64 PLANT-BUGS INJURIOUS TO COTTON BOLLS. 
the total of over 1,200 eggs collected in the field. Of 156 eggs, rep- 
resenting the five batches collected in the field from which no par- 
asites were reared, only 1 egg failed to hatch. It has been stated that 
in the laboratory all but about 7 per cent of fertile eggs hatched. 
Even allowing for eggs destroyed by predaceous insects and the small 
percentage which normally fails to hatch, it is evident that the total 
percentage of conchuela eggs destroyed by Proctotrypid parasites is 
from 15 to 25 per cent above the percentage shown in the table from 
which parasites actually matured and emerged. 
Parasites Attacking Adults and Nymphs. 
The only parasite of the conchuela attacking the adults and nymphs 
which has come under the writer's observation, is the Tachinid fly 
Gymnosoma fuliginosa Desv. (PI. Ill, figs. 9, 10). The female of this 
species deposits her eggs on the adults and nymphs in the fifth 
nymphal instar, usually near the margin, on the anterior half of 
the body (PL III, fig. 9) . So far as observed, the percentage of these 
bugs which are parasitized by this fly is not large. Observations at 
Tlahualilo, Mexico, and at Barstow, Tex., in 1905, indicated that it 
was never more than 5 per cent. Under favorable conditions these 
Tachinid flies might attain a high degree of usefulness, but it is prob- 
able that they seldom exert much influence toward the reduction of 
the numbers of the conchuela and other Pentatomid pests. 
Predatory Enemies, 
invertebrates. 
No one of the invertebrate enemies of the conchuela or of other 
Pentatomids has, in the writer's experience, shown itself to be of any 
great importance. Taken together, however, they form a group 
entitled to consideration. 
Attacking eggs. — Nymphs of other species of Pentatomids as well 
as of the conchuela itself may destroy eggs in the field. The only 
species observed actually engaged in feeding on unhatched eggs of the 
conchuela is Thyanta custator Fab., the specimens being in the fifth 
instar. The well-known predaceous Anthocorid, TripMeps insidiosus 
Say, doubtless is as fond of the eggs of Pentatomids as of the eggs 
of other insects. The same may be said of the larvse of various species 
of Chrysopa, although specific observations have not been recorded 
in either case. It is not uncommon to find the remains of eggs of 
the conchuela which have the almost unmistakable appearance of 
having been destroyed by predatory insects provided with mandibles. 
Entire batches consisting of as many as 14 eggs have been found in 
this condition with the circumstances indicating that a single insect 
had been responsible for the destruction of each batch. It is probable 
