A New Species of Diptilomiopus Nalepa (Acarina : Eriophyidae)
Together with a Key to the Genus
[Read before the Auckland Institute November 21, 1951, received by the Editor, December 21, 1951]
This paper describes a new species of Diptilomiopus (Acarina), D. cerinus, from Northcote, Auckland, found on Coprosma auslralis, and gives a key to all the species of the genus.
In 1917 Nalepa crected the monotypical genus Diptilomiopus for the species D. javanicus, which he described from galls of Eriophyes hemigraphidis Nal. on Hemigraphis confinis Cogn. Since this species was described from Java, seven further species (all from North America) have been described.
The known species of the genus are listed as follows.
D. Javanicus Nalepa, 1917. Verh k.k. Zool.-Bot. Ges. Wien. 67: 226–232.
D. arctostaphyli Keifer, 1938, Bull Dept. Agric State of California 27 (3): 305.
D. prunorum Keifer, 1939, Ibid., 28 (2). 149.
D. sacramentae Keifer, 1939 Ibid., 28 (3). 232.
D. abronius Keifer, 1939 Ibid., 28 (7, 8, 9) 492.
D. carolinensis Keifer, 1940. Ibid., 29 (3). 168.
D. aleyrodiformis Keifer, 1940 Ibid., 29 (3) 168–169.
D. calicoryli Keifer, 1943 Ibid, 32 (3) · 216.
A further species of Diptilomiopus has been collected recently as an inquilme on erinose leaves of Coprosma australis (A Rich) Robinson. The erineum has been described before (Lamb, 1952) and attributed to Phyllocoptes coprosmac Lamb. Only a few specimens of Diptilomiopus were found, together with large numbers of another Phyllocoptine mite (Vasates sp.). The inquiline is described below as a new species.
Diptilomiopus cerinus sp. nov.
Female · 175–250μ long, 75μ wide. spindle-shaped; in life exuding white wax in three dorsal ridges extending the whole length of the abdomen Rostrum 20μ long, stout, directed downwards, stylets prominent. Thoracic shield semi-circular, acute at apex, 40μ long and 63μ wide, with a reticulate pattern of striae Dorsal setae present in nymph but lacking in adult.
Fore-legs 47μ long, six jointed (patella present) Shaft of featherclaw split in two, each half bearing two series of delicate rays; claw bristle with a distinct knob; femur 17μ long, patella 5μ long, tibia 8μ long, tarsus 12μ long. Hind-legs 42μ long, featherclaw 10μ long and as above, claw bristle with a distinct knob; femur 13μ long, patella 5μ long, tibia 8μ long, tarsus 12μ long. The tarsi of both
legs have a single pair of dorsal setae. Setac are lacking on all patellae and femora.
First pair of thoracic setae vestigial or absent, second pair 27μ long, third pair 42μ long. Sternum broad, simple, extending to level of thoracie setae II.
Abdomen with a median dorsal arch flanked by a shallow furrow on either side; 64 smooth tergites and about 80 finely microtuberculate sternites. Lateral setae absent. Ventral setae I, 67μ long, located on about the 20th postgenital ring. Ventral setae II, 12μ long, located on about the 40th postgenital ring. Ventral setae III, 37μ long, located on 9th ring from rear. Caudal setae about 80μ long. Minute accessory caudal setae present.
Epigynium bowl-shaped, 32μ wide and 20μ long. Coverflap smooth. Genital setae 12μ long, located at sides of epigynium (Fig. 1).
Male: 178μ long and 67μ wide. Generally resembling the female and with a similar setal distribution.
Type locality: Northeote, Auckland.
Collected by Miss J. Dingley, September 24, 1951.
Host: Coprosma australis (A. Rich.) Robinson.
Relation to host. Inquiline on erinose leaves.
Type material. Type slide so designated and with the above data and a single paratype slide from the same material. Both slides located in the collection of the Plant Diseases Division, Department of Scientific and Industrial Research, Auckland, New Zealand.
This species is closest to D. javanicus, which it resembles in setal reduction and general form. However, it is readily distinguished by the presence of patellae on both pairs of legs These are lacking in D. javanicus. Both males and females of D. cerinus sp nov. produce large quantities of a white, waxy substance. This appears to be exuded mainly as three longitudinal ridges of flocculent material. In this character the species resembles D. aleyrodiformis, but differs from it in setal reduction.
Nalepa's original description of the genus Diptilomiopus may be translated as follows:
“Abdomen not uniformly ringed, dorsal half rings broader than ventral half rings. Leg joint 3 absent, legs therefore 5 jointed. Shaft of the featherelaw forked.”
The deeply forked featherclaw is a striking characteristic of this genus. Each half of the featherelaw resembles a miniature pretarsus in itself. Though Nalepa stressed the absence of leg joint 3 (patella or genu) as a generic character, its presence in other members of the genus indicates that this character is really of specific value only. Other characteristies of the genus are the massive rostrum, prominent stylets, broad sternum and varying degrees of setal reduction. Setal reduction reaches a maximum in D. javanicus and D. cerinus, where the dorsal, lateral, patella and femoral setae are absent In D. arctostaphyli, D. abronius, and D. carolinensis the dorsal, later and hind patella setae are absent. In D. pr [ unclear: ] orum, D. sacramentae, D aleyrodiformis, and D. calicoryli all the major body setae are present. The furrowing of the abdomen is suggestive of that found in Epitrimerus (sl).
Keifer (1944) erected a new tribe (Diptilomiopini) for Phyllocoptinae with a large rostrum set at right angles to the body and large, abruptly curved chelicerae He included in this tribe Phyllocoptyches Nal., Diptilomiopus Nal., Rhyncaphytoptus Keif, and Quadracus Keif. The latter three genera are very closely related, Diptilomiopus being distinguished by its two-lobed featherclaw. There appears to be little reason for separating Rhyncaphytoptus and Quadracus. The form of the abdominal rings in Phyllocoptyches renders it quite distinct from the other members of the tribe.
The known species of Diptilomiopus may be separated by the folowing key.
|1. Legs 5-jointed (patella absent)||D. javanicus Nal|
|Legs 6-jointed (patella present)||2|
|2 Dorsal and lateral setac absent||3|
|Dorsal and lateral setae present||6|
|3. Patella setae lacking on both paris of legs||D. cerinus sp. nov|
|Patella setae present on fore-legs||4|
|4 Less than 50 tergites||D. carolinensis Keif.|
|More than 60 tergites||3|
|5 Ventral setae II and III subequal||D. arctostaphyli Keif.|
|Ventral setae III more than 3 times as long as ventral setae II||D. abronius Keif.|
|6. Dorsal setae much shorter than ventral setae II (about ⅛ as long).||D. prunorum Keif.|
|Dorsal setae equal to or longer than ventral setae II||7|
|7. Dorsal setae 1 ½ times as long as ventral setae II||D. calicoryli Keif.|
|Dorsal setae and ventral setae II subequal||8|
|8 Ventral setae I and lateral setae subequal||D. aleyrodiformis Keif.|
|Ventral setae I more than twice as long as lateral setae.||D. sacramentae Keif.|
Keifer, H. H., 1944. Eriophyid Studies. XIV. Bull. Dept. Agric. State of California 33 (1): 18–38.
Lamb, K. P., 1952. New plant galls. I. Mite and insect galls. Trans. Roy. Soc. N.Z., 79, 349–362.