Table 3 Key for ectoparasites identification

1a

Three pairs of legs

2

1b

Four pairs of legs

13

2a

Body laterally flattened (SIPHONAPTERA)

3

2b

Body dorsoventrally flattened (PHTHIRAPTERA)

10

3a

Pronotal and/or genal ctenidia present

4

3b

Pronotal and genal ctenidia absent

6

4a

Genal ctenidium absent and pronotal ctenidium present

Nosopsyllus fasciatus

4b

Genal and pronotal ctenidia present

5

5a

Genal ctenidium with the first seta much shorter than the others (Figure 3A; arrowhead); posterior tibia with two simple setae between the penultimate and the last double setae (Figure 3A; arrows)

Ctenocephalides canis

5b

Genal ctenidium with the first seta approximately the same length of the remaining (Figure 3B; arrowhead); posterior tibia with one simple seta between the penultimate and the last double setae (Figure 3B; arrow)

Ctenocephalides felis felis

6a

Thoracic segments narrow (Figure 3C; arrow), ocular and occipital setae absent; front of the head angular (upturned) (Figure 3C; arrowhead)

Tunga penetrans

6b

Not as above

7

7a

Abdominal segments with two rows of setae in the dorsal border

Rhopalopsyllus lutzi lutzi

7b

Abdominal segments with one row of setae in the dorsal border

8

8a

Occipital region with one seta (Figure 3D; arrow)

Pulex irritans

8b

Occipital region with two rows of setae arranged in a “V”

9

9a

Male antepygidial seta inserted on a discrete tubercle; female with body of spermatheca (in black) not larger than the base of tail (Figure 3E)

Xenopsylla cheopis

9b

Male antepygidial seta inserted on a well-developed tubercle; female with body of spermatheca (in black) larger than the base of tail (Figure 3F)

Xenopsylla brasiliensis

10a

Head longer than large (Figure 3G; arrow); sucking mouthparts

Linognathus setosus

10b

Head as large as long; chewing mouthparts

11

11a

Tarsus with two claws (Figure 3H; arrow)

Heterodoxus spiniger

11b

Tarsus with one claw

12

12a

Head rounded anteriorly (Figure 3I)

Trichodectes canis

12b

Head triangular in shape (Figure 3J)

Felicola subrostratus

13a

Body length equal or less than 0.5 mm; Haller’s organ absent

14

13b

Body length larger than 0.5 mm; Haller’s organ present on first tarsi (IXODIDA)

19

14a

Body carrot-shaped or with a bell pepper shape (TROMBIDIFORMES)

15

14b

Body not as above, usually rounded in shape (SARCOPTIFORMES)

16

15a

Body long and slender (carrot-shaped) (Figure 3K)

Demodex spp. ^a

15b

Body with a bell pepper shape; well-developed mouthparts; palpi that end in prominent hooks (Figure 3L; arrow)

Cheyletiella spp. ^b

16a

Body rounded

17

16b

Body cylindrical and elongate, heavily striated (Figure 3M)

Lynxacarus radovskyi

17a

Legs long, with short, unjointed pedicels (Figure 3N)

Otodectes cynotis

17b

Legs short, with long, unjointed pedicels

18

18a

Anus dorsal (Figure 3O; arrow)

Notoedres cati

18b

Anus terminal (Figure 3P; arrow); body surface covered by several triangular spines arranged in rows

Sarcoptes scabiei

19a

Inornate; basis capituli hexagonal; coxa I bifid

Rhipicephalus sanguineus s.l. ^c

19b

Usually ornate; basis capituli variable in form

Amblyomma spp. ^d