SECRETARY'S REPORT. 177 



different wings. This section comprises the " boat-men " 

 " water-skaters " and many otlier aquatic species, all insectiv- 

 orous, the Reduviid(c of Stephens, and other terrestrial groups, 

 containing some of the most useful destroyers of insects, and a 

 number of families almost exclusively herbivorous, and among 

 the enemies of mankind, such as the bed-bug, squash-bug, 

 plant-bugs of various kinds found on fruit and generally of an 

 offensive smell and taste. The other sub-order Homoplera 

 from the Greek meaning similar wings contains the vegetable- 

 devouring species such as the Aphides, the vine and tree-hoppers, 

 the harvest-flies, and the scale-insects or coccidce all of which 

 subsist by sucking the sap of various plants, and are of great 

 damage to agriculture. Many of the scale-insects, however, 

 furnish mankind with substances of infinite value in the arts. 

 The lac so extensively used throughout the world in the manu- 

 facture of varnishes, sealing wax, &c., is produced by the 

 punctures of the Coccus ficus of Fabricius ; the manna, which 

 according to ancient history preserved the children of Irsael 

 from starvation, and is used in the East to the present day as 

 an article of food, is the production of another species of this 

 wonderful family ; and the Mexican Coccus cacti furnishes the 

 invaluable red coloring-matter known by the name of cochineal. 

 The most prominent of the Heterdplera that are found in 

 this State, feeding upon other insects are the following : the 

 Noloneclidce, from the Greek, meaning back-swimmers, and 

 often called boatmen, these are seen just beneath the surface of 

 any still pool resting with the long hind-feet at right angles 

 with the body, the tip of which just reaches the surface, while 

 the head and body hang at an angle of several degrees. When 

 disturbed they ply their oar-like feet with great rapidity steering 

 for the bottom of the pool, but soon return to the top and keep 

 watch for any unfortunate insect that may fall into the water, 

 or the water-inhabiting species that are weaker and less active 

 than itself. Figure 50 represents a species common in 

 this State called Notontcta unduldta by Say, or the 

 wavy boat-man. It is of a greenish white color above, 

 with a black scutel, the anterior part of which seen 

 beneath the semi-transparent thorax, tinges it with dusky 

 or blackish ; the hemelytra or wing-covers are marked 

 with brownish spots or streaks, those behind the middle *"'«• so. 



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