96 Predaceous Insects and their Prey. 
Prey of a BemBex Wasp. 
Illustrative of the remarkable voracity of a species of Bembea wasp, 
a series of sixteen examples and their prey (Diptera) is of interest 
and some biological value. They were collected in two days, with the 
help of two or three natives, by Mr. J. D. Casey at Lit: wandié Drift, 
Shire River, between Zomba and Fort Johnstone, Nyasaland. 
Eleven of the victims are Asilide of seven distinct species, gradu- 
ating in size from large to small. The two largest, a male and female 
of the same species are as robust and considerably longer than the 
Bembex. Three are flies of the genus Tabanus, and the two last 
are Glossina morsitans, Westw. (Tsetse fly) and Sarcophaga hemorr- 
hoidalis, Mg. (Tachinide). 
It will be noted that the majority of the prey are Asilide, them- 
selves the most voracious of flies, many of them even preying on 
Sphegid wasps or bees (instances being included in the table above). 
The Bembevidee, unlike the majority of the Sphegide, feed their larvee 
on fresh food daily, instead of storing up live insects stung into a 
comatose state upon which to deposit their eggs. Their hunting is, 
therefore, kept up for a much longer period and the open sand banks 
in which they nest afford good opportunities for observation. 
Though not strictly applicable to the subject, the aggressors being 
web-less spiders, I am adding the two following occurrences as 
interesting. Many butterflies also fall victims to spiders of the active 
running types as well as to those that snare their prey in webs. 
LOCALITY 
LLECTOR. 
AND DATE. Co 
CAPTOR. PREY. 
White hairless Spider, on|Acridian: Zonocerus elegans| Springvale, |E. E. Platt 
a sugar-bush. Prey Thunb. nr. Durban, 
held firmly by head 14 iv. 18 
and thorax, dead 
but quite fresh. 
Yellow Spider, smaller|Syrphus fly _... ...| Durban, |C. N. Barker 
than above, but pro- 20 iv. 18 
bably of same genus. 
JOHN SINGLETON & SONS, PRINTERS, DURBAN, 
