Common Insects — Grasshopper aiid Honeybee 405 



A minute drop of poison from the sting helps to preserve the honey. An 

 average colony of bees in an average season may collect about forty 

 pounds of honey. 



Pollen is rich in protein which honey lacks, so pollen {''bee bread'') is 

 essential in the diet of bees. The pollen collected in the pollen basket 

 is placed in certain "cells" of the honeycomb. "Bee-glue" or propolis 

 (Gr. pro, for; polis, city) is a resin collected from plants and is used in 

 filling cracks, cementing loose parts, etc. Various types of cells con- 

 stitute the honeycomb (Fig. 196). 



Circulation. — A long, delicate, tubular, muscular heart in the mid- 

 dorsal region of the body discharges the colorless blood toward the head 

 region. Blood enters the heart through five pairs of ostia, each pair lead- 

 ing into a chamber of the heart. Valves prevent the backflow into the 

 body during contraction. Blood discharges at the head region and passes 

 through the hemocoel (body-circulatory cavity). From the latter it 

 reenters the heart chambers. The blood plasma contains white blood 

 corpuscles. 



Respiration. — Respiration occurs through pairs of very small spiracles 

 located along the sides of the thorax and abdomen and leading into a 

 branched system of tracheae to convey air to all body parts. Certain, 

 trachea may possess enlarged air sacs. 



Excretion. — Numerous, hollow, glandular, threadlike Malpighian tu- 

 bules excrete wastes into the intestine much in the same manner as in 

 grasshoppers. 



Coordination and Sensory Equipment. — A large "brain (supraesopha- 

 geal ganglion) in the dorsal part of the head supplies nerves to the eyes, 

 antennae, etc. The brain is connected by a riiig (nerves) to the sub- 

 esophageal ganglion which supplies nerves to the mouth parts. A ventral 

 nerve chain extends posteriorly from the subesophageal ganglion along 

 the midventral side of the body. The chain is a double nerve strand and 

 connects with two thoracic ganglia and five abdominal ganglia (Fig. 

 199,2)). 



The hairlike end organs of the sense of touch (tactile) are present on 

 various body parts but are particularly numerous on the tip of the an- 

 tennae. The pair of jointed, hairy antennae have numerous, sound-sen- 

 sitive pits which are thought to be for auditory purposes. Other pits 

 on the antennae are thought to be for olfactory purposes. Bees seem 

 to use the scent-detecting mechanism for discovering food and for mat- 

 ing between drone and queen. A worker bee is able to transmit to the 



