THOUSAND CANKERS DISEASE OF WALNUT DISTRIBUTION THE FUNGUS DISEASE SYMPTOMS THE INSECT VECTOR SURVEY AND SAMPLING MANAGEMENT OF TCD

Transcription

1 THOUSAND CANKERS DISEASE OF WALNUT DISTRIBUTION THE FUNGUS DISEASE SYMPTOMS THE INSECT VECTOR SURVEY AND SAMPLING MANAGEMENT OF TCD

2 THOUSAND CANKERS DISEASE OF BLACK WALNUT (TCD) To date, no new finds in Illinois or any where else in eastern U.S.

3 DISTRIBUTION OF BLACK WALNUT AND TCD

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6 THOUSAND CANKERS DISEASE CYCLE

7 TCD SYMPTOMS Yellowing and thinning of upper crown Death of larger branches Leaf wilt Trees die within three years of symptoms

8 CANKERS ASSOCIATED WITH THOUSAND CANKERS DISEASE Primary cankers caused by Geosmithia spp. Considered an annual canker Small and develop around nuptial chambers of WTB Without WTB, cankers do not kill branches Cankers are not visible without bark peeling

9 CANKERS ASSOCIATED WITH THOUSAND CANKERS DISEASE Secondary canker caused by Fusarium solani Occurs on trees in advance states of decline Larger and more diffuse

10 CANKERS ASSOCIATED WITH THOUSAND CANKERS DISEASE Fusarium solani Botrysphaeria spp. May produce larger cankers Diplodia seriata All these pathogens appear to be more virulent and produce larger cankers

11 CANKERS ASSOCIATED WITH THOUSAND CANKERS DISEASE Eastern isolates of TCD were dominated by Trichoderma spp. Trichoderma spp. may serve as a biological control agent

12 WALNUT TWIG BEETLE AND THOUSAND CANKERS DISEASE Beetle is native to North America and range coincides with Arizona walnut (Juglans major) Wide spread decline of walnut began in the late 1990 s and early 2000 s.

13 WALNUT TWIG BEETLE (Pityophthorus juglandis) Yellowish-brown beetle 1/20 inch long Attacks one inch diameter branches and greater Overwinters as an adult with peak emergence mid July-late August Two or more generations per year

14 COLONIZATION OF JUGLANS BY WTB All Juglans are susceptible Eastern black walnut (EBW) is highly susceptible Hickory and pecan are not susceptible

15 WALNUT TWIG BEETLE (Pityophthorus juglandis) Considered weak flyer Can fly up to 2 miles, but usually ¼ mile Peak flight is May-July and September-October Nocturnal flier at o F Flight drops off with wind speeds > 3mph.

16 WTB RESPONSE TO FUNGAL VOLATILES Beetle is attracted to non-girdled and girdled trees branches and synthetic volatiles Beetle does not respond to Gm volatiles Repelled by limonene Attracted to other fungal volatiles (i.e. Fusarium)

17 COLD TOLERANCE OF WTB 50% mortality of WTB at -6 o F and 90% at -36 o F Illinois falls in the 50-75% mortality range for normal cold temperatures

18 BARK WEEVILS ASSOCIATED WITH BLACK WALNUT (Stenomimus pallidus and Himatium errans) Recovered from black walnut trees in Indiana TCD fungus was recovered from three weevils Suggests a very casual relationship as vector for TCD fungus limiting ability to affect tree health

19 OTHER INSECTS AND FUNGI THAT COLONIZE STRESSED WALNUT Assorted exotic ambrosia beetles Xyleborinus saxeseni Xylosandrus crassiusculus Xylosandrus germanus Known to readily attack black walnut Geosmithia pallida and Fusarium solani (stem canker pathogen) found associated with ambrosia beetles

20 DISTRIBUTION OF AMBROSIA BEETLES BARK BEETLES, AND WEEVILS IN INDIANA AND MISSOURI IN 2011 Black Dots: insects trapped Blue Dots: 501-1,000 insects trapped Green Dots: 1,001-2,500 insects trapped

21 2011 TRAP SITES AMBROSIA AND BARK BEETLE, AND WEEVILS ON STRESSED BLACK WALNUT IN INDIANA AND MISSOURI Star ( ): Site with Geosmithia morbida positive weevil Triangle ( ): Sites with weevils, but negative for G. morbida Dot ( ) : Site with neither weevils nor G. morbida

22 ILLINOIS FOREST HEALTH TRAPPING SITE LOCATIONS

23 THE WORLD OF AMBROSIA BEETLES Predisposed to advanced forms of sociality and fungi-culture Females are similarly related to their own sisters, own offspring and all other colony offspring Beetle-fungus association is maintained by females transferring spores of specific ambrosia fungi and potential other micro-organisms Spores are carried either in the gut or in mycetangia or mycangia from natal nest to new found galleries

24 AMBROSIA BEETLES Attack stressed plants from spring to fall Some overwinter as adults, others overwinter in all four life stages

25 SUMMARY OF AMBROSIA TRAP CATCHES FOR SPECIES COLLECTED (Approximately 3,000 specimens) % OF TOTAL BEETLES Xylosandrus crassiusculus 95% Xyleborinus saxeseni 2% Xylosandrus germanus 1%

26 SUMMARY OF AMBROSIA AND BARK BEETLES RECOVERED FROM BLACK WALNUT TRAP TREES FOR 2016 SPECIES # OF SPECIMENS % TOTAL Xyloborinus saxesenii 14 1% Xylosandrus crassiusculus 1,014 96% Xylosandrus germanus 5 <1% TOTAL 1,051

27 SUMMARY OF AMBROSIA AND BARK BEETLES POSITIVE FOR G. morbida (Gm) for 2016 SPECIES TOTAL # # POSITIVE % OF TOTAL Stenomimus pallidus % Xyloborinus saxesenii % Xylosandrus crassiusculus % Xylosandrus germanus % TOTALS %

28 SUMMARY OF LOCATIONS AND POSITIVES FOR Gm fungus for 2015 and 2016 LOCATION # SAMPLES # POSITIVES % TOTAL Lincoln Trail (E) (2015) % Walnut Point (EC) % Wayne-Fitzgerald (S) % Washington County (SE) (S. brevis) % Kickapoo (EC) (2016) % S.A. Forbes (SE) % Wayne-Fitzgerald (S) % Eldon-Hazlet (S) % Morraine View (C) % Randolph County (SW) % Lake Le-Aqua-Na (N) % Weinberg-King (W) %

29 DISTRIBUTION OF Gm BY ILLINOIS COUNTIES

30 MANAGEMENT OF THOUSAND CANKERS DISEASE No control available at present Rapid detection and sanitation are critical Insecticide sprays for beetle are not practical

31 MANAGEMENT OF THOUSAND CANKERS DISEASE Heavy reliance on fumigation with methyl bromide Wood penetration is a factor Loss of log quality and energy needed Steam treatment has potential Takes 3-5 hours No effect on log quality

32 BUR OAK BLIGHT

33 How widespread is BOB? Bur Oak Distribution Map for US BOB is in Kansas, Nebreska, Minnesota, Iowa, Wisconsin, Illinois and Missouri MN IA WI NE KS MO IL

34 2017 BUR OAK BLIGHT SURVEY

35 What are the symptoms of BOB? 1. Brownish lesions develop on veins on the underside of leaf 2. Brown veins and wedge shaped lesions form on leaf

36 Black fruiting structures of the fungus on leaf veins Wilted leaves overwintering

37 What s causing this disease? The fungus Tubakia sp. Petiole with black Tubakia pustules

38 How will BOB affect bur oaks?

39 Managing BOB BOB is a late season disease Removal of fallen leaves is not effective Maintain health and vigor Tests with Alamo (propiconazole) look promising Arbortech also shows promise but bur oaks seem very sensitive to injections

40 Research to Understand BOB Most research is being done at Iowa State with Dr. Tom Harrington- his website has a short video that is very informative

41 Sampling for BOB Please collect branch tips with symptomatic and healthy leaves from several locations on the tree, wrap them in dry paper toweling (no plastic bags, please) Contact Stephanie Adams at for specific instructions on submitting your sample of BOB

42 THANK YOU FOR YOUR ATTENTION!