Immature stages of the genus Oxythyrea (Coleoptera: Scarabaeidae: Cetoniinae) with a key to third instar larvae, and notes on the biology of the genus
Author
Vondráček, Dominik
Author
Hadjiconstantis, Michael
Author
Šípek, Petr
text
Zootaxa
2018
2018-10-01
4486
4
401
434
journal article
29367
10.11646/zootaxa.4486.4.1
de2f897b-3d16-4bcd-99a7-fb46a61b5bd1
1175-5326
1442168
7652EE8A-437B-4A61-ACF6-4A3BF6553808
Key to third instar larvae of Palaearctic
Oxythyrea
species
1 Raster more or less horseshoe-shaped, various habitats (
Fig. 10B–C, E–H, K–L, N–Q
).............................. 4
- Raster composed of two or more parallel rows of pali. Habitat in sand dunes, usually near shoreline of the Mediterranean Sea (
Fig. 10
A
, D, I, J, M, R
)................................................................................ 2
2 Raster (
Fig.
10I
, R
) monostichous (sometimes few pali scattered around main row), each row of pali with approximately 18–23 pali on each side, tegilla and dorsal parts of last abdominal segment covered with more or less sparse setae, medium and long setae sparse, almost absent. Zygum (
Fig.
5I
) with transverse, arcuate or angulate row of 12–15 stout setae and posterior group of another 4–7 stout setae. Habitat in shoreline sand dunes (
Tunisia
,
Libya
).............................
O. tripolitana
- Raster monostichous or polystichous with more than 24 pali on each side, tegilla and dorsal parts of last abdominal segment densely setose with numerous medium and long setae (
Fig. 10
A
, D, J, M
). Zygum with transverse, arcuate or angulate row of 11–15 stout setae and posterior group of another 10–14 stout setae (
Fig. 5
A
, D
)................................... 3
3 Cranium width
2.55–2.7 mm
; cranium pale brown, sclerotised parts of antennomeres uniformly pale brown (
Fig. 4
A
). Habitat in shoreline sand dunes (
Cyprus
,
Israel
,
Lebanon
,
Syria
,
Egypt
)..........................................
O. abigail
- Cranium width
2.89–3.04 mm
; cranium chestnut brown, sclerotised parts of antennomeres brown to dark brown, often with ultimate and penultimate antennomera darker than the preceding antennomers (
Fig. 4D
). Note: the discrimination between
O. abigail
and
O. dulcis
based purely on larval characters is merely impossible and the characters given here might be an artefact of the breeding conditions or of the storing of the larval samples. Habitat in shoreline sand dunes (
Montenegro
,
Greece
, western and southern coast of
Turkey
)...................................................................
O. dulcis
4 Dorsum of last abdominal segment more or less truncate, with distinct round field of short ovate or scale-like setae (exception- ally also hammate setae) bordered by more or less distinct ring of long erect setae (
Fig. 11B, C, F
). Distance between ridges of mandibular stridulatory field more or less equal, or only slightly dwindling towards both ends (
Fig. 7B, C, F
)............ 5 - Dorsum of last abdominal segment not truncate, lacking distinct round field and the circular row of long setae, setae on dorsum of last abdominal segment hammate. Distance between ridges of mandibular stridulatory area distinctly uneven: ridges very fine in proximal third, while very distant in remaining area (distance between two ridges about 4 times larger than in proximal area). Note: rarely sparse circular row of long setae is present on dorsum of last abdominal segment also in
O. funesta
(
Fig. 11E, M
), thus it is important to examine carefully mandibular stridulatory area (
Figs. 7E
;
8
A
, B
)!..................... 7
5 Dorsum of last abdominal segment with circular row of long setae composed of only single row of setae, circular field with short ovate setae (
Fig. 11B
). Chaetopariae of epipharynx with 45–52 and 30–36 setae on right and left side respectively, cranial width between 2.01 and
2.21 mm
, mandibular stridulatory area with 9–11 ridges (
Figs. 7B
,
8E
). Wide range of habitats, usually open grasslands and shrubs, steppe, with more continental climatic conditions (Eastern Mediterranean to
Central
Asia)................................................................................................
O. albopicta
- Dorsum of last abdominal segment: circular row of long setae composed usually of more than one row of setae, inner circular field with short ovate or scale-like setae (
Fig. 11C, F
). Chaetopariae of epipharynx with more than 54 and 36 setae on right and left side, respectively; stridulatory area of mandibles with 13–25 ridges (
Figs. 7C, F
,
8F
,
9C
)......................... 6
6 Body whitish, setose fields of each (sub)lobe yellowish-brown. Oval field on dorsum of last abdominal segment with short ovate setae. Chaetopariae of epipharynx with 63–77 and 36–53 setae on right and left side, respectively; stridulatory area of mandibles with 13–20 ridges (
Figs. 7C
,
8F
). Wide spectrum of habitats in different altitudes (Eastern Mediterranean to
Central
Asia)......................................................................................
O. cinctella
- Body more or less uniformly whitish. Oval field on dorsum of last abdominal segment with short scale-like setae. Chaetopariae of epipharynx with 54–70 and 43–53 setae on right and left side, respectively; stridulatory area of mandibles with 20–25 ridges (
Figs. 7F
,
9C
). Wide spectrum of habitats in different altitudes (
Cyprus
,
Israel
,
Jordan
,
Lebanon
,
Syria
,
Egypt
,
Turkey
)...................................................................................................
O. noemi
7
O. funesta
complex (
O. funesta
,
O. pantherina
,
O. subcalva
). Note: The discrimination of larval forms of these three species remains merely impossible without knowledge of the origin of the material. Larvae from Europe and Asia belong to
O. funesta
.
However, specimens from
Northern
Africa remain impossible to determine according to their morphological characters. The only clue might be the size (
O. pantherina
tends to be slightly larger with cranial width above
2.55 mm
), and the ecological characteristics of the locality (
O. funesta
is usually found in wetter coastal areas and mountain ranges, while
O. subcalva
lives in more dry conditions on the edge of sandy deserts).