Antonina graminis (Maskell)

Williams, D. J., 2001, African species of the mealybug genus Antonina Signoret (Hemiptera: Coccoidea: Pseudococcidae), Journal of Natural History 35 (6), pp. 833-848 : 835-837

Antonina graminis (Maskell)

(®gure 1)

Sphaerococcus graminis Maskell, 1897: 244 . Lectotype adult m, Hong Kong, on grass, designated by Williams, 1985: 45.

Antonina graminis (Maskell) , Fernald, 1903: 121; Williams, 1985: 45; Williams and Watson, 1988: 20; Ben-Dov, 1994: 38; Hendricks and Kosztarab, 1999: 103.

Antonina indica Green, 1908: 27 , Lectotype adult m, India, Bengal, on grass, designated by Williams, 1985: 45. Synonymized by Zimmerman, 1948: 156.

For the complete synonymy, see Ben-Dov (1994) and Hendricks and

Kosztarab (1999).

Comments

In recent years this species has been discussed at length by Williams and Watson (1988), Hendricks and Kosztarab (1999) and other workers, so only diagnostic characters are given here. Teneral females are almost quadrate in shape. The dorsal setae are minute, lanceolate to conical and the posterior marginal setae are mostly stiOE and blunt. Large-type tubular ducts form a band across the bases of abdominal segments VII and VIII and on the lateral margins of abdominal segment VI on the dorsum and venter. A narrow type of duct is abundant on both surfaces, anterior to the large ducts. Multilocular disc pores are con®ned to the venter, across the medial areas of the thorax and abdomen, except for a small band surrounding the anal opening and one or two on the dorsum. They are absent from the spiracular openings but surround the spiracles. Trilocular pores are present on the dorsum and venter, each about half as wide as a multilocular disc pore except for smaller trilocular pores, present in compact groups immediately next to the spiracular openings. The disc-like pores each have a well de®ned rim and a tessellated surface, and vary in size from smaller than a trilocular pore to about as large as a multilocular disc pore. They form wide submedial ventral bands from the metathorax to abdominal segment VII, lateral to the multilocular disc pores. The vulva has a speckled appearance and the lateral and posterior apophyses are slender and only slightly clavate. In most species of Antonina the medial segmentation, just anterior to the vulva, is clearly de®ned but in A. graminis it is more obscure.

Among the African species, A. graminis is close to A. transvaalensi s in possessing compact groups of trilocular pores adjacent to the spiracular openings and in lacking multilocular disc pores in these positions. The anterior dorsal setae in A. graminis , however, are minute, almost conical, whereas in A. transvaalensi s they are slender and ¯agellate. Moreover, the disc-like pores are conspicuous in A. graminis and are arranged from the metathorax to abdominal segment VI, whereas in A. transvaalensi s they are obscure and fewer, occurring only from abdominal segments II±IV. Yang and Kosztarab (1967) described the ®rst, second and third instars of A. graminis .

Usually known as the Rhodesgrass Scale, A. graminis is the most widespread and injurious species of the genus. It has been reported from most tropical and temperate areas, often causing damage to pasture and lawn grasses, and is often reported from bamboo species. Chada and Wood (1960) discuss the damage and host plant range; although based mainly on the USA, the account is still one of the most comprehensive for use throughout the world.

The accompanying illustration is new and is based on specimens collected in India, Orissa, Cuttack, on grass, collected in 1971.

Because A. graminis is widespread in Africa (Ben-Dov, 1994; Hendricks and Kosztarab, 1999; Commonwealth Institute of Entomology, 1985), the countries are not listed here. The species is discussed mainly to allow comparison with the other three African species.