Corresponding author: Rafał Gosik (
Academic editor: M. Alonso-Zarazaga
The mature larva and pupa of
Gosik R, Sprick P, Morris MG (2019) Descriptions of immature stages of four species of the genera
In this continued contribution on larvae of the subfamily
In the present paper we describe for the first time the mature larva and pupa of
From the tribe
Despite the frequency and abundance of
The aim of this paper is to describe the mature larvae of the four
Specimens of three of the four species studied were collected in the field under certain plants and usually
All specimens studied were fixed in 75% ethanol and examined under an optical stereomicroscope (Olympus SZ 60 and SZ11) with calibrated oculars. Measurements of larval instars were made for: body length (
The observations and measurements were conducted using a light compound microscope with calibrated oculars. Drawings and outlines were made using a drawing tube (MNR–1) installed on a stereomicroscope (Ampliwal) and processed by computer software (Corel Photo-Paint X7, Corel Draw X7). Photos were taken with an Olympus E-M10 or using an Olympus BX63 microscope and processed by Olympus cellSens Dimension software. The larvae selected for pictures using SEM (scanning electron microscope) were
We follow
All these specimens are deposited in the collection of the Department of Zoology, Maria Curie-Skłodowska University (Lublin, Poland). In Table
Larval instar determination is based on Dyar’s law (
Body length: 6.8–8.5 mm, body width: 3.0–3.4 mm, head width: 1.53–1.55 mm, head height: 1.35–1.37 mm.
Body (Figs
Head (Fig.
Body length (♂, ♀): 7.5–9.0 mm; body width (
Body moderately slender, straight, yellowish. Cuticle smooth (Figs
Chaetotaxy well developed, setae variable in lengthand shape: spine-like or capilliform, dark yellow to brown, usually located on visible protuberances. Head capsule and rostrum include 1
Rearing was started on 02.05.2012 in the climate chamber of JKI in flowerpots with mainly
Body length: 6.5–7.7 mm, body width
Body (Figs
Head (Fig.
Body length: 6.5–8.2 mm, body width
Body (Figs
Head (Fig.
Body length: 8.3–10.0 mm, body width
Body (Figs
Head (Fig.
1 | Abdominal segment 9 about regular structure (type “A” Van |
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– | Abdominal segment 9 strongly reduced, consisting of four well-isolated lobes (type “B” Van |
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2 | Abdominal segment 9 with 3 |
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– | Abdominal segment 9 with 4 |
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3 | Abdominal segment 9 with 2 |
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– | Abdominal segment 9 with 3 |
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There are some strange statements about the number of larval instars in the larval stage of species of genus
In
For the exact determination of the number of larval instars we summarized and assessed our own measuring data and added data from literature, if necessary (Tables
Due to the dubiousness of the number of larval instars in
We also needed to determine the number of larval instars for both species: there are data for L1 and for mature larvae, and in
The determination of larval instars is mainly based on the method of
In
For larval instar determination in
From Table
For this approximation it is only necessary to know the head width of the L1 larva and that of the last instar. And the
An instar determination is also possible for
In
Head width measuring data of the species studied. Results in mm; n – number of specimens measured, in adults behind eyes; L1 – first instar larva; ML – mature larva; *: an assignment to this instar is doubtful. A transfer to ‘mature larvae’ would change the average value only slightly; **: data from
Species | Larval instars | Pupa | Adult | ||
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L1 larvae | Premature larvae | Mature larvae | |||
0.572; 0.603; 1.001; 1.072; 1.171 | 1.373; 1.402; 1.431; 1.472; 1.506; 1.534; 1.551 | 1.131; 1.171; 1.201 | 1.051; 1.151; 1.21; 1.253; 1.33; 1.41; 1.451; 1.51 | ||
Mean value (x¯) | 0.34 | 0.806 | 1.471 | 1.167 | 1.283 |
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– | – | 0.871; 0.902; 1.105; 1.133; 1.174 | 1.001; 1.051 | 0.751; 0.851; 0.952; 1.02; 1.0251; 1.21 |
Mean value (x¯) | – | – | 1.083 | 1.025 | 1.025 |
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– | 0.601; 0.674; 0.731 | 0.971;1.001; 1.031 | – | 1.051; 1.12; 1.2251; 1.251; 1.3751; 1.42 |
Mean value (x¯) | – | 0.668 | 1.00 | – | 0.966 |
– |
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– | – | ||
Mean value (x¯) | – | 0.662 | 1.056 | – | – |
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– | – | – | – | 1.302 |
Mean value (x¯) | – | – | – | – | 1.30 |
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0.341; 0.372; 0.385; 0.392; 0.402 | – | 1.621; 1.701; 1.801 | – | 1.2751;1.4251; 1.51; 1.551; 1.61 |
Mean value (x¯) | 0.380 | – | 1.717 | – | 1.470 |
Head width measuring data of
Instar | Mean value (mm) | Specimens measured | Source |
---|---|---|---|
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L1 | 0.35 | 12 larvae |
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L2 | 0.56 | 7 larvae |
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L3 | 0.77 | 5 larvae |
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L4 | 1.27 | 4 larvae |
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Mature larva | – | calculated value | |
Adult weevil | 1.30 | 2 adults | own data |
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L1 | 0.38 | 12 larvae | own data (see Tab. |
Mature larva* | 1.71 | 3 larvae | own data (see Tab. |
Mature larva | 1.71 | 5 larvae |
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Adult weevil | 1.47 | 5 adults | own data |
Larval instar determination for
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Growth factor (to be tested) | 1.40 | 1.45/1.46 | 1.50 |
L1 (measured) |
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L2 (calculated) |
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L3 (calculated) |
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L4 (calculated) |
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L5 (calculated) |
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Mature larva (measured) |
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Growth factor (to be tested) | 1.40 | 1.44/1.45/1.46 | 1.50 |
L1 (measured) |
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L2 (measured) | 0.56 | 0.56 | 0.56 |
L2 (calculated) |
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L3 (measured) | 0.77 | 0.77 | 0.77 |
L3 (calculated) |
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L4 (measured) | 1.27 | 1.27 | 1.27 |
L4 (calculated) |
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L5 (calculated) |
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Mature larva (calculated; see Tab. |
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*: measuring data from
Number of setae in mature larvae of
Part of body | Setae | a | b | c | d |
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Prothorax |
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8 | 9 | 9 | 11 |
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2 | 2 | 2 | 2 | |
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1 | 1 | 1 | 1 | |
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6 | 4 | 9 | 6 | |
Meso-, metathorax |
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1 | 1 | 1 | 1 |
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4 | 4 | 4 | 4 | |
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1 | 1 | 2 | 2 | |
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3 | 2 | 3 | 2 | |
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1 | 1 | 1 | 1 | |
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1 | 1 | 1 | 1 | |
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1 | 1 | 1 | 1 | |
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6 | 4 | 9 | 6 | |
Abdominal segments 1–8 | 1 | 1 | 1 | 1 | |
1 | 1 | 1 | 1 | ||
5 | 5 | 5 | 5* | ||
4 | 4 | 5 | 4 | ||
2 | 2 | 2 | 1 | ||
1 | 1 | 1 | 0 | ||
2 | 2 | 3-4 | 2 | ||
2 | 2 | 2 | 2 | ||
2 | 2 | 2 | 2 | ||
2 | 2 | 2 | 2 | ||
1 | 1 | 1 | 1 | ||
1 | 1 | 1 | 1 | ||
2 | 2 | 2 | 2 | ||
2 | 2 | 2 | 2 | ||
Abdominal segment 9 |
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3 | 4 | 2 | 3 |
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2 | 1 | 1 | 1 | |
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2 | 2 | 2 | 2 | |
Abdominal segment 10 |
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2 | 2 | 0 | 3 |
Head |
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4 | 4 | 5 | 4 |
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2 | 2 | 3 | 2 | |
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2 | 2 | 2 | 2 | |
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3 | 7 | 4 | 5 | |
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1 | 0 | 1 | 2 | |
Mouthpart |
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2 | 2 | 2 | 2 |
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3 | 3 | 3 | 3 | |
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2 | 2 | 2 | 2 | |
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3 | 3 | 3 | 4 | |
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3 | 3 | 3 | 3 | |
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2 | 1 | 2 | 2 | |
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7 | 7 | 8 | 7 | |
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4 | 4 | 4 | 4 | |
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2 | 2 | 2 | 2 | |
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1 | 1 | 1 | 1 | |
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1 | 1 | 1 | 1 | |
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1 | 1 | 1 | 1 | |
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3 | 3 | 3 | 3 | |
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1 | 1 | 1 | 1 | |
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3 | 2 | 2 | 2 |
* only abdominal segment 7 with 6
According to
The mature larva of
In
From morphological data, the taxonomic position of
Moreover, a detailed analysis of the structure of antennae disclosed only ostensible similarities between
Van
The description of the pupa of
Habitats, host plants, digging sites and larvae of soil-dwelling weevils.
We thank Dr Martin Hommes for the chance to use a climate chamber in the Julius-Kühn-Institute (JKI) in Braunschweig, and Manfred Lehmann and Dr Jörn Lehmhus (JKI) for the presentation of the sites of