Pyemotes muraiae sp. IL (Acait Heterostigmata: Pyemotidae) parasitizing a Hymenoptera larva Sándor MAHUNKA and Luise MAHUNKA-PAPP Zoological Department, Hungarian Natural History Museum, H-1088 Budapest, Baross u. 13, Hungary (Received 30 September, 1998) Abstract: Description of a new Pyemotes species, parasitzing Eurytoma amygdali (Hym.: Chalcidoidea), from Hungary. With 9 figures. Key words: Acari, Pyemotidae, Pyemotes muraiae sp. n., parasite of Hymenoptera. INTRODUCTION The research workers of the Entomological Department of the University for Horticulture and Food Industry, Budapest, Dr. A. Haltrich and Dr. V. Marko, bred specimens of Eurytomoa amygdali (Hymenoptera: Chalcidoidea). Large number of specimens of Pyemotes species was present in this breeding. The acari were sent to us for identification. A close inspection revealed a species new to science, whose description is given hereunder. The species of Pyemotes are unequivocally leading a parazitoid mode of life, particularly favouring the various developmental stages of mostly insects. The attachment is explained by their capability for easily piercing the cuticle with their chelicerae in order to suck the larvae. Owing to their parazitoid mode of life and aggressive attack on their prey they might be considered as potential tools in biological control. A rather profuse explanation of this mode of life was given by Krczal in 1959. He listed all the literature references complemented with his own observations. Consequently, we well know that there is a long list of host animals, among them the members of Coleoptera, Lepidoptera, Diptera, Heteroptera, Hymenoptera. Recently the larvae of Scolytidae came in focus (Moser et al. 1987, Cross et al. 1981). A particular feature of their mode of life is polymorphism, which question has been tackled by various authors. However, this phenomenon could not be ascertained in the present case. When describing the new species we use the terminology nearly of Lindquist et al. (1990).
48 Mahunka, S. and Mahunka-Papp, L. RESULT Pyemotes muraiae sp. n. Holotype: male, Hungary, Budapest, Gazdagrét, Laboratórium. From Eurytoma amygdali (Hymenoptera, Chalcidoidea) breeding, taken from larvae and pupae. 3. III. 1998. Leg. A. Haltrich and G. Marko. Paratypes: 56 paratypes from the same sample. Holotype (1610-HT-98) and 50 paratypes (1610-PT-98) (with identification numbers of the specimens in the Collection of Arachnida) deposited in the Hungarian Natural History Museum, Budapest, and 3 paratypes in the Muséum d'histoire naturelle, Geneve and 3 paratypes in the Collection of the University of Hamburg, Deutschland. Description of female: Body length 219 to 264 u,m, body width: 76 to 110 urn. Pro dorsum: Prodorsal shield elongated, much longer than wide, its rostral margin convex. Three pairs of prodorsal setae present, setae sc extremely long, setae V\ and v 2 nearly equal in length. Peritremes very long, directed inwards, well observable (Fig. 1). Sensillus simple, with short peduncle. Notogaster: Borders of tergites well visible, tergite C the largest and widest of all. The other tergites gradually narrowing posteriorly. All no togastral setae simple and smooth. Among the setae great differences exist in length, setae c\ shorter than setae e and h 2 much shorter than setae/ or h\. Ventral regions (Fig. 2): Typical. Apodemes normally developed, anterior sternal apodeme interrupted anteriorly, among the apodemes ap. 2 run tranversally. Apodemes 3 and 4 well sclerotized. Ventrocaudal lobe between legs III and IV wide, inverse V-shaped. All epimeral setae fine and simple, no essential difference among them. Setae la slightly longer than lb. Epimeral setal formula 2-2-3-3, setae 4b located far posteriorly. Legs: Solenidium of leg I short, wide, 92 of tibia very long, bacilliform, cp] much shorter. Solenidium of tp of leg III located far from setae d (Fig. 4). Claw of leg I much thicker than the same on the others legs. Legs setal formulae typical for the genus: I: 1-4 - 4-5+2-10?+2-1 (Fig. 3); IV: 1-2 - 2-4+1-6 -1 (Fig. 5). Description of male: Body length 171 to 175 u,m, body width 90 to 93 p.m. Prodorsum: Nearly triangular, slightly rounded anteriorly. Four pairs of prodorsal setae arising on it, among them sc\ longest of all, slightly dilated basally, sc 2 nearly half as long as the previous one. Setae v\ minute, v 2 short (Fig. 6). All setae smooth. Notogaster: Its form typical for the genus. Tergites C and D fused together, tergites E, F and H much narrower. Among the setae great differences exist, first of all setae c\ c 2 and setae d and/much longer and thicker than the others, C\ t ci } and setae d are equal and extremely long. Ventral regions (Fig. 7): Typical for the genus. Apodemes on the posterior sternal region connected with each other on both sides. No sternal apodeme on the posterior part visible. Legs: Their form and setation as shown in Figs 8 and 9. Legs setal formulae: 1:1-4-4-5+2-11 + 1-1 (Fig. 8); IV: 1-2 - 2-4+1-6 -1 (Fig. 9). Remarks: The species of the genus Pyemotes was surveyed by Cross et all. (1981), who also published a determination key for the species. The new species is well characterised by the form of the solenidia of leg I of the female and the extremely long
Figs 6-9. Pyemotes muraiae sp. n. male (6- body in dorsal view, 7-body in ventral view, 8-leg I, 9-leg IV)
setae of tergites C-D of the male. It stands nearest to P. schwerdtfegeri Krczal, 1959, however, the length of the sc 2 different and also completely different is the setation of legs IV. Etymology: We dedicate the new species to Mrs Éva Murai-Kovács, the excellent research worker of the Hungarian Natural History Museum, Budapest, who has been the editor of Parasitologia Hungarica for over two decades, on the occasion of her 70th birthday. Mahunka, S. és Mahunka-Papp, L.: Hymenoptera lárvákon élő parazitoid Pyemotes muraiae sp. n. (Acari: Heterostigmata: Pyemotidae) leírása Dr. Haltrich A. és Dr. Marko V. a budapesti Kertészeti és Élelmiszeripari Egyetem Rovartani Tanszékének munkatársai Eurytoma amygdali-t (Hymenoptera: Chalcidoidea) tenyésztettek. A tenyészeten nagyszámban jelentek meg egy Pyemotes faj példányai, amelyek azonosítására a szerzőket kérték fel. A faj a tudományra nézve újnak bizonyult. REFERENCES Cross, E. A., Moser, J. C, and Rack, G. (1981): Some new forms of Pyemotes (Acari: Pyemotidae) from forest insects, with remarks on polymorphism. Internat. J. Acarol. 7: 179-196. Krczal, H. (1959): Systematik und Ökologie der Pyemotiden. In.: Stammer, H-J (Ed.): Beiträge zur Systematik und Ökologie der mitteleuropäischer Acarina. Akad. Verlag. Gesch. PortigK.-G, Leipzig. 1, 2: 385-625. Lindquist, E. E., Kaliszewski, M. and Rack, G. (1990): Athyreacaridae, a new family of mites (Acari: Heterostigmata) associated with scarab beetles of the genus Neoathyreus (Coleoptera: Scarabaeidae). Acarologia 31:161-176. Moser, J. C., Smiley, R. L. and Otvos, L. S. (1987): Anew Pyemotes (Acari: Pyemotidae) reared from the Douglas-fir cone moth. Internat. J. Acarol. 13:141-147.