BEHAVIOR OF SPIDERS AND OTHER INSECTS 389 



fleas prefer, as food, dust from the room and dried insect skins 

 to dry blood. 



It is well known that crab-spiders (Thomisidae) frequent 

 flowers for the purpose of preying on insects. Lovell (79) dis- 

 covers that they feed on bumble-bees, honey-bees, butterflies, 

 dragon-flies, large flies and wasps. 



Rau (100) finds that both the larva and adult of the meal- 

 worm eat feathers, seed and dead insects. 



Zetek (130) states that the mosquitoes Anopheles albimanus 

 Wied. and A. tarsimaculata Goledi prefer human blood to any 

 other food. 



According to Essenberg (34) the water-striders feed upon a 

 large variety of animal food, most of which is captured upon 

 the surface of the water. Food is never secured under water 

 and the insect will not touch larval mosquitoes. They often rest 

 quietly upon aquatic plants and catch mosquitoes by leaping 

 upon them. In confinement they are cannibals. 



Turner (119) finds that the ant-lion feeds upon a variety of 

 small invertebrates that happen to fall into the pits which it 

 forms in any kind of friable material that is protected from the 

 rain. Two methods are used by the ant-lions in forming these 

 pits. " Usually it furrows backward, excavating a series of 

 concentric, adjacent, circles, each deeper than the last, and 

 shovelling out the soil with its head. The front of the body is 

 so curved as to make it easy for the dirt to fall forward on the 

 head. In the second method, the larva simply burrows down- 

 ward into the ground and tosses out the soil with its head until 

 the sides of the pit become stable. Pits formed by the second 

 method are usually subsequently enlarged. He confirms the 

 often discredited statement of early investigators that this insect 

 removes obstacles from the pit by backing up the side thereof 

 with the object balanced on its abdomen. 



Lloyd (77) describes a species of caddis worm (Ganonema 

 nigrum) which in its habits is unlike all others except a New 

 Zealand species (Triplectides obsoleta) described by Hudson in 

 1904. Instead of constructing the orthodox dwelling of con- 

 glomerated stones or twigs or tubes of silk, it selects a short twig 

 from the stream bottom, hollows it from end to end, and lines 

 the cavity with silk. When this tube becomes too short, the 

 insect glues it, end to end, to another twig and treats the addition 



