146 THE UNIVERSITY SCIENCE BULLETIN. 



food reaction Belostoma rests obliquely in the water. If hungry, they 

 respond to any impact in the water and will, on occasion, employ all 

 their limbs to hold some obstreperous prey. 



DESCRIPTION OF STAGES. 

 Egg Stage. 



Size. 2.66 mm. long; .9 mm. in widest diameter. 



Color. Silvery gray, the top appearing darker to the unaided eye, 

 and opaque white through the binocular. A brownish spot appears to 

 one side of the top. This is the micropylar area. An irregular tracery 

 of hexagonal figures can be discerned upon careful scrutiny. 



Shape. The general shape is best shown by the drawing on plate XVIL 

 It is an elongate cylindrical form, rounded on anterior end, more pointed 

 on posterior. The eggs and egg masses often appear grey and fuzzy, 

 due to colonies of Epistyllis and Vorticella. The pointed end of the egg 

 is set into a transparent gelatinous plate. This plate can be removed 

 from the bug, carrying all the eggs with it. It is pliable when fresh 

 and looks like a sheet of agar-agar. 



First Instar. 



Size. Total length, 4.6 mm.; greatest width across abdomen, 2.35 

 mm. The other measurements are shown in the chart with those of the 

 other instars below. 



Color. Dorsum: brown, thorax with a few lighter markings and ab- 

 domen decorated with light areas in 6 rows. The marginal spots large 

 and rectangular. There is a faint series of median dots on the abdo- 

 men, which is extended forward across the thorax and head as a slender 

 light line. 



Venter. Smoky brown, barred with pale yellow. The eyes dark red; 

 fore femora barred; fore tibise with 2 broad yellow bands. All the 

 femora bear 2 yellow bands and the remaining tibiae 2 yellow bands. 



Shape Much as in adult. Relative distance between the eyes greater. 



Structural Peculiarities. The tarsi are all 1-segmented and armed 

 with two claws each. Bueno says the antennae are short club-shaped, and 

 1-segmented, about 1% times as broad at the base as at the apex, and 

 twice as long as the greatest diameter. The ventral portion of the abdo- 

 men is densely clothed with minute hairs, the metasternal shield present 

 but not relatively as large as in the older forms. Spiracles evident, 

 caudal pair much larger and guarded by hairs in such a manner as to 

 provide a channel to margin of abdomen. 



Second Instar, 



Size. Length, 5.75 mm. to 7 mm.; width, 3.2. Other measurements 

 on chart. 



Color. The pattern about as in first instar, but general color much 

 lighter, the dark brovra of first instar being replaced by a lighter green- 

 ish brown, with the bars reaching the lateral margins more pronounced, 

 due to a darker smoky coloring. The ventral aspect much lighter than 

 in the first instar. 



