Biodiversity Data Journal :
Data Paper (Biosciences)
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Corresponding author: Bernardo F Santos (bernardofsantos@gmail.com)
Academic editor: Jose Fernandez-Triana
Received: 25 Nov 2016 | Accepted: 28 Dec 2016 | Published: 04 Jan 2017
© 2017 Bernardo Santos, Alexandre Aguiar, Anazélia Tedesco, Julio Fontenelle
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:
Santos B, Aguiar A, Tedesco A, Fontenelle J (2017) Long-term seasonal dominance of the wasp Trihapsis polita Townes (Hymenoptera, Ichneumonidae) in the Brazilian Atlantic Forest. Biodiversity Data Journal 5: e11337. https://doi.org/10.3897/BDJ.5.e11337
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The temporal dynamics of insect populations in tropical environments is highly complex and poorly known. Long-term seasonality studies are scarce, and particularly so for ichneumonid wasps (Hymenoptera Ichneumonidae). This study represents an effort to elucidate aspects of seasonality and forest succession in the Brazilian Atlantic Forest.
We report on the seasonal and successional dominance of the ichneumonid wasp Trihapsis polita (Cryptinae). A long-term survey of Cryptinae was carried out in a protected area of Brazilian Atlantic Forest, in primary, tall secondary and low secondary forest areas. Specimens were collected during rainy season (RS) and dry season (DS) between 2000 and 2008, with total sampling effort of 4,095 trap-days. A total of 8,385 specimens of Cryptinae were collected, of which 6,655 (79.4%) belonged to T. polita. The occurrence of T. polita species was heavily concentrated in the RS, with abundance 148× higher than during the DS. Seasonal fluctuation was also detected for Cryptinae as a whole, but was two orders of magnitude lower. Sampling efficiency also varied widely among areas, with the peak of abundance at the tall secondary forest. The dominance of T. polita in secondary vegetation might be of general interest, as this type of forest is currently on the rise, due to unprecedented levels of human pressure.
Malaise trap; parasitoid; phenology; outbreak; Trihapsis polita; secondary forest
The temporal dynamics of insect populations in rainforests is highly complex and poorly studied (
Herein we report the seasonal distribution of a dominant cryptine species, Trihapsis polita Townes (Fig.
Fieldwork was conducted over the course of eight years (2000–2008). In each year, one field excursion was conducted during the dry season (DS, July-August), and one during the rainy season (RS, October-November). Three Malaise traps (
Total sampling effort was 4,095 trap-days, 1,827 in the DS and 2,268 in the RS. Sampling efficiency is expressed as the ratio between number of specimens and number of trap-days. The number of collected specimens and sampling efficiency for T. polita were compared to that of all other Cryptinae combined in order to contextualize its relative abundance and to compare the temporal dynamics of this particular species to the “background” of closely related species in the area. All specimens are deposited in the entomological collection of Universidade Federal do Espírito Santo (Brazil). The full dataset is available as supplementary material (Suppl. material
The study was conducted at Parque Estadual do Rio Doce, a 36,000 ha protected area in the Brazilian Atlantic Forest, state of Minas Gerais. Three sites within the park were sampled (Fig.
19˚48’18” and 19˚29’24” Latitude; 42˚38’’30” and 42˚28’’8” Longitude.
Original raw data: number of female and male specimens of Trihapsis polita and other Cryptinae in each collected sample.
Column label | Column description |
---|---|
Area | Sampled area by successional state. LSF, low secondary forest; HSF, high secondary forest; PF, primary forest. |
Dates-Start | Starting day for that sample, corresponding to the day when the Malaise trap sample corresponding was initially set. |
Dates-End | Ending day for that sample, corresponding to the day when the Malaise trap sample was collected. |
Season | Categorical variable indicating whether sample was collected during the dry season (DR) or rainy season (RS). |
Cryptinae | Number of specimens of Cryptinae (except T. polita) collected in that sample. |
Trihapsis polita-Males | Number of male specimens of T. polita collected in that sample |
Trihapsis polita-Females | Number of female specimens of T. polita collected in that sample |
Total | Total number of specimens of T. polita collected in that sample |
Pluviosity (mm) | Ammount of precipitation recorded during the week at which the sampling took place. |
A total of 8,384 specimens of Cryptinae were collected, of which 6,657 (79.4%) belonged to T. polita, and 1,727 (20.6%) to all other Cryptinae combined (Table
Total number of specimens collected for T. polita vs. other Cryptinae in all areas (PF, primary forest; TSF, tall secondary forest; LSF, low secondary forest) and seasons (DS, dry season; RS, rainy season). Sampling effort was identical for all sampling areas, adding to 4,113 trap-days total, but different between seasons (DS=1,836, RS=2,277).
Specimens |
% |
||||||||||
PF |
TSF |
LSF |
Total |
DS |
RS |
PF |
TSF |
LSF |
Total |
||
Trihapsis polita |
1956 |
4691 |
10 |
6657 |
36 |
6621 |
69.2 |
86.9 |
6.4 |
79.4 |
|
other Cryptinae |
871 |
710 |
146 |
1727 |
416 |
1275 |
30.8 |
13.1 |
93.6 |
20.6 |
|
Total |
2827 |
5401 |
156 |
8384 |
452 |
7896 |
33.7 |
64.4 |
1.9 |
100.0 |
Mean number of specimens per sample (total of 3 traps; 195 samples/8 years), with standard error bars, comparing T. polita (Tp) with other Cryptinae (Cr) in three successional areas, primary forest (PF), tall secondary forest (TSF), and low secondary forest (LSF) (left chart), and in the dry season (DS) vs. rainy season (RS) (right chart). PERD.
Total number of specimens collected in each sampling week (=each black & white bar pair, equivalent to 3 areas x 3 traps) for T. polita (white, first plane) vs. other Cryptinae (black, behind), along the sampled seasons (Day number of year, where DS=183–215, RS=286–322), discriminated for each year (0–1 = 2000–2008). Left wall (YZ axes) shows daily records of precipitation (cumulative values within each month), for all years (2893 records total); right wall (YX axes) shows average of precipitation for each Day number of year (each day = average of all years). Scale for number of specimens and precipitation (Y-axis) are identical.
For Cryptinae as a whole, sampling efficiency during the RS was 0.56, versus 0.25 in the DS, that is, 2.25× higher in the rainy season. The increase matches the observations of
Comparison of sampling efficiency during the dry season (DS) vs. rainy season (RS) in the three sampled successional areas. RS/DS, how many times larger was the sampling efficiency in the rainy season in relation to the dry season. Sampling effort was identical for all areas, adding to 4,113 trap-days total, but different between seasons (DS=1,836, RS=2,277). %, percentage of specimens.
T. polita |
other Cryptinae |
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Area |
% |
DS |
RS |
RS/DS |
% |
DS |
RS |
RS/DS |
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Primary forest (PF) |
29.4 |
0.03 |
2.55 |
82.2 |
50.5 |
0.37 |
0.85 |
2.3 |
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Tall secondary forest (TSF) |
70.5 |
0.02 |
6.16 |
251.4 |
41.1 |
0.26 |
0.72 |
2.8 |
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Low secondary forest (LSF) |
0.2 |
0.00 |
0.01 |
3.2 |
8.4 |
0.10 |
0.11 |
1.1 |
|
PERD Total |
79.4 |
0.02 |
2.91 |
148.3 |
20.6 |
0.25 |
0.56 |
2.3 |
The seasonal dominance of T. polita in the park was not a happenstance: it occurred repeatedly through the years (Fig. 4), as evidenced by its nearly uninterrupted numerical superiority in the samples (Table
Number of females and males of T. polita collected, as opposed to all other Cryptinae combined. % ♀, the percentage of specimens of T. polita that are females; % T. polita, the percentage of the total specimens that correspond to T. polita
Season, Year |
T. polita ♀ |
T. polita ♂ |
other Cryptinae |
% ♀ |
% T. polita |
RS, 2000 |
695 |
648 |
173 |
51.75% |
88.59 |
DS, 2001 |
0 |
3 |
64 |
0.0% |
4.48% |
RS, 2001 |
370 |
280 |
135 |
56.92% |
82.80% |
DS, 2002 |
6 |
6 |
129 |
50.00% |
8.51% |
RS, 2002 |
639 |
758 |
382 |
45.74% |
78.53% |
DS, 2003 |
3 |
6 |
82 |
33.33% |
9.89% |
RS, 2003 |
137 |
637 |
110 |
17.70% |
87.56% |
DS, 2004 |
2 |
3 |
34 |
40.00% |
12.82% |
RS, 2004 |
1084 |
606 |
150 |
64.14% |
91.85% |
DS, 2005 |
1 |
1 |
27 |
50.00% |
6.90% |
RS, 2005 |
131 |
49 |
142 |
72.78% |
55.90% |
RS, 2006 |
23 |
45 |
62 |
33.82% |
52.31% |
DS, 2007 |
1 |
1 |
60 |
50.00% |
3.23% |
RS, 2007 |
364 |
155 |
121 |
70.13% |
81.09% |
DS, 2008 |
1 |
0 |
59 |
100% |
1.67% |
Overall DS |
14 |
20 |
455 |
41.18% |
6.95% |
Overall RS |
3443 |
3178 |
1275 |
52.00% |
83.85% |
Total |
3457 |
3198 |
1730 |
51.95% |
79.37% |
There was a distinctive quantitative difference among the three successional areas for the occurrence of both T. polita and other Cryptinae (Table
Parasitoid wasps in general are most abundant in the rainy season, as compared to dry periods (
The notorious success of T. polita in the tall secondary forest, as well as its distinct population dynamics in relation to other Cryptinae, suggest it may naturally act as a large-scale parasitoid in intermediate successional stages. This might also reveal to be of more general interest, now or in the future: this type of forest is predicted to increase in the 21st century due to industrialization and urbanization (
Rogério P. Martins (UFMG, Belo Horizonte) received BFS and AMT in a scientific visit and donated the material used in this study. Maria Célia L. Carreiro kindly helped to count the specimens. This project benefited from funding by the Conselho Nacional de Pesquisa e Desenvolvimento/CNPq (Processes 520031/98-9 and 926.656.810), Brazil.
Original data, discriminated by individual trap-samples (585 records), presented as Python lists (compatible with R, and most other computer languages). All variables contain 585 items, with data corresponding according to position (index).