LIBRARY

DIPTERA 783
shortened; oval, cylindrical, pyriform, or nearly hemispherical; spiracles protruding
through the larval skin, sessile or on tubes, on segments IV and V; skin
ruptures dorsally to release the adult.
Members of this family are quite diverse in size, form, and habits. In size
the adults vary from the widely distributed lesser bulb fly, Eumeros strigatus
FIG. 288. Egg of the large syrphid fly among the exuvire or cast skins of aphids.
(From Insects of Western Nortit America.)
(Fallen), 4-6 mm. long, to the large black and whitish New Zealand Pilinasica
t£ngulata (Fab.) , 19 mm. long. Members of the genera Eristalis and Pocota
St. Farg. and Servo mimic honeybees; Cerioides Rand. and Syrphus, wasps;
and Merodon, bumblebees. The so-called Bugonia Myth of the ancients, the
belief that honeybees were spontaneously generated in carcasses of animals,
was held until only a generation ago when C. R. Osten Sacken showed that
the drone fly, Eristalis tenax (Linn.), and related species which resemble honeybees
were really the insects that developed in dead carcasses and filth.
The adults feed upon nectar in flowers and are responsible for much good in
cross-pollination of agricultural as well as wild plants. Others imbibe the sap of
trees and juices from decaying organic materials. The feeding habits of the
larVal are exceedingly varied, and the genera may be segregated into the following
groups according to the food of the maggots:
1. Saprophagous
1. Decaying vegetation - Tubifera Meig.,l Eumeros Meig.. Copestylum
Macq., Chrysoloxum Meig.
2. Liquid filth - Eristalis Latr.
1 The genus Tubi/era Meig. is used for Eumeros Meig. (Heliophilu$ Meig.) and for Erislalis
by some recent workers.