Melody A. Keena

Anoplophora glabripennis (Coleoptera: Cerambycidae) fecundity and longevity under laboratory conditions: Comparison of populations from New York and Illinois on Acer saccharum

Abstract Reproductive traits and longevity of Anoplophora glabripennis (Motschulsky) from the Ravenswood, Chicago, IL, and Bayside, Queens, NY, populations were compared for first-generation adults that emerged from cut infested wood and for second-generation adults that were reared on artificial diet. Illinois females were significantly more fecund than those from New York when they emerged from infested wood and tended to be more fecund when reared on artificial diet. Weights of adult females that emerged from infested wood varied with the hosts they emerged from; but when reared on artificial diet, Illinois females were significantly heavier than New York females. There were no significant differences between the two populations in egg viability or adult longevity. In general, females laid more eggs and survived longer in the laboratory on sugar maple, Acer saccharum Marshall, than has generally been reported for this tree species. Larval food source and quality had significant effects on female fecundity and longevity. The above differences between the two populations and the effects of host quality and host species should be taken into account when management decisions are made in the current eradication program for A. glabripennis in the United States.

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

Abstract Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is a recently introduced non-native invasive species in North America that has the potential to destroy several tree species in urban and forest habitats. Adult survival, reproduction, and egg hatch of A. glabripennis from two populations (Ravenswood, Chicago, IL, and Bayside, Queens, NY) were evaluated at seven constant temperatures (5, 10, 15, 20, 25, 30, and 35°C), and adult survival was evaluated at −1°C. Nonlinear regressions were used to estimate the temperature optimum and thresholds for each life history parameter. The estimated optimum temperature for median longevity was 18°C, and upper and lower thresholds were 39 and −3°C for females and 38 and −2°C for males. The estimated upper and lower thresholds for fecundity were 35 and 11°C for the New York population and 34 and 14°C for the Illinois population. The estimated optimum temperature for maximum fecundity was 23 and 24°C for the New York and Illinois populations, respectively. Both longevity and fecundity declined as temperature increased or decreased from the optimum. Oviposition was arrested at temperatures ≤10 and ≥35°C, and either eggs did not mature or were reabsorbed by females that did not oviposit at the higher temperatures. Days to first oviposition approached infinity near 10°C and declined exponentially to a minimum of 16 d at 30°C. The lower threshold for egg hatch was estimated as 10°C and the upper threshold at 32°C, and eggs would be predicted to hatch the fastest at 29°C. Maximum percentage hatch was estimated to occur at 23°C, and the estimated upper and lower thresholds were 34 and 12°C, respectively. These results indicate that summer temperatures throughout most of the lower 48 United States should support beetle survival and reproduction, although oviposition may be suspended and adult survivorship would decline when summer temperatures are sustained for full a day or more at or above 30°C, and there are no cooler locations where the beetles can retreat. In addition, although beetles may survive into the fall, they may lay fewer eggs at lower temperatures, and those eggs may not hatch until spring. These responses of A. glabripennis to temperature can be used for predicting the potential geographical range of this species and in developing phenological models to predict the timing of egg hatch and adult mortality, which are important for management programs.

Pourable Artificial Diet for Rearing Anoplophora glabripennis (Coleoptera: Cerambycidae) and Methods to Optimize Larval Survival and Synchronize Development

Abstract Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is a recently introduced non-native invasive species in the United States that has the potential to destroy several tree species in urban and forest habitats. The ability to rear A. glabripennis in quarantine is critical to rapid progress on techniques for the exclusion, detection, and eradication of this pest. Survival and development were compared for larvae from two populations (Chicago, IL, and Queens, NY) on six diets containing varying levels of Fe (69–237 mg/liter) and for three populations (Illinois and New York plus Hohhot, Inner Mongolia, China) under four larval chill treatments (6, 9, 12, or 16 wk of development before chill). Larval survival and percentage pupation significantly decreased and developmental time slightly increased with increasing Fe levels in the diet. Larval survival and percentage of pupation were highest, adults weighed the most, and developmental time was shortest when larvae were reared on a pourable modification of the Enaphalodes rufulus (Haldeman) (ER) diet. Individuals from the China and Illinois populations were heavier than those from New York. On average, larvae from the Illinois population were ready to pupate sooner than those from New York or China. Some larvae that had not reached their critical weight for pupation before the chill period required a second chill period before initiating pupation. Overall survival increased as the developmental time period before chill increased. Further evaluation of the effects of temperature on development is needed to better understand the triggers for pupation and to predict the timing of various stages.

World distribution of female flight and genetic variation in Lymantria dispar (Lepidoptera: Lymantriidae).

Abstract Female gypsy moths, Lymantria dispar L., from 46 geographic strains were evaluated for flight capability and related traits. Males from 31 of the same strains were evaluated for genetic diversity using two polymorphic cytochrome oxidase I mitochondrial DNA restriction sites, the nuclear FS1 marker, and four microsatellite loci. Females capable of strong directed flight were found in strains that originated from Asia, Siberia, and the northeastern parts of Europe, but flight capability was not fixed in most strains. No flight-capable females were found in strains from the United States or southern and western Europe. Wing size and musculature were shown to correlate with flight capability and potentially could be used in predicting female flight capability. The mtDNA haplotypes broadly separated the gypsy moth strains into three groups: North American, European/Siberian, and Asian. Specific microsatellite or FS1 alleles were only fixed in a few strains, and there was a gradual increase in the frequency of alleles dominant in Asia at both the nuclear and microsatellite loci moving geographically from west to east. When all the genetic marker information was used, 94% of the individuals were accurately assigned to their broad geographic group of origin (North American, European, Siberian, and Asian), but female flight capability could not be predicted accurately. This suggests that gene flow or barriers to it are important in determining the current distribution of flight-capable females and shows the need for added markers when trying to predict female flight capability in introduced populations, especially when a European origin is suspected.

Evaluating the use of Male-Produced Pheromone Components and Plant Volatiles in Two Trap Designs to Monitor Anoplophora glabripennis

ABSTRACT Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), commonly known as the Asian longhorned beetle, is a wood-boring invasive species introduced from Asia to North America and Europe in solid wood packing material. Efficient monitoring traps are needed to assess population density and dispersal in the field and to detect new introductions at ports of entry. For this purpose, we conducted field trapping experiments in China in the summers of 2007 and 2008. In 2007, we tested Intercept panel traps hung on poplar trees. In 2008, we used Intercept panel traps hung on poplar trees, screen sleeve traps wrapped around poplar trunks, and Intercept panel traps hung on bamboo poles 20 m away from host trees. Traps were baited with A. glabripennis male-produced pheromone alone or in different combinations with plant volatiles. Traps baited with the male-produced pheromone alone caught significantly more females than control traps in both years. The addition of a mixture of (-)-linalool, (Z)-3-hexen-1-ol, linalool oxide, trans-caryophyllene, and trans-pinocarveol to the pheromone significantly increased trap catches of females, 85% of which were virgin. Screen sleeve traps baited with a combination of (-)-linalool and the pheromone caught the highest number of beetles overall in 2008, whereas traps placed on bamboo polls caught the lowest number. Although the logistics for the most effective implementation of a trapping program using a mixture of the pheromone and plant volatiles require additional studies, these results indicate that this pheromone has considerable promise as a monitoring tool for A. glabripennis in the field.

Attraction of Anoplophora glabripennis to Male-Produced Pheromone and Plant Volatiles

ABSTRACT The male-produced pheromone of Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), which is an equal blend of 4-(n-heptyloxy)butan-1-ol and 4-(n-heptyloxy)butanal, was used in laboratory bioassays and in the greenhouse to determine its potential for attracting A. glabripennis adults. In modified “walking wind tunnels,” virgin females were most attracted to the alcohol component, and virgin males were repelled by the pheromone blend at the lowest and highest amounts offered. Y-tube olfactometer bioassays also showed that females were significantly more attracted to the pheromone and its components than males were. However, males were more attracted to plant volatiles than females. Of 12 plant volatiles tested, &dgr;-3-carene and (E)-caryophyllene were highly attractive to males, whereas (Z)-3-hexenyl acetate was repellent to males. Combining the male pheromone blend with (-)-linalool alone or with (Z)-3-hexen-1-ol attracted significantly more males than did the pheromone alone. We tested four trap designs in our quarantine greenhouse with eight different lures. The Intercept Panel traps and the hand-made screen sleeve traps caught more beetles than the Plum Curculio traps and Lindgren funnel traps. Intercept traps worked best when baited with male blend and (Z)-3-hexen-1-ol, whereas screen sleeve traps were most attractive when baited with (-)-linalool. Our findings provide evidence of the attractiveness of the A. glabripennis male-produced pheromone and suggest that it has a role in mate-finding. It is also a first step toward the development of an efficient trap design and lure combination to monitor A. glabripennis infestations in the field.

Effects of Temperature on Anoplophora glabripennis (Coleoptera: Cerambycidae) Larvae and Pupae

ABSTRACT Developmental thresholds, degree-days for development, larval weights, and head capsule widths for each larval instar and the pupal stage of Anophphora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) were studied at eight constant temperatures (5, 10, 15, 20, 25, 30 ,35, and 40°C) for two source populations (Ravenswood, Chicago, IL [IL], and Bayside, Queens, NY [NY]). The estimated lower threshold temperature for development of instars 1–5 and the pupal stage was near 10°C and was near 12°C for the higher instars. Developmental rate was less temperature sensitive for instars 5–9 compared with instars 1–4. Development for all but the first instar was inhibited at constant temperatures >30°C, and all instars failed to develop at 40°C. Although the two source populations had similar responses to temperature, IL larvae were heavier than those from NY. Temperature and its influence on larval weight had profound impacts on whether a larva proceeded to pupation. Based on the temperature effects detailed here, larval development and pupation should be possible in most of the continental United States where suitable hosts are available. These data can be used to develop a degree-day model to estimate beetle phenology; however, at least 2°C should be added to air temperatures to adjust for the mediation of temperature by the wood. These data provide a basis for predicting the potential geographical range of this species and for developing phenological models to predict the timing of immature stages, both of which are important for management programs.

Inheritance of female flight in Lymantria dispar (Lepidoptera: Lymantriidae).

Abstract A clinal female flight polymorphism exists in the gypsy moth, Lymantria dispar L., where female flight diminishes from east to west across Eurasia. A Russian population where females are capable of sustained ascending flight and a North American population with females incapable of flight were crossed: parentals, reciprocal F1 hybrids, double reciprocal F2 hybrids, and all possible backcrosses to both the parental lines were compared. Heritabilities were estimated using a threshold model, female offspring on female parent regressions, and joint-scaling analyses. Heritability of female flight capability measured using a free flight test was at least 0.60, and variation in wing size, muscle strength, and flight behaviors contributed to the flight polymorphism. Relative wing size varied continuously and had a heritability of 0.70. Environmental variation accounted for >90% of the variation in female preflight weight and relative flight muscle strength, as estimated by an inverted female’s ability to right herself. Preflight walking behavior and early deposition of eggs were each inherited through a single gene with two co-dominant alleles. There was no evidence for sex-linkage or maternal effects in female flight capability or associated traits. Continued vigilance to exclude and eradicate introductions of strains capable of female flight in North America is warranted even in areas where no females fly, because some of the alleles needed for full flight capability may not be present in the North American populations, and some flight capability is maintained in the hybrids that could increase the rate of spread of L. dispar.

Development and evaluation of a trapping system for Anoplophora glabripennis (Coleoptera: Cerambycidae) in the United States

ABSTRACT Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), commonly known as the Asian longhorned beetle, is an invasive wood-boring pest that infests a number of hardwood species and causes considerable economic losses in North America, several countries in Europe, and in its native range in Asia. The success of eradication efforts may depend on early detection of introduced populations; however, detection has been limited to identification of tree damage (oviposition pits and exit holes), and the serendipitous collection of adults, often by members of the public. Here we describe the development, deployment, and evaluation of semiochemicalbaited traps in the greater Worcester area in Massachusetts. Over 4 yr of trap evaluation (2009–2012), 1013 intercept panel traps were deployed, 876 of which were baited with three different families of lures. The families included lures exhibiting different rates of release of the male-produced A. glabripennis pheromone, lures with various combinations of plant volatiles, and lures with both the pheromone and plant volatiles combined. Overall, 45 individual beetles were captured in 40 different traps. Beetles were found only in traps with lures. In several cases, trap catches led to the more rapid discovery and management of previously unknown areas of infestation in the Worcester county regulated area. Analysis of the spatial distribution of traps and the known infested trees within the regulated area provides an estimate of the relationship between trap catch and beetle pressure exerted on the traps. Studies continue to optimize lure composition and trap placement.

Female Flight Propensity and Capability in Lymantria dispar (Lepidoptera: Lymantriidae) from Russia, North America, and Their Reciprocal F1 Hybrids

Abstract In the laboratory, the timing of both preflight and flight behaviors of the Asian strain of female gypsy moths, Lymantria dispar L., was regulated primarily by light intensity. The shortest times to initiation of wing fanning and flight occurred at 0.1 lux, the lowest light intensity evaluated. A gradual decrease in light intensity, compared with an instantaneous decrease, prolonged time to flight. The highest percentage of female flight was observed at 0.1 lux. A higher percentage of females initiated flight when exposed to lower light intensities after the onset of normal scotophase rather than before scotophase. Virgin females were less likely to fly than mated females. Females fanned their wings longer at lower temperatures and when they were capable of only a gliding flight. Females that were flight-tested the same day they emerged tended to take longer to initiate flight than those 1–2 d old. At 0.1 lux, the majority of the Asian females, less than 2% of the F1 hybrid females, and none of the North American females exhibited strong, directed flight. Over half of the F1 hybrids glided for a few meters while flapping their wings, whereas none of the North American females exhibited even this level of flight. Thus, female flight capability will be reduced when flighted and nonflighted forms initially hybridize.