i2 4 WASP STUDIES AFIELD 



the specimens taken from the Marquesas Islands are iden- 

 tical with others which he has from the Sandwich Islands. 

 Ashmead finds this species parasitized by two species of 

 cuckoo-bees, Chrysis coerulans Fabr., and C. perpnlchra Cr. 

 Robertson 9 and Cockerell 10 have written on its flower-fre- 

 quenting habits. C. H. Turner 11 has gathered some very 

 interesting experimental data on the homing habits of this 

 species. 



Chalybion caeruleum Linne. 



While breaking open the mud nests of these wasps at 

 9 p. m. on July 21, we were startled by a buzz. We traced 

 the noise to our very finger-tips, and there in one of the cells 

 we spied the insect's jaws protruding from the pupal sack; 

 the young wasp was furiously biting an opening and all the 

 while spitting much saliva about the point of attack. In 

 less than five minutes the new fledgling was free and flying 

 about the room in circles. We wonder if they sometimes 

 normally emerge at night, or whether our rough handling 

 caused the wasp to make its exit at this unexpected hour. 

 It would be interesting to know, too, if the abundant saliva 

 is of use in breaking down the heavy mud seal of the nest. 



Howard, in the Insect Book, records the observation of 

 Schwarz. He found C. caeruleum "was engaged in captur- 

 ing a certain kind of spider which hid itself so carefully that 

 it was most difficult to find. Instead of spending the time in 

 fruitless searching, the wasp would entangle herself in the 

 web of the spider, when the latter would immediately dart 

 out from her hiding-place, thus exposing herself to the 



9 Trans. Acad. Sci. St. Louis 6: 453. 1894. 



"Nature 48: 438. 1893. 



11 Biol. Bull. 15: 215-222. 1908. 



