200 



SCIENCE-GOSSIP. 



seven -jointed, formula 7142(36)5 (i) ; 4 is notice- 

 ably longer than 3, but 3 is not very much shorter 

 than 2 ; 5 is nearly as long as 6, it is longer than 

 broad ; 7 is longer than 4 and 5. Rostral loop 

 short, about as long as an antenna. Legs short, 

 femur rather stout, tibia and tarsus shorter than 

 femur and trochanter. Tarsus only a little shorter 

 than tibia. The legs of the adult female are stouter, 

 but only the merest trifle longer than those of the 

 embryonic larvas within her body. The antennae 

 of the adult are considerably longer than those of 

 the embryonic larvae, but not twice as long. Claw 

 moderately long, slightly curved, broad at base. 

 Anal ring with six hairs. Caudal tubercles ex- 

 tremely low, almost obsolete, each with a bristle 

 resembling those of the anal ring, seven to nine 

 short spines, and round gland orifices. Tarsal 

 digitules filiform not very long, with minute knobs. 

 Digitules of claw rudimenlary, very short. Claw 

 with a denticle on its inner side. 



Some of the specimens are attacked by a fungus. 



Embryonic larva turns dark violet in caustic 

 soda. Antennae six-jointed, 6 much longest, 

 formula 6(1235)4. 



Lately hatched larva, pinkish-brown, with pale 

 yellowish legs and antennae. Larvas hatching in 

 October. 



Habitat — Fort Collins, Colorado, on flowering 

 stems of Artemisia frigida; September, 25th, i8g6. 

 Collected by Professor C. P. Gillette. 



Another curiously abnormal species which might 

 form the type of a new genus is Dactylopiiis tiipce, 

 Maskell, which should be looked for on palms in 

 English hothouses. It was originally described by 

 Maskell and Newstead, in 1893, from specimens 

 found in Demerara. Mr. Urich has found a slight 

 variety of the same species in Trinidad, on midribs 

 of guava leaves, tended by an ant, Azteca chartifer, 

 Forel MS. Professor Davis has met with it on 

 palms in a hothouse in Michigan, U.S.A. I will 

 quote an unpublished description by Mr. Pergande, 

 of the United States Department of Agriculture, 

 made from the Michigan specimens : 



Dactylopius nip^, Maskell. 

 " Adult female ; colour, bright red or orange ; 

 shape, broadly oval; length about 2 mm., diameter 

 about i'4 mm., exclusive of the excretion. Excre- 

 tion white or sometimes slightly yellowish on 

 the dorsum. Excretion short, but dense, forming 

 four dorsal rows of somewhat squarish, stout, 

 conical tubercles, and a fringe of, apparently 

 twenty-four, white projections around the entire 

 margin ; those of the head and thorax are 

 shortest and broadly triangular in shape, while 

 those of the abdomen are much more slender, 

 cylindrical and of an elongated conical shape, all 

 are directed backwards and become gradually 

 somewhat longer and more slender towards the 

 end of the body. The characters of the adult 

 females, after boiling in potash, are as follows ; 

 Antennae seven-jointed; the last joint being much 

 the longest and almost equal in length with joints 

 4-6 combined. Joints 2-4 are sub-equal in length, 

 with the third slightly shorter than the other two, 

 each of them being longer than any of the others; 

 the fifth being shortest of all. Legs rather stout, 



(1) The antennal formula is made by enumerating the joints 

 in the order of their Itngth, beginning with the longest and 

 bracketing together those of equal length. 



especially the femora. Femora and tibiae nearly 

 equal in length ; tarsi somewhat shorter than tibiae 

 and provided with four knobbed digitules. Ano- 

 genital ring with six stout bristles, and one bristle 

 at each of the anal lobes. There are also numerous 

 small pores or spinnerets distributed over the whole 

 body intermixed with a few short, stout spines ; a 

 pair of still longer and stouter spines may also be 

 observed on each side of the thoracic and ab- 

 dominal segments, and quite a number on the head 

 and anal lobes. 



"Male: length about 08 mm.; colour, yellow, 

 the head somewhat reddish ; eyes, purplish ; 

 antennae, brownish-yellow ; disk of thorax more or 

 less distinctly dusky, with the lateral margin of the 

 different parts blackish. Legs yellow, with a 

 dusky tinge. Style, short, conical, with two long 

 and fine bristles each side of it. Antennas ten- 

 jointed, the third, sometimes also the fourth and 

 the last joint, longest. Wings faintly brownish, 

 particularly along the costa and towards the base " 

 (Theo. Pergande, MS.) 



On comparison with Maskell's description, the 

 Michigan specimens exhibit slight differences, 

 which Mr. Pergande summarises thus : 



" Maskell says that the antennae are either seven 

 or eight-jointed ; in this species, however, of which 

 twenty-two specimens were prepared, there are 

 uniformly but seven joints in all the examined 

 specimens. He states also that the third and 

 penultimate joints are slightly longer than the rest, 

 whereas in the specimens before me the second, 

 third and fourth are somewhat longer (together) 

 than the seventh, the third being slightly shorter 

 than the second, while the fifth is shortest of 

 all." 



Mr. Urich's Trinidad specimens showed the 

 tibia distinctly longer than the tarsus ; the legs 

 became colourless on boiling. The antennae were 

 seven-jointed, 7 longest, and a little longer than 4 

 and 5 ; 4,5, 6, equal ; 3 nearly the same, but a little 

 shorter ; 2 longer than 3 or 4, but shorter than 7. 

 Formula 72(1456)3. In another example joint 3 

 was as long as 2. 



After comparing the descriptions of Maskell, 

 Newstead and Pergande, and examining specimens, 

 I am quite satisfied that we have to do with a 

 single very distinct but variable species. 



I have introduced the above descriptions, not 

 only as a contribution to the knowledge of the sub- 

 ject, but to indicate the characters which are used 

 in the identification of mealy-bugs. In conclusion, 

 I will give a list of the mealy-bugs found in 

 Europe up to the present date, whether native or 

 in hothouses. 



(i) Dactylopius alaterni, Signoret ; on Rhamntis 

 alaternus. A doubtful species found in France. 



(2) D. carious, Gennadius ; on Pinus. Not found 



in Europe proper, but in Asia Minor. Two 

 millimetres long, reddish, covered with a 

 cottony substance. A quite imperfectly-known 

 species. 



(3) D. ceratoni. Sign. ; in the -Maritime Alps. 



Similar to D. vitis. 



(4) D. citri, Risso ; south of France, Italy, etc. ; 



on citrus and a variety of other plants. A 

 common greenhouse species with little cottony 



