FIRST RECORD OF AENASIUS ARIZONENSIS ( GIRAULT , 1915 ) ( HYMENOPTERA , ENCYRTIDAE ) , A PARASITOID OF PHENACOCCUS SOLENOPSIS TINSLY , 1898 ( HEMIPTERA , PSEUDOCOCCIDAE ) IN IRAQ

This article reports the first record of Aenasius arizonensis (Girault, 1915) (Hymenoptera, Encyrtidae) parasitizing the recently introduced species of cotton mealybug, Phenacoccus solenopsis Tinsly (Hemiptera, Psedococcidae) infesting Lantana camara L. (Verbeneceae) as well as other ornamental plants in Baghdad province, Iraq. A short morphological description is also presented.


INTRODUCTION
The cotton mealybug, Phenacoccus solenopsis (Girault) (Hemiptera, Psedococcidae), is an important pest of cotton and ornamental plants; this species is a polyphagus and has been reported to be feeding on at least 219 host plant species that belong to 53 plant families (Ben-Dov et al., 2017).Some of these hosts are considered economically important plants, such as cotton and horticulture crops in both indoor and outdoor productions (Culik and Gullan, 2005;Hodgson et al., 2008;Afzal et al., 2009;Wang et al., 2009;Yi-Yong et al., 2011); infestation by this mealybug causes huge yield loss; reducing the cotton yield by up to 40-50 % as was reported from some infested fields in India (Jhala et al., 2008).So far, this mealybug had been reported from 37 countries in various biogeographical zones such as South East Asia, North Africa and the Mediterranean (Ben-Dov et al., 2017).
Phenacoccus solenopsis was found for the first time in Iraq in 2014, in Baghdad province (Abdul-Rassoul et al., 2015) on eleven host plant species that belong to nine families.
Each sample was placed in a plastic bag and brought to the laboratory for examination and kept in glass jars provided with a gauze cover for proper ventilation for the emergence of parasitoids; these jars were kept under observation to record emergence of the adult parasitoids at room temperature (range 25-35cº), and relative humidity of 35±5%, by using the Hygrothermograph.The emerged parasitoids were mounted on small card, and identified by the author according to available literature given by Girault (1915) ;Noyes, (1980); Noyes and Ren (1995); Hayat (2009); Poorani et al. (2009) and was determined as Aenasius arizonensis (Girault, 1915) (=Aenasius bambawalei Hayat, 2009).Photographs were made using the camera of Samsung galaxy A5, and using a binocular dissecting microscope (WILD M5, Switzerland) to magnify the morphological features.This parasitoid was first described and named by Girult from U.S.A-Arizona in 1915, as Chalacspis arizonensis (Girult, 1915); Noyes and Woodlley in 1994 transferred this parasitoid to the genus Aenasius Walker, 1846.Hayat (2009) described A. bambawalei from India, and later Fallahzadeh et al. (2014) synonymized it with A. arizonensis; this parasitoid is known as a solitary nymphal endoparasitoid of cotton mealybug, Phenacoccus solenopsis, which induces up to more than 80 percent parasitization in India (Ram et al., 2009).

RESULTS AND DISCUSSION
Diagnosis: Aenasius arizonensis is easily recognized from the other species of Aenasius by the following characters: Antenna with scape cylindrical, about six times as long as wide; fore wing with a hyaline streak adjacent to the postmarginal and stigmal veins; costal cell with one line of setae dorsally.The following is a short morphological description given here based on the Iraqi specimens for the simple identification; moreover the female of A. arizonensis is easily separated from the male by having different shape of antenna.Female (Pl.1):Length: 1.08-1.62mm.Body short and broad, shiny black with metallic reflections.Legs are metallic green except the tarsi and tips of the middle tibiae which are reddish like the scape.Antennae are reddish except the bulb of scape and the pedicel, which are metallic dark green; club sometimes blackish.
Head wider than thorax, with thimble-like punctures; anterior part of vertex wide, at narrowest point about half as wide as head; malar space longer than length of eye; occipital margin sharp; mandibles bidentate.Antennae (Pl.2) club-shaped, Scape cylindrical, are about six times as long as wide, upper margin of scape markedly bowed downward before middle; flagellum clavate; pedicel somewhat longer than wide; funicle with six segments and transverse, subequal in width, broadening towards clava, sixth largest.Clava large, obliquely truncate, longer than funicle segment together and usually much wider than funicle.Tegulae large; Mesoscutum very short, only half as long as scutellum, with a sculpture very similar to that of head.Scutellum slightly wider than long; axillae separated by a rather long median suture.Fore wings (Pl.3) of normal length, exceeding apex of gaster; fore wings basally infuscate, distal half and costal cell hyaline, with a hyaline streak adjacent to the postmarginal and stigmal veins.Marginal vein very short; postmarginal vein as long as stigmal; costal cell with one line of setae dorsally; Hind wings hyaline.Hypopygium reaching apex of gaster.
Male (Pl.4):Length: 0.27-1.27mm;differs from the female in its generally smaller size, more uniformly black with less metallic in color, in antennal structure, and wings venation.Funicle with two segments much wider than long.Clava one-segmented, long, curved bannashaped.Fore wigs hyaline, venation as in female.
Biology: In addition to the taxonomic characters, some observations were made on the biology of the parasitoid, the laboratory rearing of the field collected mummies on different host plants showed that maximum mummies were collected from Lantana camara (Verbenaceae) followed by Iresine herbstii (Amaranthaceae), and Portulaca oleracea (Portulaceae).It attacks the third instar nymphs of the host and kills the host before reaching maturity and this met with Ashfaq et al. (2010).The parasitoid took 10-12 days to complete its development in the host and caused transformation of parasitized mealybug into reddishbrown mummies which could be easily identified on the plants and can easily be distinguished from the healthy colony.It turns the mealybug into barrel-shaped mummy (Pl.5) with dark brown in color.This result is in agreement with Jhalal et al. (2008), Ram et al. (2009) and Prasad et al. (2011).This mealybug and its parasitoid were observed for the first time in Iraq simultaneously, so it is possible that this parasitoid is transferred with the mealybug into the newly invaded countries as was also noticed by Muniappan, 2010;Solangi and Mahmood, 2011.Comments: Our specimens of Aenasius arizonensis quite agree with the description which were given by Girult (1915) in describing his new species of Chalacspis arizonensis (=Aenasius arizonensis), and fit with the characters which were given by Hayat (2009) and Poorani et al. (2009) by having a hyaline streak adjacent to the postmarginal and stigmal veins in the fore wing.However, our specimens disagree with other authors who used some characters such as the color of the antennal segments.This character is probably unreliable according to Noyes and Ren (1995).Therefore, in this study, reliable characters were used to define this species.

Plate (2):
Antenna in the female of A. arizonensis.