Evening star., 1954-10-15
Scouts With Lures
Of Light Fight Bugs
Traps Detect Presence and
Number Of Crop Pests
By Thomos z. Henry


Robot scouts with lures Of invisible
light now are on the front line Of the
Nations endless war against bug In.
vaders.
They are light traps which are able
to detect the presence and approxi-
mate numbers Of crop pests long be-
fore the start of their seasons Of de-
structiveness. About so are being used
experimentally in all parts of the
country by Agriculture Department
entomologists. The light is used on
the edge of the completely invisible
ultraviolet which, for unknown reas-
ons, seems particularly attractive to
many night flyers. It Is almost un-
detachable to the human eye.
These light traps were used in South
ern States early this season. Early in
February, for example, they detected
the presence of moths Of cutworms
and army worms in destructive abund-
ance in Louisiana. Three weeks later
a moderately heavy infestation Of these
insects was detected in wheat and oats.
Shortly afterwards the light traps
cotton bollworm.
Others Taken.
Further northward the first army
worm moths were taken in Tennessee
yellow striped army worms, seed corn
beetles and. seed corn maggot flies
followed. BY mid-April. due to the
early warning, control measures were
in readiness for a fairly serious IN
festation Of army worms.
During April the light traps picked
UP tobacco moths and sugar cane
beetles in Louisiana. Early in May
army worm moths were captured in
Iowa, indicating serious infestation
later in the season, and moths Of cut
worms and army worms were found in
Kentucky, Missouri, South Carolina
and Pennsylvania.
These robot scouts were made pos
sible by the development of the fluores-
cent lamp. In such lamps the charac-
ter of the light can be controlled by
coating the inner surface Of the glass
tube with various phosphorescent ma
terials. Thus it can be made to provide
the radiation in the ultraviolet range
which is most attractive to the in
vading insects.
A strange little ocean "bug" which
always is born male and dies female
and which has been lost to science for
25 years has just been rediscovered
by biologists of the Scripps Institution
of Oceanography of La Jolla, Calf.
This creature, Liveneca convexa, Is
closely related to the pill bug and SOW
bug found on land.
It is a multi-legged animal which
reaches maximum length of hall
inch and spends all its adult life in the
gills and mouths of fish.
200 More Found.
The only known specimen in th'
world up to now was collected in thu
Gulf of Panama in 1885 and placed II
the geological collection of the Uni
versity of Pennsylvania. Now more
than 200 specimens have been foune
by California tuna fishermen, mostly
in one species of tuna, and identified
by the Scripps Institution scientists.
The bug is born and develops to ma
turity as a male. During this stage i
is true fish parasite. living in the gil
chamber of the fish host and otter
causing serious damage 10 Cne Tissue
Then it becomes quite abruptly &
female, apparently due to the action Of
some hormone, or powerful biological
chemical. This hormone presumably il
present from birth but, like time
bomb. is set to go into action only al
a certain time. In all kinds of animals
and plants sex is determined largely by
such hormones which usually function
from the start.
After changing sex the bug migrate
to the mouth of the fish and ceases tt
be real parasite. Apparently it live
on the food which the fish ingests from
the water and does no further damag'
to the host. The largest females, th'
Scripps scientists report, are found IL
the largest fish.
Studies of these little bugs are o
particular interest to biologists, accord
ing to the Institutions report, becaus
of the light they throw on the evolu
ton of several families of similar ami
mails. Specimens of both males ant
females have been deposited with tn
Smithsonian Institution.