Dasyneuriola prolifica Dorchin & Danon, 2019

Dorchin, Netta, Danon, Gilad & Dor, Roi, 2019, Gall midges (Diptera: Cecidomyiidae) associated with Suaeda (Chenopodiaceae) in Israel and the Mediterranean Basin, Israel Journal of Entomology (Oxford, England) 49 (2), pp. 99-134 : 106-111

publication ID

https://doi.org/10.5281/zenodo.3366130

publication LSID

lsid:zoobank.org:pub:088B3531-A07E-42B1-A26F-1372435F9E85

persistent identifier

https://treatment.plazi.org/id/03D487FB-FFA1-422A-FE92-FDE5366EF9C8

treatment provided by

Felipe

scientific name

Dasyneuriola prolifica Dorchin & Danon
status

sp. nov.

Dasyneuriola prolifica Dorchin & Danon View in CoL , n. sp.

( Figs 1–13)

LSID: urn:lsid:zoobank.org:act:7D8988EC-C6DD-4462-AEE4-C130773E9CE5 .

Etymology: The name prolifica refers to the great abundance of this species, as attested by tens of thousands of galls at specific sites, hundreds of galls on individual plants, and multiple generations over several months.

Description:

Gall and biology: This species induces simple galls in apical and axillary buds. Galls are 1–2 cm long and 1–1.5 cm wide, and are composed of distorted leaves that are much thicker and wider than normal leaves ( Figs 1, 2). The larvae feed gregariously among the deformed leaves, and each gall contained 3– 30 larvae, which can be seen easily if the leaves are separated. The inside of a young gall is moist, and the tiny first instars can be seen close to the leaf bases. Mature galls contain fewer larvae (usually 3–12), suggesting that intra-specific competition limits the number of larvae that complete their development within a gall. Third-instar larvae spin white silky sheets that divide the space inside the gall into compartments in which they pupate. In the laboratory, many larvae leave the galls at this stage and pupate in the soil or on the bottom of the rearing cages, but the extent of this phenomenon in nature is unknown.

The entire life cycle, from egg to adult, may take only three weeks and the species completes at least four generations between December and April, depending on the amount of rainfall. Galls appear on the plants soon after the first rains and the population peaks in February–March, when single S. fruticosa shrubs can support thousands of galls ( Fig. 3). Galls are much less common and conspicuous on S. asphaltica , and their abundance on that plant depends on the amount of rainfall in a particular year. In relatively wet years, S. asphaltica plants in some localities may support hundreds of galls, whereas in dry years it is difficult to find any galls in the very same localities. Larvae of the last generation (in March–April), and possibly a certain proportion of larvae from other generations, do not pupate inside the galls but leave them and dig into the soil, where they diapause until December. These larvae pupate and emerge as adults beginning from December–January. Based on laboratory and greenhouse observations, males live less than one day whereas females may live for 2–3 days at most. A newly emerged female exerts and waves her ovipositor, probably emitting pheromones to which the males are attracted. Mating, in a side-to side position, typically takes 10–30 seconds, after which the female retracts her ovipositor and usually does not mate again. Eggs are laid on leaves surrounding an apical bud and the larvae hatch and start feeding within 1–3 days. Galls become evident after about a week, and take about 20 days to reach their final size. Greenhouse experiments showed that a single female can easily spread her eggs among 15–20 buds, in which her offspring will develop successfully. Females are monogenous, hence each gall produces single-sex adults. Galls that produce adults of both sexes result from oviposition by more than one female.

This species has been the subject of extensive studies in recent years on the mechanism of speciation through a host shift between S. asphaltica and S. fruticosa ( Danon et al. 2017) . It has been found that the gall midges on these plants constitute genetically and ecologically distinct populations that are in early stages of separation, and that the original host plant was apparently S. asphaltica from which the gall midges shifted to S. fruticosa . In rare occasions we found single galls on S. aegyptiaca , which grows in the same habitats with S. fruticosa . The genetic profile of the midges reared from these galls was similar to that of midges from S. fruticosa rather than midges from S. asphaltica ( Danon et al. 2017) .

Adult. General color brownish orange, female abdomen pinkish red ( Fig. 4).

Head: Eye facets round; gap between eyes on vertex 1.5–2.5 facets wide.Antennal flagellomeres 11–13 in female, 13–16 in male; number sometimes differs between antennae of same individual. Male flagellomeres each, except last, composed of node and neck ( Fig. 5), necks 0.76–1.17 as long as nodes (n=40), first two flagellomeres partially fused; nodes entirely setulose, girdled by 1–2 loops of closely appressed, anastomosing circumfila and numerous strong setae originating from prominent sockets; necks bare. Apical flagellomere without neck, node smaller than nodes of preceding flagellomeres, tapering, vestiture as on nodes of preceding flagellomeres; sometimes fused with node of preceding flagellomere to form a single long node. Female flagellomeres cylindrical, without necks, about twice as long as wide, two basal flagellomeres partially fused, apical flagellomeres sometimes fused in one or both antennae to form a single unit 2–3 times as long as preceding flagellomeres; vestiture as in male. Frontoclypeal membrane with group of 8–10 very long, thin setae on each side. Palpus 3–4-segmented ( Fig. 9), rarely 2-segmented. First and second segments 1–2 times as long as wide, third (and fourth if present) 2–3 times as long as preceding; when 2 or 3-segmented, last segment often appears composed of two merged segments. First segment often rudimentary, resembling palpiger. Segment number occasionally differs between palpi of same individual.

Thorax: Wing transparent, sparsely covered by fine microtrichia. R 1 reaching C shortly before wing mid-length, R 4+5 straight, reaching C shortly before wing apex, M 4 and CuA weak, forming a fork. Wing length 1.27–2.08 mm in female (n=130), 1.48–2.25 mm in male (n=104). Legs densely covered by scales; claws evenly curved, with long and thin tooth; empodia considerably longer than bend in claw ( Fig. 10).

Female abdomen: Tergites 1–6 with anterior pair of trichoid setae and posterior row of long setae; tergite 7 ( Fig. 11) about twice as long as wide, divided anteriorly into two lobes, each with trichoid seta, widest posteriorly, with several rows of strong setae; tergite 8 ( Fig. 11) divided into two enlongate sclerites, each with anterior trichoid seta as the only vestiture, with diffusing pigmentation toward wider posterior section. Sternites 2–7 anteriorly with closely situated pair of trichoid setae, transverse patch of weak pigmentation proximal to 1–2 posterior rows of long setae, and numerous long setae medially. Ovipositor 3–7 times as long as tergite 8 (n=40). Fused cerci evenly setulose, with several long and thick setae ( Fig. 6). Hypoproct evenly setulose with a couple of long apical setae.

Male abdomen: Sclerites only slightly differentiated from surrounding tissue. Tergites 1–7 with anterior pair of trichoid setae, posterior row of long setae and few long setae medially, more numerous on posterior tergites; tergite 8 much smaller than preceding, with anterior pair of trichoid setae as the only vestiture. Sternites each with closely situated pair of trichoid setae anteriorly, and scattered long setae medially and posteriorly. Terminalia ( Fig. 12): Gonocoxite cylindrical, dorsally with numerous strong setae, anterior part of mediobasal lobes globose, densely setose, posterior part rectangular, not tapered distally, strongly ragged and setose, clearly shorter than aedeagus; gonostylus approximately same width throughout length, evenly and thoroughly setulose with numerous strong setae and medium-sized apical tooth. Cerci ragged, separated almost to base, rounded apically, densely setose and setulose, each with two very long setae apically and numerous long setae elsewhere; hypoproct relatively narrow, same width throughout length, apically bilobed, strongly ragged and setose, with numerous strong setae apically on each lobe; aedeagus truncate apically.

Larva (third instar) ( Fig. 13). Light orange; length: 1.38–2.57 mm (n=11). Integument rugose. Posterolateral apodemes longer than head capsule. Spatula longshafted, with trapezoid anterior lobe; on each side with two sets of three tiny lateral papillae. Terminal papillae with very short setae.

Pupa ( Figs 7, 8). Light orange. Antennal bases developed into short, tapered ‘horns’. Face smooth, without papillae. Cephalic seta long and fine. Prothoracic spiracle very long and tapered. Abdominal segments evenly covered by tiny spicules.

Holotype: ♀, Israel: Givat Gorni [31°19'07.59"N 35°19'54.41"E], 2.ii.2014, N. Dorchin & G. Danon, ex bud gall on Suaeda asphaltica . On permanent microscope slide in Euparal (SMNHTAU). GoogleMaps

Paratypes: Israel: From Suaeda asphaltica : 2♀, same data as holotype GoogleMaps ; 3♀, 1♂, Mizpe Yeriho , 1 km E, Rt. 1 (sea level sign), 9.ii.2012, N. Dorchin ; 4♀, Nabi Musa , 9.ii.2012, G. Danon ; 1♀ 14♂, Nabi Musa , 6.xii.2012, G. Danon ; 1♀ 2♂, Mizpe Yeriho , 1 km E, Rt. 1, 13.ii.2013, G. Danon & M. Baharal ; 4♂, Nahal Havarim , En Ovdat Nature Reserve, 3.iii.2013, G. Danon ; 2♀ 3♂, Har Yishay , 10.iii.2013, G. Danon ; 3♀ 3♂, Arad , 10 km E, Rt. 31, 200 ASL sign, 12.iii.2013, G. Danon .

From Suaeda fruticosa : 2♀ 1♂, Lido junction, 1 km W, Rt. 1, 31.i.1995, N. Dorchin ; 4♀ 3♂, En Gedi Nature Reserve , 13.ii.1996, N. Dorchin ; 2♀ 3♂, Zohar junction, 12.iii.2001, N. Dorchin ; 2♀ 2♂, Lido junction, 1 km W, Rt. 1, 20.i.2013, G. Danon ; 2♂, Enot Zuqim Nature Reserve , 9.ii.2013, N. Dorchin & G. Danon ; 3♀ 2♂, Nahal Mor , Rt. 90, 10.iii.2013, G. Danon .

Other material examined: Israel: 11 larvae (on four slides), Nabi Musa, 29.xi.2012, G. Danon, ex Suaeda asphaltica ; 5 larvae (on two slides), Nabi Musa, 6.xii.2012, G. Danon, ex Suaeda asphaltica ; 4 larvae, En Gedi Nature reserves, 13.ii.1996, N. Dorchin, ex Suaeda fruticosa ; 6 larvae (on two slides), Lido junction, 1 km W, Rt. 1, 20.i.2013, G. Danon, ex Suaeda fruticosa . Spain: 5♀ 6♂, Almeiria Province, Aguadulce, 19.iii.1982, E. SylvÉn ( NHRS-GULI 000013507-17); 8♀ Fuerteventura, Jandia, Punta del Matorral, 5–7, 17.xii.1986, E. Sylvén ( NHRS-GULI 000015383-90); 3 gall samples, Aguadulce, 19.iii.1982, E. Sylvén (host plant incorrectly identified as Suaeda maritima / S. vera ), deposited in NHRS (gall samples: NHRS-GULI 000011390,1,2).

Distribution: Probably circum-Mediterranean, as the species was reared from similar galls on S. fruticosa in Israel and Spain (incl. Canary Islands). Known in Israel from the northern Dead Sea area (on S. fruticosa ) and the Judaean Desert (on S. asphaltica ), and in southern Spain from Aguadulce, near Almeria and Fuerteventura in the Canary Islands.

Host plants: Suaeda fruticosa and S. asphaltica (rarely S. aegyptiaca ).

Remarks: Dasyneuriola species are morphologically similar and, in the lack of molecular data, the best attributes for distinguishing among them are those of the galls and host associations. The structure of D. prolifica galls and their great abundance resemble those described for D. suaedae Marikovskij from Suaeda microphylla in Kazakhstan ( Marikovskij 1961), although D. suaedae was reported to have a single generation a year, whereas D. prolifica is multivoltine. The host plants belong to the same section within the genus Suaeda (sect. Salsina; Schütze et al. 2003) but it seems unlikely that the gall midges on them belong to the same species given the vast geographic distance and the different habitats where the plants grow (Central Asia vs. Mediterranean; Dehghani & Akhani 2009).

Dasyneuriola salicorniae Fedotova from Suaeda altissima and D. suaedigemmae Fedotova from S. acuminata in Kazakhstan form bud galls that are similar to those of D. suaedae and were distinguished from D. suaedae based on morphological attributes that appear superficial (Fedotova 1995). The rarer and smaller galls of D. suaedigemmae and its pupation in the soil could be attributed to the association with that particular host plant. D. suaediramea Fedotova develops in multi-chambered stem galls on S. physophora , which are strikingly different from the galls of all other Dasyneuriola species on Suaeda , and the host plant belongs to a very different section within Suaeda (sect. Suaeda ; Schütze et al. 2003).

In summary, three of the Central Asian species of Dasyneuriola ( D. suaedae , D. salicorniae and D. suaedigammae ) appear similar to each other and a molecular study may show that they are conspecific. Despite the general morphological similarity of these species to D. prolifica , we describe the latter as new to science based on its geographical distribution, habitat and host range, a decision that could be tested by molecular data once available.

NHRS

Swedish Museum of Natural History, Entomology Collections

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Cecidomyiidae

Genus

Dasyneuriola

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