The inventory of arthropods captured by the three sampling methods enabled the capture of the species presented in the following table:
The inventory carried out in the almond plot allowed us to capture 108 species distributed over 55 families, 16 orders and 05 animal classes which are Arachnida, Crustacea, Myriapoda, Enthognata and Insecta.
The recorded results are evaluated by the quality of sampling and then exploited by the ecological indices of composition and structure (Table 1).
Exploitation of the results by the quality of sampling by the use of different methods at the level of the different study plot
The values of the sampling quality of the species captured using the different sampling methods at the level of the study greenhouse are presented in the table.
The values of the species captured only once and in a single specimen by the different sampling methods at the level of the study plot are between 0.05 and 0.55, which indicates that the sampling quality is considered very good because the values approach zero (Table 2).
Exploitation of the results by the ecological indices of composition
The results obtained are exploited using ecological indices of composition, namely total richness and relative abundance.
Total richness of arthropod species captured using the three sampling methods at the study plot
The total richness of species captured is expressed in the Table 3.
Using the sweep net, the total richness is 21 species. Barber pots or land traps captured a total of 65 species. A total richness of 69 species is harvested with colored or aerial traps.
Percentage frequencies or relative abundances (AR %) applied to the orders of arthropods identified at the level of the study plot by the use of three sampling methods
The relative abundances of invertebrates harvested at the level of the study greenhouse by the application of the three capture methods (sweep net, colored traps and Barber pot) vary from one method to another. The dominance of some species over others depends on the capture method used.
The order best represented by the use of the sweep net is that of Coleoptera and Homoptera with a relative frequency of 54.49% and 25.84% respectively, followed by Spiders and Heteroptera with respectively 7.86% and 6.17%. Mantoptera and Orthoptera are present with a relative frequency of only 2.8%. Coleoptera, Hymenoptera and Diptera are abundant through the use of Barber pots, with a relative frequency equal to 29.38%; 25.05% and 19.36% respectively, followed by Heteroptera and Isoptera with a relative frequency equal to 6.83% and 4.33%. The scutigeromorpha and the Thysanoptera are represented with a low percentage equal to 0.91% and 0.68%. Species belonging to the order Homoptera and Hymenoptera are the most counted in aerial yellow traps. These orders present a relative frequency of 26.17% and 25.5%, followed by Diptera and Coleoptera with a percentage of 20.13% and 14.54%. Mantopteraare poorly represented with only 0.45% (Fig 1).
Diet of the various arthropological groups
Several diet types of arthropod species are determined, which are Predators, Phytophageous, pollinators, Detritivores, Hamatophageous, Necrophageous and Omniphageous (Fig 2).
The group best represented by the use of the sweep net is that of phytophagous and predators with 55% and 32% respectively. Next come pollinators, with 9%. Omnivores account for a low rate equal to 4% of all catches. Phytophagous and predators groups are the most abundant through the use of aerial yellow traps, with a relative frequency equal to 39% and 19% respectively. Next come omnivores with 11% and pollinators; scavengers; hematophagous and necrophages with 5% each (Fig 2).
The phytophaga group is the most accounted for in terrestrial trappings or Barber pots with a relative frequency equal to 45%. Predators follow with 23%. Pollinators, omnivores and scavengers are estimated at 13%, 7%, 7% and 5.55% respectively. Finally, parasitoids and haematophagous account for low rates with 4% and 1% of all catches (Fig 2).
Exploitation of the results by ecological indices of structure for the sampled species
The results obtained are exploited using ecological indices of structure; see Shannon’s diversity and equitability indices.
The results relating the indices of Shannon’s diversity (H'), maximum diversity (H'
max) and evenness (E) applied to the arthropod species sampled by the different types of traps at the plot level study are shown in the Fig 3.
The values of the Shannon’s diversity index are quite high at the level of the almond plot, H'= 2.27 bits for the sweep net, H'= 3.38 bits for the yellow traps and H'= 3.34 bits for the pots Barber. The maximum diversity is equal to H'
max= 4.41 bits for the sweep net, H
max= 6.14 bits for the yellow traps and H'
max= 6.05 bits for the Barber pots (Fig 4).
The study of the arthropodological fauna on almond cultivation in the rural region of Tafoughalt (Tizi-Ouzou) made it possible to list 108 species distributed in 54 families, belonging to 16 orders and 05 systematic classes using three techniques of capture. The results obtained show that the best represented class is that of insects with a percentage of 95.78%, In the same vein,
Souttou et al., (2006) captured 70 species of arthropods, belonging to 3 classes, including that of insects, represented by 69 species, divided into 36 families of 8 orders using the Barber pot technique in a palm grove in OuedSidiZarzour (Biskra) 90.69% and 59.49% of insects are noted by
Hadjoudj et al., (2018) in dunesand palm groves respectively. The realization of an inventory of arthropods in a palm grove shows that the class of insects is the most populated by 46 species, or 95.84% of the total, followed by crustaceans and arachnids by one species and a percentage of 2.08% each (
Achoura and Belhamra, 2010).
Fekkoun et al., (2011), during a study on the effect of climatic conditions on the entomomacrofauna of the
Citrus grove in the plain of Mitidja, report that the class of insects is the most abundant with 88.4%, followed by arachnids and crustaceans with 5.6% and 4.5% respectively. The total richness of the species captured is very variable, it depends on the type of trap used, by using the sweep net it is 21 species, 65 species for the Barber pots and 69 for the colored traps.
Frah et al., (2015) during their study on the arthropodological fauna in Sefiane (Batna) estimated the total richness at 71 species using the Barber pots, 63 for the colored traps and 54 using the sweep net. The Barber pots and the yellow traps respectively, which indicates that the sampling quality is judged to be very good because the values are approaching zero. Along the same lines,
Oudjiane et al., (2014) estimated the quality of sampling at Q = 0.55 in the Tigzirt region.
Ounis et al., (2014) during an estimation of soil biodiversity in an apricot plot reported that the Coleoptera order dominates with a percentage of 46.67%.
Guermah et al., (2021) noted that the order of beetles is best represented with an abundance of 25.69% by the use of Barber pots, by the use of the sweep net the beetles dominate with a percentage frequency of 27.68%, the yellow plates attract diptera with a frequency equal to 42.31.
Beddiaf et al., (2014) during a study carried out on the arthropodological fauna in the Djanet region, report that the Hymenoptera order is the best represented with a relative abundance equal to 78.6%.
Depending on the diets, we noted 5 groups, the most represented phytophagous with 44.23%; followed by predators with 26.92%, pollinators with 8.97%, omnivores with 8.33% and necrophages with 5.12%, finally parasites and polyphages with a rate of 02.08% each. Our results corroborate those of
Lestari et al., (2020) who notedthe abundance of phytophagous on different rice varieties,
Achoura and Belhamra (2010) who noted five groups whose phytophagous are the best represented with 56.25%. They are followed by predators with 20.83%, saprophages with 18.78% and finally parasites and polyphages with 2.08%.
Mahdjane (2013) obtained a frequency of 57.4% for phytophagous, followed by predators with a value of 20.63% and polyphagous with 18.87%, in his inventory on plum insects in the area of Tadmait, Tizi-Ouzou. Similarly
Guermah et al., (2021), who noted a percentage of 53% phytophagous on
Opuntiaficus indica. We also note the presence of coprophages, necrophages, bioindicators and hematophages in limited numbers. According to
Dajoz (1975), coprophages live on animal excrement and help structure nitrogen in the soil. Values of the Shannon diversity index are quite high at the level of the study plot, they are H'= 2.27 bits for the sweep net, H'= 3.38 bits for the aerial colored traps and H'= 3.34 bits for ground traps or Barber pots. Our results are close to those obtained by
Guermah et al., (2022) in a plot of
Pyruscommunis. The variations in the values of the Shannon index are explained by
N’zala et al., (1997) who pointed out that if the living conditions in a given environment are favourable, many species are captured and each of them is represented by a small number of individuals. In the case where the conditions are unfavorable, a small number of species is noted, each of which is represented by a large number of individuals.
Barbault (1981) adds that the quantity of plant species available affects the richness of the animal procession. Our results are similar to those of
Guermah and Medjdoub-Bensaad (2016) who report a Shannon diversity equal to H'=4.31 bits with a maximum diversity equal to H
max = 6.64 bits applied to the arthropods sampled by the use of the sweep net on a plot of apple tree in the Tizi-Ouzou region.
Yasri et al., (2006) in a study on arthropods in the Djelfa region, mention a diversity of 4.63 bits. Using the Barber pot technique for the study of arthropod biodiversity in an olive plot in Sefiane (Batna),
Frah et al., (2015) report a diversity value is H=4.7 bits, using Barber pots; H' = 4.6 bits, using the colored traps and H' = 5.2 bits, using the sweep net.
Mezani et al., (2016) evaluated Shannon diversity for Barber pots and colored traps at H'= 4.95 and H'= 4.6 respectively on a bean crop in the Tizi-Ouzou region. The values of the equitability obtained for each type of trap in the study plot vary from E=0.51 for the sweep net, E= 0.55 for the aerial colored traps as well as the Barber pots, these values tend towards 1, which reflects a balance between the species living in the study plot. Our results are close to those of
Belmadani et al., (2014) in a study on the distribution of arthropods in a pear orchard in Tadmait obtained the value of E=0.3.
Ounis et al., (2014) found an evenness ranging from 0.12 to 0.47.
Frah et al., (2015) during a study on the arthropodological fauna in an olive plot evaluated the evenness at 0.77 using Barber pots and colored traps and 0.90 using the sweep net.
Guermah and Medjdoub-Bensaad (2016) found an evenness of 0.65 in an apple plot.