include reduction of antimicrobial components to the lowest functional level; change of protein sources from wheat germ, brewer’s yeast, and casein to soy flour and casein; reduction of diet moisture content to 50%; and adding a fresh layer of diet to spent diet half-way through larval development. The artificial diet represents a step toward the development of a standardized mass- production system for A. planipennis

Sensory Aspects of Trail-Following Behaviors in the Asian Longhorned Beetle, Anoplophora glabripennis

Abstract Anoplophora glabripennis has a complex suite of mate-finding behaviors, the functions of which are not entirely understood. These behaviors are elicited by a number of factors, including visual and chemical cues. Chemical cues include a maleproduced volatile semiochemical acting as a long-range sex pheromone, a femaleproduced cuticular hydrocarbon blend serving as a sex-identification contact pheromone, and a recently identified female-produced trail sex pheromone that is followed by mate-seeking males. However, the sensory appendages and sensilla on these appendages used to detect the trail sex pheromone are unknown. We evaluated the ability of virgin male A. glabripennis to follow a sex pheromone trail after removal of the terminal four antennal segments and/or the maxillary and labial palps using a twochoice behavioral bioassay. We also tested the ability of males to follow the trail sex pheromone using volatile pheromone cues only, without physical contact with the pheromone. Results indicate that the palps are primarily responsible for sensing the pheromone, with males lacking palps unable to respond behaviorally to the trail sex pheromone. Under the conditions of this study, males could not follow the sex pheromone trail without direct contact, suggesting that olfaction may not be involved in detection of this pheromone. However, we did not determine to what degree the trail pheromone chemicals can volatilize under our experimental conditions. This work is important in elucidating the behaviors and sensory structures involved in mate-finding J Insect Behav (2016) by this species on host trees, and these studies may help determine whether the trail sex pheromone has applications for monitoring and management

Hybridization Potential of Two Invasive Asian Longhorn Beetles

The Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) and citrus longhorned beetle (CLB), Anoplophora chinensis (Förster) (both Coleoptera: Cerambycidae: Lamiinae), are high-risk invasive pests that attack various healthy hardwood trees. These two species share some similar host plants and overlapping distributions in large parts of their native ranges in China and the Korean peninsula as well as similar reproductive behaviors. The original Anoplophora malasiaca (Thomson) occurs in Japan and has been synonymized as CLB (hereafter referred to JCLB). In this study, a 30-min behavioral observation of paired adults, followed by a four-week exposure to host bolts, showed that ALB could not successfully cross with CLB. Mating was observed between female CLB and male ALB but not between female ALB and male CLB, no laid eggs hatched. JCLB males successfully crossed with ALB females to produce viable eggs although the overall percentage of hatched eggs was lower than those from conspecific mating pairs. However, ALB males could not successfully cross with JCLB females. CLB and JCLB mated and produced viable hybrid offspring and the hybrid F1 offspring eggs were fertile. These results suggest an asymmetrical hybridization between ALB and JCLB, and that both CLB and JCLB might be considered as two subspecies with different hybridization potential with congeneric ALB. Given their potential impacts on ecosystems and many economically important tree hosts, invasion of these geographically isolated species (ALB and JCLB) or distant subspecies (CLB and JCLB) into the same region may facilitate potential hybridization, which could be a potential concern for the management of these two globally important invasive forest pests. Further studies are needed to determine if fertile hybrid offspring are capable of breeding continually or backcrossing with parental offspring successfully

Comparison of Survival and Development of Gypsy Moth Lymantria dispar L. (Lepidoptera: Erebidae) Populations from Different Geographic Areas on North American Conifers

Host utilization information is critical to managers for estimating the hosts at risk and potential geographic range for gypsy moths from different geographic origins. In this study, the development and survival of gypsy moths from all three subspecies on 13 North American conifers and three broadleaf hosts were compared. There was variation in the ability of gypsy moth larvae from different geographic origins to utilize (survive and develop on) key North American conifers. However, that variation was not consistent within gypsy moth subspecies, but instead was more consistent with populations from different origins being preadapted to utilize different hosts and having different biologic traits. Some Asian populations developed and survived well on some conifers while populations from Europe and North America gained weight faster and/or survived better than some Asian populations. Although development was slower and survival poorer on several of the conifers, first instar larvae were able to utilize conifers unless the needles were tough or feeding deterrents were present. Host phenology was also critical since the early instars fed preferentially on new foliage or buds. Gypsy moth larvae can utilize many hosts, so this makes it a very adaptable invasive species that warrants taking measures to prevent its spread

Survival and Phenology of \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae) Reared on a Newly Developed Artificial Diet Free of Host Material

The final phase in the development of an artificial diet that contains no ash host material and the phenology of the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Bupresidae) on that diet are documented. A diet containing powdered ash phloem exists, but host material introduces potential variability and contamination, and the cost and effort needed to collect and process it can be high. The post-embryonic development of A. planipennis was evaluated on four artificial diets lacking host material, and effects of variations in diet layer thickness and moisture content were also investigated. The best diet and rearing method resulted in 67.8% survival to pupation and 51% to adult. Larval size and development rate were comparable to published accounts for emerald ash borer larvae developing on susceptible host plants. Important advances include reduction of antimicrobial components to the lowest functional level; change of protein sources from wheat germ, brewer’s yeast, and casein to soy flour and casein; reduction of diet moisture content to 50%; and adding a fresh layer of diet to spent diet half-way through larval development. The artificial diet represents a step toward the development of a standardized mass- production system for A. planipennis

Effects of Temperature on Anoplophora chinensis (Coleoptera: Cerambycidae) Adult Survival, Reproduction, and Egg Hatch

Anoplophora chinensis (Forster) is an invasive species that can damage many tree species in orchard, urban, and forested habitats. Adult survival, reproduction, and egg hatch of A. chinensis from Italy and China are evaluated at eight constant temperatures (5, 10, 15, 20, 25, 30, 35, and 40 °C) under laboratory conditions. The estimated Tmax for longevity was 42 and 33 °C for females and 42 and 39 °C for males from China and Italy, respectively. The estimated Tmax, Tmin, and optimum temperature for fecundity were 35, 9, and 29 °C, respectively. Females laid eggs at 15–30 °C and eggs hatched at 15–35 °C. Days to first oviposition increased exponentially from 13 days at 30 °C to >300 days near 10 °C. The estimated Tmin for egg hatch was 13 °C, the Tmax at 38 °C, and the optimum 29 °C. Percentage hatch was estimated to be highest at 26 °C and have a Tmax of 31 °C and Tmin of 10 °C. These results indicate that summer temperatures over a wide range of latitudes should support beetle survival and reproduction, but at temperatures ≥35 °C, oviposition ceases, and adult survivorship declines. In addition, females may survive into the fall, but lay fewer eggs that may not hatch. These responses of A. chinensis to temperature can be used for developing phenological models to predict the timing of stages for management or eradication efforts

Potential Differences and Methods of Determining Gypsy Moth Female Flight Capabilities: Implications for the Establishment and Spread in Novel Habitats

The introduction of the Asian gypsy moth into novel environments continues with frequent interceptions in North America. There is a concern that these subspecies will pose a greater threat to the forests and urban environments of North America than the established gypsy moths (Lymantria dispardispar L.), due to their greater capacity for female flight. Asian gypsy moth populations vary in many key traits, including female flight capabilities. The potential impacts of female flight, in combination with the other key traits, on the ecology and spread of this insect are first discussed in this communication. This also provides the first review of most of the current literature on the variations in flight capability and flight distance of gypsy moth populations, as well as variation in other traits of concern and the potential methods of identification, with special attention paid to the Asian subspecies Lymantria dispar japonica Motschulsky and Lymantria dispar asiatica Vinkovskij. There are currently good tools for identifying the general origin of introduced gypsy moth populations, but these do not provide enough information to effectively manage introductions. Gypsy moth key traits differ among populations, even within each subspecies of the gypsy moth, so introduction of gypsy moths from other world areas into locations where the gypsy moth is already present could result in unwanted changes in gypsy moth biology. It also appears that the introduction of flight-capable females could enhance a population’s dispersal capability and require modifications to management protocols used for flightless females. Therefore, rapid tools to assess key traits in introduced populations are needed to adequately plan for, or deal with, new introductions into novel habitats.Forestry, Faculty ofNon UBCForest and Conservation Sciences, Department ofForest Resources Management, Department ofReviewedFacult

Complex invasion history of the Asian long-horned beetle: Fifteen years after first detection in Europe

The Asian long-horned beetle (ALB), a Cerambycidae, is an urban tree pest native to East Asia accidentally introduced to other continents via solid wood packing material. It was first detected in Europe in 2001, and since then infestations have been found in ten European countries. Using a 485-bp-long fragment of the mitochondrial barcode gene (COI), we studied the genetic diversity and structure of ALB populations in both native and invaded ranges, with a specific focus on Europe. Three main haplotypes were found across the native and invaded distribution of ALB. The native area in Asia was the most diverse with 23 haplotypes, but a low genetic structure was observed. Our results revealed up to nine distinct haplotypes that was diverged by no more than six mutational steps in European populations collected from 2001 to 2016. Nevertheless, the genetic structure was characterized by one widespread dominant haplotype in Europe. The overall complex genetic structure observed in Europe suggested a convoluted invasion scenario. Indeed, invasion history may include several introduction events as well as secondary dispersal. (Résumé d'auteur

Potential Differences and Methods of Determining Gypsy Moth Female Flight Capabilities: Implications for the Establishment and Spread in Novel Habitats

The introduction of the Asian gypsy moth into novel environments continues with frequent interceptions in North America. There is a concern that these subspecies will pose a greater threat to the forests and urban environments of North America than the established gypsy moths (Lymantria dispardispar L.), due to their greater capacity for female flight. Asian gypsy moth populations vary in many key traits, including female flight capabilities. The potential impacts of female flight, in combination with the other key traits, on the ecology and spread of this insect are first discussed in this communication. This also provides the first review of most of the current literature on the variations in flight capability and flight distance of gypsy moth populations, as well as variation in other traits of concern and the potential methods of identification, with special attention paid to the Asian subspecies Lymantria dispar japonica Motschulsky and Lymantria dispar asiatica Vinkovskij. There are currently good tools for identifying the general origin of introduced gypsy moth populations, but these do not provide enough information to effectively manage introductions. Gypsy moth key traits differ among populations, even within each subspecies of the gypsy moth, so introduction of gypsy moths from other world areas into locations where the gypsy moth is already present could result in unwanted changes in gypsy moth biology. It also appears that the introduction of flight-capable females could enhance a population’s dispersal capability and require modifications to management protocols used for flightless females. Therefore, rapid tools to assess key traits in introduced populations are needed to adequately plan for, or deal with, new introductions into novel habitatsISSN:1999-490