Ophiogomphus smithi

Tennessen, K. J., 2008, Gynandromorphs in the genera Ophiogomphus Selys, 1854 and Ischnura Charpentier, 1840 (Odonata: Gomphidae, Coenagrionidae), Insecta Mundi 2008 (37), pp. 1-3 : 1-2

Gynandromorph of Ophiogomphus smithi

COLLECTION DATA: WISCONSIN, Eau Claire County, Eau Claire River, Co. Rd. D, 16 June 1994, leg K. J. Tennessen .

HEAD. On the right side of the occiput, there is an acute anterior horn and a blunt posterior horn, normal for females of this species ( Tennessen and Vogt 2004), but on the left side no horns are discernible, which resembles the male condition.

THORAX. The right fore wing (length 29.5 mm) and hind wing (length 28.0 mm) are fully formed. The right hind wing lacks a distinct basal triangle and the hind angle is rounded, typical of females of this species and gomphid females in general. The left fore wing (length 28.0 mm) is slightly shorter than the right, and the left hind wing, although atrophied (length about 18.0 mm), has a distinct basal triangle and the hind angle is angulate, typical of males. It is fairly well developed out to the nodus, but has only 8 antenodal crossveins (normally 9-10 in males, 9-11 in females); the wing is shortened distal to the nodus, the veins are thickened, and the cells are small.

ABDOMEN. Length 31.0 mm, which is small for either sex (range 31.5-34.5 mm for normal males, 31.0- 33.5 mm for normal females; Tennessen and Vogt 2004). The auricles on segment 2 are male-like, although the one on the right side is slightly smaller and misshaped. Segments 2 and 3 bear male accessory genitalia: the anterior and posterior hamules are well developed on the left side but atrophied on the right

1

side; the genital ligula is nearly fully formed but is

angled to the left and slightly twisted, probably

because its base on the right side is poorly devel-

oped. The sternum of segment 9 has a nearly fully

formed ovipositor (Fig. 1), although it is slightly

narrower than in normal females and the arms Figure 1-2. Ophiogomphus smithi Tennessen and Vogt , curve to the left (Fig. 2). On the sternum, to the adult. 1) Abdominal segments 8-10 + anal appendages, right of the ovipositor, there is a small cavity that ventrolateral view. 2) Abdominal segment 9 sternite and is probably a vestigial male genital opening (Fig. vulvar lamina, ventral view. 2). The anal appendages are formed as in normal

males (Fig. 1); the left cercus is 1.55 mm long, which is at the small end of the range of measurements for male cerci, 1.56-1.78 mm, as given by Tennessen and Vogt (2004). The dorsal color pattern of segments 1-10 is more like that of typical males than females. Whether or not this individual could have mated is unknown, as would be its mating preference. Although the male-like anal appendages appear capable of holding a female in tandem, the misshaped male accessory genitalia on segments 2 and 3 probably would not function properly for transferring sperm. The external morphological features indicate that the left side of the body is predominantly male, the right side predominantly female, although most of the sexual characteristics of both male and female are fully developed. A web site maintained by Roy Beckemeyer (http://www.windsofkansas.com/ gynandro.html) has a photograph of a live Sympetrum frequens Selys gynandromorph; the left wings are shorter than those on the right side, indicating they are of male origin. This left/right separation may occur in most odonate gynandromorphs.