388 BULLETIN 416, U. S. DEPARTMENT OF AGRICULTURE. 
probable that the daily average of No. 2 (Table VII), which was over 
35 eggs per day, represents the normal capacity of the species. 
TaBLe VII.—Red spiders consumed by Scolothrips sermaculatus, Batesburg, S. C. 
Consumption. | 
Individ- | Feeding 
ual No. days. Active | Eggsand 
Eggs. | individ- | activein-| Average 
uals. dividuals. per day. 
v 
1 1 7 DS ik Rt (ip se UR eee 
2 | 2 Wb teow eps Ue 4.5 
2} hey £7) (og ae ee eee ee ice ae 
794) OF Nes eos S22 See ee ees Sete 
3 [bd Aes eee ae ce retteeeeee 
a Ta aoe oe aS be eee ats aes |) 55-5 BIS Te 
15 Teen ee 176 | 35.4 
3 and 4 1 8 1 90) 9.0 
| i 35h Lea Son eee 
6 1 4 | a 8 8.0 
Total 6 | 10 232 | 5 PANE Ny apa | 
| 
1 This was first adult day. 2 Average. 
Moulton, the first investigator to establish that thrips in general 
are preyed upon by the insidious bug, states that Triphleps insidiosus 
is the most serious enemy of thrips. Quaintance also states that 
thrips, in addition to being attacked by the insidious bug, are para- 
sitized by nematode worms. At Batesburg we find that 7. insidi- 
osus is very often present with Scolothrips and other thrips, and that 
it commonly feeds upon Scolothrips in the absence of more desirable 
food. The time required by Triphleps adults to drain a thrips aver- 
ages about 24 minutes. A half-grown chrysopid larva was observed 
to grasp and drain a nymphal thrips in 1 minute 35 seconds, and 
immediately seized other thrips, repeating the operation. 
Euthrips fuscus Hinds.—This thysanopteron, while frequently col- 
lected in red-spider colonies, has not been observed in the act of 
devouring red spiders; but our observations and those of other 
workers indicate that this species is also an occasional enemy of the 
mites. 
Euthrips occidentalis Perg.—This species has also been seen from 
time to time in red-spider colonies. The evidence concerning it is 
not absolute, but it is believed to be, like the two foregoing thrips, a 
predatory species. 
HEMIPTERA. 
ANTHOCORIDAE. 
Triphlepsinsidiosus Say .—This predacious bug (fig. 10) seems to have 
been first recorded as a natural enemy of the red spider by the senior 
author in an earlier (1912) circular. Since then it has been recorded 
as predatory on the common red spider by Quayle (1913) and Ewing 
