Chrysomphalus dictyospermi (Morgan)

Lázaro-Castellanos, Carlos, González-Hernández, Héctor, Nápoles, Jesús Romero-, Ortega-Arenas, Laura D., Equihua-Martínez, Armando & Ochoa-Ascencio, Salvador, 2023, Armored scale insects (Hemiptera: Diaspididae) associated with avocados (Persea americana) in México’s main production areas, with keys for identification and natural enemies, Zootaxa 5357 (2), pp. 241-269 : 252-253

Chrysomphalus dictyospermi (Morgan)

Aspidiotus dictyospermi Morgan 1889: 352 .

Aspidiotus dictyospermi arecae Newstead 1893a: 185 .

Aspidiotus mangiferae Cockerell 1893b: 255 .

Aspidiotus dictyospermi jamaicensis Cockerell 1894: 129 .

Chrysomphalus dictyospermi (Morgan) ; Maskell 1895: 44.

Aspidiotus minor Cockerell 1896: 334 .

Chrysomphalus minor Berlese in Berlese & Leonardi 1896: 346.

Chrysomphalus mangiferae (Cockerell) ; Leonardi 1899: 199.

Chrysomphalus dictyospermi minor (Berlese in Berlese & Leonardi); Marchal 1904: 246.

Aspidiotus agrumincola De Gregorio 1915: 125 , 164.

Chrysomphalus castigatus Mamet 1936: 94 .

Chrysomphalus dictyospermi (Morgan) ; Ferris 1938: 200.

Field diagnosis. Adult female scale cover circular and flat, about 1.7 mm in diameter, gray to brown or dark brown; according to Watson (2002), it can have a diameter of 1.5 to 2.0 mm and be greyish to reddish brown with yellow central exuviae. Body of live adult female pyriform, white to yellow, membranous, with a diameter of about 1.1 mm.

Discussion. Chrysomphalus dictyospermi is easily distinguishable from other Chrysomphalus species by having clavate processes on two plates lateral to each L3, and by lacking clusters of dorsal prepygidial ducts ( Miller & Davidson 2005).

Habits on the hosts. The scale was found on branches, leaves, and fruits, but was most common on branches. It was detected in groups or individually on the different substrates; on leaves it was observed on both adaxial and abaxial surfaces. Generally, Chr. dictyospermi was found associated with other species of armored scales such as Ac. scutiformis , D. near coccois , H. crescentiae , H. diffinis , H. lataniae , H. rapax , Ho. biclavis and Cl. herculeana .

Hosts. Chrysomphalus dictyospermi is a highly polyphagous species that attacks members of 188 plant genera belonging to 80 families, several of which are economically important, such as citrus, mango, annona, coconut, banana, papaya, date palm and avocado, as well as other tropical and subtropical plants ( Watson 2002; Smith-Pardo et al. 2012; García Morales et al. 2016). In this work, the scale was found associated with the avocado varieties Fuerte, Hass, Mexicano 1 and Padua.

Distribution. The species is cosmopolitan but is found mainly in tropical and subtropical regions ( Smith-Pardo et al. 2012). Chrysomphalus dictyospermi has been recorded in 102 countries on five continents worldwide ( Watson 2002, García Morales et al. 2016). In México it has been reported in the state of Veracruz ( García Morales et al. 2016) and the central region of México on mango, pear, and citrus (González Hernández & Atkinson 1984). In the present study, it was recorded in the following states and orchards: Puebla: Acapulco and La Cuesta; Colima: Rancho Alto and La Calma; and Nayarit: UAN, Crucero la Curva, Los Terreros, Camichin1, Camichin 2, and La Fortuna.

Natural enemies.Among the natural enemies reported to be associated with Chr.dictyospermi are listed 21 genera belonging to eight families, particularly the hymenopteran parasitoids: Aphelinus , Aphytis , Coccophagus , Encarsia , Marietta and Pteroptrix (Aphelinidae) ; Comperiella , Metaphycus (Encyrtidae) ; Arrenophagus , Coccidencyrtus , Habrolepis (Encyrtidae) ; Tetrastichus (Eulophidae) ; Theocolax (Pteromalidae) ; and Signiphora , also Thysanus (Signiphoridae) . Predators of the scale particularly include beetles in Chilocorus , but also in Exochomus , Halmus , Rhyzobius (Coccinellidae) , and predatory mites in Hemisarcoptes (Hemisarcopidae) ( García Morales et al., 2016; Noyes 2019). In the present study, 20 parasitoid specimens were obtained from Chr. dictyospermi : Aphytis holoxanthus (9F, 2M), Aph. lepidosaphes (1F), Aph. melinus (1H, 2M), Encarsia juanae (1F), E. perniciosi (1F), Signiphora dozieri (1F) and S. falcata (1F, 1M).