寄生在蚜虫上的足绒螨属一新种(真螨目:绒螨科)

A NEW SPECIES OF LARVA OF PODOT HROMBIUM BERLE-SE, 1910 PARASITIC ON APHIDS FROM CHINA (ACARIFORMES: TROMBIDIIDAE)

足绒螨属 Podothrombium 隶属绒螨科(Trombidiidae)。在已知的34种7亚种,只有4种有幼螨的描述。本文描述了寄生在蚜虫上的一种足绒螨属的幼虫新种,寡毛足绒螨 Podothrombium paucisetarum sp.nov.。与已知的4种足绒螨幼螨相比,该新种在背腹毛总数(NDV)、须跗节毛数、足指数(Ip)、盾板长(SD)、跗节Ⅰ、Ⅱ和Ⅲ的普通毛数、跗节Ⅰ、Ⅱ和Ⅲ的荆毛数等各主要特征上都与其它种不同。

In this paper a new species of larva of Podothrombium is described from China. Unit of measurements used in the text is micron. Terminology used in the description is adapted from Robaux (1974). Podothrombium paucisetarum sp. nov. (figs. 1-7)Larva: Body color red in life. Idiosoma 644(540-760) long, 424(360-500) wide.Dorsal side of idiosoma: Anterior scutum with a pair of nude sensillae and 3 pairs of barbed setae. Posterior end of the scutum convex. Lateral to the postlateral angles of the scutum two pairs of eyes with eye plates. Posterior to scutum a small scutellum. Measurements of the scuta as shown in the text. Besides two scuta, idiosoma dorsally with 47(44-52) setae, each with a setal platelet, arranging in 6 rows. fD = 47(44-52).Ventral side of idiosoma: Coxa Ⅰ and Coxa Ⅱ contiguous, and with a urstigma between them. Coxa Ⅰ ventrally with one barbed seta near the two ends of the anterior side each, dorsally with one small nude seta on anterior basal end. Coxa Ⅱ and Coxa Ⅲ each with one barbed seta near the basal end. fCx = NBB-B-B. Between Coxa Ⅲ a pair of sternal setae, barbed, with setal platelets at their base. fSt = O-O-B. Posterior to Coxa Ⅲ 37(34-40) ventral setae, each with a setal platelet. fV=37(34-40). Anal opening small, near the posterior end of idiosoma.Gnathosoma: Dorsal side of cheliceral base with a pair of small nude setae. Palpal tro-chanter small, without seta, femur and genu with one barbed seta each, tibia with 3 nude setae, the one near the tibia claw thicker than the other two. Tibia claw simple. Palpal tarsus with 2 barbed seate, 6 eupathidiae and one solenidia. fPp = 0-B-B-NNNl-BBωσξ. Sclerotized digi-tus mobilis with one denticle. Geleal setae small and nude. Posterior to geleal setae a pair of long and barbed setae.Legs: Each leg with 6 segments, fSp = 6-6-6. Excluding claw, length of leg Ⅰ, Ⅱ and Ⅲ502(488-520), 454(445-470) and 503(495-515) respectively. Length of tarsus Ⅰ, Ⅱ and Ⅲ 114(108-120), 101(100-105) and 113(105-120) respectively. Each tarsus with two claws and one empodium. Leg chaetotaxy as shown in fable 1.Types: Holotype, collected by Zhang Zhi-Qiang in Boshan County, (31.4N, 121 AE) Shanghai on I986-V-7. Paratypes collected by Zhang Zhi-Qiang Hong Mei and Yu Hong in Shanghai on 1986-V-7, 1982-V-15 and 1984-V-7 respectively. All types deposited in the Department of Biology, Fudan University, Shanghai, China.Host: AphididaeRemarks: This new species differs from all known larvae of the genus markedly. Comparisons of the key characters of all known larval Podothrombium as shown in table 2.