8 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1936 
THE IMNI.AI'W M MKUVIili, IN PUERTO U 
A survey of Puerto Blco showed that the pineapple mealyl ;i distrib- 
oted in varying over the Island od pineapple and 11 other host plants, 
mostly weeds and grasses in and near pineapple fields. The Are ant was found 
to be tiif mosl widely distributed of i I of ants seen attending the mealy- 
d pineapple plants. Pheidole megacepHakk P., the most abundant ant 
attending this species in Hawaii. was not found associated with it OU pineapple 
in Puerto Rico. 
JAPANESE AND ASIATIC BEETLES 
Population studies carried on in New Jersey and nearby State- indicated an 
increase of approximately 1,700 square miles in the area generally infested by 
the Japanese beetle at the close of 1935. The population in the older tni 
areas has continued to show more or less of a decrease. During the winter of 
1985-36 mortalities of 50 percent or more among larvae in the ground occurred in 
the area south of Philadelphia and in southern New Jersey. The lack of Snow 
COver and the presence of ice on the surface of the ground during the i>eriod 
of low temperatures seem to have been factors contributing to this unusual 
mortality. 
Many materials were tested in comparison with acid lead arsenate as stomach 
poisons "i- repellents for the Japanese beetle, including compound arsenal 
the alkali and alkaline earth metals, homologues of paris green, organic sulphur 
compounds, and other materials, but no outstanding substitute for add lead 
arsenate was found. The year's work further demonst rated that early ripening 
apples can be protected from beetle attack to a considerable extent by the use 
of a -pray of lime and aluminum sulphate, the residue remaining being nontoxic 
and readily removed. Protect ion of early ripening peaches was again obtained 
by applications of a repellent spray composed of derris and rosin-residue emul- 
sion, which leaves a nontoxic and inconspicuous residue. Control of the adults 
on asparagus brush was obtained with a spray consisting of lime, aluminum 
BUlphate, and sodium Lauryl sulphate, when it was applied frequently enough to 
keep the new growth covered. Cakes of pumice, clay, or porcelain were found 
to be satisfactory substitutes for bottle and wick for dispensing the geraniol bait 
in Japanese be. tie traps. 
A large number of organic and inorganic materials, including a numb- 
arsenicals, fluorine compounds, and such organic substances as pyrethrum, 
rotenone, and hellebore, were tested under laboratory conditions t<» determine 
their relative value as stomach poisons against third-instar larvae of the 
Japanese beetle, but no satisfactorj substitute for acid lead arsenate was found. 
A study of the effect Of arsenicals OD larvae in the soil showed that as soon as 
arsenic i- Ingested the larvae stop feeding and Lose weight. It was found that 
when applied as a top dressing lead arsenate was equally effective in protecting 
turf, whether applied as a spray or mixed with sand, tankage, or activated 
Sludge, but that when used with a complete fertilizer or uiven-sand marl the 
effectiveness of the treatment was decreased. 
The use of lead arsenate tor the control of Japanese beetle larvae in the 
Boil of Beedbeds in coniferous-tree nurseries did not prevent germination of the 
-ceil, hut in most cases it Interfered seriously with the growth of the seedlings, 
and it appears to be a questionable practice. Cultivators of the ordinary type 
were found to have relatively little value in reducing larva] populations wh< 
those of 'he rotary type were very much more effective for this purp< 
Paradichlorobeuzene was successfully used a- a tumigant tor destroying 
larvae about the roots of azaleas and certain other plants of the same type, ami 
this treatment has been approved as a method of meeting quarantine require- 
ments for these plants. 
Studies have been made of methods of applying lead arsenate to nurser; 
for the protection of growing nursery Btock. Hoeing out the soil between the 
plants previous t" treatment, then sweeping the soil back into the rows after 
hemical ha- been distributed, placed about two-third- of the poison in the 
rows about the plants. The most uniform distribution was obtained by applying 
the lead arsenate by means of a hand duster over all of the area t«» be treated. 
The several types of disease organisms found anion- Japanese beetle larvae 
in the soil have been classified into four general groups the black group and 
the while or "milky" group (both caused by bacteria of protozoal, the fungUS 
group, ami the nematode group. Particular attention has been given to the 
