250 



wings with a narrow curved transverse dusky band reaching from the bend of the 

 submarginal vein to hind border of wing including the patch of wing bristles ; also 

 with a large nearly circular dusky shade below stigma and reaching nearly across 

 wing; legs uniformly honey- yellow with the coxie sometimes brownish above. Ab- 

 domen with basal joint dark brown, and more or less brown at sides and near tip. 



Male. — Slightly smaller ; sculpture identical throughout. Pile very inconspicu- 

 ous, dark. General color black, shining ; all legs honey-yellow ; the upper sides of 

 the hind femora and tibse somewhat darkened ; hind coxse black; front aud middle 

 coxa? honey-yellow at tip ; antennae with the scape honey-yellow, and the funicle 

 brownish ; wings perfectly hyaline. 



Described from four female and two male specimens reared by F. S. 

 Crawford, at Adelaide, from specimens of Icerya purchasi received from 

 S. Australia, 50 miles south of Adelaide. 



EXTRACTS FROM CORRESPONDENCE. 



The Orchid Isosoma in America. 



A friend of mine, by occupation a florist, has applied to me for information concern- 

 ing an insect pest affecting the genus of orchids known as Cattleya, more especially 

 C. triance, eldorado, and gigas. Said insect belongs to a group I have studied but 

 very little, and as the matter is of general interest I appeal to you. 



During the resting season of these plants the pseudo-bulb will sometimes be ob- 

 served to suddenly start into activity, increasing rapidly in size and becoming swol- 

 len spherically. On examination this enlargement is found to contain a cavity in 

 which are several (3 to 8) insects. Those which I have had an opportunity of study- 

 ing were in the last stages of development ; I inclose examples in the light-colored 

 pupa stage, the dark-colored stage preparatory to transformation, and the adult. 

 They make their escape by gnawing a hole from the cavity sufficiently large to allow 

 their egress. The size of the cavity is dependent on the number and state of devel- 

 opment of its inhabitants. The larvae have been described to me as "little white 

 grubs." All the adults that I have seen have had clear wings, but my friend states 

 that is unusual ; he has generally found them with dark wings, apparently identi- 

 cal. (I expected to find a Cynips, but is not this a Chalcid ?) He thinks the pest is 

 imported with the plants (which mostly come from New Granada), and finds com- 

 fortable quarters and a field for activity in greenhouses; he has found them in plants 

 recently imported, together with unmistakable signs of their former presence. 



Their depredations are followed by disastrous results. Of course no flowers are to 

 be expected from the bulb attacked, and this abnormal growth taking place during 

 the resting season so saps the vitality of the plant that it behaves as if it were at- 

 tacked by slow consumption, the leaves lose their vigor and consistence, wither, fade, 

 and gradually die in from one to two years after being seriously attacked. 



Any information you can give me concerning this pest, its name, life history, habits, 

 remedies, etc., will be very gratefully received. Will send you sketches of its work 

 if desired. — [Albert P. Morse, South Natick, Mass. 



Reply. — Your letter of November 29, together with specimens of the Chalcidid 

 reared from the pseudo-bulb of Cattleya, has been received. These specimens form a 

 very desirable addition to the collection of the National Museum, for the reason that 

 we already possessed the swellings from which they issue, and which were given us a 

 few years since in France. I rof. J. O. Westwood, in the Transactions of the Ento- 

 mological Society of London for 1882, figures and describes what is probably the same 

 species under the name of Isosoma orchidearum. The specimens which you seud us 



