Hindgut volatiles from attacking, unmated males of Ips avulsus, I. calligraphus, I. grandicollis , and I. pini were analyzed by combined gas chromatography and mass spectrometry. Based on the quantitative identifications of hindguts and subsequent individual aerations, baits were formulated and a combined species-specific subtractive field bioassay was set up for the four bark beetle species. The bioassays were subtractive for the compounds identified in the hindgut analysis of each species, and volatiles identified in sympatric species were added as potential inhibitors alone and in combination. The trap catches from this bioassay revealed strong interspecific inhibition. The subtractive assays showed that I. grandicollis and I. calligraphus share (–)-(4 S )- cis -verbenol as one pheromone component, while their second, synergistic pheromone component, (–)-( S )-ipsenol in I. grandicollis and (±)-ipsdienol in I. calligraphus , acts as an interspecific inhibitor to the other species. I. avulsus and I. pini were found to have very similar production of hindgut volatiles, and both use ipsdienol and lanierone as synergistic pheromone components. No beetle-produced interspecific inhibitor was identified between these two species. Lanierone was found to be an interspecific inhibitor for both I. calligraphus and I. grandicollis .

The male-produced bicyclic acetal endo-brevicomin is a component of the pheromone blend that mediates colonization of host pines by the bark beetle Dendroctonus frontalis Zimmermann. Efforts to identify its behavioral function have been complicated by contrasting reports that it either enhances or reduces attraction of flying beetles. Our studies failed to support the hypothesis that this published variability is due to differences in release rate and/or the enantiomeric composition [i.e., the beetle-produced (+)-enantiomer vs. the racemate] of the endo-brevicomin used in the experiments. In trapping trials within active D. frontalis infestations, racemic and (+)-endo-brevicomin did not differ from each other in behavioral effects when tested at seven different release rates ranging from 0.005 to 3 mg/d. At the highest release rates, racemic and (+)-endo-brevicomin similarly reduced catches in traps baited with an attractant (frontalin and turpentine), but neither enhanced catches at any release rate. Furthermore, the activity of racemic endo-brevicomin baits depended on trap proximity to D. frontalis infestations. Addition of these baits to attractant-baited traps located inside active infestations reduced catches, but they enhanced catches at traps located either 100 or 200 m outside these infestations. The contrasting responses may reflect differences in host-seeking strategies by either aggregated or dispersing D. frontalis, and may be elicited by differing abundance of natural sources of semiochemicals or differing responsiveness of beetles inside vs. outside of infestations. We suspect that much of the published variability in D. frontalis responses to endo-brevicomin is attributable to differing proximity of experimental field sites to infestations.

Imidacloprid, a systemic insecticide that acts on the nervous system, is currently being used to control hemlock woolly adelgid (Adelges tsugae Annand), which is damaging hemlock trees. The objective of this study was to determine whether soil injection with imidacloprid for hemlock woolly adelgid control near streams adversely affects aquatic invertebrates. Eastern hemlocks (Tsuga canadensis) in the watersheds surrounding four streams in the southern Appalachian region of Georgia and North Carolina were treated with imidacloprid. Addie Branch was the only stream that exhibited a possible effect from imidacloprid treatment. However, the data followed the same pattern as the other treatment streams, but with a more pronounced decrease in taxa due to adult emergence. Only a trace amount of imidacloprid was detected in one water sample from Holcomb Tributary over a period of 2 years, and no effect was observed on the aquatic macroinvertebrates in that stream. However, caution should be used when applying these results to other areas with different soil types (e.g., low organic matter content) that may not bind imidacloprid as tightly. Our results indicate that soil injections of imidacloprid can safely be used in the southern Appalachian area to control hemlock woolly adelgid.

Understanding the seasonal phenology of an insect pest in a specific geographic region is essential for optimizing the timing of management actions or research activities. We examined the phenology of hemlock woolly adelgid, Adelges tsugae Annand, near the southern limit of the range of eastern hemlock, Tsuga canadensis (L.) Carriere, in the Appalachians of northern Georgia, where adelgid phenology has not been previously reported. Adelges tsugae-infested hemlock trees were visited at various sites from 2004 - 2007. Two hemlock twigs were collected from each of 3 hemlock trees per site, except during the final 3 months of sampling when 1 twig was collected from each of 3 trees per site. Progrediens adults initiated oviposition by midMay, 2 - 4 weeks earlier than has been reported for more northern parts of the adelgid range. Sistens eggs were present until late-June (2006) or early-July (2004 - 2005). After aestivation, sistens nymphs resumed development by early October. Sistens adults were first found in early January and were present until midMay. Progrediens eggs were noted as early as February (2005 - 2007), were abundant in March and April, and persisted until midMay. Progrediens crawlers were present by early March and occurred throughout the next 2 - 3 months. Progrediens adults were found between midMay and late June. This information may be used to help optimize release of biological control agents to insure proper synchronization with adelgid life stages and to aid in collection of food for predator rearing facilities.

Semiochemicals that inhibit the response of the southern pine beetle, Dendroctonus frontalis Zimmermann, to its aggregation pheromone have been used with varying degrees of success to protect individual trees from attack and to stop infestation growth. However, semiochemical disruptants have not experienced wide use in management of D. frontalis, due in part to the normally prohibitive expense associated with treatments using verbenone and 4-allylanisole, the two EPA-registered semiochemicals for this species. Therefore, we conducted some initial trap-based screenings of candidate compounds with the aim of discovering alternative inhibitory semiochemicals for use in management of D. frontalis. In separate experiments in Mississippi and Georgia, baits containing either 2-phenylethanol or myrtenol significantly reduced attraction of one or both sexes of D. frontalis to traps baited with a standard attractant (i.e., the D. frontalis aggregation pheromone frontalin and the host monoterpene alpha-pinene). In combination, the two compounds caused a 92% decrease in total beetle response to the standard attractant, although this reduction was not significantly greater than that produced by 2-phenylethanol alone. In one test, a blend of nonhost volatiles (1-hexanol, cis-3-hexen-1-ol, hexanal, and nonanal) significantly reduced attraction of male D, frontalis, but these observations were not duplicated in a second test. Another combination of candidate inhibitors (the nonhost blend plus guaiacol and benzaldehyde) also significantly inhibited response of male beetles. At the specific doses used in our tests, we failed to observe reduction in D. frontalis attraction by the following compounds presented singly: benzaldehyde, guaiacol, 3-methylcyclohex-2-en-1-one (3,2-MCH), myrtenal, and verbenone.

old (Berisford 1988). In the Southeastern United States, preferred hosts include loblolly (Pinus taeda L.), shortleafThe Nantucket pine tip moth, Rhyacionia fiustrana (Comstock) (P, echinata Mill.), and Virginia (P.virginbna Mill.) pines.(Lepidoptera: Tortricidae), is a common pest of Christmas tree and Slash (P.elliottii Engelm.) and longleaf (P.palustris Mill.) pine plantations throuaout much o f the Eastern United States.The moth completes two to five generations annually, and insecticide pines are considered resistant to attack (Berisford 1988, spray timing models are currently available for controlling Yates 1960).populations where three or four generations occur.The thermal * requirements for the Nantucket pine tip moth to complete a generation were obtained from published data and used along with historical temperature data to produce maps indicating the number of annual generations predicted to occur throughout seven Southeastern States.Spray timing prediction values were also obtained &om published data and used to predict optimal spray periods based on 5day increments for each location where either three or four generations occurred.Approximately 80 percent of the predicted optimal spray petiods were within one optimal spray period of previously field-determined spray dates.Land managers who use contact insecticides, such as synthetic pyrethroids, may find the predicted optimal spray periods useful in optimizing spray effectiveness.

Female white pine cone beetles,Conophthorus coniperda, attacking second-year cones of eastern white pine,Pinus strobus L., produced a sex-specific pheromone that attracted conspecific males in laboratory bioassays and to field traps. Beetle response was enhanced by host monoterpenes. The female-produced compound was identified in volatiles collected on Porapak Q and in hindgut extracts as (+)-trans-pityol, (2R,5S)-(+)-2-(1-hydroxy-1-methylethyl)-5-methyltetrahydrofuran. Males and females produced and released the (E)-(-)-spiroacetal, (5S,7S)-(-)-7-methyl-1,6-dioxaspiro[4.5]decane, which was not an attractant for either sex, but acted as a repellent for males. Porapak Q-trapped volatiles from both sexes contained (+)-trans-pinocarveol and (-)-myrtenol. In addition, hindgut extracts of females containedtrans-verbenol, while males had pinocarvone and verbenone. Work in Georgia and Canada confirmed that the same isomers of pityol and spiroacetal are present in two distinct and widely separated populations ofC. coniperda.

Effects of herbicide and insecticide applications on parasitism of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) were examined in 2-yr-old loblolly pine (Pinus taeda L.) plantations in Georgia. Total parasitism rates varied significantly among tip moth generations, but there were no differences in parasitism rates between herbicide-treated and untreated plots. Significant differences in the relative abundance of parasitoid species were found among generations, with Eurytoma pini Bugbee being the most common in summer and Lixophaga mediocris Aldrich the most abundant in spring. Plots treated with the insecticide, Orthene, had significantly less parasitism than plots treated with tebufenozide, Bacillus thuringiensis var. kursfaki, or untreated check plots. Effects of acephate treatments were species-specific, with no apparent effects on parasitism by L. mediocris Aldrich but significantly decreased parasitism by Haltichella rhyacioniae Gahan.