XIV , 2 Banks: Bloodsucking Insects of the Philippines 175 
mosquito, so-called from its habit of breeding in depressions 
in the bowlders of rocky streams where rain water collects. 
One mosquito, though formidable in appearance, is beneficial 
in habit ; this is the elephant mosquito, Worcesteria grata Banks,^® 
which feeds only on fruit juices in the adult stage and, as a 
larva, destroys large numbers of the larvae of noxious species. 
HORSEFLIES 
The horseflies are known wherever domestic or wild horses 
and cattle occur. They are fairly abundant in the Philippines 
and are of numerous species. At least one species, Tabanus 
striatus L., is abundant. Its life history is fully discussed by 
Mitzmain, who also gives an excellent account of the blood- 
sucking habits of the adult. 
These flies not only annoy domestic and wild animals, but 
they also attack human beings, especially children who may be 
asleep in the vicinity of cattle or horses. The species of the 
genus Chrysops, commonly known as deer flies, are annoying 
in the open forests of these Islands, and Tabanus striatus L. has 
been definitely proved to be a transmitter of surra. Four 
genera and ten species are recorded from the Philippines. 
MOTH FLIES 
The moth flies (Psychodidse) are extremely minute, woolly 
insects having the general appearance of tiny moths, due to 
the hairy covering of their wings, which are held out from the 
body at an angle of about 30 degrees. Few of these insects 
measure more than 2 millimeters in length and the average 
is about 1.5 millimeters. Most of the species found in the Phil- 
ippine Islands belong to the genus Psychoda, the members of 
which do not suck blood, but at least one is a species of the 
genus Phlebotomus. The common Filipino name for this fly is 
nicnic, and I have used this as the specific name for the 'species, 
which is described in the preceding paper. 
The nicnic is a very slender insect and does not exceed 2.2 
millimeters in length. Its head is bent downward, giving it 
the humpbacked appearance common in this and related flies. 
Its gray, shaggy aspect causes it to blend perfectly with the 
color of the skin. Even when the pain produced indicates that 
a nicnic is biting the hand or the arm, it is extremely difficult 
^''Philip. Journ. Sci., Sec. A (1908), 3, 435. 
Philip. Journ. Sci., Sec. B (1913), 8, 197, Pis. I to VII. 
“Ibid., 223. 
