208 REPOirr of the commissioner of agriculture. 



When white ants infest living plants, they attack that part which is 

 at or just below the surface of the ground. In the case of pampas grass, 

 the hase of the stalk is hollowed; with woody plants, as orange trees 

 and guava bushes, the bark ol the base of the trunk is eaten, and fre- 

 quently the tree is completely girdled; with sugar-cane, the most serious 

 injury is the destruction of the seed cane. 



The white ants may be destroyed by water heated sufficiently to kill 

 the insects without injury to the infested plants. In the case of orange 

 trees, much can be done to prevent the attacks of these insects. My 

 experience convinces me that it is those trees about the crown of whose 

 roots the soil has been heaped that are most liable to become infested. 

 It follows that care should be taken to remove such soil imDiediately 

 after each cultivation of the grove, leaving the crown of the roots ex- 

 posed. It is also important to remove all old wood, especially pine, 

 from near the trees, as such wood is liable to become infested and the 

 white ants to spread from it to the orange trees. 



TWO NEW PARASITES ON ORANGE INSECTS. 



The leavBS of the terminal twigs of orange trees are frequently in- 

 fested, especially in the spring, by numerous dark-green plant-lice, 

 which do considerable injury by checking the growth" of the young 

 shoots. At Eock Ledge, Fla., I found that these plant-lice were de- 

 stroyed in great numbers by a small black Ichneumon liy, a description 

 of which has not heretofore been published. I bred the same species 

 from plant-lice infesting the cotton plant, and from the common grain 

 plant-louse {Aphis avenae). The specimens were referred to Mr. E. T. 

 Oresson, who prepared the following characterization of the species: 



Trioxys testaceipes Cresson (n. sp.)- 



Female. — Piceoiis or shining black, smooth and polished, imprmctured ; niandihlpg 

 and palpi pale ; antennae broTvnish-black, sometimes more or less pale beneath, 1:5- 

 jointed, the joints faintly fluted or grooved, the last one longest and thickest ; wings 

 hyaline, ii-idcscent, stigma pale; legs, including coxae, yellowish-testaceous, the pos- 

 terior pair generally more or less fuscoxis or blackish ; abdomen often brov/n or pale 

 piceous, with the first, and sometimes part of the second, segment more or less testa- 

 ceous. Length, .07 inch. 



JJai. — Rock Ledge, Fla., Selma, Ala,, and Pocomoke City, Md. Parasitic upon an 

 aphid infesting twigs of orange, an a^ihid on the cotton plant, and A^his avenae Fabr. 



Another uudescribed species of Ichneumon fly was bred from cocoons 

 which I found upon an orange leaf at Rock Ledge, Fla. This species 

 is probably parasitic on some larvae infesting the orange tree. It was 

 also referred to Mr. Cresson, who characterizes it as follows : 



PoLYSPHixcTA ALBIPES Cresson (n. sp.). 



Male. — Sanguineous, smooth and polished ; head black ; clypeus, mandibles and palpi, 

 white; antennae long, slender, black; tegulae and dot before, white; wings hyaline, 

 eubiridescent, nervnres and stigma fuscous; legs, including coxae, white, xii^s of tarsi 

 blackish ; second and following- segments of abdomen with a transverse black spot on 

 each side at tij), and a transverse deeply impressed line near base and apex, the lateral 

 middle being therefore more or less swollen; basal segment with a median shallow 

 groove al)ove, and a short, stout tubercle on each side ; venter yellowish- white. 

 Length, .28 inch. 



Eab. — Rock Ledge, Florida. Found on an.orange leaf. 



