Phytoseiidae

Sahraoui, H., Kreiter, S., Lebdi-Grissa, K. & Tixier, M. - S., 2016, Sustainable weed management and predatory mite (Acari: Phytoseiidae) dynamics in Tunisian citrus orchards, Acarologia 56 (4), pp. 517-532: 520-524

publication ID

http://doi.org/ 10.1051/acarologia/20162240

persistent identifier

http://treatment.plazi.org/id/891C612B-FB51-FFBC-FF5A-1654FD06DE5E

treatment provided by

Marcus

scientific name

Phytoseiidae
status

 

Phytoseiidae   on citrus trees. Three Phytoseiidae   species were found on citrus trees: Euseius stipulatus (Athias-Henriot)   , Neoseiulus californicus (McGregor)   and Typhlodromus (Anthoseius) rhenanoides   Athias-

Henriot ( Table 1); the most abundant was E. stipulatus   whatever the weeding management. Considering the overall dataset, mean densities were significantly lower in the Mod.2 (herbicide treatment) than in the three others (H (3, 4800) = 15.30, P = 0.001) ( Figure 3a View FIGURE ). These differences were observed on 09- VI (H (3, 4800) = 23.12, P = 0.00) and 23- VI (H (3, 4800) = 11.27, P = 0.01). After this latter date, Phytoseiidae   densities decreased in all the modalities, and no more significant difference was observed.

Phytoseiidae   on weeds. Eight Phytoseiidae   species were collected on weeds; two are new for the Tunisian fauna ( Kreiter et al. 2010): Typhlodromus (Anthoseius) pegazzani Ragusa and Swirski   and Amblyseius meridionalis Berlese   ( Tables 1, 2 View TABLE ). Euseius stipulatus   clearly dominates whatever the weed management strategy; N. californicus   and T. (A.) rhenanoides   are the second and third prevalent species on weeds. Euseius stipulatus   was found on nine plants with the highest densities observed on Amaranthus retroflexus   L. ( Amaranthaceae   ). Neoseiulus californicus   was collected on seven plants and was particularly abundant on Cynodon dactylon   (L.) Persoon ( Poaceae   ). Finally, T. (A.) rhenanoides   was collected on five plants ( Table 2 View TABLE ). Although the total number of Phytoseiidae   collected during all the experiment was higher in the modalities wild cover (Mod.1) and mown weeds (Mod.3), mean densities were not statistically different between the four modalities (H (3, 160) = 7.41, P = 0.06) ( Figure 3b View FIGURE ). No significant difference was either observed at each date.

Phytoseiidae   captured. The three most abundant species found on trees and weeds were also caught; the most captured was E. stipulatus   (67 %) whatever the weeding modality ( Table 1). Species dispersing downwards and upwards were the same. Female was the most captured stage (75 %) followed by immature (21 %) and males (4 %). Higher densities were caught in the direction "weeds to tree" than in the direction "tree to weeds" ( Figure 3c View FIGURE ) (H (1,32) = 8.07, P = 0.004). Considering each modality separately, this trend was only significant for the Mod.1 (wild cover) (H (1, 80) = 4.97, P = 0.026) and the Mod.4 (ploughed ground) (H (1, 80) = 5.26, P = 0.021). In this latter modality, the mean number of Phytoseiidae   moving upwards was significantly higher than in the other modalities (H (3, 160) = 23.29, P <0.01), especially at 09- VI (H (1, 32) = 5.38, P = 0.02) and 16- VI (H (1, 32) = 5.56, P = 0.01). Phytoseiidae   densities dispersing from trees to the weeds were not significantly different between the four modalities (H (3, 160) = 2.25, P = 0.52).

Relationships between Phytoseiidae   densities on trees, weeds and in traps. A positive linear significant correlation was observed between Phytoseiidae   mean densities on citrus and weeds for the Mod.1 (wild cover) ( R 2 = 0.51, P = 0.018). Positive

significant correlations were found between Phytoseiidae   mean densities on weeds and those moving upwards in the Mod.3 (mown weeds) ( R 2 = 0.42, P = 0.03) and Mod.4 (ploughed ground) ( R 2 = 0.53, P = 0.01). No significant correlation was observed between Phytoseiidae   mean densities in weeds and those moving downwards, whatever the modality considered. A significant correlation between densities on trees and those moving downwards was observed for the Mod.1 (wild cover) ( R 2 = 0.57, P = 0.01). A positive significant correlation was also found between Phytoseiidae   mean densities on trees and those moving upwards for the Mod.2 (glyphosate) ( R 2 = 0.59, P <0.01) and Mod.4 (ploughed ground) ( R 2 = 0.59, P <0.01) (Table 3).

TABLE 2: Number of specimens of Phytoseiidae species collected on weeds in the inter-rows of the citrus orchards studied in two experimental sites.

    Amblyseius   * meridionalis Euseius   * stipulatus Iphiseius   * degenerans Neoseiulus   * barkei Neoseiulus   * californicus Neoseiulus   * cucumeris Neoseiulus   * longilaterus Neoseiulus   * paspalivorus Phytoseiulus   *persimilis Typhlodromus   . * (A.) * rhenanoides Typhlodromus   * (T.)* exhilaratus Typhlodromus   * (T.)* phialatus
Experimental,site,1 Amaranthus   * retroflexus     35     3         2    
  Beta   * arvensis     19                    
  Bromus   *diandrus   1                    
  Chenopodium   * murale                     2    
  Convolvulus   * arvensis   1 8     4         2    
  Conyza   *canadensis   12     6              
  Cynodon   * dactylon           12 1       5    
  Hordeum   *murinum         13              
  Malva   ,sp.   1               2 5  
  Mercurialis   *annua   5                    
  Solanum   * nigrum     9             2      
Experimental,site,2 Strobilanthes   ,sp.   2     2              
C.*limetta Amaranthus   *blitum   7 3     1         61 7
  Arisarum   *vulgare   1 2                  
  Beta   * vulgaris   *     4                  
  Chenopodium   * murale               1 1       2
  Convolvolus   * arvensis     2 11               3  
  Conyza   *canadensis                     1 3
  Cynodon   * dactylon             4 3          
  Ecballium   *Elatrium                     10  
  Malva   * sp.                     6  
  Solanum   * nigrum     3 75               9 2
C.*clementina Bromus   *rigidus*Roth.   3     4   2       1  
  Chenopodium   * murale                       36  
  Convolvolus   * arvensis     7 1   7 3     34   7  
  Conyza   *canadensis                       4
  Cynodon   * dactylon               1       3  
  Hordeum   *murinum                     3  
  Lolium   ,sp.   1         1          
  Malva   * sp.   1             5   1 3
  Mercurialis   *annua   5                 29  
  Solanum   * nigrum     16 22   3       2   34 3
C.*sinensis Amaranthus   *blitum   2                   7
  Bromus   *hordeaceus             1          
  Chenopodium   * murale     132     1 7 4       225 25
  Convolvolus   * arvensis     11   2 2 1 1   4   8 5
  Conyza   *canadensis                     14  
  Cynodon   * dactylon             3         1  
  Ecballium   *Elatrium                     9  
  Emex   * spinosa     13                 7  
  Lolium   * sp.   1                    
  Mercurialis   *annua                 1   23  
  Phalaris   *brachystachys   2                    
  Phaseolus   * vulgaris                       2  
  Solanum   * nigrum       2           1   1  
VI

Mykotektet, National Veterinary Institute

R

Departamento de Geologia, Universidad de Chile