armored scale insect

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 : 247-248

Key to armored scale insect species found on avocado in central México (adult females), partly based on Evans, Watson & Miller (2009)

1 Pygidium with 1-barred macroducts. L2 and L3 not divided. Plates present between pygidial lobes, usually fringed but sometimes fleshy and blunt.Anterior spiracles usually not associated with disc pores. Each antenna usually with only 1 obvious seta ( Aspidiotinae ).................................................................................... 2

- Pygidium with 2-barred macroducts. L2 and L3 usually divided, bilobate. Pointed gland spines often present between pygidial lobes. Anterior spiracles usually associated with disc pores. Each antenna usually with 2 or more setae (Diaspidinae)..... 15

2(1) Pygidial paraphyses present............................................................................. 3

- Pygidial paraphyses absent............................................................................. 14

3(2) Paraphyses originating only from basal angles of lobes, never present in interlobular spaces. All paraphyses shorter than L1 (except for 1 pair of very long outer L1 paraphyses in Clavaspis )............................................... 4

- With at least a few paraphyses originating within interlobular spaces. All paraphyses longer than L1, except in Aonidiella ... .................................................................................................. 10

4(3) Perivulvar pores present................................................................................ 5

- Perivulvar pores absent................................................................................. 7

5(4) L2 reduced to a single sclerosed point, L3 absent. Each L1 outer paraphysis conspicuously long, with a globular inner end. Each side with 2 or 3 perivulvar pores distributed singly.......................... Clavaspis herculeana Cockerell & Hadden

- L2 developed or reduced; L3 present but reduced. Each L1 outer paraphysis lacking a globular inner end. Perivulvar pores present or absent, when present distributed in groups......................................................... 6

6(5) Anal opening large (longer and wider than L1), separated from bases of L1 by no more than twice L1 length. L1 without basal sclerosis. Prosomal margin opposite anterior spiracle without sclerotized spur. L1 slightly convergent, each with lateral margin notched distally and slightly longer than inner margin................................ Hemiberlesia lataniae Signoret

- Anal opening small (smaller than L1 or same size), separated from bases of L1 by more than twice L1 length. L1 with well-developed basal sclerosis. Prosomal margin opposite anterior spiracle with sclerotised spur. L1 parallel, each with a distal notch on either side.............................................................. Hemiberlesia cyanophylli Signoret

7 (4) Anal opening large (longer and wider than L1), separated from base of L1 by no more than twice L1 length............. 8

- Anal opening small (shorter and narrower than L1), separated from base of L1 by more than twice L1 length............ 9

8(7) L2 and L3 each reduced to a sclerotized point, never toothed. Anal opening large, located no more than 1x length of L1 from L1 bases. Plates anterior to L3 not branched......................................... Hemiberlesia rapax Comstock

- L2 well developed, with slightly toothed lateral margin (with 1 or 2 teeth). Anal opening smaller, located at 1‒2x its diameter from L1 bases. Plates anterior to L3 branched....................................... Hemiberlesia diffinis Newstead

9(7) L2 and L3 absent. Pygidium wider than long, with relatively wide margins. Plates in first interlobular space short; other plates long, flattened, bifurcate or only slightly fringed................................... Hemiberlesia crescentiae (Ferris)

- L2 and L3 present. Pygidium longer than wide, with narrow margins. Plates in first interlobular space longer than adjacent lobes; long plates between other lobes with apices fringed, but plates lateral to L3 usually more-or-less bifurcate..................................................................... Davidsonaspis aguacatae (Evans, Watson & Miller)

10(3) Mature adult females with prosoma expanded and sclerotized, kidney-shaped. Perivulvar pores absent. Venter of pygidium with 2 pairs of linear prevulvar scleroses and 1 pair of apophyses.............................. Aonidiella aurantii Maskell

- Mature adult female with prosoma usually membranous or only slightly sclerotised, not kidney-shaped. Perivulvar pores present or absent. Venter of pygidium with linear prevulvar scleroses and apophyses absent or poorly developed............... 11

11(10) Body circular except for front part of head protruding and sclerotized, like a cap. Pygidium very short, wide, and rounded, with L4 well developed. Perivulvar pores absent........................................ Mycetaspis personata Comstock

- Body pyriform or oval, front of head not protruding and usually membranous. Pygidium long, narrow, and more angular, with L4 not well developed. Perivulvar pores present or absent.................................................... 12

12(11) Pygidial base wide, with sides straight and apex more-or-less rounded; apical angle usually greater than 90 o. Pygidial plates between L3 and L4 longer than lobes; with 2 plates lateral to L3 each with a fleshy filament. Prepygidial segments without any dorsal groups of 4 or more ducts; second and third pygidial furrows each with macroducts in a single row...................................................................................... Chrysomphalus dictyospermi Morgan

- Pygidium long, with base wide and sides often concave, tapering to a point; apical angle less than 90 o. Details of plates and distributions and numbers of macroducts different from above................................................. 13

13(12) L2 with paraphysis arising at external angle about 2x as long as paraphysis arising from inner angle. Anal opening elongate oval. Pygidium with macroducts in the third sclerotized area close to anal opening........... Acutaspis albopicta Cockerell

- L2 with paraphysis arising at external angle shorter, only 1.0‒1.6x longer than paraphysis arising from inner angle. Anal opening subcircular. Pygidium lacks macroducts in the third sclerotized area close to anal opening................................................................................................. Acutaspis scutiformis Cockerell

14(2) Anal opening obviously smaller than L1, located at about first basal fifth of pygidium. Pygidial macroducts relatively long and narrow (approximately 15x longer than wide). L3 developed, with apex rounded. Dorsal setae associated with L2 and L3 thickened, swollen basally.................................................. Oceanaspidiotus spinosus Comstock

- Anal opening same size or larger than L1, located at about first apical third of pygidium. Pygidial macroducts short and wide (approximately 5x longer than wide). L3 reduced to a sclerotised point. Dorsal setae associated with L2 and L3 not thickened or swollen basally................................................................... Aspidiotus nerii Bouché

15(1) Body elongate, at least 2x longer than wide, with lateral margins divergent posteriorly. L1 clearly separate. Each pre-pygidial segment with a sclerotized secondary lobe at the anterior lateral angle. Perivulvar pores present. Dorsal bosses absent............................................................................ Lepidosaphes pinnaeformis (Bouché)

- Body oval, turbinate or almost circular, less than 2x longer than wide. Perivulvar pores present or absent. L1 separated by a narrow or wide space................................................................................. 16

16(15) L1 widely separated, by at least 1x width of L1. Plates between L1 together fishtail-shaped; gland spines absent. Perivulvar pores present....................................................... Pseudoparlatoria parlatorioides Comstock

- L1 separated by only a narrow space, narrower than width of L1. Plates between L1 together not fishtail-shaped; slender gland spines may be present. Perivulvar pores present or absent.................................................... 17

17(16) Apex of pygidium with L1 asymmetrical, each lobe with inner margin longer than outer margin, forming a deep notch between lobes. Perivulvar pores present. L1 without any basal sclerosis. Gland spines between lobes present singly........................................................................................ Diaspis near coccois Lichtenstein

- Apex of pygidium with L1 more-or-less symmetrical, not forming a deep notch. Perivulvar pores absent. Inner basal corner of L1 with an elongate, club-shaped basal sclerosis. Gland spines between lobes present in groups of 4 or more......................................................................................... Howardia biclavis (Comstock)