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Insects | Credits


SCAFFOLDS Fruit Journal, Geneva, NY                  Volume 4 
Update on Pest Management and Crop Development       July 31, 1995

COMING EVENTS


                                                     43F       50F
Current DD accumulations (Geneva 1/1-7/31):         2292      1646
                       (Highland 3/1-7/30):         2476      1712

Coming Events:                              Ranges:
Codling moth 2nd flight peak                   1587-3103   1061-2212
STLM 2nd flight subsides                       1773-2484   1148-1740
Oriental fruit moth 2nd flight subsides        1806-2783   1164-1963
American plum borer 2nd flight peak            1975-2612   1407-1840
Apple maggot flight peak                       2033-2688   1387-1778
Redbanded leafroller 2nd flight subsides       2037-3045   1342-2160
Comstock mealybug 2nd gen crawlers emerging    2106-2768   1447-1924
San Jose scale 2nd flight peak                 2136-2533   1567-1818
Obliquebanded leafroller 2nd flight begins     2330-3040   1526-2076


TRAP CATCHES (Number/trap/day)
Geneva:   
                                  7/17   7/20   7/24   7/27   7/31
Redbanded Leafroller               0.3    0.4    0.2      0      0
Spotted Tentiform Leafminer        599    291    161     82     79
Oriental Fruit Moth (apple)        1.9    1.1    0.5    1.0    2.3
Lesser Appleworm                   0.9    1.8    0.7    0.3    0.9
Codling Moth                       2.9    2.1    7.7    6.2    5.4
San Jose Scale                     9.0    5.1    5.8   13.8    0.9
American Plum Borer (cherry)       1.9    3.0    3.1    1.5    3.5
Lesser Peachtree Borer (peach)     2.9    1.5    3.3    4.0    2.8
Lesser Peachtree Borer (cherry)    3.4    1.5    1.2    1.8    2.3
Peachtree Borer                    1.9    2.0    1.5    1.8    3.3
Obliquebanded Leafroller           0.1      0      0      0    0.1*
Pandemis Leafroller                  0      0      0      0      -
Apple Maggot                       1.1    0.5    1.4    1.8    1.1

Highland (Dick Straub, Peter Jentsch)
                                   7/3   7/10   7/17   7/24   7/31
Redbanded Leafroller                 0    1.6    1.6    0.6      0
Spotted Tentiform Leafminer        2.6   24.9   35.9   20.8   20.3
Oriental Fruit Moth                0.6    1.4    0.9    1.1    1.7
Fruittree Leafroller               0.3      0    0.1      0      0
Codling Moth                       0.8    0.4    0.6    1.1    1.1
Lesser Appleworm                     0      0      0    0.6    1.6
Sparganothis Fruitworm             3.8    1.1    0.6      0    0.3
Tufted Apple Budmoth               2.8    0.1    0.4      0      0
Variegated Leafroller                -      0    0.1    0.1      0
Obliquebanded Leafroller           7.2    0.9    0.1    0.2    0.3
Apple Maggot                         0      0      0    0.2*   0.1

                                                        * = 1st catch

PEST FOCUS
Geneva: 
   Obliquebanded Leafroller 2nd flight began 7/31.


BOTANICAL INSECTICIDES

By:Dave Kain, Entomology, Geneva

POWER PLANTS

Naturally occuring pesticides that are derived from plants or plant parts are commonly referred to as "botanicals". Botanicals have been around for quite a while. Along with arsenicals and other inorganic pesticides, they were pretty commonly used before the advent of the synthetic, organic pesticides rendered them "obsolete". From time to time they're re-examined for various reasons and may be familiar. Botanicals are of interest to those concerned with pest management for a variety of reasons. They are generally less toxic to the applicator than many synthetic pesticides. They may be acceptable in the organic market where synthetic pesticides are not. Because, in general, they break down quickly, they may also be of use near harvest, when control is needed but other materials may not be applied owing to PHI restrictions. Rapid degradation also means they are less likely to become environmental problems. Botanicals, however, are not without concerns. They are usually broad spectrum poisons that can be hard on beneficial insects. And, unlike "biological" pesticides like insect growth regulators and pheromones, they are somewhat acutely toxic to humans and other mammals. The fact that they break down rapidly in the environment, while an advantage in some respects, also means that sprays need to be

 
 		- timed precisely to coincide with pest events, 
 		- applied at lower thresholds and,possibly, 
		- applied more often. 
 		

They are also very expensive.

The four most common botanicals available for use in fruit crops today are rotenone, pyrethrin, sabadilla and ryania. Information on these products appears in the 1995 Tree-Fruit Recommendations (pp. 20-21). A relatively newer, and increasingly more common botanical insecticide that is receiving a lot of attention these days is azadirachtin (or neem).

ROTENONE Rotenone is derived from the root of various plants of the Derris or Lonchocarpus species from Southeast Asia, Central and South America. It is available as at least 118 formulated products from a large number of manufacturers. It is synergized by the addition of piperonyl butoxide (PBO), which is another botanical material. Rotenone is expensive compared with synthetic insecticides, but is moderately priced for a botanical. It is the most commonly mentioned of the botanicals in pre-synthetic literature and is at least somewhat effective against a large number of insect pests. These include: pear psylla, strawberry leafroller, European corn borer, European apple sawfly, cherry fruit fly, apple maggot, cranberry fruitworm, raspberry fruitworm, pea aphid (which is similar to rosy apple aphid), European red mite and two-spotted spider mite, codling moth, plum curculio, Japanese beetle and tarnished plant bug. Unfortunately, it is also toxic to ladybird beetles and predatory mites. But, it is non-toxic to syrphid flies that feed on aphids, and to honeybees. Rotenone is rapidly degraded by sunlight, lasting a week or less.

Of the botanicals mentioned here, rotenone is the most toxic to humans and other mammals. The acute oral LD50 is from 60-1500 mg/kg. In small doses it may be irritating or numbing to mucous membranes. It is highly toxic to fish, having been commonly used as a fish poison. It is also toxic to birds and pigs.

A recent regulatory development illustrates the tenuous situation of many minor-use materials and may end up rendering the preceding discussion academic before long. According to a USDA news release and as quoted in the Federal Register (July 20, 1995), the Rotenone Task Force has announced that it plans to delete all the agricultural uses from rotenone labels because of the cost of reregistration; these uses include all tree fruits and small fruits. The registrants plan to maintain rotenone uses for fish control and flea/tick/mite control on dogs and cats. They will reconsider the plans for deletion if someone is willing to develop the necessary data for reregistration. For additional information, contact Mr. Joe Conti, The Rotenone Task Force, AgrEvo Environmental Services, (201) 307-3366.

PYTRETHRIN (Pyrethrum) This compound is produced in the flowers of Chrysanthemum cinerariaefolium and is the forerunner of the synthetic pyrethroid insecticides.

There are not nearly as many commercially availableformulations of this chemical as there are for rotenone, but it is available as an emulsifiable concentrate, in combination with rotenone, or alone as a wettable powder, from at least a couple of sources. Pyrethrin is the least expensive of these four materials. Depending on the rate used, it may be less expensive than many synthetic insecticides. It is also synergized by PBO. Pyrethrin is labelled against a large number of pests. An addendum to the label for one formulation of pyrethrin showed it to be moderately to highly effective (61-100% control) against the following pests of fruit: grape leafhopper, potato leafhopper, leaf curl plum aphid, blueberry flea beetle, blueberry thrips and blueberry sawfly. It is also effective against cranberry fruitworm. It is quickly broken down in the environment and may be used up to and including the day of harvest.

Pyrethrin is relatively non-toxic to humans and other mammals, although the dust produces allergy attacks in people who are allergic to ragweed pollen. The acute oral LD50 is 1200-1500 mg/kg. It is toxic to fish, but "relatively" non-toxic to honey bees.

SABADILLA The source of sabadilla is the seed of a tropical lily. There are very few commercial formulations of this material. It is available as a dust that may also be added to water and sprayed, but clogging of the nozzles has been noted. It is moderately priced for a botanical (similar to rotenone). It will control potato leafhopper and is somewhat effective against tarnished plant bug. It has little effect on predators/parasitoids, except for the predatory mite Typholdromus pyri, to which it was extremely toxic in recent tests by Joe Kovach. Sabadilla may be used up to 24 hours before harvest. Apple is the only deciduous tree fruit crop specifically mentioned on the label of the one product we found registered for N.Y. use. In previous articles about botanical insecticides printed in Scaffolds, it was stated that sabadilla is not toxic to honeybees. However, the information provided by different sources since then has been ambiguous. Some say that it is relatively non-toxic to honeybees, and others (including the manufacturer) say it is toxic. The confusion may lie in the fact that sabadilla is toxic to honeybees on contact, but without any residual activity. In the interest of playing it safe (especially given the current state of bee health), it would probably be best to consider sabadilla a hazard to honeybees and to follow all necessary precautions to prevent their exposure to the material.

Sabadilla is less toxic to mammals than rotenone or pyrethrin; the acute oral LD50 is greater than 4000 mg/kg.

RYANIA A product of the roots and stems of Ryania speciosa of Trinidad, ryania acts as both a stomach and contact poison on target insects. It is the most expensive of the materials covered in this article, and is not as readily available as rotenone or pyrethrin. Ryanodine, the active ingredient, is formulated as a wettable powder and is labelled for use against the codling moth in apples. It is also toxic to the European corn borer and may control cranberry fruitworm. In Joe Kovach's tests it provided excellent control of a pest complex comprising codling moth, oriental fruit moth and lesser appleworm. It also controlled aphids, white apple leafhopper and spotted tentiform leafminer. It is more persistent than rotenone or pyrethrin and is more selective. It is generally not very harmful to pest predators and parasites, but is somewhat toxic to the predators Atractotomus maliand Diaphnocoris spp. It may also be used up to 24 hours before harvest.

The acute oral LD50 of ryania is 750-1200 mg/kg, less toxic than rotenone and slightly more toxic than pyrethrin. It is also toxic to fish.

AZADIRACHTIN (Neem) Azadirachtin is derived from the seeds of the neem tree, Azadirachta indica, which is widely distributed throughout Asia and Africa. The observation that the desert locust did not eat the leaves of the neem tree, and another, closely related species, led to the isolation and identification of azadirachtin in 1967. Since then, azadirachtin has been shown to have repellent, antifeedent, and/or growth regulating insecticidal activity against a large number of insect species and some mites. It has also been reported to act as a repellent to nematodes. Neem extracts have also been used in medicines, soap, toothpaste and cosmetics.

The most common commercial formulation of neem available for N.Y. tree fruit is Neemix, which lists leafminers, mealybugs, aphids, fruit flies, caterpillars and psylla on the label. Azadirachtin has shown good activity against spotted tentiform leafminer in tests in past years, but the formulation that was available at that time was somewhat phytotoxic. In Dick Straub's insecticide trials in 1992 with another azadirachtin product called Margosan-O, the insecticide showed good activity against STLM and leafhopper. Margosan-O is not labelled for fruit crops, however. In recent laboratory tests by Jan Nyrop's lab, toxicity to the predatory mite Amblyseius fallacis was very low. Field trials are being conducted this year against OBLR.

Azadirachtin is relatively short-lived and mammalian toxicity is low (rat oral LD50 >10,000). It can be used up to and including the day of harvest and reentry is permitted without protective clothing after the spray has dried. It is toxic to fish and aquatic invertebrates.

PIPERONYL BUTOXIDE (PBO) PBO is a synergist (in this case, a material that when added to a pesticide increases the activity of its active ingredient) of both rotenone and pyrethrin. It is also a botanical product, being derived from Brazilian sassafras. Acutely, it is very safe, having an acute oral LD50 of greater than 7,500 mg/kg, but it may be chronically toxic in high doses.


BIBLIOGRAPHY

Allen, T.C. 1945. A compilation of recent insecticidal tests of Sabadilla, Schoenocaulon spp. Dept. of Economic Entomology, Univ. of Wisconsin, Madison Wisconsin. NOT RELEASED FOR PUBLICATION

Brown, A.W.A. 1951. Insect Control by Chemicals. Wiley & Sons, Inc. New York.

Garman, P. 1943. Control of the apple maggot with rotenone dusts. Bulletin of the Connecticut Agricultural Experiment Station. Bull. 474 pp. 435-442.

Hardman, J.M., H.J. Herbert, K.H. Sanford and D. Hamilton. 1985. Effect of populations of the European red mite,Panonychus ulmi, on the apple variety Red Delicious in Nova Scotia. Can. Entomol. 117: 1257-1265.

Hofstetter, B. 1991. Before you buy botanical pest controls ... The New Farm. Dec. 1991. pp. 36-39.

Kovach, J., H. Reissig and J. Nyrop. 1990. Effect of botanical insecticides on the New York apple pest complex. Reports from the 1989 IPM Research, Development and Implementation Projects in Fruit. New York State IPM Program, Cornell Univ. and NYS Dept. of Ag. and Markets. IPM Publication #202. pp. 40-44.

Morse, J.G. and T.S. Bellows, Jr. 1986. Toxicity of major citrus pesticides to Aphytis melinus (Hymenoptera: Aphelinidae) and Cryptolaemus montrouzieri (Coleoptera: Coccinellidae). J. Econ. Entomol. 79: 311-314.

Morse, J.G., H.S. Elmer, O.L. Brawner. 1986. Resistant thrips: The 1986 control recommendations for California. Citrograph, the magazine of the citrus industry. Riverside, CA 71(6): 118-120.

Morse, J.G., J.A. Immaraju, O.L. Brawner. 1988. Citrus thrips: Looking to the future. Citrograph, the magazine of the citrus industry. Riverside, CA 73(6):112-115.

Strickler, K. and B.A. Croft. 1985. Comparative rotenone toxicity in the predator, Amblyseius fallacis (Acari: Phytoseidae), and the herbivore, Tetranychus urticae (Acari: Tetranychidae), grown on lima beans and cucumbers. Environ. Entomol. 14: 243-246.

HOPPING AGAINST HOPE

The Miles representative advises us that those growers who may beconsidering a Provado application to clean up white apple leafhopper adults should probably re-think their strategy. Provado is quite effective against the nymphs, but the adults are not so easily controlled (by any material) so it makes more sense to control the youngsters. If your WALH populations are mostly adults, no material will do a tremendous job against them, but it's better to use something like Sevin, Thiodan, Carzol, Cygon or Lannate rather than Provado to lower their numbers, unless you're trying to target STLM without disturbing predatory mites.

CODLING MOTH MODEL

The developmental model for 2nd generation codling moth larvae predicts that a control spray should be applied in problem orchards 1260 DD (base 50 F) after the start of the FIRST flight (5/17 in Geneva, 5/15 in the Hudson Valley). As of today, 7/31, 1646 DD have accumulated in Geneva and 1619 at Highland. A spray in problem orchards should already have been applied last week in western N.Y. That spray should be followed by a second one in 10-14 days. The second spray in the Hudson Valley should be going on this week.


Scaffolds is published weekly from March to September by Cornell University -- NYS Agricultural Experiment Station (Geneva), and Ithaca -- with the assistance of Cornell Cooperative Extension. New York field reports welcomed. Send submissions by 3 p.m. Monday to:

Scaffolds Fruit Journal
Editors: A. Agnello, D. Kain
Dept. of Entomology, NYSAES
Geneva, NY 14456-0462
Phone: 315-787-2341 FAX:315-787-2326
E-mail: art_agnello@cornell.edu

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