360 
Journal of Agricultural Research 
Vol. IX, No. 10 
The first four of these species are parasites of the pupa. These species 
have other hosts besides P. gossypiella , and they play practically no 
r 61 e in the reduction of the species, since altogether they do not kill 
more than a fraction of i per cent. 
The last-named bethylid, Parisierola emigrata, is an external parasite 
of the full-grown larva. The female works her way either through the 
exit hole of the cotton worm or through the lint of the opened boll into 
the cell in which the larva is preparing to pupate. She jumps upon the 
larva and paralyzes it by inserting her sting into the nervous system of the 
caterpillar, usually just behind the last thoracic legs. When the parasite 
has assured itself by biting and pulling the body of the larva that the 
paralyzation is effective, it deposits its eggs. These are rather large, 
glassy white, and normally placed one on a segment, in two rows on the 
underside of the caterpillar. Four to six eggs are most commonly laid 
on one host larva, but as many as seventeen were laid in captivity, and 
repeatedly eight to twelve could be found in the field. These eggs hatch 
within 24 hours, and the parasitic larvae grow quickly and form a rosette 
on the shriveling body of the host. They become full grown in two or 
three days and then spin their cocoons near the host larva. The spinning 
of the cocoon occupies nearly two days, and before it is completed the 
larva voids a large fluid excrement through an opening left in the as-yet- 
unfinished cocoon. These excrements harden into a characteristic 
bifurcated black substance, which often serves to glue the cocoon to the 
supporting surface. 
When there have been many parasites (8 to 17) on a single caterpillar, 
their cocoons are flimsy and white; but, when only four to six parasites 
have found nourishment in a single larva, they average larger in size and 
their cocoons are more substantial and are brownish in color. 
The pupa of the parasite is at first white, with coral-red eyes, but it turns 
blackish within a few days. The parasite issues in from 10 to 15 days 
after the egg is laid. 
It may be mentioned that a very large percentage of these parasites are 
females, about 30 to 1 male, and that parthenogenesis was repeatedly 
observed—seemed in fact to be the normal condition. Four generations 
consisting exclusively of females were produced in one experiment from 
a single unfertilized- female. 1 
This bethylid was first recorded from Hawaii in 1912 and had been 
introduced only shortly before that time, probably from the United States. 
It is found rather commonly in all cotton fields on Oahu and in the Kona 
district,Hawaii, and it is the only parasite of P. gossypiella of any impor¬ 
tance at present in the Hawaiian Islands. It is by no means an 
effective check, however, and destroys only 1 to 4 per cent of the larvae. 
1 The life history of this species was published by the writer (40) and notes on the species by Fulla- 
way (29). 
