- 
 
 Circular \ 
 
 
 United States Department of Agriculture^ 
 
 MUKLAg OF ENTOMOLOGY, 
 t .> how a ii ran. 
 
 i;i: \ I* in N< ILE. 
 ui<ii>. i 
 
 Sami 
 
 From even State nasi <>!' the Mississippi Uiver, and from Missouri, 
 Arkansas, Louisiana, Tex 
 as, Minnesota, and the 
 Province <>t' < mtario, 
 ada, the terrapin scale has 
 been reported and authen- 
 tic specimens have been 
 received by ilii- Office. It 
 i*. noteworthy that this spe- 
 cies of scale, more conspic- 
 nously marked than any 
 other of the genus, is the 
 most generally injurious 
 one. In consequence <>t" ii- 
 wide range of food plants. 
 including both wild and 
 cultivated trees, it must be 
 considered a dangerous 
 pest, which may be con 
 trolled but never eradi- 
 cated. 
 
 This scale insect can be 
 rnized and identified 
 especially well i'i the hiber- 
 nating u inter stage i fig. I). 
 when it appears as ;i red- 
 dish hemispherical scale 2 
 nun. in length, mottled 
 with radiating streaks of 
 black w hich are especially 
 conspicuous about the mar- 
 gin. Sometimes these radi 
 ating streaks coalesce, 
 forming's subdorsal dark Imnd surrounding the central reddish boss, 
 isionally individuals are founSi which are entirely red or black. 
 
 
Although this species was not described until 1898,° the describer, 
 Mr. Theodore Pergande, of this Office, hud known it since 1872, when 
 it was found upon peach trees at Hillsboro, Mo. 
 
 FOOD PLANTS. 
 
 For many years the terrapin scale has been considered a specific 
 enemy of the peach and lias been confounded by many entomologists 
 and others with Eylecanium persicae (Fab.), the preeminent peach soft 
 scale of Europe. At present we know it as infesting a large number 
 of host plants, including many varieties of peach and cultivated plum; 
 various species of wild plums and cherries; Prunus simonii, apple; 
 pear; quince; several species of Crataegus; three species of maple, par- 
 ticularly Acer saccharinum; oriental and western sycamores; Carolina 
 poplar; olive; blueberry (Vhccmium -p.): Bumelia, and spice bush 
 {Benzoin benzoin ). 
 
 DESCRIPTION. 
 
 The following technical description is inserted to facilitate the deter- 
 mination of this species by entomologists, or anyone who may have 
 access to a compound microscope. 
 
 Adult female (fig. 2) . — Nearly hemispherical, small. Length ."> to 3.5 mm., exhibiting 
 many of the superficial characters of the hibernating form described above, though 
 showing a tendency to fade rapidly after oviposition until by the 
 autumn she is plain dull yellow or terra-cotta color. Fresh 
 unrubbed specimens are covered by a thin glassy secretion of wax 
 which scales off readily. When cleared by boiling in a solution 
 of potassium hydroxid, the derm is left quite colorless, excepting 
 the brown chitinized anal lobes and a narrow chitinized area 
 surrounding the lobes. Antenna- (iig. 3, b) composed of six 
 segments; segment,;! which, occasionally shows a pseudo-joint, is 
 FlG ' , 2- ~ T f rra ? in equal in length to 4. 5, and 6 together; next in order of length 
 
 scalf I Lull mil i u in l " c , . ' . 
 
 nigrofasciatum \: come segments 2 and 1 m order. The antenna' exhibit the ordi- 
 
 Adult female, nary cheetotaxy. Legs well developed: tibia slightly longer than 
 
 Enlarged (after tarsus, bearing a pair of Long, knobbed tarsal digitules and a pair 
 
 of long expanded ungual digitules. There are irregular rows of 
 
 many pores leading from the spiracles to the spiracular spines (fig. 3, c) on the 
 
 margin of the body. The median spiracular spine of each group is robust and about 
 
 50 mm. long, three times the length of the two shorter spines; marginal sp 
 
 (fig. 3, d) slender, about equidistant, except four, which are closely crowded at the 
 
 anterior median point. 
 
 The distinguishing microscopical characteristic i if this species is the irregular single 
 or double mid-dorsal row of 25 to 40 low, subcorneal appendages i fig. 3, - ), appearing 
 like pores, extending from near the anal lobes to nearly above the sucking mouth- 
 parts. These pores are usually quite evident in a mounted specimen and serve to 
 separate this species surely from all others. The thick anal plates (fig. .">. a) are 
 quite symmetrical, somewhat longer than broad, with the posterior lateral margin 
 rounded and thickened. Each plate bears two minute apical and two subapical 
 
 «Bul. 18, n. s., Div. F.nt., V. S. Dept. Agric, pp. 26-29. 
 
 [Cir.88] 
 
8 
 
 loiigei --I ■ii' 
 ih ter ■ 
 
 Tin' in. ill- "i tin- -|" i hiili 
 
 1-1 i. I'll, ii! H-vnt wings have an < nit 4 mm. 
 
 ii -I. with - lark n icic band, 
 
 This species should riul be confounded with / m priin 
 
 I onMc), :i small, \<t\ convex, dark red, shining species, which has ;i 
 group of mam (200 to 3< H)) pores with interspersed spines, extending 
 from the anal lobes i«> mar the anterior margin; the spiracular spines 
 are nearh uniform in length, being scarcely longer than i h«- marginal 
 spines. The latter specie** «:i- first recorded from the United States 
 in November, 1894, when il wassenl to this Office from Columbia, Pa., 
 <ui plum twigs. Europe is it- original borne, whence it must have 
 been exported to the l T nited States on nursen stock or cuttings. 
 
 I 
 
 r \i; \-i ii-. 
 
 Very small, parasitic four-winged flies of the genus Coccophagus, 
 family Chalcidicbe, are our greatesl benefactors in the control of thi- 
 scale insect. 
 
 i;imi I'll B. 
 
 Unfortunately 1 1 1 » • lime-sulphur wash, which i- such an excellent 
 remedy for the San Jose scale and which at the same time controls the 
 peach leaf -curl, is worthless for treating the terrapin scale. Numerous 
 experiments in the use of the lime-sulphur wash against this scale on 
 various host plant- have produced only negative results. 
 
JL 
 
 4 3 1262 09216 4473 
 
 Kerosene emulsion has proved to be the most effective remedy for 
 
 the control of this pest. This emulsion, when properly made accord- 
 ing to the formula below, can be sprayed with safety on any tree dur- 
 ing the dormant period— in winter or early spring lie fore the buds 
 (l pen at a strength of 20 to 25 percent. A nozzle throwing a fine 
 spray should he used. Care should always he exercised to prevent the 
 liquid from running down the trunk of the tree and collecting ahout 
 the root-, as the oil. which will lie retained by the soil around the root- 
 for an indefinite period, might seriously injure or kill the tree. 
 
 KEROSENE EMULSION. 
 
 stork solution (66 per cent "il). 
 
 Kerosene i coal-oil, lamp-oil I gallons.. 2 
 
 Whale-oil or laundry Boap »rl quart soft soap i pound., J 
 
 Water gallon.. I 
 
 Dissolve the soap in boiling water, fin ,< remove from thefre, add the 
 kerosene immediately and thoroughly agitate the mixture until a creamy 
 solution is obtained. This can be done by pouring the mixture into 
 the tank of a spray-pump and pumping the liquid through the nozzle 
 back into the tank. This i- a stock solution which must be diluted 
 before using. In order to make a 20 per cent emulsion, add to each 
 gallon <»f the stock solution about 2i gallons of water and agitate thor- 
 oughly before using. For a 25 per cent solution add to each gallon of 
 the stock solution 1| gallons of water and agitate thoroughly. This 
 strength will kill a large percentage of the hibernating female-, with- 
 out injury to the tree-. 
 
 If a good naphtha soapcan be obtained the preparation of the emul- 
 sion will be simplified. It will be unnecessary to heat the solution, 
 Since the kerosene will combine readily with the naphtha and soap and 
 form a perfect, cold, milky-white emulsion when the mixture is thor- 
 oughly agitated. If naphtha soap is used, double the amount called 
 for by the formula, and emulsify in soft (rain I water. 
 
 Approved: 
 
 James Wilson, 
 
 Secretary of Agriculture. 
 Washington, D. C, Aprils, 1907. 
 
 Cii -'- 
 
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