The Redefinition of the Ejaculatory Reservoir s. st r. in Pentatomomorpha (Hemiptera: Heteroptera) Jing-Fu Tsai , Man-Miao Yang, and Chung Tu Yang Department of Entomology, National Chung Hsing Universit y, Taichung, Taiwan. Species Examined in This Investigation and t he Findings. The EJR in Coridiellus figlinus (Dinid oridae) (Fig. 1) is hypothetically the start ing point where the EJR begins to differenti ate. Comparing Fig. 2A to Fig.1, we suggest that the EJR in the genus Coridiellus represent s the most primitive character state in the Pentatomomorpha with three following reasons: 1) It is still the continuous tube-shaped s tructure but closed at the end and twisted. 2) The nature of the EJR is the same as the expansion of the ejaculatory duct ( Fig. 1A, b). 3) Compared with other types of EJRs, it is the least modified. Redefinition of the Ejaculatory Reservoir s. str. and Reservoir Lumen. The EJR is defin ed here as a structure protruding from the d orsobasal portion of the expanded ejaculator y duct at the middle of the aedeagus. The pa rt of the structure outside the base of the aedeagus is the EJR and the other part withi n the aedeagus, plus the expanded ejaculator y duct, is the reservoir lumen (Fig. 2C). Further Consideration of the Reservoir Lu men. In Cyclopelta obscura (Dinidoridae), S cutelleridae except H. curculionoides , Tessara tomidae, and Cydnidae, the reservoir lume n is separated into dorsoapical lumen and ventrobasal lumen (Fig. 2D, Fig. 3A-D). I n H. curculionoides and the other remainder fa milies of Pentatomomorpha, the ventrobasa l lumen is reduced and the end of the eja culatory duct is retracted. According to the relative position, quality as express ed in function, and features compatible w ith the delimitation of a monophyletic ta xon, the structures found in C. figlinus and the other remainder families of Pentatomo morpha are judged homologous. Prevailing Views of Ejaculatory Reservoir (EJR). Singh-Pruthi (1925) defined the ejac ulatory reservoir as “an expansion of the ej aculatory duct at the base of the vesica [= aedeagus] present in Heteroptera” (Fig. 2B). However, Dupuis (1970) considered that the e jaculatory duct comprises two distinct parts by means of the EJR as a baseline, a proxima l and a distal one, naming them the ductus s eminis proximalis and ductus seminis distali s, respectively (Fig. 2B). INTRODUCTION The higher classification of Di nidoridae is the topic of the J.F.T.’s MS th esis (Tsai, 2003). Scutelleridae, Tessaratom idae, and Cydnidae were selected as outgroup s. After examining the external male genital ia, the definition of Singh-Pruthi could not be satisfactorily applied to the above-menti oned families. The major purpose of this pap er is to reevaluate the terminology of male genitalia applied to the Pentatomomorpha and propose a clear definition based on comparat ive morphological study. Taxonomy of Pentat omomorpha followed Henry (1997) and Schuh an d Slater (1995). Comparison of Our Redefinition and That o f Singh-Pruthi. There are three differen ces between our interpretation and that o f Singh-Pruthi. 1) The original position of EJR is near the middle of the aedeagus, not at its base. 2) EJR is the structure protruding from the expanded ejaculatory duct and it is a derived structure, not a n expansion of the ejaculatory duct. 3) E JR is present only in Pentatomomorpha, no t in all Heteroptera. Additional explanat ions are given below. The position of ejaculatory duct connect s to the EJR. Many species examined is the same as that of C. figlinus, i.e. connecting position near middle of the aedeagus (Fig. 3A-D). Exception of Hotea curculionoides (Scu telleridae) and the remainder families of Pentatomomorpha, the ejaculatory duct conn ects to the EJR at its basoventral portion (Fig. 3F-J). The presence of EJR. According to the e vidence homology criterion: “Features comp atible in their distribution with the deli mitation of monophyletic taxa (Remane 195 2)”, the similar structure (EJR) found in other infraorders is not homologous. The s truts in Reduviidae (Cimicomorpha) is not EJR. It is judged as “support bridge- the differentiated structure of dorsoanterior upper portion of the phallobase (Yang and Chang, 2000). The EJR of C. figlinus is the l east modified. If it is really the most pl esiomorphic condition of the EJR, it is re asonable to hypothesize that it is restric ted to the Pentatomomorpha. RESULTS AND DISCUSSION Fig. 1. Ejaculatory duct and a derived structure o f the aedeagus of C. figlinus. (A) Lateral view. (B) Dors al view. a, ejaculatory duc t; aed, aedeagus; b, the ex pansion of the ejaculatory duct; c, part of protruding structure termed the “reser voir lumen”; d, part of pro truding structure, ejaculat ory reservoir; phc, phallob asal conjunctiva. Fig. 3. Illustrations on the ejaculatory rese rvoir of some species in Pentatomomorpha. (A) C. obscura (Dinidoridae). (B) Chrysocoris grandis (Scu telleridae). (C) Eurostus vallidas Dallas (Tessarato midae) (D) Adrisa sp. 1 (Cydnidae) (E) Hotea curculi onoides (Scutelleridae). (F) Daulocoris formosanus (A radidae). (G) Andrallus spinidens (Pentatomidae). (H) Daclera sp. (I) Pachyphlegyas modiglian (Lygeaida e). (J) Physopelta guttata (Largidae). hp, holding p late; other abbreviations are the same as in Fig. 2. Fig. 2. Diagrammatic stylized illustration showin g the various types of the ejaculatory reservoir in Heteroptera. (A) Based on Heteroptera without the ejaculatory reservoir. (B) Contrasts of Sing h-Pruthi’s view (above labels) and Dupuis’s view (below labels) of male genitalia. (C) Based on C. figlinus (Dinidoridae), most species in Dinidoridae belong to this type. (D) Based on C. obscura (Dinid oridae), Scutelleridae, Tessaratomidae, and Cydni dae (see Fig. 3A-D). (E) Based on H. curculionoides (Scutelleridae), and other remainder families of Pentatomomorpha (see Fig. 3E-J). aed, aedeagus; da l, dorsoapical lumen; du. sm. d, ductus seminis dist alis; du. sm. p, ductus seminis proximalis; ejd, eja culatory duct; ejr, ejaculatory reservoir; phc, phal lobasal conjunctiva; vbl, ventrobasal lumen. phc aed ejd ejd du.sm .p. du.sm .d. ejr ejr Singh-Pruthi D upuis Fig.2B phc aed ejd ejd du.sm .p. du.sm .d. ejr ejr Singh-Pruthi D upuis phc aed ejd ejd du.sm .p. du.sm .d. ejr ejr Singh-Pruthi D upuis Fig.2B phc aed ejd ejr rel phc aed ejd A C phc aed dal vbl ejd ejr D phc aed ejd rel ejr E phc aed ejd ejr rel phc aed ejd ejr rel phc aed ejd phc aed ejd A C phc aed dal vbl ejd ejr D phc aed dal vbl ejd ejr D phc aed ejd rel ejr E phc aed ejd rel ejr E aed vbl dal rel ejr phc ejd B aed dal vbl ejr phc ejd rel A aed vbl dal rel ejr phc ejd aed vbl dal rel ejr phc ejd B aed dal vbl ejr phc ejd rel aed dal vbl ejr phc ejd rel A aed rel dal vbl ejd hp phc ejr D vbl aed dal rel phc ejr ejd C aed rel phc ejr ejd aed rel ejd phc ejr aed rel phc ejr ejd G rel ejd phc ejr aed aed rel phc ejr ejd I rel aed phc ejr ejd J H E F aed rel dal vbl ejd hp phc ejr aed rel dal vbl ejd hp phc ejr D vbl aed dal rel phc ejr ejd vbl aed dal rel phc ejr ejd C aed rel phc ejr ejd aed rel phc ejr ejd aed rel ejd phc ejr aed rel ejd phc ejr aed rel phc ejr ejd aed rel phc ejr ejd G rel ejd phc ejr aed rel ejd phc ejr aed aed rel phc ejr ejd aed rel phc ejr ejd I rel aed phc ejr ejd rel aed phc ejr ejd J H E F B ae d b a c d ph c ae d A