I’SYCHE 
HIOLOCK'AI. NOTES ON 'HIE ('0[.0RA1)0 POTATO BEETLE, LEI'- 
TIXOT.UhSA DKriCMLINKATA (SAY), WI'l'H 'rECIINirAL 
DESCRIPTION OE ITS STALES. 
«Y A. A. GIHAULT AM) A. II. KO.SENKEI.I). 
Duhing IIk' .sprinjj and .sninmor of P.KKl it became coiivenieTil to make a I)ri<’f 
study of tliLs insect, more in reference to the biological aspects of its life than other- 
wise. 'J’here .seem to be but few records in onr literature concerning the duration 
of its different stages, especially in the southern United States. The following facts 
are therefore pre.sented for publication without further comment. 'Phe ob.s('rvations 
were made at Myrtle, (!a., about 32 degrees, 30 minutes north latitude. 
The Egg. 
De-icripfion . — Length, 1.70- 1..S0 mm.; 1.7.5 mm., average. Width, 0..S0 mm., 
average, greatest diameter. Body uniformly bright orange, opaipie, the ends paler, 
yellowish, and translucent. .Sha])e elongate oval, the outline slightly irregular, and 
the caudal end or base, and the ape.x, regularly rounded. Surface .simple, glabrous, 
a])|)arently very minutely ])unctidate, with a moist ap])earance. iNIicropyle .simple, 
inconspicuous. Chorion soft, easily crushed, and more or le.ss elastic. To the 
naked eye, con.spicuous. 
Deposited erect, in small irregular mas.ses of 20 or 30, more or le.ss, generally 
on the under surfaces of the leaves. Caudal end held by a small orange pad of 
adhesive matter. (From many specimens.) 
E.rtmm! Dcvclopmrnt . — The egg shows no sign of embryonic development 
externally until about the twelfth hour before hatching, when the [lerfeet embryo 
is visible, together with all of tlu- markings of the first larval instar at eclosion. 'Phe 
ocellar spots are in a rectangle at the anterior end of the egg, and the larger lateral 
tubercle areae and .s])iraeles are distinctly visible on the sides. 'Phe setae are visible 
as blackish .streaks along the sides in nearly regular rows. 'Phe disposition of the 
ap|)endages is not distinct. The markings are more distinct as the egg approaches 
the time of hatching. 
Duration of Starp ’. — In all the period of incubation for five hundred eggs has 
been determined to the hour, as accurately as possible under laboratory conditions. 
