Buprestidae, Cerambycidae, and Scolytidae Associated with Successive Stages of \u3ci\u3eAgrilus Bilineatus\u3c/i\u3e (Coleoptera: Buprestidae) Infestation of Oaks in Wisconsin

The species of Buprestidae, Cerambycidae, and Scolytidae found in association with Agrilus bilineatus (Weber) in declining oaks, Quercus spp., in Wisconsin, were Chrysobothris femorata (Olivier) and Dicerca sp. (Buprestidae); Amniscus macula (Say),Cyrtaphorus verrucosus (Olivier), Euderces picipes (Fabricius), Graphisurus fasciatus (DeGeer), Neodytus acuminatus (Fabricius), Sarosesthes fulminans (Fabricius), and Xylotrechus colonus (Fabricius) (Cerambycidae); and Monarthrum fasciatum (Say), Monarthrum mali (Fitch), Pseudopityophthorus minutissimus (Zimmerman), and Xylaterinus politus (Say) (Scolytidae). In general, weakened oaks were first attacked by A. bilineatus. and at times that same year by C. femorata. G. fasdalus, and P. minutissimus. Infestation by M.fasciatum, M. mali, and X. politus began the season following first attack by A. bilineatus. With the exception of A. bilineatus, the above mentioned Buprestidae and Cerambycidae appeared to preferentially infest dead wood, often those portions that had died the previous season

\u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae) Reproduction and Behavior on Scotch Pine Christmas Trees Taken Indoors

Tomicus piniperda, the pine shoot beetle, is an exotic insect that was first found in North America in 1992. A federal quarantine currently restricts movement of pine products, including Christmas trees, from infested to uninfested counties. We conducted a study to determine if T. piniperda would re- produce in Christmas trees that were cut and taken indoors during the Christmas season. Twelve Scotch pine, Pinus sylvestris, Christmas trees infested with overwintering T. piniperda beetles were cut in Indiana in early December 1993 and taken to Michigan. Four trees were dissected immediately, while the other 8 trees were taken indoors, placed in tree stands, and watered regularly. After 4 weeks indoors, 4 trees were dissected, and the other 4 were placed outdoors in Michigan for 7 weeks. Upon dissection, all overwintering sites occurred along the lower trunk within the first 40 em of the soil line; 81% were found within 10 em of the soil line. Adults collected from the 4 trees dissected in December produced viable progeny adults when placed on Scotch pine logs in the laboratory. Overwintering beetles became active and laid eggs in 4 of the 8 trees that had been taken indoors. All adults and progeny found in the 4 trees that had been placed outdoors for 7 weeks during cold January and February temperatures were dead. Overall, T. piniperda can become active and breed in Christmas trees that are cut and taken indoors in December. Tomicus piniperda survival in trees that are discarded outdoors at the end of the Christmas season will depend largely on the prevailing temperatures

Historical Population Increases and Related Inciting Factors of Agrilus anxius, Agrilus bilineatus, and Agrilus granulatus liragus (Coleoptera: Buprestidae) in the Lake States (Michigan, Minnesota, and Wisconsin)

Three native species of tree-infesting Agrilus have regularly reached outbreak levels in the Lake States (Michigan, Minnesota, and Wisconsin), including A. anxius Gory (bronze birch borer), A. bilineatus (Weber) (twolined chestnut borer), and A. granulatus liragus Barter & Brown (bronze poplar borer). The main host trees for these Agrilus are species of Betula for A. anxius, Castanea and Quercus for A. bilineatus, and Populus for A. granulatus liragus. Based on 197 annual forest health reports for Michigan (1950–2017, 66 years), Minnesota (1950–2017, 64 years), and Wisconsin (1951–2017, 67 years), A. bilineatus was the most often reported Agrilus species in all three states (mentioned in 90 annual reports), with A. anxius second (71 reports) and A. granulatus liragus third (21 reports). Drought was the most commonly reported inciting factor for outbreaks of all three Agrilus species, with defoliation events ranking second. The top two defoliators reported as inciting outbreaks of each species were, in decreasing order, Fenusa pumila Leach (Hymenoptera: Tenthredinidae; birch leafminer) tied with Malacosoma disstria Hübner (Lepidoptera: Lasiocampidae; forest tent caterpillar) for A. anxius; M. disstria and Alsophila pometaria (Harris) (Lepidoptera: Geometridae; fall cankerworm) for A. bilineatus; and M. disstria and Choristoneura conflictana (Walker) (Lepidoptera: Tortricidae; large aspen tortrix) for A. granulatus liragus. Other environmental factors occasionally listed as inciting Agrilus outbreaks included late spring frosts, ice storms, and strong wind events

Efficacy of Three Insecticides Applied to Bark to Control \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae)

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious exotic pest of ash (Fraxinus) trees in North America. In 2003 and 2004, we tested the efficacy of different insecticides sprayed on the bark of cut ash logs for killing emerging EAB adults. Logs (means: length = 30 cm; diam. = 16 cm) were cut from infested ash trees and treated prior to adult emergence. In 2003, we applied imidacloprid at 2 times its label rate to logs 5 days before adults began emerging from logs stored indoors. No adults successfully emerged from the imidacloprid treated logs, while an average of 108 adults per m2 emerged from untreated control logs. In 2004, we tested perme- thrin and bifenthrin at their label rates, and imidacloprid at its label rate and at 2 times its label rate. Logs (means: length = 25 cm; diam. = 12 cm) infested with EAB and stored outdoors were sprayed once or twice 4-5 wk prior to adult emergence; or once or twice 1-2 wk prior to adult emergence. Overall, mean percent adult mortality was higher for treated logs (90% mortality) compared to control logs (17%). Logs that received two applications had significantly higher mean percent mortality compared with logs that received one application. There was no significant difference in percent adult mortality among the three chemicals tested or between timing of application. In conclusion, permethrin, imidacloprid and bifenthrin were very effective at killing adult EAB emerging from cut logs, and were most effective when applied twice 1-5 wk prior to initial adult emergence

\u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae): Is Shoot Feeding Required for Reproductive Maturation?

The pine shoot beetle, Tomicus piniperda (Coleoptera: Scolytidae), is a univoltine pest of pine in its native range of Europe and Asia. Tomicus piniperda is now widely established in the Great Lakes region and poses a potentially significant threat to other pine-producing areas in North America. An unusual aspect of the life history of T. piniperda is the extended period of maturation-feeding that takes place in the shoots of living pine trees and subsequent overwintering before adults reproduce the following year. We investigated the extent to which shoot-feeding is required by newly-emerged T. piniperda before introduction into Scotch pine (Pinus sylvestris) logs and before any overwintering, in order for successful reproduction to occur. Tomi­cus piniperda F1 adults successfully reproduced in pine logs in the laboratory after either no shoot-feeding or after 2 to 10 weeks of shoot-feeding. Thus, it is theoretically possible for T. piniperda to be multivoltine, yet it remains univoltine

Can Emerald Ash Borer, \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae), Emerge From Logs Two Summers After Infested Trees Are Cut?

Emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of ash trees (Fraxinus spp.) in North America. Much of EAB’s range expansion has been attributed to human-assisted movement of infested items such as ash logs and firewood. It is unclear the amount of time that logs cut from live EAB-infested ash trees should be restricted from movement until they are no longer capable of producing viable EAB adults. In March and April 2004, we cut log sections from EAB-infested green ash (F. pennsylvanica Marsh) trees in Ann Arbor, Washtenaw County, Michigan. Log sections (mean length = 24.8 cm; diam. = 11.6 cm) were stood upright on one cut end and stored beneath a hardwood forest canopy. Adult EAB were allowed to freely emerge from log sections during summer 2004. When logs were dissected in November 2004 to January 2005, approximately one half of the total EAB life stages that were present in the logs were dead, while the other half either emerged as adults in summer 2004 or were live prepupae. Also, adults emerged from a subset of these log sections when reared in the laboratory in January to February 2005. These data suggest that EAB adults can emerge from logs for two successive emergence periods after infested ash trees have been cut

Comparison of Different Trap Colors and Types for Capturing Adult \u3ci\u3eAgrilus\u3c/i\u3e (Coleoptera: Buprestidae) and Other Buprestids

Numerous research studies have focused on the development of effective traps for surveying and monitoring for emerald ash borer, Agrilus planipennis (Fairmaire) (Coleoptera: Buprestidae), since it was discovered in North America. However, little attention has been placed on developing effective traps for monitoring and surveying other Agrilus and Buprestidae. In 2009–2011, we conducted several studies to test the attractiveness of different trap colors and types of sticky traps to Agrilus and other Buprestidae. We found green (peak reflectance: 530–536 nm, 57.6%) sticky traps that consisted of custom colored corrugated plastic, and were coated with insect trapping glue to be the most effective traps for capturing the most Agrilus individuals and species. These same green traps were also effective at capturing other buprestid genera, with the exception of Chrysobothris which were most attracted to purple sticky traps. In 2012, we conducted a study to compare the three most effective sticky traps from our 2009–2011 studies along with black and green (530 nm, 57% reflectance) multifunnel traps for capturing Agrilus and other Buprestidae. Overall, we found CoroplastTM green sticky traps to be the most effective traps for capturing the most Agrilus individuals. Green multifunnel traps captured more buprestids compared to black multifunnel traps. In addition, green multifunnel traps captured the most Agrilus species

Seasonal Shoot-Feeding by \u3ci\u3eTomicus Piniperda\u3c/i\u3e (Coleoptera: Scolytidae) in Michigan

Seasonal shoot-feeding by Tomicus piniperda (L.) was monitored at 2­ week intervals on 15 Scotch pine, Pinus sylvestris L., trees from 8 April through 16 November 1994 in southern Michigan. All shoots that showed evidence of T. piniperda attack were removed every two weeks. In 1994, initial spring flight of T. piniperda began on 22 March. At least two live T. piniperda adults were found on the 15 trees on each sampling date from 8 April through 1 November 1994. In addition, at least one freshly attacked, beetle- free shoot was found on each sampling date except for 1 November. The greatest numbers of newly attacked shoots, with or without adults present, were found from mid-June through mid-August. All adults found in April and May were likely parent adults, while those from June onward were primarily brood adults. Therefore, at all times of the year, live T. piniperda adults can be found on live pine trees, either feeding in the shoots or overwintering at the base of the trunk. Implications of these findings are provided in light of the US federal quarantine on T. piniperda

Observations on the Oak Twig Pruner, Anelaphus villosus (Coleoptera: Cerambycidae), in Michigan: Size of Twigs Pruned, Insect Survival, and Seasonality of Twig Drop

The oak twig pruner [OTP; Anelaphus villosus (Fabricius)] is likely a species complex, with A. parallelus (Newman) recently recognized as a synonym. The parallelus form of A. villosus is considered the subject of this paper. In Michigan, OTP has a 2-year life cycle, with twigs pruned primarily in even-numbered years and adults emerging from the fallen twigs in odd-numbered years. During 1990 to 2011, I studied various aspects of OTP life history in southern Michigan (Ingham County). Based on measurements from over 300 infested oak twigs, they averaged 43.1 cm long, 9.4 mm in diameter at the pruned end, weighed 22.9 g (dry weight of woody material), and had 57 leaves. OTP adults emerged in 1991 from 15.9% of 290 pruned twigs that had fallen in 1990 and were left on the forest floor until December 1990 and then placed in individual sleeve cages and later reared indoors in early 1991. Likely parasitoids of OTP emerged from 15.5% of these same 290 twigs. No linear relationship was found between the dry weight of OTP adults and the size or weight of the twigs in which they developed. During inspections along the same 1-km-long forest path from 1994 to 2011, recently-fallen pruned twigs were only found in even-numbered years, usually starting in late May to early June, peaking between late June to mid-July, and ending between August to December. The annual number of pruned twigs found along this same 1-km section of trail, varied from a low of 24 twigs in 2004 to a high of 168 in 2006. For all years combined, 89% of the recently fallen infested twigs collected on the ground in June had green foliage, compared with 52% of the twigs collected in July, 7.3% in August, and 2.6% in September

Bark- and Wood-Infesting Coleoptera and Associated Parasitoids Reared from Shagbark Hickory (Carya ovata) and Slippery elm (Ulmus rubra) in Ingham County, Michigan

Ten species of bark- and wood-infesting Coleoptera (borers) and five parasitoid species (Hymenoptera) were reared from shagbark hickory (Carya ovata) branches 1-2 years after tree death, and similarly, seven borers and eight parasitoids were reared from slippery elm (Ulmus rubra) branches one year after tree death in Ingham County, Michigan, in 1986-87. The borers were species of bostrichids, buprestids, cerambycids, and curculionids (including Scolytinae). The parasitoids were braconids, chalcidids, eurytomids, ichneumonids, and pteromalids. One new larval host record was recorded: the cerambycid Urgleptes querci (Fitch), being reared from U. rubra. This paper presents new Michigan state records for the eurytomids Eurytoma conica Provancher and Eurytoma phloeotribi Ashmead, the ichneumonid Xorides humeralis (Say), and pteromalid Cheiropachus quadrum (Fabricius). At the same field site where the above rearings occurred, when newly cut shagbark hickory branches were placed on the ground and at two canopy levels in a healthy hickory tree in May 1986 and then collected 11 months later in April 1987 and placed in rearing cages, borers (two species) and parasitoids (four species) were reared from the branches that had been suspended in the canopy, but none emerged from the branches that had been on the ground, suggesting vertical stratification of both borers and parasitoids