W. NOWKLL . r ). r ) 



larva is not attached to its host. The difference from Tiphia in these 

 points is no doubt correlated with the fact that the Ligyrus grub does 

 not recover its activity after being stung by Campsomeris, but remains 

 in a quiescent condition, making only slight movements of its logs when 

 disturbed. Since, as will be mentioned later, Phytalus is occasionally 

 successfully parasitized by this wasp, it appears likely that its sting has 

 the same effect on the larva of that insect. 



The development of the Campsomeris larva is very similar to that 

 of Tiphia. The history of the specimen above mentioned may be 

 continued as an example. The egg was laid during the night of the 

 13th or, more probably, early in the morning of the 14th of February. 

 The further observations made are summarised below: 



Grub with the newly deposited egg plaeed in insectary. 



Not hatched at 1 p.m. 



No observation. 



Egg found to be hatched when examined at 10 a.m. 



Parasite well grown ; host still shows faint movements. 



Parasite growing fast; host doubtfully alive. 



Host quite dead, skin half empty; parasite more than 



doubled in length since last observation. 

 „ 25 12 Skin empty except for earthy matter in alimentary 



canal. Parasite disengaged itself during day and 



began to spin up. 

 „ 26 13 Cocoon getting well into shape at 9 a.m. 



The actual date of emergence is not known. The cocoon was found 

 empty on April 15th, the wasp having escaped unnoticed. 



The duration of the egg stage was thus 3-4 days ; the host remained 

 alive 6-7 days after the parasite hatched ; spinning began on the 9th 

 day after hatching. The duration of the cocoon stage was not more 

 than 48 days, probably some days less. 



The cocoon of Campsomeris is* easily distinguishable from that of 

 Tiphia. The shape is cylindrical-oval. The outer envelope is not 

 loose and fluffy as in Tiphia, but has a consistency like that of loose- 

 textured tissue paper. It encloses the inner envelope somewhat 

 slackly. The method of emergence is also different: the wasp cuts 

 round the cocoon near one end and pushes to one side the neat cap thus 

 formed. 



Campsomeris is by far the most common of the flower-visiting 

 Hymenoptera in Barbados, but although it is very plentiful the per- 

 centage of Ligyrus parasitized at Spencers has not been found to be 

 large in the situations explored. Pond mud, of close texture and very 



