There are very few chemicals that have the qualifications of a good soil 

 poison, which are, primarily, permanency an^l minimum toxicity to plants 

 and animals. The opportunities for improved termite control opened up by 

 the development of new insecticides and equipment now require considerable 

 research to evaluate and adapt them to practical use as soil poisons, wood 

 impregnants, and surface treatments* 



Nonsubterranean termites are more important as wood destroyers in certain 

 localities than are the subterranean species. Further, they present a 

 greater problem because of the greater difficulty of control, 



Tliese termites are widely distributed over the Vforld, reaching their opti- 

 mum development in semi-tropical and tropical climates. In this country 

 they are confined to the extreme southern region — in fact, to a narrow -t 

 strip near the coast, from Virginia around to northern California, They 

 are particularly severe in southern Florida and on the Florida Keys, and, 

 to a slightly lesser extent, in southern California. 



As their name implies, nonsubterranean termdtes, which include drywood, 

 damp-wood, and rotten-wood species, have no contact with soil but rather 

 attack v;ood directly. It is for this reason that they are, in a sense, more 

 difficult to combat than the subterranean forms. There is little evidence 

 of attack until damage occurs. There are no conspicuous colonizing flights, 

 such as in the subterranean group, to indicate the presence of an infesta- 

 tion. However, such flights are made, and during the flights males and 

 females shed their wings, pair off, and bore into the wood, sealing the 

 entrance with a plug. Tunneling of the wood is begun immediately and in- 

 creases in intensity as the colony grows. There are only tv;o castes 

 represented — the reproductives and the soldiers. /hile colonies are small 

 compared to the subterranean species, considerable destruction is caused 

 by the species before evidence of activity appears. One of the best signs 

 of damage is the tiny pellets of partly digested food that the termites 

 expel from their galleries. This may be of little value as an indicator, 

 however, if the infestation is in inaccessible places. 



This group of insects, particularly the dry-wood termite, is probably best 

 knoTfm'for its damage to furniture, although; any cellulose material may be 

 attacked, including woodvrork of buildings, transmission line poles, lumber, 

 paper, cloth, insulation board, etc. The problem is most severe in the 

 Tropics— in Key West, Cuba, Puerto Rico, Panama, and Hawaii. Dry-wood 

 termites are the No. 1 problem in wood deterioration in these areas. 



Various methods of control have been tried for many years, ranging from 

 the injection of insecticides into furniture vath a hypodermic needle to^ 

 the enclosing and fumigating of an entire building and its cont ents within 

 a tent. Use of fine screen has been recommended to prevent entry of termites 

 into buildings, and the application of heavy coats of paint has been employed 

 to deter outside attack. Inorganic stomach poisons or contact insecticides, 

 principally dusts, have been largely used for controlling infestations. 

 These measures have been effective only to a lirited extent, have been of 



