THE HABITS OF MONODONTOMERUS. 97 



passage from the Proceedings of the Entomological Society*, printed in 1848, records the 

 exhibition, by myself, at that time, of specimens of the Imago insect, reared from the 

 larvse mentioned at p. 67, found on the 12th of September, 1847 : — " July 3rd, 1848. 

 Mr. Newport exhibited a new species of the genus Monodontomerus, belonging to the 

 family of the Chalcididce, reared from larvse which he had found in the nests of Antho- 

 phora retusa. He proposed for it the name of M. nitidus." 



Thus my recent observations on Monodontomerus in its natural haunts, supported by 

 further examination of the anatomy of its digestive organs (figs. 3 & 4), have fully 

 confirmed my former opinions as regards the nature of the larva, that it is an external 

 and not an internal feeding parasite, and that some remains of the destroyed bee-larva 

 are always found in the cell. They confirm too the observation that the bee-nymph 

 is preyed upon ; as well as that the larva of Monodontomerus is carnivorous ; but they do 

 not support the statement, and the inference to be deduced from it, that "not a vestige" 

 of the bee is left in the cell. Further, they give strength to the opinion I have advanced 

 respecting the mode and time of introduction of the eggs of the parasite ; viz. by perfora- 

 tion of the cell. The circumstance of the bee-nymph being preyed upon, as well as the 

 larva, goes far to establish this, as in each instance the parasites with the nymph were 

 scarcely more than one-half grown. This seems to show that they had been introduced 

 at the time of change, or at a very late period of the larva state. There seems reason 

 to believe also that the eggs are seldom conveyed into the cell until long after this has 

 been closed, and consequently when the bee-larva within has far advanced in growth, as 

 in no one instance could I discover a particle of the food of the larva. 



Being desirous, however, of ascertaining facts by direct observation, rather than of 

 arriving at views by inference, I placed, on the 17th of September, twenty of the most 

 healthy middle-sized specimens of the larval Monodontomeri with a single larva of Antho- 

 phora, in one division of a glass tube ; and twenty smaller specimens, with a nymph of 

 this bee, in another division of the same tube, separating the two sets with a piece of 

 sponge, and closing the tube with a cork. On the following day the parasites had arranged 

 themselves with their heads towards the body of the larva, but they did not appear to have 

 commenced their attack, probably from a cause which I shall presently mention. On the 

 next day, however, the third of inclusion in the tube, I saw one individual attack the 

 nymph, and in precisely the same way in which the larva of Paniscus attacks the caterpillar, 

 by piercing the skin, and imbibing the fluid as it transudes. On the 22nd of September, 

 the fifth day of inclusion, I was surprised to find that some of the specimens were changing 

 colour, and looking unhealthy, and that not one of them appeared to be feeding. On the 

 following day the whole Avere slightly discoloured ; and, on very close inspection, I then 

 first noticed that their bodies were covered with multitudes of little spherical bladder-like 

 objects, exactly similar, at first view, to microscopic drops of fluid transuded through 

 punctures in the skin. My hope to follow out a series of observations on these larvse was 

 now at an end, as it was evident to me that they were diseased and perishing. But I was 

 entirely at a loss to imagine the cause of this failure, as at the time the specimens were 

 collected, the whole were perfectly healthy and strong. On the 24th September they were 



* Trans. Entomological Society, vol. v. part 5, 1848, p. 42. 



