Efficacy of Pesticides on the Asian Longhorned Beetle Anoplophora glabripennis Toxicity and Efficacy of Imidacloprid to Anoplophora glabripennis (Coleoptera: Cerambycidae)
Evaluation of Systemic Insecticides to Control Anoplophora glabripennis (Coleoptera: Cerambycidae)
Efficacy of Pesticides on the Asian Longhorned Beetle Anoplophora glabripennis
Baode Wang1, Victor C. Mastro1, Winfred H. McLane1, Richard C. Reardon3 & Gao Ruitong2One of the major APHIS-PPQ cooperative projects since 1997 has been evaluating the efficacy of different insecticides in China against the Asian longhorned beetle, Anoplophora glabripennis. Following the field test conducted in 1998, more studies were done in 1999.
Five systemic insecticides including Disyston (AI: Disulfoton), Merit (AI: Imidacloprid), Metasystox-R (AI: Oxydemeton-methyl), Monitor (AI: Methamidophose), and Othene (AI; Acephate) were tested in filed through soil injection, trunk injection and trunk implanting at two sites in Gansu province of China. Trees at the first site were primarily Popular alba var pyramidalis (height = 8.5 m, and DBH = 10.9 cm) that was once considered to be one of the least preferred species by the beetle. These were ornamental trees on roadside, and close to city residential area. Applications were made three times at this site: April, June and September for soil injection, and May, June, and July for trunk injection and implanting. Trees at the second site were mainly P. nigra var thevestina (height0 =8.0 m, and DBH = 8.6 cm). These were windbreak trees planted in rows and surrounded by farmland. They are highly preferred and heavily attacked by the beetle. Applications were made two times at the second site: July and September for soil injection, trunk injection and trunk implanting. Efficacy of these insecticides were evaluated by checking the mortality of adult beetles during flight season, and by checking mortality of all stages of beetles through dissecting trees in late November.
The following 8 insecticides were tested in laboratory together with water as the control: Biflex 2 EC (bifenthrin), DeltaGard* 5C (deltamethrin), Astro 3.2 (permethrin), Orthene 75S (acephate), Dursban 4E (chlorpyrifos), Lindane 20%, FICAM (bendiocarb), and Regent (fipronil). Three dosages of each insecticide were tested. Newly collected willow twigs were dipped into insecticide solutions for 1 minute and then placed in cages together with a pair of beetles at 25-32°C. Fipronil and permethrin were also selected for testing their residual effects to the beetle. This was done by spraying insecticides onto tree twigs at different times of the year and then providing beetles with these treated twigs. Mortality of beetles was checked once every 24 hours for a week for both tests.
All data collected from the field tests are still in evaluation. However, based on our preliminary analyses, efficiency of different insecticides varied depending on the time of application and tree species as well as population level and stage of the beetle. Generally, imidacloprid seemed to cause higher mortality to the beetles than other insecticides tested, especially, when applied through trunk injection. Samples of different parts of treated trees have been collected for chemical analyses of the levels of insecticides in trees. Similar chemical analyses for treated trees in the US started in 1999, when imidacloprid and Bidrin (dicrotophos) were applied through soil injection, trunk injection and, implanting to sugar maple (Acer sacchaurm) and red maple (Acer rubrum) located in western Massachusetts. These data together with data that will be collected in 2000 by dissecting treated trees left from 1999 will provide us more information about the efficacy of these insecticides against the beetle.
Results of laboratory test showed that the 8 tested insecticides had very good immediate effects on adult beetle, i.e., an almost 100% mortality within 72 hours from each insecticide, though there were slight differences among different insecticides. However, fipronil and permethrin showed very poor residual effects against the beetle. Less than 25% mortality resulted when the two insecticides were applied to twigs 2 weeks before the treated twigs were provided to the beetle.
More field and laboratory tests of insecticides for controlling the beetle together with residual analyses of these insecticides will be conducted in China and the US in 2000.
Toxicity and Efficacy of Imidacloprid to Anoplophora glabripennis
(Coleoptera: Cerambycidae)*
Baode Wang1, Ruitong Gao2, Victor C. Mastro1, Win H. McLane1, and Richard C. Reardon3The efficiency of the insecticide, imidacloprid against Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) was evaluated in both laboratory and field conditions in China. In laboratory, adult beetles were provided with twigs or leaves of host trees treated with different concentrations of imidacloprid to evaluate the efficacy of the insecticide through oral or contact or both entries. Beetles were checked once every 24h and the areas of twigs and leaves consumed by tested beetles were recorded immediately after the beetle was found dead. The actual level of imidacloprid in twigs and leaves were analyzed, and this level was plotted against the applied concentration of imidacloprid to determine the relationship between the two. The LC50 values for applied level of imidacloprid to adult beetle for 24h, 48h, and 72h was 87.4 ppm, 43.1 ppm, and 27.3 ppm, respectively. These values correspond to 5.0, 2.9 and 1.9 ppm of the actual level of imidacloprid detected in twigs. Our results indicated that mortality of adult beetles resulted not only from the oral and contact poison, but also from their refusal of feeding. In field test, adult beetles were caged with live twigs of trees treated with imidacloprid through soil injection, trunk injection and trunk implanting. The status of adult beetles caged with live twigs of treated trees was checked every day and the level of imidacloprid in leaf, twig, and bark and xylem area of the treated trees were analyzed different days following the insecticide application. The results indicate imidacloprid caused high mortality of adult beetles, but not larvae of the beetle, although mortality of adults and larvae may differ for different application methods and timings of applications. The levels of imidacloprid in leaf, twig, and bark and xylem of treated trees in field were comparable to the LC50 values detected in treated twig and leaf in laboratory.
*An abstract prepared for the USDA Interagency Research Forum on Gypsy Moth and Other Invasive Species
(January 16-19, 2001 Annopolis, Maryland)1USDA APHIS PPQ Otis Plant Protection Center, Building #1398, Otis ANGB, MA 02542
2Research Institute of Forest Ecology, Environment, and Protection, Chinese Academy of Forestry, Beijing 100091, China
3US Department of Agriculture, Forest Service, Forest Health Enterprise Team, Morgantown, WV 26505
Evaluation of Systemic Insecticides to Control Anoplophora glabripennis
(Coleoptera: Cerambycidae)*
Therese M. Poland, Robert A. Haack and Toby R. PetriceUSDA Forest Service, North Central Research Station
1407 S. Harrison Rd., Rm. 220, East Lansing, MI 48823The use of systemic insecticides may prove useful in controlling Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), adults during maturation twig feeding and larvae when feeding in the cambium and sapwood. In 1999, we evaluated imidacloprid as a systemic insecticide against A. glabripennis. We used four injection methods: Mauget (Imicide, J.J. Mauget, Co.) and Wedgle (Pointer, Arbor Systems, LLC) trunk injectors, ACECAP trunk implant (Creative Sales Inc.), and Kioritz soil injector (Merit, Bayer Corp.). All injection methods were tested in four tree species which were known to be hosts in China and were infested in New York City and Chicago: American elm, Ulmus Americana L., boxelder, Acer negundo L., quaking aspen, Populus tremuloides Michx., and silver maple, Acer sacharinum L. Tree samples were collected 4, 8, and 16 weeks after injection and presented to A. glabripennis adults and larvae. Testing of A. glabripennis was conducted in the USDA Forest Service quarantine facility in Ansonia, CT. Branch sections were presented to mating pairs of adults to test oviposition success, twigs were presented to individual adults to assess mortality during maturation feeding, and artificially reared first instar larvae were inserted into branch sections to assess larval mortality. Chemical residue analyses were conducted on foliage and twig samples at the USDA APHIS laboratory in Gulfport, MS. Overall, little adult or larval mortality occurred during the 2-6 week feeding tests. Adults fed on the outer bark of the twigs and thus not deep enough into the wood to receive a lethal dose. The highest levels of A. glabripennis larval mortality occurred in branch samples from boxelder trees that were collected 16-weeks post-injection. The chemical residue analyses suggested that the imidacloprid did not spread evenly throughout the trees. Of the four injection techniques, imidacloprid was most commonly detected in trees treated with the Mauget trunk injection method.
In 2000, in addition to imidacloprid, we also evaluated azadirachtin (the active ingredient in neem seed extract) and emamectin benzoate in both the U.S. and in China. In the U.S., we tested two doses of imidacloprid using Mauget trunk injection devices (Imicide), two doses of azadirachtin (Oranzin, Amvac Chem. Corp.) using both the Kioritz soil injector and systemic tree injection tubes (STIT), and one dose of emamectin benzoate using trunk injection (Shot One, Novartis). In the U.S., we tested imidacloprid in both boxelder and silver maple trees, whereas azadirachtin and emamectin benzoate were tested only in boxelder trees. Samples of trees injected with azadirachtin were collected 4 weeks after injection and larvae were inserted under the bark in the Ansonia quarantine lab. Larvae were allowed to feed for 8 weeks prior to dissection of the branch samples. Samples from trees injected with imidacloprid and emamectin benzoate were collected 12 weeks after injection and larvae were allowed to feed for 4 weeks prior to dissection. Overall, we found very low mortality in all lab bioassays in 2000. Residue analyses are still being completed.
We are currently conducting laboratory bioassays with A. glabripennis and cottonwood borer, Plectodera scalator (Fabricius) (Cerambycidae) feeding on artificial diet treated with various concentrations of imidacloprid and azadirachtin. The cottonwood borer is being reared in a non-quarantine laboratory in East Lansing, MI as a surrogate for A. glabripennis. Preliminary results demonstrate a strong anti-feedant effect for both insecticides. As concentrations of imidacloprid and azadiractin increase in the diet, larvae feed less and lose weight. For P. scalator no mortality was seen until 8 weeks of feeding. After 12 weeks, several larvae feeding on diet treated with concentrations of imidacloprid or azadirachtin greater than 50 ppm had died, while larvae on doses as low as .005 ppm lost weight and displayed various signs of decline. For A. glabripennis, mortality was first seen after 4 weeks of feeding and after 8 weeks, a few larvae had died and similar reductions in feeding, weight loss, and signs of decline were observed. These results may help explain why we observed such low larval mortality in the insecticide treated branch samples in 1999 and 2000, i.e., that the larvae may require more time to feed before branch dissection and assessment of mortality. In addition, the small larvae that were inserted into the branch samples may not have received a lethal dose because they feed very little and primarily in the phloem tissue.
In June 2000, we injected 48 elm trees, 48 poplars, and 48 willows in Gansu Province, China. For each tree species, 24 of the trees were currently heavily attacked by A. glabripennis and 24 were lightly attacked. Equal numbers of trees were injected with imidacloprid using Mauget trunk injectors (Imicide, high dose), azadirachtin using systemic tree injection tubes (Ornazin, high dose), or emamectin benzoate using trunk injection (Shot One). In July, 4 weeks after injection, four mating pairs of A. glabripennis were caged on each of the lightly infested trees to ensure that some larvae would be present. In October, 4 months after injection, we cut down and dissected half of the trees. Mortality varied by A. glabripennis life stage, tree species, and insecticide. Overall, moderate levels of mortality were found for all three insecticides tested. The highest larval mortality rate (81% of the larvae that were in the sapwood) occurred on poplar trees that had been injected with imidacloprid. The remaining trees will be cut and dissected in May or June 2001. Additional doses and compounds will be tested in 2001. In addition, trees will be injected simultaneously with dye and each of the different insecticides using different doses and number of injection sites to determine translocation patterns and the optimal delivery protocols to ensure complete coverage.
*An abstract prepared for the USDA Interagency Research Forum on Gypsy Moth and Other Invasive Species
(January 16-19, 2001 Annopolis, Maryland)Top
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