Scientific Reports 
The Scientific Reports section of this and the next issue is devoted to host- 
vector systems involving hosts other than E. coli. In this issue there are 
reports on various Bacillus species and possible vectors. In addition the 
next issue will include reports on HV1 and HV2 systems in the yeast Sac- 
charomyces cerevisiae. At the time of this publication, there are no 
approved HV1 systemsthowever, HV1 and HV2 lower eukaryote and HV1 
Bacillus subtilis systems are presently being evaluated by NIH (see Issues 
Pending). 
Pathogenic Bacteria of Pest Insects 
as Host-Vector Systems 
Robert M, Faust, Ph.D. 
United States Department of Agriculture 
SEA, AR, NER 
Plant Protection Institute 
Insect Pathology Laboratory 
Agricultural Research Center 
Beltsville, Maryland 20705 
In the formulation of the new revised guidelines 
published in the Federal Register (December 
22,1978) attention was focused on bacteria which 
have the potential for pathogenicity to economic 
plants and animals. There are, of course, bacteria 
which are beneficial to man from an environmen¬ 
tal viewpoint. Among the “beneficial” bacteria are 
those which are pathogenic to specific pest insect 
species. Twenty years of research by scientists in 
the USDA, industry, and at the university level 
have concentrated on establishing the safety of 
some of these bacteria with regard to plants, ver¬ 
tebrates and non-target invertebrates. The safety 
tests were sufficiently convincing to the U.S. Envir¬ 
onmental Protection Agency (EPA) to permit their 
use as biological insecticides in both agricultural, 
community, and forest pest-management 
systems. 
Considering the importance these bacteria 
have assumed in terms of environmental improve¬ 
ment (i.e. by reducing dependence on non¬ 
specific chemical insecticides), the safety of 
these bacteria with regard to non-target orga¬ 
nisms, and the desirability of genetic engineering 
research to develop or more fully understand 
these biological insect control agents, this mate¬ 
rial is presented here to inform interested 
researchers and the Recombinant Advisory Com¬ 
mittee on the nature of these bacteria, document 
the safety of these bacteria as possible model 
host-vector systems for a variety of recombinant 
DNA studies and give rationale for their certifica¬ 
tion as hosts for HV-1 systems. 
1. The Nature of Entomopathogenic Bacteria 
The “beneficial” insect bacterial pathogens 
may be defined as those bacteria which are 
pathogenic to specific pest insects. Included in 
this group are the more than 20 varieties of Bacil¬ 
lus Ihuringiensis, B. popilliae, B. lentimorbus, B. 
euloomarahae, B. fribourgensis, B. sphaericus, B. 
morital, certain strains of B. cereus, Clostridium 
brevifaciens, and C. malacosomae. The first eight 
of these organisms are presently being used com¬ 
mercially or show the greatest potential for use. 
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