4-H CLUB INSECT MANUAL 31 
barns, outbuildings, and houses provide effective and lasting fly con- 
trol. Good sanitation is an important supplement to DDT sprays. 
Destroy breeding places and dispose of manure properly. 
Syrphid flies—Another family of flies that are quite often found 
hovering around flowers, or places where there is an abundance of 
plant lice, is the syrphid flies, of which there 
are a great many kinds. Although there is a 
wide variation in these insects, many have de- 
cided markings on the abdomen. The adults 
of this group have two wings and sucking 
mouth parts. These flies have complete life 
changes. Some larvae feed on aphids. One 
would need to examine but few colonies of 
plant lice before finding a very small, leg- 8 — a 
less, sluglike creature feeding on the lice. This 
is the larvae of the syrphus fly. These flies  rrevre 76—syrphus fly. 
remain over winter in the pupal stage among 
leaves on the ground or on stems of plants. Since they are bene- 
ficial, no control measures are necessary. The syrphus fly shown here 
is Syrphus ribesii, which varies from three-eighths 
4 to one-half inch in length. 
Blowflies.—During the summertime any meat or 
dead animal will draw a number of blowflies. The 
adults feed upon carrion and flowers, and the mag- 
gots of most species feed mainly on decaying meats. 
They overwinter in puparia in the soil. 
In general, blowflies are considered beneficial 
because the maggots destroy dead animal matter. 
If they become so abundant that they are a nuisance, 
the maggots may be controlled by burying or burn- 
ing the material in which they breed. Adult flies 
FiGuRE 77._Flesh fly, May be destroyed by sprays. 
Flesh flies are blowflies, but differ from the 
others in that the female gives birth to living maggots. Other blow- 
flies deposit eggs. The flesh flies are rather large and grayish in color 
with black stripes on their backs. Their abdomens are covered with 
hairs. The flesh fly here shown is Sarcophaga plinthopyga. 
Green-bottle and blue-bottle flies are blowflies | 
also. The bodies of these flies are metallic green or 
blue in color and shiny. ‘These flies are larger than 
houseflies. 
Larvae of one species of blowfly are called screw- 
worms. They infest wounds on animals and, by 
feeding on living tissue, cause suffering and great 
loss of livestock, mostly in the Southern States. 
Smear 62 (see item 131, p. 56) should be used to 
treat infested wounds and to protect against fur- — Fieckr 78.—Green- 
ther blowing by the flies. pee 
The green-bottle fly pictured here is Phaenicia sericata. ‘This species 
of fly is from one-fourth to three-fourths of an inch long. 
