Materials highly toxic to bees.

Materials that kill bees not only at the time of application but may kill those that visit the field for several days after treatment. (If these materials are used, the bees should be removed from the area.) The group includes such materials as arsenicals, aldrin, BHC, chlordane, Diazinon, Dibrom, dieldrin, Dimethoate, EPN, Guthion, heptachlor, lindane, Metacide, methyl parathion, parathion, Phosphamidon, and Sevin.

Materials that kill bees primarily on contact. (These materials should not be applied when bees are visiting the field.) This group includes malathion, Phosdrin, sabadilla, and TEPP.

Materials moderately toxic to bees. (These materials may be used with limited damage to bees if applied during the hours bees are not visiting the field.) This group includes cryolite, DDT, endrin, isodrin, Perthane, tartar emetic, TDE, Tedion, Thiodan, toxaphene, and Trithion.

Relatively nontoxic materials. (These materials have no effect on bees, or kill only on direct contact. With normal precautions they can be used at any time without serious damage to bees.) This group includes fungicides, hormone weed sprays, defoliants, allethrin, Aramite, chlorbenside, Delnav, demeton, Dilan, Dipterex, ethion, methoxychlor, Neotran, nicotine, ovex, Phostex, pyrethrum, rotenone, ryania, schradan, silica gel-78, sulfur, and Sulphenone.

With such an array from which he may choose, the grower can usually select a material that is safe for bees. If he needs one of the more toxic materials to control certain pests, he can take the proper precautions to prevent damage to his pollinators.

In general, this relative toxicity of pesticides to honey bees probably applies equally to native (wild or solitary) bee pollinators. For example, alkali bees (Nomia) are highly susceptible to parathion but not to toxaphene. Our knowledge of native bees is limited, but the indications are that any protection given to honey bees would tend also to protect them.

We know of no practical way to repel bees from an area to be treated. If a. material could be found that would "black out" the area for bees during the danger period, serious loss to the bees might be prevented.

Likewise, no attractant has been found to lure the bees into an area where their pollination services are desired or to pull them away from treated areas.

The development of either a repellant or an attractant, or both, would be of value in reducing losses of bees by insecticides.

SEVERAL STATES have attempted to solve the problem of bee poisoning through legislation.

California, with its broad interests in seed production and fruit growing, makes special endeavors to protect bees through local enforcement of agricultural laws. Pest control operators are required to obtain permits and to operate under strict conditions set up by county agricultural commissioners. This close supervision, which covers both time of application and materials applied, has reduced poisoning of bees in the State.

Despite such precautions, damage to colonies still occurs. For example, the pesticide may drift from an unattractive field onto one attractive to bees or even into the apiary itself and cause damage. Such damage may occur from simultaneous applications of materials to more than one field.

The extent of the loss may depend on the time it occurs. The colony may lose its field force at the end of the flowering season, with no economic loss to the beekeeper. The same number of bees lost earlier in the season could render the colony valueless to both grower and beekeeper for the remainder of the year. Both the source and the extent of damage therefore usually are difficult or impossible to establish legally.

Contracts between the seedgrower and the beekeeper who provides pollination service should (and usually do) contain clauses concerning the use of insecticides. They define what insecticides may be used, how they may be applied, and provide for financing of the moving of bees if highly toxic materials must be applied.

A community approach to the problem has many advantages, particularly in concentrated seed-growing sections where bees are an economic necessity. As bees cannot be confined to a particular crop or field, the improper use of insecticides can reduce production of neighbor seedgrowers. Community education can be undertaken to focus attention on the problem. If the area is of sufficient size, an entomologist may be employed to supervise pest control with due regard to the protection of pollinators. Where large ranches are engaged in seed growing, the protection of pollinators often is handled in this way.

Education and cooperation offer the best solution to the protection of pollinators. Seedgrowers do not intentionally kill their pollinators, but the pertinent points may not be widely understood.

They are:

Choose the material least harmful to bees.

Make applications during the hours bees are not visiting the field.

Avoid making applications directly over colonies.

Consider all hives within one-half mile of the field.

When highly toxic materials are used, remove colonies from the area before the application is made.

When these essentials are followed, the "miniature airport," the beehive, usually hums with activity, and the prospects are brighter for a good harvest by both the seedgrower and the beekeeper.

FRANK E. TODD became Head of the Bee Culture Laboratory, Tucson, Ariz., in 1950. He joined the Department of Agriculture in 1931 to do research on honey bees. He served successively as the Senior Apiculturist and Assistant Division Leader at Beltsville and Head of the Legume Seed Research Laboratory at Logan, Utah.

S. E. McGREGOR entered the service of the Department of Agriculture in 1936 at Baton Rouge, La., where he did research on bees. Later he worked in Arkansas, Wisconsin, and Texas before he joined the Bee Culture Laboratory in Tucson.