Lepidosaphes pinnaeformis (Bouché)

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 : 260

Lepidosaphes pinnaeformis (Bouché)

Aspidiotus pinnaeformis Bouché 1851: 111 .

Mytilaspis pinnaeformis (Bouché) ; Signoret 1870: 97.

Mytilaspis machili Maskell 1898: 230‒231 .

Lepidosaphes machili (Maskell) ; Fernald 1903: 311.

Lepidosaphes pinnaeformis (Bouché) ; Green 1905: 28.

Lepidosaphes tuberculata Malenotti 1916: 183‒185 .

Scrupulaspis machili (Maskell) ; MacGillivray 1921: 288.

Parlatoria pinnaeformis (Bouché) ; Bodkin 1922: 60.

Lepidosaphes cymbidicola Kuwana 1925: 48‒50 .

Lepidosaphes ezokihadae Kuwana, 1932: 147 .

Lepisodaphes cinnamomi Takahashi 1933: 48‒50 .

Lepidosaphes pinniformis (Bouché) ; Schmutterer 1952: 578.

Eucornuaspis pinnaeformis (Bouché) ; Wise 1977: 108.

Mytilococcus machili (Maskell) ; Zahradnik 1977: 120.

Field diagnosis. Adult female scale cover elongated, often with caudal region widened, giving it an oyster- or mussel-like appearance; slightly convex, narrow, or curved, 2.5‒3.5 mm long, brown with terminal exuviae yellow or slightly orange. Body of live adult female membranous, elongate, with rounded head, creamy white or pearly.

Discussion. In the field, L. pinnaeformis could be confused with L. beckii because the adult female scale covers are usually very similar in shape and color; however, in L. pinnaeformis they remain brown throughout development, whereas according to Watson (2002), those of L. beckii are dark brown but occasionally have light tan edges, and the posterior end of each exuviae often has a red spot. Morphologically, in slide mounts, the adult females do not show much similarity characteristics of L. beckii according to Watson (2002) given in parenthesis; L. pinnaeformis has each eye developed into a sclerotized spur (not developed into a spur), lateral marginal spurs present on margins of prepygidial segments II, III and IV (lateral marginal spurs absent); and pygidium with five or six marginal macroducts on each side (six marginal macroducts on each side). In the present study, in samples from the state of Morelos where this species was collected, empty purplish scale covers were found but female specimens could not be obtained to confirm whether L. beckii was present.

Habits on the hosts. The scale was found on branches in small groups or individually, associated with other armored scales such as Da. aguacatae , Diaspis near coccois , H. diffinis and H. lataniae .

Hosts. Lepidosaphes pinnaeformis is a polyphagous species that attacks members of 34 genera belonging to 21 plant families, some of which are of economic importance such as lemon, peach, tea and avocado, among others ( Watson 2002; García Morales et al. 2016). In this study it was found associated with the avocado varieties Fuerte, Mexicano 1 and Vitacalli.

Distribution. The scale is known to be present in 35 countries on five continents ( Watson 2002; García Morales et al. 2016). In the present study it was recorded in the following states and orchards: Morelos: Isla Chica 1 and Paluca 2; and Puebla: La Aguacatera.

Natural enemies. Among the natural enemies associated with L. pinnaeformis are species in 12 genera belonging to seven families: Hymenoptera : Aphelinidae , Encyrtidae , Mymaridae and Signiphoridae ; Coleoptera : Coccinellidae ; Lepidoptera : Noctuidae ; and Thysanoptera : Phlaeothripidae . Some of the genera notable for the number of their species that attack L. pinnaeformis are the parasitoid wasps, Aphelinidae : Aphytis (4) and Encarsia (6); and other genera each represented by only one species: Marietta and Pteroptrix ; Encyrtidae : Metaphycus ; Mymaridae : Arescon ; and Signiphoridae : Signiphora . The predators include the Coccinellidae : Chilocorus , Coccidophilus , Exochomus ; Lepidoptera : Prospalta ; and Phlaeothripidae : Karnyothrips ( Watson 2002; García Morales et al. 2016; Noyes 2019). However, no natural enemies were obtained from L. pinnaeformis in the present study.