TOBACCO

Wildlife is an important part of a healthy rural environment. This fact sheet is one of a series that describes how pesticides can be managed to minimize harm to wildlife on our farms, in our waters, and in our forests.

Wildlife is a valuable natural resource. Most farmers enjoy seeing wildlife on their farm, and many benefit economically by leasing hunting and fishing rights to sportsmen. In North Carolina, more than $1.1 billion is spent annually by hunters and fishermen alone.

Tobacco fields provide both food and cover for wildlife. For example, quail and other birds nest in grassy strips alongside tobacco fields. Farm wildlife such as these are often called "edge species" because they live in noncrop areas such as hedgerows or along the edges of fields. Wildlife that live in these areas find food and grit in the adjacent crop fields. Pesticides applied to the fields are therefore likely to affect wildlife. For example, researchers tested quail that had been killed by hunters and found that 60 percent of the quail had insecticides in their bodies.

Wildlife that are directly exposed to toxic pesticides can get sick or die. In a 1978 study of quail living near fields that had been sprayed with methyl parathion, 35 percent had enough insecticide in their bodies to cause sickness or death. Birds made sick by insecticides may neglect their young, abandon their nests, and become more susceptible to predators and disease.

While direct poisoning from toxic pesticides is a concern, many pesticides that are not highly toxic can still be harmful to wildlife by reducing the food and cover that wildlife need in order to survive. Insecticides reduce insect foods, and herbicides decrease plant cover. Herbicide use can reduce gamebird populations on farms by disrupting habitats that chicks use to find insects and other foods. Similarly, pesticides can decrease the number of aquatic foods necessary to the survival of ducklings.

Careful selection and use of pesticides, however, can lessen their impact upon wildlife. This publication (1) describes how pesticides used on tobacco fields can harm wildlife and (2) describes how farmers can minimize adverse effects of pesticides on Wildlife

Reducing pesticide use is one of the best ways to protect fish and wildlife resources. Using sound cultural practices reduces pest problems and, therefore, results in lower pesticide use. Cultural practices that decrease the need for pesticides include rotating crops, selecting resistant varieties (when possible), planting and harvesting at the proper time, and using integrated pest management (IPM) techniques. IPM is a farming approach that employs alternative methods of pest control, rather than relying solely on agrichemicals. With IPM, pesticides are used only when the cost of applying a pesticide is outweighed by the cost of pest damage to the crop. This threshold must be reached before chemical pest control is economically justified. In this way, IPM practices help to reduce pesticide use and protect wildlife and the environment. For further information on alternatives to pesticide use, see the list of additional readings at the end of this publication.

Wildlife are exposed to insecticides when they eat granules or residues on plants and in insects. For instance, quail chicks feed on dead and dying insects following applications of insecticides. Wildlife entering tobacco fields during or soon after an insecticide has been sprayed may be exposed when the pesticide contacts their skin and eyes or when they inhale the vapor.

Exposure to highly toxic insecticides (mainly organophosphate and carbamate insecticides) can result in death of the animal. Sublethal exposure may cause sickness. Birds made sick by insecticides are more susceptible to predation, disease, and exposure. Birds exposed to organophosphate insecticides have been found to neglect their young or even abandon their nests.

Insecticides used on tobacco range from nontoxic to extremely toxic to wildlife. Many soil applied insecticides are especially hazardous to wildlife; they include carbofuran (Furadan), aldicarb (Temik), fenamiphos (Nemacur), disulfoton (DiSyston), and ethoprop (Mocap). All of these insecticides are extremely toxic to birds and have caused wildlife deaths.

Tables 1 and 2 list insecticides recommended in the North Carolina Agricultural Chemicals Manual for use on soybeans. Table 1 rates insecticides according to their toxicities to birds, mammals, and fish. The effects of insecticides on wildlife and fish can be minimized by using the least toxic alternative. Insecticides in Table 2 are rated low, moderate, or high based on the hazard their use presents to wildlife (birds and mammals). The hazard of an insecticide is based on its toxicity to wildlife, the way it is used, and other characteristics, such as its persistence in the environment. For example, methomyl (Lannate) is acutely toxic to birds and mammals (Table 1). However, because methomyl does not persist in the field, careful use of this chemical presents only a moderate hazard to wildlife (Table 2). Wildlife exposed to insecticides rated high may die or become sick. Insecticides rated moderate may also cause death or sickness, although death is unlikely. Insecticides rated low are unlikely to harm wildlife directly.

Granular Insecticides

Granular formulations are a real hazard to birds. Birds eat granules exposed on the soil surface, mistaking the granules for food or grit. Ingesting only a few granules of a toxic insecticide can kill a small bird.

To reduce the danger to wildlife from granular insecticides:

• use the least toxic insecticide that will control the insect pest
• fully incorporate granules into the soil.

Disking spilled granules into the soil at row ends is especially important since many birds feed on the edges of fields. When soil incorporation is not possible, consider using a liquid formulation following the guidelines in the next section.

The hazard to wildlife posed by some soil applied systemic insecticides may warrant forgoing their use. Before using soil applied systemic insecticides, consider their advantages and disadvantages discussed in the "Insect Management" section of the Tobacco Information handbooks (AG­376 and AG­178) published by the North Carolina Cooperative Extension Service.

Foliar Insecticides

The hazards of foliar­applied insecticides to wildlife range from low to high (see Table 1). Several insecticides are relatively safe; they include Bacillus thuringiensis (Biobit, Dipel, or Javelin), carbaryl (Sevin), malathion, and acephate (Orthene). Other foliar insecticides, such as methomyl (Lannate), methidathion (Supracide), and methyl parathion are highly toxic to wildlife. Most foliar insecticides used on tobacco are short­lived in the environment, so the hazard to wildlife is short term.

To reduce hazard to wildlife from liquid formulations:

• spray only when IPM thresholds are met
• use the least toxic insecticide that will control the insect pest
• minimize drift of insecticides into wildlife habitats.

Drift can be minimized by using application equipment with low drift characteristics, replacing inappropriate or worn nozzles, using appropriate pressure and volume for the chosen nozzle, and adding a drift control agent. Ultra­low­volume sprays are more likely to cause drift than low­pressure sprays. Of course, avoid spraying when the wind is blowing faster than 8 mph.

Nematicides

Several soil­incorporated granular insecticides are also used as nematicide treatments and are highly toxic to wildlife; these include fenamiphos (Nemacur), aldicarb (Temik), ethoprop (Mocap), and carbofuran (Furadan). If these pesticides are used, it is very important to incorporate the granules into the soil to reduce wildlife hazard. Also, liquid formulations, rather than granular, may reduce wildlife hazard. Chlorpyrifos (Lorsban) and oxamyl (Vydate) are the least hazardous nematicide alternatives but are not as effective as some others in controlling nematodes.

Some fumigants are less hazardous to wildlife than nonfumigants because of their short duration of activity. These fumigants include dichloropropene (Telone II) and methyl bromide with chloropicrin (Brom­O­Sol).

Proper cultural practices, including crop rotation, stalk and root destruction, and use of resistant tobacco varieties, help to reduce the use of nematicides. For more information, see Extension Service publication AG­187, Tobacco Information.

Fungicides

Fungicides used on tobacco are only slightly toxic to wildlife; these include metalaxyl (Ridomil), ferbam (Carbamate), and mancozeb (Dithane M­45). Their use does not present a hazard to wildlife. However, mancozeb is highly toxic to fish.

Fungicide use can be reduced by controlling seedling diseases with cultural practices such as proper rotation, timely planting, and proper seed selection.

Herbicides

Most herbicides used on tobacco are only slightly toxic to wildlife (although some are highly toxic to fish). However, herbicides can destroy wildlife habitats and reduce the food and cover available to wildlife. When habitats are reduced on a farm, there is a tremendous effect on the wildlife populations there. Wildlife populations decline when herbicides or mechanical methods are used to maintain "clean" fence rows, ditch banks, and field borders. These strip habitats provide wildlife valuable cover for nesting, brood rearing, and escaping from predators.

Many species of wildlife, including quail and rabbits, benefit from strip habitats. Where possible, consider maintaining these areas in wildlife cover. Protect these areas from herbicides and mow less frequently. Consider mowing filter strips and ditch banks only once per year, preferably in early spring. In fields where weeds have been a problem, prevention of weed seed production in noncrop habitats may be accomplished by using selective herbicides that allow grass cover to be maintained.

Pesticide (Brand Name)	Birdsa	Mammalsa	Fishb
acephate (Orthene)	M	L	L
aldicarb (Temik)	Hc	H	EH
carbaryl (&vin)	L	L	M
carbofuran (Furadan)	Hc	H	H
chlorpyrifos (Lorsban)	H	L	EH
diazinon (Diazinon)	Hc	M	EH
disulfoton(Di­Syston)	Hc	H	H
endosulfan (loden)	M	H	EH
ethyl parathion (Parathion)	Hc	H	H
fenamiphos (Nemacur)	Hc	H	EH
fonofos (Dyfonate)	H	H	EH
malathion	L	L	EH
methidathion (Supracide)	H	M	EH
methomyl (Lannate)	H	H	H
methylparathion (Penncap­M)	Hc	H	H
oxamyl (Vydate)	H	H	M

aWildlife hazard is based on the following toxicities:

H (Highly toxic) ­ LD50 less than 30 mg/kg and/or LC50 less than 500 ppm
M (Moderately toxic) ­ LD50 greater than 30 end less than 100 rng/kg and/or LC50 greater than 500 and less than 1,000 pprn.
L (Low toxicity) LD50 greater than 100 mg/kg and LC50 greater than 1,000 ppm.
NT (Not toxic)

bFish 96 hour LC50 toxicities are as follows:

EH (Extremely toxic) less than 0.1 ppm
H (Highly toxic) 0.1 - 1.0 ppm
M (Moderately toxic) 1 - 10 ppm
L (Low toxicity) greater than 10 ppm

To convert fish toxicities to pounds of active ingredient per acre-foot of water, multiply by 2.7.

cActive ingredient (not necessarily a specific product) has caused wildlife deaths.

Pest Problem	Insecticide(Brand Name)	Wildlife hazard.	Killsb	Comments
Soil­Applied Insecticides
Aphids	aldicarb (Temik 15G)	high	yes	Temik granules exposed on the surface are a hazard to birds. (Flue­cured tobacco only.)
Aphids (suppression only)	acephate (Orthene 75SP) disulfaton (Di­Syston 15G) disulfoton + ethoprop (Mocap Pius 10 + 5G) fenamiphos (Nemacur 3E)	low high high   high	no yes yes   yes	Di­Syston and Mocap Plus granules on soil surface are a hazard to birds.
Flea beetles	oxamyl (Vydate L) disulfoton (Gy­Syston 8) ethoprop + disulfoton (Mocap Plus EC) carbofuran (Furadan4F) aldicarb (Temik 1 5G)	low moderate moderate   high high	no yes yes   yes yes	Temik granules exposed on the soil surface are a hazard to birds.     (Flue­cured tobacco only.)
Flea beetles and early­season hornworms	carbofuran (Furadan 4F)	high	yes	Minimize drift into wildlife habitat.
Wireworms	chlorpyrifos (Losrban 4E) chlorpyrifos (Lorsban 1 5G) fonofos (Dyfonate 1 OG) fonofos (Dyfonate 50W) ethoprop (Mocap 1 OG, 6EC) carbofuran (Furadan 4F) parathion (Parathion 4G,10G)	low moderate moderate low high high high	no no no no yes yes yes	Fully incorporating granules reduces hazard. Disk under granules spilled at row ends or use liquid fomnulation.   (Fine­cured tobacco only.) (Flue­cured tobacco only.)
Remedial Treatmenta for Inaect Control in the Field
Aphids	acephate (Orthene 75SP) endosulfan (Thiodan 3EC) methomyl (Lannate 1 .8L 90SP)	low moderate moderate	no no no	Thiodan and Lannate are more toxic to birds and mammals.
Budworms	Bacillus thunngiensis (Dipel, Javelin, Biobit) Supracide, Lannate, or acephate (Orthene75SP) methidathion(Supracide2EC) endosulfan(Thiodan3EC) methomyl (Lannaate 90SP,1 .8L) methyl parathion (Penocap­M)	safe   moderate moderate moderate moderate moderate	no   no no no no yes	Orthene is safer than   Thiodan. Uquid methyl parathion is more hazardous than Penncap­M. However, Penncap­M is a hazard to bees.
Cutworms	carbaryl (Sevin 5% bait) trichlorfon(Dylox, Proxd) acephate (Orthene 75SP)	low low low	no no no	Dylox and Proxal are highly i toxic to fish and bees.
Flea beetles	carbaryl (Sevin 1 OD,80S,4F) acephate (Orthene 75SP) methidathion (Supracide 2EC) methomyl (Lannate 90SP, 1 .8L) methyl parathion (Pennca~M)	low low moderate moderate moderate	no no no yes yes	See budworm comments for Penncap­M. Supracide is less toxic than Lannate.
Grasshoppers	malathion 5 Ib/gal EC acephate (Orthene 75SP) carbaryl (Sevin 10D,50W,4F) methyl parathion (Penncap­M)	low low low moderate	no no no yes	See budworm comments for Penncap­M.
Hornworms	Bac//lus thuring/ensis (Dipel, Javelin, Biobit) carbaryl (Sevin 80S,1OD,4F) acephate (Orthene 75SP) methidathion (Supracide 2EC) methomyl (Lannate90SP, 1.8L) methyl parathion (Penncap­M)	safe   low low moderate moderate moderate	no   no no no no yes	Lannate is hazardous when drift or spray reaches wildlife directly. See comments on Penncap­M under budworm.
Japanese beetles	carbaryl (Sevin)	low	no
Loopers	Bacillus thuringiensis (Dipel, Javelin, Biobit) acephate (Orthene 75SP) methomyl (Lannate 90SP 1.8L)	safe   low moderate	no   no no	See above for Lannate.
Slugs	metaldehyde + carbaryl bait hydrated lime	high low	no no	Birds may be killed in methaldehyde­treated areas.

aWildlife hazards:

high indicates possible wildlife deaths;
moderate indicates possible wildlife sickness, deaths less likely;
low indicates sickness unlikely.

bKills:

yes indicates wildlife deaths due to use of the insecticides (active ingredient) have been reported.
no indicates wilolife deaths have not been reported when pesticide is used according to label.

• Incorporate IPM practices into your tobacco production.
• Use proper cultural practices that help to reduce pesticide use.
• Use the pesticide least toxic to fish and wildlife to get the job done.
• Protect field borders and other noncrop habitats from herbicides and insecticides.
• Never spray leftover pesticides into wildlife habitats.
• Fully incorporate pesticide granules, especially spilled granules at the ends of rows.
• Minimize drift when applying chemicals around fish and wildlife habitats by using low­pressure sprays and selecting nozzles that produce large droplets.
• Protect fish ponds and wetlands by avoiding spraying over ponds or drainage ditches.
• Never wash equipment or containers where rinse water could enter ponds or streams.
• Read and follow the instructions on the pesticide label.

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