Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Our laboratory has been developing non-woven fiber bands impregnated with cultures of the entomopathogenic fungus Metarhizium anisopliae for biological control of invasive Asian longhorned beetles. These bands contaminate adults with spores of the fungus when adult beetles walk across them. We have now shown that aside from those beetles walking across bands, adult beetles can become infected from fungal spores vectored by mates, by other beetles that have walked across bands and by walking near bands and becoming contaminated with spores that dispersed from bands onto nearby tree bark. We have also shown that M. anisopliae fungal bands can be used in conjunction with imidacloprid, although our studies have confirmed published literature that imidacloprid decreases feedingf and our studies suggest that Asian longhorned beetles feeding on imidacloprid could disperse if they did not initially receive a very high dose. In addition, we have worked on the new invasive woodwasp Sirex noctilio, working toward biological control of this invasive. Finally, work has also focused on invasive ambrosia beetles, the wood-rot fungi that they carry and interactions between these fungi and entomopathogenic fungi. Results from these studies have been presented at conferences and in university seminars. PARTICIPANTS: Individuals working on the project: Fan Peng, Sana Gardescu, Ryan Shanley, Calum Russell, Ann Hajek, Collaborators: Zengzhi Li, Anhui Agricultural University, Hefei, Anhui, China; Aijun Zhang, USDA, ARS, Beltsville, MD. Training: Fan Peng, visiting graduate student from Anhui Agricultural University, Hefei, Anhui, China; Calum Russell, Department of Entomology, Cornell University, Tim Hwalek, undergraduate at Cornell University. TARGET AUDIENCES: The public, scientists and land managers interested in invasive species, and, in particular, biological control and management of Asian longhorned beetle, Sirex noctilio and black stem borer. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Our laboratory continued studies toward use of non-woven fiber bands containing cultures of the fungal entomopathogen Metarhizium anisopliae for control of adult Asian longhorned beetles (ALB). Studies were continued by determining that male and female ALB can vector M. anisopliae spores to sexual partners. When a male was exposed to fungal bands and then partnered with a female, he transferred more spores to his mate than were transferred when a female was exposed to a fungal band and then partnered with a male. We hypothesize that this differential vectoring is due to ALB behavior because ALB males frequently guard females, remaining in contact for some time after mating, and thus there are more opportunities for spore transfer from males to females than from females to males. The principal method used for eradication of ALB in the US is injection of trees or the soil beneath trees with imidacloprid. Our studies with ALB investigated interactions between imidacloprid and M. anisopliae. Results have been written for publication in a peer-reviewed journal. Studies with the invasive woodwasp Sirex noctilio have concentrated on the symbiotic white rot fungus that is carried by adult females and which is required for larval survival and growth. We found that two different strains of this fungus (Amylostereum areolatum) are now being carried by Sirex noctilio in the United States. We also found that two species of native Sirex woodwasps carry A. areolatum, although it was previously assumed that Sirex species native to North Ameriica only carried Amylostereum chailletii. Over 50 isolates of fungal symbionts Ambrosiella were obtained from invasive black stem borers (an ambrosia beetle). Isolates are phenotypically variable. Molecular characterization to date has shown at least two distinct genotypes and petri dish assays have demonstrated that Ambrosiella is inhibited by entomopathogenic fungi.
Publications
- Hu, J., Angeli, S., Schuetz, S., Luo, Y., Hajek, A.E. 2009. Ecology and management of exotic and endemic Anoplophora glabripennis (Coleoptera: Cerambycidae). Agric. For. Entomol. 11: 359-375.
- Nielsen, C., Williams, D. W., Hajek, A.E. 2009. Putative source of the invasive Sirex noctilio fungal symbiont, Amylostereum areolatum, in the eastern United States and its association with native siricid woodwasps. Mycol. Res. 113: 1242-1253.
- Faria, M., A. E. Hajek, S. P. Wraight. 2009. Differential tolerance to imbibitional damage in conidia of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Metarhizium anisopliae var. acridum. Biol. Control 51: 346-354.
- Nielsen, C., A. A. Agrawal, A. E. Hajek. 2009. Ants defend aphids against lethal disease. Biol. Lett. (doi:10.1098/rsbl.2009.0743).
- Shanley, R.P., J. Leland, M. Keena, M.M. Wheeler, A.E. Hajek. 2009. Evaluating the virulence and longevity of non-woven fiber bands impregnated with Metarhizium anisopliae against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae). Biol. Control 50: 94-102.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Our laboratory continued studies toward use of non-woven fiber bands containing cultures of the fungal entomopathogen Metarhizium anisopliae for control of adult Asian longhorned beetles (ALB). Results from studies of environmental contamination from M. anisopliae bands demonstrated that few spores are shed from fungal bands and the few spores shed were mostly found below bands during rainy periods. A laboratory study conducted to determine whether spores from M. anisopliae fungal bands can be vectored by ALB to other ALB confirmed that spores can be vectored by fungal-inoculated ALB. Studies were continued by determining that male and female ALB can vector M. anisopliae spores to sexual partners. When a male was exposed to fungal bands and then partnered with a female, he transferred more spores to his mate than were transfered when a female was exposed to a fungal band and then partnered with a male. We hypothesize that this differential vectoring is due to ALB behavior because ALB males frequently guard females, remaining in contact for some time after mating, and thus there are more opportunities for spore transfer from males to females than from females to males. The principal method used for eradication of ALB in the US is injection of trees or the soil beneath trees with imidacloprid. Our studies with ALB investigated interactions between imidacloprid and M. anisopliae. ALB adults were fed two doses of imidacloprid and were also treated with M. anisopliae. We found that adult beetles dosed with both the fungus and 100 ppm imidacloprid died more quickly than adults dosed with 10 ppm imidacloprid or controls. On petri dishes with lower strength media, imidacloprid causes some inhibition of spore production by M. anisopliae. While we did not find that fewer cadavers of ALB adults killed by M. anisopliae plus imidacloprid produced spores, we definitely found that the cadavers from ALB killed by imidacloprid plus fungus produced fewer spores. With Chinese collaborators, field trials with fungal bands plus attractants were attempted in Anhui Province, China. However, a major flood occurred part of the way through the field study and the experiment was ruined. Dr. Hajek spent her sabbatical leave in New Zealand from January through early May, working on an edited book: Use of Microbes for Control and Eradication of Invasive Arthropods, which has now been published by Springer. This work covers different types of arthropod pathogens associated with invasive hosts ranging from aphids and mites to mole crickets, honeybees, beetles and moths. These hosts are pests in many different systems. Pathogens have been applied in different ways, including very successful use for eradication, and both short and long term control. PARTICIPANTS: Individuals working on the project: Ryan Shanley, Calum Russell, Ann Hajek, Fan Peng, Sana Gardescu Collaborators: Zengzhi Li and Longwa Zhang, Anhui Agricultural University, Hefei, Anhui, China; Aijun Zhang, USDA, ARS, Beltsville, MD; Travis Glare and Maureen OCallaghan, AgResearch, Lincoln, New Zealand, L.S. Bauer, USDA, Forest Service; S.P. Wraight, USDA, ARS Training: Fan Peng, visiting graduate student from Anhui Agricultural University, Hefei, Anhui, China; Calum Russell, Department of Entomology, Cornell University TARGET AUDIENCES: Public, scientists and land managers interested in invasive species, biological control and management of Asian longhorned beetle PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Studies with Asian longhorned beetle have been working toward control of this invasive using non-woven fiber bands impregnated with cultures of the entomopathogenic fungus Metarhizium anisopliae. These bands contaminate adults with spores of the fungus when adult beetles walk across them. We have now shown that aside from those beetles walking across bands, adult beetles can become infected from fungal spores vectored by mates, by other beetles that have walked across bands and by walking near bands and becoming contaminated with spores that dispersed from bands onto nearby tree bark. We have also shown that M. anisopliae fungal bands can be used in conjunction with imidacloprid, although our studies have confirmed published literature that imidacloprid acts as an antifeedant and our studies suggest that Asian longhorned beetles feeding on imidacloprid would disperse if they did not initially receive a very high dose. Our new book summarizes use of arthropod-specific pathogens for control of invasive arthropods. We predict that this book will demonstrate how useful these successful applications of arthropod-specific pathogens have been in a diversity of systems. Since the numbers of invasive species are only increasing, this information could be useful toward developing methods for control of new invasive arthropods.
Publications
- Shanley, R.P., and Hajek, A.E. 2008. Environmental contamination with Metarhizium anisopliae from fungal bands for control of the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae). Biocontrol Science and Technology, 18: 109-120.
- Hannam, J.J., Liebherr, J.K., and Hajek, A.E. 2008. Climbing behavior and aphid predation by Agonum muelleri (Carabidae). The Canadian Entomologist, 140: 203-207.
- Hajek, A.E., Lund, J., and Smith, M.T. 2008. Reduction in fitness of female Asian longhorned beetle (Anoplophora glabripennis) infected with Metarhizium anisopliae. Journal of Invertebrate Pathology, 98: 198-205.
- Dubois, T., Lund, J., Bauer, L.S., and Hajek, A.E. 2008. Virulence of entomopathogenic hypocrealean fungi infecting Anoplophora glabripennis. BioControl 53: 517-528.
- Hajek, A.E., T.R. Glare, and M. OCallaghan. 2009. Use of Microbes for Control and Eradication of Invasive Arthropods. Springer, Dordrecht, NL. 366 pp.
- Hajek, A.E. 2008. Invasive arthropods and approaches for their microbial control, Chapter 1 In A.E. Hajek, T.R. Glare and M. OCallaghan (eds.), Use of Microbes for Control and Eradication of Invasive Arthropods. Springer, Dordrecht, Netherlands, p. 3-15.
- Hajek, A.E., and Bauer, L.S. 2009. Use of entomopathogens against invasive wood boring beetles in North America, Chapter 10 In A.E. Hajek, T.R. Glare and M. OCallaghan (eds.), Use of Microbes for Control and Eradication of Invasive Arthropods. Springer, Dordrecht, Netherlands, p. 159-179.
- Glare, T.R., OCallaghan, M., and Hajek, A.E. 2009. Considerations for the practical use of pathogens for control and eradication of arthropod invasive pests, Chapter 18 In A.E. Hajek, T.R. Glare and M. OCallaghan (eds.), Use of Microbes for Control and Eradication of Invasive Arthropods. Springer, Dordrecht, Netherlands, p. 331-349.
- Wraight, S.P., and A.E. Hajek. 2009. Use of arthropod pathogens for integrated pest management Chapter 11 In E.B. Radcliffe, W.D. Hutchison and R.E. Cancelado (eds.), Integrated Pest Management: Concepts, Tactics, Strategies and Case Studies. Cambridge University Press, Cambridge, United Kingdom, p. 131-150.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: Our studies addressed the wood-boring invasives Asian longhorned beetle (which we have studied for 10 years) and Sirex noctilio (a new project). Studies conducted to optimize rearing Asian longhorned beetle for experiments, demonstrated that adult females prefer and produce more larvae when provided with striped maple during summer compared with sugar maple. Studies of the effect of fungal infection on fecundity of adult female Asian longhorned beetles were analyzed and published. We also investigated environmental contamination from non-woven fiber bands impregnated with cultures of the entomopathogenic fungus Metarhizium anisopliae F-52 and wrapped around trees, the application method we have been developing. Fungal spores were transferred to both above and below fungal bands but densities at both locations were not high and spore dispersal was associated with rainfall. We conducted studies with 1 or 5 beetles contacting M. anisopliae bands and then walking on tree bark.
Healthy beetles were then exposed to the bark contaminated with M. anisopliae spores and, especially with the 5 beetle exposures, the healthy beetles became infected and died more quickly than controls. The goal with these studies was to see if beetles walking near bands, but not contacting bands, could receive a high enough dose of fungal spores to become infected. To help with interpretation of these data, studies of the densities of fungal spores per square centimeter required for 50% mortality have been conducted using M. anisopliae F-52. These results will be published along with results of studies of persistence of activity of fungal bands on trees in Queens, New York City in 2001-2004. New studies were initiated with the fungal symbiont of the invasive woodwasp Sirex noctilio which was first detected in North America in 2004. To date, we have collected S. noctilio from many locations and have isolated the symbiotic fungus Amylostereum areolatum from them. We have also collected
native siricids and isolated fungal symbionts from them. The overall goals of this project are to examine the geographic variability among fungal symbionts of S. noctilio, to investigate the effect of different pine species on the fungal symbiont and to improve methods for growing this fungal symbiont.
PARTICIPANTS: Ryan Shanley, Department of Entomology, Cornell University, Ithaca, NY Dr. Michael T. Smith, USDA, ARS, BIIRL, Newark, DE Jennifer Lund, Department of Entomology, Cornell University, Ithaca, NY
TARGET AUDIENCES: Public, scientists and land managers interested in invasive species, biological control and management of Asian longhorned beetle and Sirex noctilio.
Impacts
Studies with Asian longhorned beetle have been working toward control of this invasive using non-woven fiber bands impregnated with cultures of the entomopathogenic fungus Metarhizium anisopliae. These bands contaminate adults with spores of the pathogen when adult beetles walk across them. We have now shown that aside from those beetles walking across bands, adult beetles can become infected from fungal spores deposited by other beetles that have walked across bands or from walking near bands and becoming contaminated with spores that dispersed from bands onto nearby tree bark. In addition, male beetles can become infected by mating with adult females that have been exposed to fungal bands. Thus far in our studies with the fungal symbiont of Sirex noctilio we have collected fungal isolates and molecular studies to compare fungal strains will begin soon.
Publications
- Filotas, M.F., Hajek, A.E. 2007. Variability in thermal responses among Furia gastropachae isolates from different geographic origins. J. Invertebr. Pathol. 96: 109-117.
- Hajek, A.E., Kalb, D.M. 2007. Suitability of Acer saccharum and Acer pensylvanicum for rearing Anoplophora glabripennis (Coleoptera: Cerambycidae). Can. Entomol. 139: 751-755.
- Dubois, T., Lund, J., Bauer, L.S., Hajek, A.E. 2007. Virulence of entomopathogenic hypocrealean fungi infecting Anoplophora glabripennis. BioControl DOI 10.1007/s10526-007-9112-2.
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Progress 01/01/06 to 12/31/06
Outputs
Studies continued to emphasize effects of use of non-woven fiber bands impregnated with cultures of the fungal entomopathogen Metarhizium anisopliae F-52 for control and eradication of Asian longhorned beetles. Fungal bands are placed around tree trunks and adult beetles inoculate themselves when wandering. Studies of the effect of fungal infection on fecundity of adult female Asian longhorned beetles were completed and data were analyzed. These final replicates were conducted by exposing young females to M. anisopliae, just after they had become adults and would have emerged from beneath tree bark (beetles we used were from our laboratory colony where they develop on artificial diet). Fungal-exposed young adult females laid very few eggs and, among the eggs that were laid, a percentage did not hatch due to fungal infections. In summary, if females contacted fungal spores soon after becoming adults, their reproduction was almost totally prevented (less than 1 egg
hatching per fungal-infected female), while healthy females lived many weeks and on average produced 75 eggs that hatched. We also investigated environmental contamination from non-woven fiber bands impregnated with cultures of M. anisopliae. We conducted studies with 1 or 5 beetles contacting M. anisopliae bands and then walking on tree bark. Healthy beetles were then exposed to the bark contaminated with M. anisopliae spores and, especially with the 5 beetle exposures, the healthy beetles became infected and died more quickly than controls. We also conducted studies sampling tree bark above and below fungal bands at different times after bands were placed in the field around tree trunks at 3 m height. The goal with these studies was to see if beetles walking near bands, but not contacting bands, could receive a high enough dose of fungal spores to become infected. Fungal spores were transferred to both above and below fungal bands but densities at both locations were not high and
spore dispersal was associated with rainfall. To help with interpretation of these data, studies of the densities of fungal spores per square centimeter required for 50% adult mortality have been conducted using M. anisopliae F-52 but these studies are still in progress. We did not conduct field studies in China during summer 2006 due to lack of funding.
Impacts
Asian longhorned beetle is a serious threat to North American forests, especially since these beetles continue to be found in New York City and, in 2003, in Toronto. There are few ways to control this pest and use of non-woven fiber bands impregnated with cultures of entomopathogenic fungi is clearly the biological control option that is closest to being put to use for control in the U.S. Studies being conducted in our laboratory are answering questions that are critical to use of these bands for eradication of Asian longhorned beetles in North America.
Publications
- Hajek, A.E., Huang, B., Dubois, T., Smith, M. T. and Li, Z. 2006. Field studies of control of Anoplophora glabripennis (Coleoptera: Cerambycidae) using fiber bands containing the entomopathogenic fungi Metarhizium anisopliae and Beauveria brongniartii. Biocontr. Sci. Technol. 16:329-343.
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Progress 01/01/05 to 12/31/05
Outputs
Studies with the quarantine colony of Asian longhorned beetles documented that striped maple is superior to sugar maple relative to female choice, oviposition and larval growth and survival. Our studies continue with development of non-woven fiber bands impregnated with cultures of entomopathogenic fungi and hung in trees where wandering adult beetles inoculate themselves. Field studies were conducted in a poplar plantation in Linhe, Inner Mongolia that hosted a naturally occurring infestation of Asian longhorned beetles. Use of fungal bands alone was compared with use of fungal bands plus attractants versus controls by collecting beetles to document time to death and by quantifying oviposition and emergence. The attractant that was used was both a chemical extract of Acer mono and a synthesized contact pheromone. Unfortunately, it was very difficult to find an infested stand and this site was not appropriate due to the extremely dry climate which was not optimal for
activity of entomopathogenic fungi or representative of the areas of North America where Asian longhorned beetles occur. We plan to conduct field studies in 2006, searching hard to find a more climatically amenable site with an infestation. Studies using fungal bands were conducted to investigate the effects of infection on female oviposition and survival of larvae. Infected females lay few eggs and a low percentage of eggs hatch compared with controls. In addition, females that have walked across fungal bands and pass the inoculum to mates.
Impacts
Asian longhorned beetle is a serious threat to North American forests, especially since these beetles continue to be found in New York City and, in 2003, in Toronto. There are few ways to control this pest and use of non-woven fiber bands impregnated with cultures of entomopathogenic fungi is clearly the biological control option that is closest to being put to use for control in the U.S. Studies being conducted in our laboratory are answering questions that are critical to use of these bands for eradication of Asian longhorned beetles in North America.
Publications
- Lund, J., A. Hajek. 2005. Reduction in reproduction and pathogen transmission during mating by Asian longhorned beetle (Anoplophora glabripennis) adults infected with Metarhizium anisopliae. USDA, Forest Service, Gen. Tech. Rpt. NE-337: 61.
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Progress 01/01/04 to 12/31/04
Outputs
Studies with the quarantine colony of Asian longhorned beetles identified a method for field crews to differentiate between males and females. Studies have begun to document that striped maple is superior to sugar maple relative to female choice, oviposition and larval growth and survival. Bioassays with strains of the fungal pathogen Metarhizium anisopliae were continued to compare the EPA-registered strain F-52 against Asian longhorned beetle with other strains of this fungal species. F-52 killed ALB adults as quickly as ESC-1 and VD-1. Two strains of M. anisopliae were used to continue tests of the effects of fungal infection on female reproduction of Asian longhorned beetle and the extent to which males are contaminated by inoculated females. Inoculated females laid fewer eggs before death, compared with untreated controls. More eggs from these fungal-inoculated beetles did not hatch and more larvae died, compared with controls. Males exposed to fungal-inoculated
females died from fungal exposure although their time to death was somewhat longer than females, probably becuase their dose was lower. Persistence of activity of non-woven fiber bands impregnated with cultures of F-52 hung in Queens, NYC was evaluated, as with other fungal strains in previous years. Bands retained over 1 x 107 conidia per square centimeter, the presumed threshold, throughout the 3 months that they were monitored. Persistence of F-52 conidia sprayed on street trees in Ithaca was also evaluated to compare trunk, branches, twigs and foliage. Although conidial densities initially applied were unexpectedly low, percentages of active conidia were after 2 days were very low, either due to conidia washing off or conidial mortality.
Impacts
Asian longhorned beetle is a serious threat to North American forests, especially since these beetles continue to be found in New York City and, in 2003, in Toronto. There are few ways to control this pest and use of non-woven fiber bands impregnated with cultures of entomopathogenic fungi is clearly the biological control option that is closest to being put to use for control in the U.S. Studies being conducted in our laboratory are answering questions that are critical to eventual use of these bands for control of ALB in the U.S.
Publications
- Dubois, T., Hajek, A.E., Jiafu, H. and Li, Z. 2004. Evaluating the efficiency of entomopathogenic fungi against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae), by using cages in the field. Environ. Entomol. 33:62-74.
- Dubois, T., Li, Z., Jiafu, H. and Hajek, A.E. 2004. Efficacy of fiber bands impregnated with Beauveria brongniartii cultures against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae). Biol. Contr. 31:320-328.
- Hajek, A.E., Curtiss, R.T. & Liebherr, J.K. 2004. Characters differentiating male from female Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae). Proc. Entomol. Soc. Wash. 106:928-931.
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Progress 01/01/03 to 12/31/03
Outputs
The Asian longhorned beetle, Anoplophora glabripennis, (ALB) was first found in the United States in 1996 and in Canada in 2003, attacking urban street trees. This tree-killing invasive has been a major pest in China and is difficult to control because immature stages live within wood and long-lived adults are usually high in tree canopies. A quarantine colony of ALB continues to be maintained, primarily for studies of use of insect pathogenic fungi for control of this urban invasive. However, our ALB colony was also used extensively for studies of ALB chemical communication. Bioassays with fungal strains were continued, in particular demonstrating virulence of the EPA-registered entomopathogenic fungus Metarhizium anisopliae strain ESC-1. Methods for producing non-woven fiber bands impregnated with cultures of entomopathogenic fungi, an application method marketed for control of longhorned beetles in Japan, were improved. Non-woven fiber bands impregnated with the
Metarhizium anisopliae isolate ESC-1 were produced in Ithaca and hung on cemetery trees in Queens, NYC in mid-summer. Bands were removed from trees at intervals for up to 3 months and were assayed in Ithaca to determine densities of fungal spores on bands, germinability of spores and whether these spores were infective (using the quarantine colony). In 2003, activity of bands persisted throughout the length of time they were assayed, demonstrating that this control method is remarkably persistent, an attribute that is often not characteristic of microbial products for control of insect pests. Field studies were not conducted in China during summer 2003 because preparations could not be made in time due to SARS. The extensive data from uncaged field trials conducted in Anhui, China during 2002 were analyzed and summarized. The Japanese product Biolisa Kamikiri, consisting of non-woven fiber bands containing cultures of Beauveria brongniartii (marketed in Japan for control of a
congeneric pest in orchards) was compared with Metarhizium anisopliae for control of A. glabripennis. Adult beetles collected from fungal-treated plots 7-21 days after bands were hung on trees died more quickly than adults from control plots. Among adults collected from fungal plots, 36-40 percent died within 10 days while 16 percent of controls died within 10 days. Oviposition in fungal-treated plots was approximately half that in control plots. Locations of adult beetles and oviposition scars within tree canopies was quantified to determine optimal locations for band placement. Bands were hung at 2-2.5 m but most beetles were found at more than 3.5 m in height, with adults in Biolisa Kamikiri-treated plots higher within trees than adults in other treatment plots, suggesting the need for further work on optimizing band placement within trees.
Impacts
Asian longhorned beetle is a serious threat to North American forests, especially since these beetles continue to be found in New York City and, in 2003, in Toronto. There are few ways to control this pest and use of non-woven fiber bands impregnated with cultures of entomopathogenic fungi is clearly the biological control option that is closest to being put to use for control in the U.S. Studies being conducted in our laboratory are answering questions that are critical to eventual use of these bands for control of ALB in the U.S.
Publications
- Hajek, A.E., Dubois, T., Bo, H. and Li, Z. 2003. The use of fungal bands for control of Asian longhorned beetle. USDA, Forest Service, Gen. Tech. Rpt. NE-315:28.
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Progress 01/01/02 to 12/31/02
Outputs
From the beginning of our work on control of Asian longhorned beetle using insect pathogens, our focus has been on control of Asian longhorned beetle with the fungal pathogen Beauveria brongniartii. A product based on this fungal species is marketed in Japan; the fungus is grown in non-woven fiber bands that are attached around tree trunks so that wandering adults inoculate themselves and transmit fungal spores to mates. Results from our bioassays (in China and in a quarantine in the U.S.) and both caged and non-caged trials in China suggested that B. brongniartii was very effective against Asian longhorned beetle. However, over the past year we found that we cannot confirm that this fungal species occurs in North America, although 9 citations and reports had previously reported that this species occurred in North America. Molecular studies demonstrated that the Japanese strain marketed as a control product is very different from tested isolates of North American
Beauveria. Therefore, registration of B. brongniartii for use in an eradication program in the U.S. seems difficult. We have begun exploring other fungal isolates as alternatives, especially because the delivery system we are working with is very good. North American strains of Metarhizium anisopliae and Beauveria bassiana have shown excellent activity against Asian longhorned beetles during bioassays and both have been successfully grown in the non-woven fiber bands as a delivery system. Non-caged trials during the 2002 field season in Bengbu, Anhui, China with M. anisopliae versus B. brongniartii demonstrated superior activity by a North American isolate of M. anisopliae. Fungal bands of M. anisopliae and B. bassiana hung in trees in Queens, NYC during the 2002 field season maintained greater than 1 x 107 living conidia/square centimeter, for over 2 months. This density is the limit of effectiveness suggested by the Japanese manufacturer for use of B. brongniartii against citrus
longhorned beetle, Anoplophora malasiaca). Therefore, these North American fungi grown in bands remain viable for an extended period and we are now pursuing development of a North American isolate for use in bands instead of B. brongniartii.
Impacts
These studies are aimed at developing a fungal pathogen for control of Asian longhorned beetle in North America. This is a very difficult invasive species to control and there are few control options. Development of a means for biological control is desired by land managers and results from our studies of fungal pathogens are very promising with regard to a biological control product for control of Asian longhorned beetle.
Publications
- Dubois, T., Hajek, A.E. and Smith, S. 2002. Methods for rearing the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae) on artificial diet. Ann. Entomol. Soc. Amer. 95:223-230.
- Dubois, T., Hajek, A., Jiafu, H. and Li, Z. 2003. First field trials with fungi against Anoplophora glabripennis. USDA Gen. Tech. Rpt. NE-300: 17.
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Progress 01/01/01 to 12/31/01
Outputs
The Asian longhorned beetle was first found in North America in 1996 and poses a serious threat to North American forests and urban and suburban trees. In order to conduct studies on use of pathogens for control of Asian longhorned beetle, first we developed a method for rearing these beetles (only in a quarantine facility). We have now published a paper describing experiments leading to a protocol for rearing these beetles. The size of our quarantine colony has grown substantially and we are presently rearing a third generation of quarantine-born insects. We have collected numerous fungal strains from Asian longhorned beetle and other longhorned beetles, both in Asia and North America. We have continued bioassays comparing strains of fungi we have isolated along with commercially produced strains, to identify an optimal isolate for use against this beetle: to date, optimal strains of Beaveria bassiana, Beauveria brongniartii, and Metarhizium anisopliae result in 50%
adult mortality after 5.2-5.8 days. In developing control measures, we are targeting adults and are specifically investigating cellulose bands containing fungal colonies, a technology developed by a Japanese company for control of a very closely related beetle. This technology takes advantage of the prematurational wandering behavior of adult beetles, during which time adults contact bands and become inoculated with fungal spores; in this scenario, adult beetles would die from infections before laying eggs. These bands have very positive attributes, being active for prolonged periods and self-degrading after use. In Bengbu, Anhui, China, we tested caged adult beetles with fungal cellulose bands or sprayed them with fungal spores, using two species of Beauveria. Results demonstrated that cellulose bands with Beauveria brongniartii gave optimal mortality and reduced oviposition. Open field trials in Huaiyuan, Anhui yielded a decrease in beetle populations compared with controls at one
site but not another. Infection levels were clearly higher at the release sites compared with controls; however, due to dispersal of beetles and ubiquity of fungal pathogens, we found some infection at control sites. From August through December, we conducted trials with B. brongniartii growing in non-woven fiber bands (product of Nitto Denko Corp., Osaka, Japan) in Queens, NYC to determine the longevity of activity of bands hung in urban shade trees; in Japanese citrus orchards, these bands are effective for 30 days. Our studies include counts of spores on bands, evaluating germination of spores and determining infectivity of adult beetles exposed to bands. Assays are conducted weekly for six weeks after bands have been hung in trees. We have also begun studies investigating effects of the strain of B. brongniartii marketed by Nitto Denko on nontarget organisms in the US, beginning with the ladybeetle, Harmonia axyridis.
Impacts
The use of pathogens for control of Asian longhorned beetle is being investigated, with emphasis on fungi. We will identify an optimal pathogen strain, test its efficacy in the laboratory and field, develop methods for application, and evaluate its environmental safety.
Publications
- Dubois, T.L.M., Jiafu, H., Li, Z., Fan, M. and Hajek, A.E. 2001. Control of Anoplophora glabripennis with entomopathogenic fungi. USDA, Forest Service, Gen. Tech. Rpt. NE-285: 48.
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Progress 01/01/00 to 12/31/00
Outputs
The Asian longhorned beetle was first found in North America in 1996 and poses a serious threat to North American forests and urban and suburban trees. In order to conduct studies of use of pathogens for control of Asian longhorned beetle, first we have been comparing artificial diets for rearing these beetles in the quarantine. Initial studies demonstrated that three recipes that included the phloem-cambial layer of trees as a phagostimulant gave similar larval growth rates. A second set of studies demonstrated that cellulose or sawdust can be substituted for the phloem-cambial layer; one diet recipe yielding excellent time to pupation, adult longevity and adult weight is now being used successfully. The size of our quarantine colony has grown substantially and we are presently rearing a second generation of quarantine-born insects. We have collected numerous fungal strains from Asian longhorned beetle and other longhorned beetles, both in Asia and North America. We
have continued bioassays comparing strains of fungi we have isolated along with commercially produced strains, to identify an optimal isolate for use against this beetle; to date, selected strains of Beaveria bassiana, Beauveria brongniartii, and Metarhizium anisopliae result in 50% adult mortality after 5.2-5.8 days. In developing control measures, we are targeting adults and are specifically investigating cellulose bands containing fungal colonies, a technology developed by a Japanese company for control of a very closely related beetle. This technology takes advantage of the prematurational wandering behavior of adult beetles, during which time adults contact bands and become inoculated with fungal spores. These bands have very positive attributes, being active for prolonged periods and self-degrading after use. In Wuhe, Anhui, China, we tested caged adult beetles with fungal cellulose bands or sprayed them with fungal spores, using two species of Beauveria. Results demonstrated
that cellulose bands with Beauveria brongniartii gave optimal mortality and reduced oviposition. Scanning electron microscopy was used to investigate how and where fungi penetrate through the thick cuticle of these beetles; germ tubes appear to penetrate via naturally occurring pore canals with occasional indication of directed growth toward pore canals.
Impacts
The Asian longhorned beetle is a major tree-killer in China where it is native. This beetle constitutes a great threat to North American forests if it becomes established in particular due to its broad host range and particular preference for maples. If this beetle becomes established in North America, methods for biological control will be essential because these beetles will infest both forest and city street trees. The goal of our studies is to develop an effective method for using fungal pathogens to control Asian longhorned beetle. We feel this tactic holds great promise since it has been adopted to control a closely related beetle damaging orchards in Japan.
Publications
- Hajek, A.E., and Dubois, T.L.M. 2000. Pathogens for control of Anoplophora. USDA, For. Serv. Gen. Tech. Rpt. NE-273:18.
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Progress 01/01/99 to 12/31/99
Outputs
The Asian longhorned beetle was first found in North America in 1989 and poses a serious threat to North American forests and urban and suburban trees. In order to conduct studies of pathogens for control of Asian longhorned beetle, first we have been comparing artificial diets for rearing these beetles in the laboratory. Initial studies demonstrated that three recipes that included the phloem-cambial layer of trees as a phagostimulant gave similar larval growth rates. A second set of studies demonstrated that cellulose or sawdust can be substituted for the phloem-cambial layer and one diet recipe excelled in time to pupation, adult longevity and adult weight. We have obtained eight strains/species of insect pathogenic fungi from larval and adult Asian longhorned beetles from China and the United States. Bioassays with insect pathogenic fungi were conducted in two provinces in China to compare five fungal isolates of Beauveria bassiana and Beauveria brongniartii
against larvae and adults at two doses. Two of the strains tested are commercially available, one in Japan for control of a closely related longhorned beetle in orchards, and one in the United States for control of a diversity of insects. Bioassay results with larvae were disappointing although we consider these cryptic wood-boring larvae the more difficult stage to control. Results from the stage we are emphasizing, adults, showed promise; LT50s for four strains against adults ranged from 7.8 to 8.7 days. We are planning further bioassays to decide on fungal strains during further laboratory bioassays with subsequent field trials in China. In particular, we will investigate use of the Japanese fungal product targetting the close relative of Asian longhorned beetle; this is applied by fastening a non-woven fiber sheet in which the fungus has been grown around tree trunks and branches where wandering adult beetles inoculate themselves.
Impacts
The Asian longhorned beetle is a major tree-killer in China and constitutes a great threat to North American trees. In North America, methods for biological control will be essential because this beetle can inhabit both forests and city streets. The goal of our studies is to develop an effective method using fungal pathogens to control this pest. This tactic holds great promise since it has been adopted to control a closely related beetle damaging Japanese orchard trees.
Publications
- Hajek, A.E., Smith, S.M. 1999. The use of entomopathogens for control of cerambycids in Japan and China. USDA, Forest Service, Gen. Tech. Rpt. NE-266: 32.
- Hajek, A.E., Dubois, T.L.M. 2000. Pathogens for control of Anoplophora. USDA, Forest Service, Gen. Tech. Rpt. (In prep.).
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