312 
bulletin of the bureau of fisheries. 
stead of standing out rigidly. The anterior margin of the prothorax is not reentrant but is cut squarely 
across. The head is shorter, and the eyes are in front of the center, the anterior ones being opposite 
the bases of the antennae. The antennae and mouth parts are much the same as in the preceding species, 
but the left mandible instead of having three teeth covered with processes has one large tooth with a row 
of processes around its broad tip. A deep groove extends along the inner margin of the mandible from 
this process to the base, and from the bottom of the groove project a row of irregular and unequal teeth. 
The inner margin in front of the groove is also irregular. 
Description of the pupa . — The pupa is similar to that of striatus and is armed with the same jointed 
styli, but the body is much narrowed and shortened posteriorly and is greener in color. The elytra, 
wings, and legs are lengthened, the tips of the wings reaching the anterior margin of the penultimate 
abdomen segment and the tips of the third legs projecting beyond the basal joint of the cerci. The 
latter are much longer, and their terminal portion is more distinctly moniliform. The head is considera- 
bly longer and narrower, and the maxillary palps project backwards to the bases of the third legs. 
Description of the adult . — This beetle is the same size as the preceding species. The thorax has 
two black spots instead of the semilunar lines of striatus, and each elytron has 10 distinct black spots — 
2 near the base, 4 in an irregular transverse line in front of the center, 3 in another irregular line behind 
the center, and 1 near the tip. The basal joint of the antenna is shorter and more strongly curved, 
and the second joint lacks the spine at its tip. The labium is longer and narrower, and the labial palps 
are not as heavily armed with setae. This species is more restricted than the preceding in its distribu- 
tion among the fishponds, but wherever it is found it furnishes excellent fish food. 
Berosus peregrinus Herbst. 
Berosus peregrinus (Herbst, 1797, p. 314). 
Berosus peregrinus (Richmond, 1920, p. 48; pi. 10). 
A life history of this species, lacking the pupal stage, was given by Richmond, 
and from it the following abstract has been condensed. 
Egg case.— Chestnut-shaped, cap end flat, cap continuous with a long narrow ribbon, the opposite 
end rounded. Length of case 0.32 mm. ; width 1.20 mm. ; height 1.60 mm. Length of ribbon 4.50 mm. 
Each case contained from 2 to 4 eggs which hatched in 6 to 8 days. 
Description of the larva . — General form similar to that of striatus, but the head and prothorax are 
relatively much wider. Total length 5.60 mm.; greatest width (second abdominal segment) 1.68 mm. 
Head ovate, a little wider than long; antennae nearer the lateral margins than in the two preceding 
species; ocular areas circular and close behind the bases of the antennae. Prothorax the same width and 
length as the head, meso and meta thorax slightly widened; body broadest through the second abdominal 
segment, then rapidly narrowed. The lateral gills are as short as those of striatus, are much more slender, 
and are trailed alongside the body like those of pcmtherinus. Color a uniform yellowish- white, the 
chi tin areas yellowish-brown. 
The mandibles are asymmetrical and resemble more closely those of striatus-, the left one has three 
larger teeth on the inner margin, covered with smaller ones. The basal joint of the maxilla is not as 
long as in the other species and is armed along its inner margin with a row of five stout setae. The labium 
is small, with two-jointed palps, each tipped with five short setae and one long one. 
Description of the pupa.— Schi0dte (1872) stated the distinguishing characters of this pupa as follows : 
Motory styli of abdominal tergites in fours; abdominal tergites with a small lateral tubercle on either side; spiracles not con- 
cealed; abdominal pleurites not distinctly separated from the tergites; styli of pleurites very short and conical; lateral styli of 
abdominal tergites very long and slender; prothoraeic styli also long and slender; cerci elongate, tapering, crooked and distally 
moniliform. 
His figure showed 26 pronotal styli instead of the 24 found in the two preceding species. 
Description of the adult .— This species is the same size as the other two. It is distinguished from 
striatus by the facts that the second, third, and fourth abdominal segments in the male have a slight 
longitudinal keel and that there is only one tooth instead of two in the middle of the notch on the fifth 
segment of the abdomen. It is distinguished from pantherinus by the fact that the spots on the elytra 
are very indistinct and are more or less fused in couples. 
It is much less abundant in the fishponds than the other two species, and only a few specimens 
were obtained, but both the larvae and the adults furnish good fish food without being at all destructive. 
