Davidsonaspis aguacatae (Evans, Watson & Miller)

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 : 253-254

Davidsonaspis aguacatae (Evans, Watson & Miller)

Abgrallaspis aguacatae Evans, Watson & Miller 2009: 58 .

Davidsonaspis aguacatae (Evans, Watson & Miller) ; Normark et al. 2014: 44.

Field diagnosis. Adult female scale cover subcircular to broadly oval and flat, flimsy, about 1.2 mm in diameter, brown to dark brown, with subcentral exuviae. Body of live adult female pyriform, with rather sharp pygidial apex, whitish yellow, about 0.9 mm in diameter. According to Evans et al. (2009), the pygidium is yellow brown with a darker apex, and the slide-mounted body of the adult female is 0.84‒1.37 mm long and 0.64‒1.07 mm wide.

Discussion. Davidsonaspis aguacatae can be confused with H. diffinis because the latter’s scale cover sometimes turns dark when honeydew from other sucking insects falls on it. The slide-mounted adult females can be separated by the following characteristics: Da. aguacatae has three well-developed pygidial lobes and L2 and L3 each have two or more lateral teeth, while H. diffinis has only two well-developed lobes, and L2 has one or two lateral teeth; L3 is only small and lacks lateral teeth.

Habits on the hosts. The scale was collected from leaves, branches, and fruits, where it was observed grouped in small to large colonies, with intermingled females and males. On leaves it was detected on the adaxial and/or abaxial surfaces. In addition, Da. aguacatae was found associated with other armored scales such as Diaspis near coccois , H. diffinis , H. lataniae and H. rapax .

Hosts. The scale has only been found attacking Persea americana ( Evans et al. 2009; García Morales et al. 2016); the present study found it on the varieties Fuerte, Hass, Mexican 1, Granón and Padua.

Distribution. Although Da. aguacatae has been recorded only from the state of Michoacán ( Evans et al. 2009; García Morales et al. 2016), previously González Hernández & Atkinson (1984) had detected it on avocado in Zacatlán, Puebla, where it was initially identified as Quadraspiditous perniciosus ( Comstockaspis perniciosa ) (Comstock). The present study recorded it in the following states and orchards: State of México: La Cabaña, Cochisquila 1, Cochisquila 2, La Colonia, Ixtlahuaca 1, La Casita, Ixtlahuaca 2, and Ixtlahuaca 3; and Puebla: La Aguacatera.

Natural enemies. Among the natural enemies of Da. aguacatae reported are the hymenopteran parasitoids Aphytis sp. , Encarsia citrina , E. juanae ( Lázaro-Castellanos et al. 2012) , E. lounsburyi ( Stocks & Evans 2017) (Aphelinidae) , and Signiphora flavella (mistakenly identified as Signiphora near borinquensis) ( Signiphoridae ); and the predatory beetle Chilocorus cacti (Coccinellidae) ( Lázaro-Castellanos et al. 2012). In the present study, we obtained 19 specimens, of which 14 were hymenopteran parasitoids and five were coccinellid predators. The species identified were the parasitoids Aph. lepidosaphes (1F), Encarsia citrina (2F), E. aurantii (1F), E. juanae (1F), E. gaonae , E. lounsburyi (4F) ( Aphelinidae ) and Signifora flavella (2F, 2M) ( Signiphoridae ); and the coccinellid predator Coccidophillus atronitens (5).