222 REPORT OF THE COMMISSIONER OF AGKICULTUEE. 



fungi, notably the genus Phoma, and to certain young homopterous galls, 

 tbau tliey do to eggs of any sort (Plate III, fig. 3.) 



The immature insect is of the same dirty brown color as the substance 

 co\ ei irig the egg, and but little darker than the %dtheriug leaf. It is of 

 a broad, Hat, oval shape, and spines seem to project from almost every 

 portiou of its body. It looks under the microscope more Like a lobe of 

 a prickly cactus than anythiug else we caij think of. The cast-off skins 

 stick to the leaf, and give it the appearance of being much more seriously 

 infested than it really is. 



The general appearance of the mature individuals is well shown by 

 Plate IV, fig. 2. Their average length is about 3""". Professor Uhler, 

 in his note determuiing the species, said : 



Yonr specimens of Tiuicis belong to tha gonns (,'orylltuca, and Beein to he a new 

 pLytophagic form of Corylhuca arcnata Say. It will Iiardly do to make a new species 

 out of this insect, as it is one of the several forms which fit into Saj's specioa. It 

 come.s near to the race belonging to the Juglans nigra. 



The dead leaves under the bushes during winter have been often 

 found to contain living and healthy eggs of the Tuigides; but the cus- 

 tomary method of hibernation is in the ad ait state alone. This form 

 can be found during winter under the loose bark of the tree, and under 

 sticks and stones upon the ground. Whenever the injuries of these 

 insects become so great as to render seme remedy necessary, syringing 

 with kerosene and water, in the proportion of 1 gill of the former to 5 

 gallons of the latter, will be found to answer the purpose. It is fair to 

 suppose, however, that if the leaves and rubbish underneath the trees 

 are destroyed, either every fall or every sprhig, a necessity for remedies 

 will not arise. 



THE LOCUST SAW FLY. 



{Nematus similaris Norton [new species].) 



Order Hymenopteea ; family Tsis^THKEDlNtDAB. 



Eating the leaves of black locust, a small, soft, green worm, with 20 legs and appar- 

 ently many segments. (Plate IV, fig. 1.) 



The life history of an interesting saw fly, the larvae of which have been 

 found in considerable numbers feeding upon the locust trees {Bohinia 

 pseudacacia) of the District, has been studied during the past season. 



The egg, which is .5'"" (.02 inch) long, white, semi-transparent, and in 

 shape resembles an irregular semi-ellipsoid, is deposited in a crescent- 

 shape cut made in the under surface of the leaf by the saw-like apparatus 

 of the female, never, so far as I am aware, near the rib. The egg being 

 deposited, the flap made by the crescent cut is forced upwards, making 

 a protuberance which is readily observable upon the surface of the leaf, 

 and which is also increased by the swelling of the egg. The time re- 

 quired for the development of the egg is short, only a few days elapsing 

 betvreeu the depositing and the hatching. 



The newly-hatched larva is pale-greenish white with a brownish head. 

 It has twenty legs, six large thoracic, twelve abdominal, and two anal. 

 It moves a short distance fi*om the place of its birth and commences 

 feeding on the lower surface of the leaf. At first a round hole is eaten 

 in the leaf; as soon as this is sulficiently enlarged the larva works within 

 it, holding its iirolegs along the cut edge, as shown in the figure. As it 

 grows larger the larva frequently leaves tlie paitially destroyed leaf and 

 migrates to another ; this one, however, it begins to eat on the edge, and 



