scholarly journals Pathogenicity of Pakistani isolates of Steinernema bifurcatum and S. affine (Rhabditida: Steinernematidae) in management of stored grain pests Lasioderma serricorne and Tribolium castaneum (Coleoptera: Ptinidae, Tenebrionidae)

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Tabassum Ara Khanum ◽  
Salma Javed

Abstract Background Stored grain products suffer a considerable economic loss due to insect infestations. The resistance of pests to insecticide, and residues on crops are produced by the application of insecticide. Nowadays, incremental necessity has been occurred to find out alternatives to chemicals. As biological control agents, entomopathogenic nematodes (EPNs) attract attention increasingly in the research area recently. Results The aim of the study was to evaluate the pathogenicity of Pakistani isolates Steinernema bifurcatum and S. affine against the stored grain pests, Tribolium castaneum and Lasioderma serricorne, under laboratory conditions. Suspensions of nematodes were applied at 4 different concentrations 0, 50, 100, and 200 IJs/ml and 3 variable temperatures 15, 30, and 45°C. Pathogenicity rate was recorded after 48 h of application. The larval stage is found more susceptible than the adult. At 200 IJs, S. bifurcatum showed high mortality of L. serricorne larva (92%) and T. castaneum larva (93%), whereas S. affine showed 90 and 95% mortality of L. serricorne and T. castaneum larva, respectively, at 200 IJs. The results revealed that both species of EPN were able to control and reproduce on L. serricorne and T. castaneum. Maximum mortality was recorded at 45 °C from S. bifurcatum whereas S. affine at 15 °C. Conclusions Therefore, S. bifurcatum and S. affine could be suggested as a biological control agent for hot and cold climatic zones, respectively.

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Fatma Dolunay Erdoğuş

Abstract Background The rust red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae) is a serious pest of stored grains and grain products across the world. This beetle is hold a significant place in Turkey by causing damages on stored products. T. castaneum primarily attacks milled grain and its derivates. Entomopathogenic nematodes (EPNs) are regarded as extremely an important biological control agent. EPNs kills their hosts within 48 h by the bacteria they carry. Results Efficacies of 4 isolates of EPNs Steinernema carpocapsae (Tokat Bakisli 05), S. feltiae (Tokat-Emir), Heterorhabditis bacteriophora (TOK-20) and H. bacteriophora (11-KG) against T. castaneum was investigated under laboratory conditions. The experiments were carried out thrice with 10 replicates at 2 different temperatures (15 and 25 ºC). EPNs isolates were tested at 3 different concentrations (250, 500 and 1000 IJs/ml) with a pure water as control. The overall mortality caused by H. bacteriophora (Kg11) was significantly higher than the other EPN species. At 25 ºC, H. bacteriophora (Kg11) at the highest concentration (1000 IJs/ml) caused 87.6% mortality after 120 h., followed by S. carpocapsae and S. feltiae with 79.22 and 75.3% mortality rates, respectively. The mortality percentages exhibited by all nematodes’ species at both temperatures were lowest at the concentration of (250 IJs/ml). At 15 °C, H. bacteriophora (Kg11) caused (55.2%) mortality rate at the highest concentration (1000 IJs / ml) after 120 h. Conclusion The study suggested that these nematodes were efficient and could be recommended to control T. castaneum in its biological control programs.


2018 ◽  
Vol 10 (4) ◽  
pp. 503-507
Author(s):  
Karim SAEIDI ◽  
Hossein PEZHMAN ◽  
Hadi KARIMIPOUR-FARD

Stored-product pests in the family Bruchidae of Coleoptera represent important pests affecting legume seeds. The lentil weevil, Bruchus lentis Froelich (Coleoptera: Chrysomelidae: Bruchinae) is one of the major lentil pests in Iran and in the world. The economic losses caused by this pest on lentil grow up to 40%. Synthetic pesticides are currently the chosen method to protect stored grain from insect damage. However, their widespread use has led to the development of pest strains resistant to insecticides and pest resurgence. In recent years, nonchemical methods, including biological agents are considered safe methods to control the stored grain pests. Positive characteristics of entomopathogenic nematodes as biological control factors of arthropod pests, introduce them as an appropriate option for controlling the integrated pest management of lentil weevil. In the present study, an isolate of entomopathogenic nematode, Steinernema feltiae, isolated from soils around Yasouj and based on morphological traits and morphometric data were identified.  Adult insects of lentil weevil were exposed to concentrations of 0; 500; 1,000; 2,000 and 3,000 infective juvenile/ml of distilled water at different temperatures (20, 23, 26 and 29 °C). Insects were placed on filter paper impregnated with 1 ml of nematode suspension in Petri dishes for three days. Mortality of the insects was recorded every 24 hours. The highest mortality was recorded after 72 hours, which represented 79.40%, at the concentration of 3,000 infective juvenile at 26 °C.


1981 ◽  
Vol 71 (1) ◽  
pp. 19-32 ◽  
Author(s):  
R. D. Pope

AbstractThe Rhyzobius (or Lindorus) ventralis frequently referred to in the literature of biological control is shown to be a mixture of two distinct, though similar, species. The origin of the confusion is traced to the nineteenth century searches in Australia for insects to control scale insect infestations on citrus and other crops in California. Adults of the two species are defined and illustrated, and a key is provided for their separation. Lectotypes are designated for R. ventralis (Erichs.), its synonym Scymnus restitutor Sharp and for S. halli Broun, newly synonymised with R. ventralis. A lectotype is designated for Platyomus forestieri Muls., the second species of the complex, here transferred to Rhyzobius, and for S. circularis Sharp, newly synonymised with R. forestieri. Distribution data for both species, based on actual specimens examined, are listed, and their Australian distribution is summarised in a map. Past usages of ‘ R. ventralis’ as a biological control agent are reviewed in the light of the revised taxonomy. The taxonomy and nomenclature of Rhyzobius Stephens is discussed in order to establish the correct generic placement of and binomina for R. ventralis and R. forestieri.


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