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Volume 19, 1886
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Art. III.Further Notes on New Zealand Coccidæ.

[Read before the Wellington Philosophical Society, 19th January, 1887.]

Plate II.
Group Coccidinæ.

Icerya purchasi, mihi. Plate II., figs. 1–4 (male).

By the kindness of the Rev. Mr. Colenso, of Napier, I have received some specimens of the male of this species. No published description of the male Icerya is known to me, though the insect must be common in California. The following description is therefore here given:—

Male insect large; body red, with a shining, diamond-shaped, black patch on the dorsal surface of the thorax; legs and antennæ black; wings dark-brown, marked with numbers of parallel, wavy, oblique, narrow stripes; main nervure red, branching once; there are also two longitudinal whitish stripes in each wing. Antennæ long, slender, with ten joints, all nearly equal; the last joint is clavate; all except the first are constricted in the middle and with two dilations, at each of which there is a ring of very long hairs, giving to the antennæ

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almost a plumose appearance. From these dilations and the median constriction the antenna appears to have nineteen joints, and it requires close examination to show that there are really only ten. Eyes very large and prominent, dark-brown, and divided into numerous semi-spherical facets; at the base of each eye is a prominent tubercle. Feet long, and very hairy; coxæ short and thick, tibiæ long and slender; claw thin. The digitules appear to be represented; by two minute bristles on the claw, as in Cœlostoma zœlandicum. Abdomen long and slender, with eight cylindrical segments, each segment bearing some hairs; the last segment ends in two conspicuous, thick, cylindrical processes which, when the insect is viewed sideways, are seen to turn upwards, and beneath them the conical, sharp-pointed sheath of the penis turns downwards (figs. 3, 4); penis large, reddish-coloured, with many recurved short hairs, and at the end a ring of short spines. Each terminal process of the abdomen bears three or four long strong setæ.

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Length of the body somewhat variable; some of my specimens attain ⅛ inch; expanse of wings ¼ inch; length of antenna 1/9 inch.

This is a very handsome insect, clearly showing the characters of the group Monophlebidœ, and a little resembling the male of Cœlostoma; but specially fine in its variety of colours. The antennæ approach those of Leachia; the two abdominal terminal processes recall the six or eight tassels of Monophlebus. Mr. Colenso informs me that the insect flies strongly and swiftly, which is rather exceptional amongst Coccids, whose wings usually seem too weak for them.

Group LecanidinÆ.

Sub-section Lecano-CoccidÆ.*

Abdominal cleft and lobes present in all stages of female. Insects covering themselves with a secretion of cottony or felted matter, forming more or less complete sacs.

Genus, Eriochiton, gen. nov.

Secretion white, felted, formed of agglutinated threads issuing from prominent spiny spinnerets; inconspicuous or absent on adult female, more or less noticeable on female larvæ and pupæ; thick on male pupa. Abdominal cleft and lobes normal. Feet and antennæ present in all stages. Adult antennæ seven-jointed.

Differs from Lecanodiaspis, Targioni, in retaining the feet, and in the antennæ; from Philippia, Targioni, in not constructing its sac, or test, simply for gestation.

[Footnote] * “Trans. N.Z. Inst.,” vol. xvi., 1883, p. 128.

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New Zealand Coccidæ

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The fact that the tibia is shorter than the tarsus in the adult female, in both the species here given, is quite exceptional in the family. It occurs only, besides in these, in some species of Acantho-coccidœ; in all others, a tibia shorter than the tarsus is an indication that the specimen examined is not full-grown. I have hesitated to include this amongst the generic characters of Eriochiton until at least a third species has been found possessing it. Some persons are fond of creating genera and species from a single specimen or two. I do not agree with this.

Eriochiton spinosus.

(Ctenochiton spinosus, mihi.)

From closer examination of the female test of this species I find that it is not formed of waxy plates but of felted threads.* and I am therefore obliged to remove it from the genus Ctenochiton. It should be described as follows:—Test of female white, thin, formed of felted threads; inconspicuous in all stages and often absent from the adult, but distinguishable on the larva and on the second, or pupal, stage.

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The male test (which I have only lately found) is white, thick, felted, oval, convex, averaging 1/16 inch in length.

To the description of the adult female already given in former papers, it must be added that the tibiæ are shorter than the tarsi, a very exceptional character.

The adult male (only lately found, and apparently very rare) is of the normal Lecanid form; colour generally dark brown. Eyes: two dorsal, two ventral; and two ocelli. Antennæ of ten joints; the second thicker than the rest, the third and fourth the longest, the eighth, ninth, and tenth moniliform; all the joints hairy, and on the five last joints are several hairs with clubbed extremities. Feet slender, hairy; digitules fine hairs. Abdominal spike somewhat strong and sharp; and on each side of its base is a tubercle bearing two long setæ, and each pair of setæ becomes enclosed in a long white cottony thread, the two threads forming conspicuous “tails,” as is common with many male Coccids.

Eriochiton hispidus, sp. nov. Plate II., figs. 5–8.

Test of female white, very thin, felted, formed of threads secreted by the numerous spiny spinnerets. At the edge

[Footnote] * The tests of all Lecanids may be said to be more or less “waxy;” and I am not certain that there is any chemical difference between them: but there must be some reason why, in certain species, the secretion forms plates of wax which are apparently homogenous, whilst in others the threads issuing from the spinneret tubes never entirely coalesce. I believe the distinction which I have made between “waxy,” “cottony,” and “felted,” and which is made also by other writers, is quite clear enough for generic purposes; though it may never be worth while for anybody to ascertain the chemical reasons for it.

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each thread corresponds with one of the marginal spines, and forms a more or less conspicuous fringe, the segments of which are cylindrical tubes, not feather-shaped as in E. spinosus. Test often absent on the adult female, and always fragmentary: it is better observed on the second, or pupal stage, or on the larva.

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Test of male white, thick, felted, oval, and convex, completely covering the pupa. Length about 1/16 inch. As the test exhibits a kind of segmented appearance, with transverse obscure grooves, it may at first sight be mistaken for a dactylopid insect.

Larva normal of the Lecanid group; flat, elliptical, active, exhibiting the abdominal cleft and lobes. Dorsal surface covered with numerous spiny spinnerets, from which issue the threads of the test and fringe.

Female of the second (pupal) stage more or less elliptical, slightly convex, reddish-brown in colour beneath the thin white felted secretion, which often presents an obscurely segmented appearance, due to the transverse rows of spiny spinnerets. Dorsum covered thickly with these spines, which are sub-cylindrical, with rounded tips, and spring from tubercular bases. On the ventral surface many small spiny hairs. Abdominal cleft normal, the lobes large. Mentum monomerous, the tip bearing several hairs. Antennæ of six somewhat hairy joints. Feet with rather large femora; digitules all fine hairs. Anogenital ring bearing several hairs.

Adult female elliptical, convex, reddish-brown in colour, hollow beneath; usually affecting the twigs of the plant in preference to the leaves. Apparently naked, but on close inspection found to retain at least portions of the thin felted secretion. Dorsum covered with great numbers of the spiny prominent sub-cylindrical spinnerets; ventral surface bearing many small spiny hairs. Antennæ of seven joints (fig. 6). Feet with large coxæ and femora; tibia a good deal shorter than the tarsus; lower digitules only fine hairs.

Adult male reddish-brown in colour; form normal of Lecanidæ. Two dorsal eyes, two ventral eyes, two ocelli. Antennæ ten-jointed, the last three moniliform; second, third, and fourth the longest. On the five last joints are several hairs with clubbed extremities. Feet slender, hairy. Abdominal spike rather strong and sharp; and on each side of its base is a broad tubercle bearing two long setæ, which become joined in long cottony “tails.”

Habitat.—On Olearia haastii, found as yet (in great numbers) only on a plant cultivated in the Botanical Gardens, Wellington. It is rapidly killing the shrub. O. haastii is, I believe, an alpine plant.

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New Zealand Infusoria

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This species is distinguished from E. spinosus by the great number of spiny spinnerets on the dorsal surface of the female, and by the cylindrical tubes of the fringe. Its colour is also rather redder and lighter; but that is not a valuable character. I cannot find any clearly distinguishing marks in the males of the two species.

Description of Plate II.

Fig. 1. Icerya purchasi, male insect.

Fig. 2. " part of antenna.

Fig. 3. " extremity of abdomen, viewed from beneath.

Fig. 4. " extremity of abdomen, side view.

Fig. 5. Eriochiton hispidus, adult female.

Fig. 6. " Antenna.

Fig. 7. " Foot.

Fig. 8. " Marginal spines and fringe of test.