Research Article |
Corresponding author: Augusto Loni ( augusto.loni@unipi.it ) Academic editor: Kees van Achterberg
© 2016 Augusto Loni, Konstantin G. Samartsev, Pier Luigi Scaramozzino, Sergey A. Belokobylskij, Andrea Lucchi.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Loni A, Samartsev KG, Scaramozzino PL, Belokobylskij SA, Lucchi A (2016) Braconinae parasitoids (Hymenoptera, Braconidae) emerged from larvae of Lobesia botrana (Denis & Schiffermüller) (Lepidoptera, Tortricidae) feeding on Daphne gnidium L. ZooKeys 587: 125-150. https://doi.org/10.3897/zookeys.587.8478
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Bracon admotus Papp, 2000, and three species of the genus Habrobracon Ashmead, 1895, H. concolorans (Marshall, 1900), H. hebetor (Say, 1836) and H. pillerianae Fischer, 1980, were obtained from the larvae of Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera, Tortricidae) feeding on Daphne gnidium Linnaeus, 1753 (Thymelaeaceae) in the natural reserve of Migliarino-San Rossore-Massaciuccoli (Pisa-Central Italy). Bracon admotus, Habrobracon concolorans and H. pillerianae were found for the first time to be associated with L. botrana, while H. hebetor was reared for the first time from the larvae of Cryptoblabes gnidiella (Millière, 1867) (Lepidoptera, Pyralidae, Phycitinae) that was found on the same host plant. Bracon admotus and H. pillerianae are new to the fauna of Italy and Western Europe. A key is proposed for the determination of Habrobracon species reared from L. botrana and related Palaearctic species of this genus. Habrobracon lineatellae Fisher, 1968 is considered as a valid species.
European grapevine moth, idiobiont ectoparasitoids, Italy, natural environment, spurge flax, Thymelaeaceae , Tuscany
With about 2,500 species from almost two hundred genera, Braconinae is one of the largest subfamilies within the family Braconidae (
Among Braconinae, Bracon Fabricius, 1804 is a cosmopolitan and very common genus composed of the largest number of species. European fauna includes about 200 species of Bracon living on larvae of Lepidoptera, Coleoptera and Diptera (van
In agreement with the latest opinions of
Habrobracon is a worldwide group of small to very small wasps (
This paper presents the results of a study carried out in the natural reserve of Migliarino-San Rossore-Massaciuccoli in the province of Pisa (Tuscany, Italy). All over this area there is a large population of spurge flax, Daphne gnidium Linnaeus, 1753, a small shrub of the family Thymelaeaceae, whose sprouts, flowers and infructescences host a large community of moth larvae, most of which are represented by Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae). This species which was recently defined as European grapevine moth (EGVM) is a major pest of grapes in the Mediterranean basin and had recently been found in the Americas (
Predators and parasitoids associated with this moth have been studied in various European countries, and more than a hundred works have been published on the subject. To date there is still an incomplete list of the natural enemies of L. botrana, and information about these enemies is contained in some works published in the twentieth century, when the moth caused the first extensive damage to European vineyards (
In Italy, about thirty studies have been published reporting on 89 species of parasitoids living on L. botrana (
One of the problems with identifying the parasitoid complex of a pest is that the much of the data regards pests in agroecosystems, which usually simply represent pests outside of their natural environment. This is also valid for the European grapevine moth. The hundred or so published papers on its parasitoids only concern the dynamics in the vineyard. There are only three exceptions, all by Italian authors (
This paper reports on a study carried out in 2014 and 2015. It provides new information on one species of Bracon and three species of Habrobracon obtained from the larvae of L. botrana living on D. gnidium in a natural reserve in Tuscany (Italy). The massive presence of this important pest in a wild area offers a very interesting environmental context where to perform observations on the relationships among this phytophagous and its parasitoids complex in comparison with the cultivated field.
Weekly surveys were carried out in 2014 and 2015 in the natural reserve of Migliarino-San Rossore-Massaciuccoli, which covers around 23,000 hectares in the provinces of Pisa and Lucca (Tuscany, Italy) (http://www.parcosanrossore.org/). The landscape has a variety of environments, such as sandy shores and dunes stretching for about 23 km along the coast, wetlands with marshes, rivers, lakes, ponds, and forests. The Tyrrhenian Sea delimits the western border, the Lake of Massaciuccoli, the northern border, and the river Arno, the southern border. To the east, the landscape changes gradually from wild to rural areas. The distance from the east border to the west coast varies ranging from 6 to 10 kilometers.
In the back dunes and the thermophile Mediterranean wood, dominated by pine tree and holm oak, Daphne gnidium L. (Malvales, Thymelaeaceae) shrubs are widespread, covering the spaces where the sun can easily penetrate and the soil is mostly sandy. From March to October, sprouts, flowers and infructescences, depending on the period, host a wide and diverse community of Lepidoptera, mainly represented by Lobesia botrana.
An experimental area was selected, delimited by the following four geographical points 43.733642 N, 10.277524 E; 43.712864 N, 10.279648 E; 43.732913 N, 10.292371 E; 43.720101 N, 10.293094 E (DDM) and characterized by various habitats (Fig.
Among the huge number of parasitoid species that emerged during the rearing period, we focused on a small group of individuals belonging to the genera Bracon and Habrobracon, examining their role in the observed context, and their geographical distribution. The species mentioned in this work were identified by K. Samartsev. The specimens are now stored both at the Laboratory of Insect Taxonomy of the Zoological Institute of the Russian Academy of Sciences (St Petersburg, Russia) and at the Department of Agriculture, Food and Environment of Pisa University (Italy). For a description of the morphological features of the species, we referred to
POL postocellar line
OOL ocular-ocellar line
Od maximum diameter of lateral ocellus
Wing venation nomenclature follows van
1-R1 metacarp
2-SR first radiomedial vein
2-SR+M second medial abscissa
3-SR second radial abscissa
m-cu recurrent vein
r first radial abscissa
SR1 third radial abscissa
marginal cell radial cell
In 2014 and 2015 approximately 4,200 infested sprouts of D. gnidium were examined, obtaining 1,254 larvae of L. botrana in 2014, and 942 in 2015. In 2014 30 specimens of two genera were obtained, Bracon spp. and Habrobracon spp., emerging from the larvae of L. botrana and Cryptoblabes gnidiella (Millière, 1867) (Lepidoptera: Pyralidae), one of the other moths found on D. gnidium, while in 2015 we obtained only one specimen of Bracon.
These specimens represent approximately 11% of the parasitoid complex emerging from all samples in 2014, the majority of which were Ichneumonidae. They were mainly represented by the species Campoplex capitator Aubert, 1960, occurring across all sites and which contributed for more than 58% of the total number of parasitoids found in 2014 (Table
List of the main parasitoids emerged from the Daphne gnidium sprouts (2014).
Campoplex capitator Auber, 1960 (Ichneumonidae) |
Other Ichneumonidae | Bracon spp. Habrobracon spp. (Braconinae) | Other Braconidae (Cheloninae and Rogadinae) |
Chalcidoidea | Diptera Tachinidae |
---|---|---|---|---|---|
126 | 35 | 30 | 9 | 13 | 7 |
Bracon admotus Papp, 2000: 237;
2 males, October 14, 2014; 1 male, October 1, 2015.
This is the first record for Italy and Western Europe and L. botrana represents a new host for this parasitoid. The most important characters for distinguishing of B. admotus from the similar species of B. variator and B. obscurator species groups are: longitudinal diameter of eye 3.3–3.4 times (about 4.4 times in males) longer than malar space (front view); hypoclypeal depression 1.5–1.6 times (1.6–1.7 times in male) as wide as distance from depression to eye; mesosoma short, about 1.4 times (about 1.5 times in males) longer than maximum height; face and frons evenly granulate; vein r issued clearly before middle of pterostigma; first metasomal tergite (if measured from basomedian tubercle) 1.1–1.3 times as long medially as its apical width; furrow of first tergite and suture between second and third tergites crenulate; metasoma usually completely smooth.
Figure
Bracon concolor Thomson, 1892: 1807;
Bracon concolorans Marshall, 1900: 345 (new name for Bracon concolor Thomson, 1892 nec Bracon concolor Walker, 1871);
Habrobracon nigricans Szépligeti, 1901: 181;
Habrobracon mongolicus Telenga, 1936: 130, 342;
1 female, May 29, 2014; 4 females from the same host larva, July 4, 2014; 2 males from the same host larva, July 23, 2014; 2 females, October 2, 2014.
Habrobracon concolorans is a Trans-Eurasian species (
The collecting period of the L. botrana larvae hosting H. concolorans ranged from May 29 to October 2. L. botrana is considered a new host for H. concolorans. Also on L. botrana, H. concolorans develops as ectoparasitoids of mature larvae showing both solitary and gregarious habit, with up to four individuals feeding on the same host larva (Fig.
Bracon hebetor Say, 1836: 252;
Bracon brevicornis Wesmael, 1838: 23;
Bracon juglandis Ashmead, 1889: 621;
Other less valuable synonyms are listed in
1 female from larva of C. gnidiella, May 29, 2014; 2 females from larvae of L. botrana, June 6, 2014.
We found two specimens on mature larvae of L. botrana, but we also obtained one specimen by C. gnidiella (Fig.
Figure
Habrobracon pillerianae Fischer, 1980: 150;
5 females and 2 males, June 27, 2014 (3 females and 1 female + 2 males from the same host larva); 2 females and 1 male (1 male and 1 female reared from the same host larva) July 23, 2014; 1 female, 4 males, July 31, 2014; 1 female September 10, 2014.
Six specimens of this species were described by
Using the most complete key for the Palaearctic species (
1 | Middle lobe of mesoscutum glabrous (as in Fig. |
H. variegator (Spinola, 1808) species group (sensu Tobias) |
– | Middle lobe of mesoscutum (often evenly) setose (Figs |
2 |
2 | Mesoscutum (except middle lobe posteriorly and notauli lines) and most of mesopleuron completely smooth. Vein 2-SR+M 0.5–0.7 times as long as vein 2-SR, 1.1–1.4 times as long as vein m-cu (Fig. |
3 |
– | Mesoscutum and mesopleuron distinctly granulose or shagreened (Fig. |
4 |
3 | Antennae not thickened; first flagellar segment 1.8–2.0 times longer than its apical width, middle flagellar segments 1.6–1.7 times longer than wide. Vein 1-R1 0.85–1.00 times as long as pterostigma, 1.1–1.3 times longer than distance from apex of marginal cell to apex of wing. Face width 1.8–1.9 times its height with clypeus. Hypoclypeal depression 1.4–1.5 times wider than shortest distance from depression to eye. Transverse diameter of eye (dorsal view) 2.3–2.6 times longer than temple. Fore wing almost hyaline. 2.0–2.6 mm | H. breviradiatus Tobias, 1957 |
– | Antennae thickened; first flagellar segment 1.5–1.8 times longer than its apical width, middle flagellar segments 1.3–1.4 times longer than wide (Fig. |
H. hebetor (Say, 1836) |
4 | Mesosoma usually black, evenly granulose (except ventral side of mesopleuron; Figs |
5 |
– | Mesosoma reddish-yellow or black, with wide reddish pattern and smoothed areas on mesoscutum, pronotum and lateral side of mesopleuron (Fig. |
8 |
5 | Vein 1-R1 0.8–1.1 times as long as pterostigma complex of species [H. didemie (Beyarslan, 2002), H. excisus Tobias, 1957, H. kopetdagi Tobias, 1957, H. marshakovi (Tobias, 2000), H. nigerrimus Fischer, 1968, H. ponticus (Tobias, 1986), H. radialis Telenga, 1936] | |
– | Vein 1-R1 1.3–1.5 times longer than pterostigma (Fig. |
6 |
6 | Vein 3-SR 0.75–0.95 times as long as vein r (Fig. |
H. concolorans (Marshall, 1900) |
– | Vein 3-SR 1.4–1.7 times longer than vein r. OOL 2.2–2.8 times Od; POL 1.3–1.9 times Od. Face width 1.4–1.6 times its height with clypeus | 7 |
7 | Second tergite basally 1.4–1.6 times wider than its median length, coarsely rugose on sides of median convex area. Fore wing almost hyaline. Vein 1-R11.8–2.1 times longer than distance from apex of marginal cell to apex of wing. Hypoclypeal depression 1.2–1.3 times wider than minimum distance from depression to eye. Middle lobe of mesoscutum sometimes only with two longitudinal stripes of smoothed sculpture. 2.3–3.2 mm | H. crassicornis (Thomson, 1892) (H. flavosignatus Tobias, 1957) |
– | Second tergite basally 1.7–2.0 times wider than its median length, evenly striate-rugose medially and without median convex area. Fore wing faintly darkened in basal half. Vein 1-R1 3.0–4.5 times longer than distance from apex of marginal cell to apex of wing. Hypoclypeal depression 0.9–1.0 times as wide as shortest distance from depression to eye. Middle lobe of mesoscutum with two smooth longitudinal stripes. 2.5–3.0 mm | H. stabilis (Wesmael, 1838) |
8 | Vein 3-SR 1.2–1.3 times longer than vein 2-SR. Vein 1-R1 1.4–1.5 times longer than pterostigma, 5.0–6.0 times longer than distance from apex of marginal cell to apex of wing. Fore wing distinctly darkened in apical half. - Second metasomal tergite coarsely rugose on sides of short, almost smooth and convex median area. Middle lobe of mesoscutum with two smooth longitudinal stripes, but sometimes completely smooth. Median area of first metasomal tergite with roughly crenulate margins. Sculpture of mesosoma and metasoma often smoothed. 2.5–3.0 mm | H. lineatellae Fischer, 1968, stat. resurr. |
– | Vein 3-SR 0.6–1.0 times as long as vein 2-SR (Fig. |
9 |
9 | Vein 1-R1 1.0–1.2 times as long as pterostigma, 1.7–2.2 times longer than distance from apex of marginal cell to apex of wing. Vein SR1 4.0–4.5 times longer than vein 3-SR. Fore wing almost hyaline. – First flagellar segment 2.1–2.3 times longer than its apical width; middle and penultimate flagellar segments 1.7–1.9 times longer than wide | 10 |
– | Vein 1-R1 1.25–1.35 times longer than pterostigma, 2.5–5.5 times longer than distance from apex of marginal cell to apex of wing. Vein SR1 2.4–3.8 times longer than vein 3-SR. Fore wing faintly darkened at least under pterostigma (Figs |
11 |
10 | Antennae 23–25-segmented. Vein 3-SR 1.75–1.85 times longer than vein r. Transverse diameter of eye (dorsal view) 1.9–2.2 times longer than temple. Lateral areas of metanotum rugose to areolate with granulation. Propodeum with median keel and rugosity on wide area. OOL 1.4–2.0 times POL; POL 0.9–1.5 times Od. 2.8–3.6 mm | H. nygmiae Telenga, 1936 |
– | Antennae 17–19-segmented. Vein 3-SR 1.0–1.4 times as long as vein r. Transverse diameter of eye (dorsal view) 2.6–3.1 times longer than temple. Lateral areas of metanotum faintly granulose to smooth. Propodeum evenly granulose, without median keel. OOL 1.1–1.2 times POL; POL 1.6–2.0 times Od. 2.0–2.6 mm | H. telengai Mulyarskaya, 1955 |
11 | In female, POL 1.2–1.6 times Od, OOL 1.5–1.7 times POL (male unknown). Metasomal sculpture finer and shiny (same in large specimens; as in Fig. |
H. viktorovi Tobias, 1961 |
– | In female, POL 1.7–2.2 times Od, OOL 1.2–1.4 times POL (Fig. |
H. pillerianae Fischer, 1980 |
Our data provide new information about host association and distribution of Bracon and Habrobracon species. In the literature, there are few reports of Habrobracon or Bracon species living on L. botrana (Table
List of records of Habrobracon and Bracon spp. on Lobesia botrana arranged in chronological order.
Names as used in scientific publication | Valid names | Geographic area | Authors |
---|---|---|---|
Habrobracon sp. | Habrobracon sp. | Sardinia |
|
Habrobracon spp. | Habrobracon sp. | South Italy |
|
Habrobracon johannseni Viereck, 1912 | Habrobracon gelechiae (Ashmead, 1889) | France, experimentally reared from L. botrana larvae |
|
Microbracon gelechiae Ashmead | Habrobracon gelechiae (Ashmead) | France |
|
Habrobracon gelechiae (Ashmead) | Habrobracon gelechiae (Ashmead) | France |
|
Bracon sp. | Bracon sp. | Northwest Iran |
|
Habrobracon sp. | Habrobracon sp. | Northwest Iran |
|
B. admotus was described by J.
H. concolorans was re-described by J. Papp in 2008; however, it is still reported as Bracon (Habrobracon) nigricans (Szépligeti) in recent papers (
Taxa | Main references |
---|---|
LEPIDOPTERA | |
GELECHIIDAE | |
Pexicopia malvella (Hübner, 1805) |
|
Phthorimaea operculella (Zeller, 1873) |
|
Tuta absoluta (Meyrick, 1917) |
|
NOCTUIDAE | |
Heliothis maritima Graslin, 1855 |
|
NYMPHALIDAE | |
Vanessa cardui (Linnaeus, 1758) |
|
PYRALIDAE | |
Assara terebrella (Zincken, 1818) (=Ephestia terebrellum Zincken nec Zeller) |
|
Etiella zinckenella (Treitschke, 1832) |
|
Loxostege sticticalis (Linnaeus, 1761) |
|
TORTRICIDAE | |
Cnephasia sedana (Constant, 1884) |
|
Cydia cosmophorana (Treitschke, 1835) |
|
Cydia strobilella (Linnaeus, 1758) |
|
Lobesia botrana (Denis & Schiffermüller, 1775) | new host for H. concolorans |
COLEOPTERA | |
ANOBIIDAE | |
Ernobius nigrinus (Sturm, 1837) |
|
Habrobracon hebetor has been re-described many times and has a large number of synonyms because of the wide distribution, the broad host range and morphological variability. Regarding its generic attribution, in addition to Bracon and Habrobracon, it was also once assigned to Microbracon Ashmead, 1890 (synonym of Bracon). Although they were synonymised for the first time more than 50 years ago (
List of records of H. hebetor on L. botrana arranged in chronological order.
Names as used in scientific publication | Geographic area | Authors |
---|---|---|
Habrobracon sp. | South Italy |
|
Habrobracon brevicornis (Wesmael) | Italy |
|
Microbracon brevicornis (Wesmael) | Italy |
|
Habrobracon hebetor (Wesmael) | South Italy |
|
Bracon sp. [Habrobracon sp.] | Italy |
|
Habrobracon hebetor (Say) | Greece, laboratory test |
|
Habrobracon hebetor (Say) | Northwest Iran |
|
All these collected Braconinae represent only a minor component of the parasitoid complex we found, mainly represented by the larval endophagous koinobiont Campoplex capitator (Hymenoptera: Ichneumonidae). They showed a reduced prevalence, occurring only in three sites out of the nine sampled, while C. capitator was found everywhere. These are the typical features of rare taxa, that can play a crucial role in the case of a local and temporal extinction of the main parasitoids (
Our findings of three Habrobracon and one Bracon species living on L. botrana larvae in the natural reserve of Migliarino-San Rossore-Massaciuccoli provide important evidence that this wild area could be of great advantage to the surrounding territories. The Tuscan rural landscape is covered in vineyards, where L. botrana is the key pest. The vineyard agroecosystem is well integrated with the surrounding areas, rich in natural habitats, and hosts a very diverse braconid fauna (
We would like to thank Dominique Zimmermann (Naturhistorisches Museum Wien, Austria) for providing the type of Habrobracon pillerianae for the study, Dr. Rebecca Marzani and Dr. Luca Gandini for their field and lab support. We are grateful to the Reserve Director, Andrea Gennai, and the ranger Marco Lorenzini, for hosting the research. This study was partly supported by grants provided by the Russian Foundation for Basic Research (grant No. 15-29-02466, 16-04-00197 and 16-34-00236) for K.G. Samartsev and S.A. Belokobylskij and by Fondi di Ateneo of Pisa University.