Research Article |
Corresponding author: Bianca Greyvenstein ( biagrey90@gmail.com ) Academic editor: Matan Shelomi
© 2021 Bianca Greyvenstein, Hannalene du Plessis, Johnnie Van den Berg.
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:
Greyvenstein B, du Plessis H, van den Berg J (2021) Life history of the false flower mantid (Harpagomantis tricolor Linnaeus, 1758) (Mantodea: Galinthiadidae) and its distribution in southern Africa. Journal of Orthoptera Research 30(1): 17-26. https://doi.org/10.3897/jor.30.52816
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The false flower mantid is the common name for the Mantodea species Harpagomantis tricolor (Linnaeus, 1758). This species uses camouflage as a defense mechanism. Limited information (
camouflage, copulation, longevity, praying mantis
Harpagomantis
Kirby is one of four genera in the newly rearranged family of Galinthiadidae (
Harpagomantis
have been described as “false flower” mantids and are pink with green bands and sometimes yellow eyes (Fig.
The aim of this study was to determine the distribution of the genus Harpagomantis in southern Africa and to study the biology of H. tricolor under captive breeding conditions.
Species distribution database.—Distribution records of Harpagomantis spp. were collected during visits to the following institutions that host curated insect collections in South Africa: Ditsong Museum of Natural History (Pretoria), Agricultural Research Council (Biosystematics Division, Pretoria), National Museum (Bloemfontein), Albany Museum (Grahamstown), Rhodes University (Grahamstown), Durban Natural Science Museum, Iziko South African Museum (Cape Town), and KwaZulu-Natal Museum (Pietermaritzburg). Most specimens in these collections were previously identified by foreign visiting taxonomists, and many were sent for identification to the Vienna Museum in Germany, the University of Drexel in Philadelphia, USA, the Muséum national d’Histoire naturelle (MNHN) in Paris, France, and the research collection of Nicolas Moulin in Montérolier, France.
Harpagomantis
specimens and distribution labels were photographed (Canon D1300) and digitized, after which this data was used to compile a distribution database of the species. The database contains the following information for each specimen record: genus and species name (to the available level of identification), collector’s details and collection date where available, and the geo-referenced locality. Scientific literature (
Rearing and biology.—Specimens were collected in the Grassland biome in the North West and Free State provinces of South Africa during the summer of 2016/2017. Adults of these field-collected individuals were mated, and nymphs that emerged from oothecae were used to rear a sufficient number of individuals to observe under captive breeding and rearing conditions. A sub-sample of the field-collected specimens was identified by Nicolas Moulin (honorary associate to MNHN) to confirm the species identification.
For breeding purposes, pairs of males and females were placed in glass containers. Glass containers (40 cm × 20 cm × 20 cm) were used to ensure that ample space was available for the male to avoid sexual cannibalism before, during, or after mating. To further limit the likelihood that females would cannibalize the males, ample food was provided before the male was introduced into the breeding container. The duration of copulation was recorded per breeding pair (Fig.
Rearing of nymphs was done under controlled conditions (Fig.
The following life history parameters were recorded during this study: size of oothecae, number of egg chambers inside fertilized and unfertilized oothecae, copulation duration, number of days between moults, and survival rate (based on nymphs reaching the adult phase). The mean number of days between moults and days to adulthood were calculated separately for males and females. The data discussed in this paper were recorded for 45 individuals (14 males and 31 females) that completed their life cycles. The mean duration of male and female life cycles was calculated, and the hatch and survival rates were determined. A distinction was also made between different types of oothecae, i.e., fertilized and unhatched (produced by field-collected females of which the mating status was not known). The length, width, and height of each ootheca were recorded based on descriptions by
Data analysis.—The descriptive statistics (means and standard error) and the statistical analyses of the developmental parameters were done using Statistica Version 13.3 (TIBCO Software Inc.,
Distribution.—The distribution records reported in this paper were compiled from records available in the seven South African institutions that host curated arthropod collections. Results should be viewed in this context, since no museum records beyond those residing in South Africa were included. The results of this study and the following previously published studies (
A total of 290 specimen records were accounted for, of which 272 were collected within the borders of South Africa (this includes specimens collected in Lesotho and Eswatini). The remaining 18 records of H. tricolor were distributed as follows: two specimens collected in Botswana, six in Namibia, four in Mozambique, and six in Zimbabwe (Fig.
Biology.—The ootheca of H. tricolor is not covered in the usual foamy sheath that is characteristic of a variety of Mantodea, although exceptions do exist (
In this study, 19 oothecae were produced by field-collected females mated under captive breeding conditions. Seven of these did not hatch and 12 oothecae did hatch. In total, 63 nymphs emerged from the 12 fertile oothecae under captive breeding conditions. No significant differences were recorded between the length, width, height, or number of eggs of the fertilized or unhatched oothecae. Mean ootheca length was 8.5 ± 4.11 mm, containing 17.26 egg ± 6.66 chambers per ootheca (Table
Developmental parameters.—Of the 63 neonate nymphs that hatched from the 12 different oothecae throughout this study, 45 completed their lifecycles (14 males and 31 females). The mean duration between mating and the production of an ootheca was 11.82 ± 9.51 days, and the act of copulation itself continued for approximately six hours (Table
No significant differences were recorded between the average duration per instar of females and males. The nymphal period took approximately 20 weeks to complete (Table
Mean size and number of egg chambers inside the various types of oothecae of Harpagomantis tricolor reared under captive breeding conditions. SD = standard deviation.
Oothecae (19) | Length (mm) ± SD | Width (mm) ± SD | Height (mm) ± SD | Number of eggs/ootheca ± SD | |
---|---|---|---|---|---|
T-test | t-value | 0.573 | 0.986 | 0.058 | 0.267 |
p-value | 0.574 | 0.338 | 0.954 | 0.792 | |
Overall (19) | 8.58 ± 4.11 | 4.37 ± 0.76 | 6.15 ± 0.83 | 17.26 ± 6.66 | |
Unhatched (7) | 7.86 ± 2.24 | 4.14 ± 0.69 | 6.14 ± 1.21 | 16.71 ± 7.20 | |
Fertilized (12) | 9.00 ± 4.63 | 4.50 ± 0.80 | 6.17 ± 0.58 | 17.58 ± 6.63 |
Mean duration (in days) of each of the life stages of Harpagomantis tricolor and differences between male and female development under captive breeding and rearing conditions. Three of the females developed to the sixth-instar and were not included in the table below.
Life stage | Mean duration (days ± SD) | t-value | p-value | ||
---|---|---|---|---|---|
Overall | Males | Females | |||
Ootheca (incubation period) | 144.71 ± 9.33 | 142.51 ± 10.90 | 145.68 ± 8.55 | 1.057 | 0.297 |
First instar | 26.62 ± 11.07 | 25.36 ± 9.91 | 27.19 11.67± | 0.373 | 0.710 |
Second instar | 24.67 ± 15.63 | 28.57 ± 17.51 | 22.90 ± 14.66 | -1.110 | 0.273 |
Third instar | 27.67 ± 13.06 | 33.38 ± 18.5 | 25.42 ± 9.37 | -1.784 | 0.082 |
Fourth instar | 41.55 ± 22.91 | 49.00 ± 29.63 | 39.24 ± 20.47 | -0.838 | 0.407 |
Fifth instar | 51.50 ± 13.28 | 54.00 ± 9.00 | 51.06 ± 14.06 | -0.499 | 0.624 |
Copulation to oothecae (days)* | 11.82 ± 9.51 | 12.27 ± 8.67 | 11.63 ± 9.99 | -0.135 | 0.894 |
Copulation duration (hours)** | 06:10 ± 0.04 | 06:15 ± 0.04 | 06:08 ± 0.03± | -0321 | 0.750 |
Total nymphal period (days)*** | 140.20 ± 31.03 | 128.00 ± 31.09 | 145.71 ± 29.88 | 1.776 | 0.082 |
Adult longevity (days)**** | 51.11 ± 39.76 | 31.57 ± 29.72 | 59.93 ± 40.97 | -0.509 | 0.613 |
Period from hatch to death (days) | 191.33 ± 37.96 | 161.71 ± 20.47 | 204.71 ± 36.58 | -0.509 | 0.613 |
The mean hatch rate, survival rate, and gender dynamics that resulted from each of the field-collected H. tricolor females (12 individuals) that were kept in the laboratory and each of their associated fertile oothecae (12).
Ootheca number | Oothecae incubation (days) | No. of eggs per ootheca | Hatch rate (%) | Survival (%) | Male (%) | Female (%) | Sex Ratio (♂:♀) |
---|---|---|---|---|---|---|---|
Ootheca 1 | 123 | 16 | 81.25 | 69.23 | 33.33 | 66.67 | 1:2 |
Ootheca 2 | 149 | 14 | 28.57 | 100 | 0.00 | 100.00 | 0:4 |
Ootheca 3 | 145 | 19 | 31.58 | 100 | 83.33 | 16.67 | 1:0.2 |
Ootheca 4 | 155 | 18 | 33.33 | 50 | 33.33 | 66.67 | 1:2 |
Ootheca 5 | 127 | 16 | 25.00 | 100 | 0.00 | 100.00 | 0:4 |
Ootheca 6 | 138 | 18 | 16.67 | 100 | 33.33 | 66.67 | 1:2 |
Ootheca 7 | 145 | 15 | 20 | 33.33 | 100.00 | 100.00 | 1:1 |
Ootheca 8 | 156 | 9 | 44.44 | 50 | 100.00 | 0.00 | 2:0 |
Ootheca 9 | 153 | 36 | 13.89 | 60 | 33.33 | 66.67 | 1:2 |
Ootheca 10 | 147 | 12 | 25.00 | 66.67 | 0.00 | 100.00 | 0:2 |
Ootheca 11 | 143 | 21 | 14.29 | 66.67 | 50.00 | 50.00 | 1:1 |
Ootheca 12 | 139 | 17 | 35.29 | 16.67 | 60.00 | 40.00 | 1:0.67 |
Mean ± (SD) | 143.33 ± 10.31 | 17.58 ± 6.63 | 30.78 ± 18. 35 | 67.71 ± 28. 04 | 43.89 ± 36.15 | 64.44 ± 33.46 | 1:1.5 |
Distribution patterns of Harpagomantis tricolor in southern Africa.—Although there have been some discrepancies in the past regarding the species within this genus, it is assumed that two morphological varieties exist: H. tricolor and H. discolor. Specimen records throughout the museum collections in South Africa exist for both morphological varieties (morphs). According to
However,
The discolor variety of H. tricolor was last recorded in 1977 in Harkerville in the western Cape, while H. tricolor (except for the specimen collected during this study) was also collected in the western Cape during 2015 at Stellenbosch. It should further be noted that 176 H. tricolor specimens were recorded during this study; however, the morphological variety of these specimens could not be identified.
Literature on H. tricolor is somewhat scarce, but some studies have reported on the distribution of this genus. For example, in 1999, H. tricolor was collected on an indigenous plant species, Delairea odorata (Asteraceae) (Cape Ivy), which occurs along the east coast of South Africa (
Ecomorphs (morphologically similar characteristics that align with particular habitats, such as certain camouflage capabilities) of mantids such as Harpagomantis are suspected to have evolved several times in different geographic regions due to similar habitats and ecological pressures (
Many specimens were collected in Gauteng province, which is the region in South Africa with the highest human population density. This high population density could explain the large numbers of specimens collected in this region (
This study suggests that provincial nature reserves, more so than national parks, may create refuge areas for species in a mosaic of disturbed and highly populated areas. An example of a provincial and/or local area that can be regarded as a refuge for birds in highly developed areas was reported by
Biology.—Since no previous information on the biology of H. tricolor could be found, comparisons of its biology are made with species such as Ephestiasula pictipes Wood-Mason, 1879 (Mantodea; Hymenopodidae) (
The number of eggs within the oothecae of P. virescences was reported to be between 12 and 13 hatchlings per oothecae (
Developmental parameters.—The extended incubation period of H. tricolor oothecae (145 days) recorded in this study was much longer than that reported by
A high hatch rate and low survival rate were reported by
The average duration of copulation for H. tricolor was six hours.
Sexual dimorphism in size where males are smaller than females has been observed in various mantid species (
This study is the first attempt at mapping the distribution of Harpagomantis in South Africa and recording the biology of H. tricolor. The distribution of false flower mantids in South Africa seems to be predominantly towards the northeastern region, in the savanna and grassland biomes. Extended copulation duration of this species could be a by-product of males trying to decrease sperm competition, which could also have led to the short duration of the male nymphs compared to female nymphs of H. tricolor. It is suggested that this species goes into diapause in the ootheca phase.
We would like to thank the following people at each of these institutions for allowing us to access the collections: Audrey Ndaba at Ditsong Museum of Natural History (Pretoria), Vivienne Uys at the Agricultural Research Council (Biosystematics Division), Asley- Kirk Springs and Burgert Muller at the National Museum (Bloemfontein), Helen James and Musa Mlambo at the Albany Museum (Grahamstown), Martin Hill and Thabisa Mdlangu at Rhodes University (Grahamstown), Kirstin Williams at the Durban Natural Science Museum, Tricia Pillay at KwaZulu Natal Museum (Pietermaritzburg), and Aisha Mayekiso at Iziko Museum of South Africa (Cape Town). We also thank Simon van Noort at Iziko Museum of South Africa, Entomology Specify. The National Research Foundation of South Africa contributed funding to this project (grant number: 101176). Lastly, we thank Nicolas Moulin for his expertise in identifying the sub-sample of species used for the biological aspect of this study.