REPORT OF THE STATE ENTOMOLOGIST I914 89 



little so far as crop production was concerned. This is particularly 

 true in cases where there is a series of two or three nearly con- 

 tiguous scars, since the chances are that such limbs will break off 

 with the first heavy load of fruit, if not earlier. 



MISCELLANEOUS 



Orchid pests. The orchid Isosoma, I. orchidearum Westw., 

 is a European insect which was first discovered in this country 

 in 1889 at Natick, Mass., undoubtedly being introduced with 

 imported plants, since Riley in 1880 records the pest as quite common 

 in some Paris conservatories. The species has apparently not 

 attracted notice subsequently until infested bulbs were received 

 last July from Mount Kisco, accompanied by the statement 

 that they had been taken in a local conservatory. Several species 

 of Cattleya, notably C. trianae, C. eldorado and C. gig as, 

 are liable to infestation. During the resting season of these plants 

 the pseudo-bulbs may suddenly start into activity, increase rapidly 

 in size and assume a spherical shape, according to Prof. A. P. Morse 

 of Wellesley. Within these pseudo-bulbs there is an irregular cavity 

 containing three to eight white maggots. The insects complete 

 their transformations within the cavity and emerge as small, greenish, 

 four-winged gall wasps. 



Infested bulbs fail to produce flowers and the consequent abnormal 

 growth, if the insects are numerous, reduces the vitality of the plants to 

 such an extent that they gradually wither and die in two to three years. 



The Cattleya midge, Parallelodiplosis cattleyae 

 Moll., lives as a yellowish maggot near the tips of the roots of these 

 orchids, producing unsightly galls, in which one to seven maggots 

 occur, each in a cavity by itself. This insect is quite different 

 from the preceding and is one of a very large number of gall midges 

 which live at the expense of many different kinds of plants. 



The most satisfactory method of controlling both of these 

 insects is to keep a close watch of the plants and promptly destroy 

 by burning any infested parts before the larvae can mature and the 

 parent flies deposit eggs upon other orchids. Fumigation has 

 also been advised for the destruction of the adults, though the 

 probablities are that this would be comparatively inefficient, owing 

 to the difficulty of timing the treatment so as to catch numbers 

 of the flies before they have had an opportunity to deposit eggs. It 

 is by all means desirable to adopt reasonable precautions for prevent- 

 ing the introduction of infested plants, and measures of this char- 

 acter will produce much more satisfactory results than is possible by 

 remedial treatment. 



