The negative effect of some selective insecticides on the functional response of a potential biological control agent, the spider Philodromus cespitum

BioControl ◽  
2010 ◽  
Vol 55 (4) ◽  
pp. 503-510 ◽  
Author(s):  
Milan Řezáč ◽  
Stano Pekár ◽  
Jitka Stará
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Peris Wangari Nderitu ◽  
Mattias Jonsson ◽  
Esther Arunga ◽  
Mark Otieno ◽  
John Jamleck Muturi ◽  
...  

Combination of pest management strategies that minimize pesticide use and conserve natural enemies is important for a sustainable environment. Overreliance on synthetic insecticides in the management of Tuta absoluta has led to pesticide resistance leading to difficulties in managing the pest. In this regard, alternative measures need to be put in place to reduce the effects of this pest. The objective of this study was, therefore, to assess the effectiveness of host plant resistance, biological control, and selective insecticides when used in combination, in the management of T. absoluta in tomato production. The study was set up in a greenhouse in a completely randomized design involving two tomato varieties, an insecticide (chlorantraniliprole), and a biological control agent(Macrolophus pygmaeus), applied singly or in combination. Data were collected on T. absoluta damage from the lower, intermediate, and upper leaves. The results from this study show that a combination of insecticide with a moderately resistant variety had a significantly lower T. absoluta damage as compared with a susceptible variety combined with an insecticide. However, the moderately resistant variety when combined with insecticide showed no effect when the biological control agent was added. The susceptible variety significantly reduced T. absoluta damage when combined with the biological control agent. These results indicate that treatment combinations in insect pest management can be utilized. The present study results indicate that using a moderately resistant variety (Riogrande VF) in combination with the insecticide chlorantraniliprole (Coragen®) and a susceptible variety (Pesa F1) in combination with the biological control agent (M. pygmaeus) can improve T. absoluta management. Under good habitat management, the susceptible variety will perform equally as the moderately resistant variety due to suppression of the T. absoluta populations by natural enemies. These findings show the importance of environmental conservation both by enhancing natural enemy abundance and use of selective insecticide in the management of T. absoluta in tomato production. Combinations in this present study are likely to reduce insecticide doses, thereby reducing the cost of production and enhancing environmental compatibility with natural enemies.


Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 196 ◽  
Author(s):  
Juan R. Gallego ◽  
Otto Caicedo ◽  
Manuel Gamez ◽  
Joaquin Hernandez ◽  
Tomas Cabello

Worldwide, the potato tuber moth (PTM), Phthorimaea operculella (Zeller), is one of the most severe pests affecting potato (Solanum tuberosum L.), whether in open-air crops or during tuber storage. This work examines the potential control of this pest by two species of predatory mites, Macrocheles robustulus (Berlese) and Blattisocius tarsalis (Berlese), on pest eggs under laboratory conditions. In the two first assays, the acceptance rate of the pest eggs was assessed for each predatory mite. Then, in a third assay, the functional response of B. tarsalis was studied. The results showed that Macrocheles robustulus did not prey on the pest eggs (number of eggs surviving = 4.33 ± 0.38), whereas B. tarsalis did (number of eggs surviving = 0.5 ± 0.5). Likewise, B. tarsalis showed a type II functional response when it killed the eggs. The results showed the potential use of Blattisocius tarsalis as a biological control agent of P. operculella in potato under storage conditions.


1970 ◽  
Vol 14 ◽  
pp. 11-16 ◽  
Author(s):  
N Islam ◽  
W Islam ◽  
KAMSH Mondal

The functional response of the parasitoid Dinarmus basalis (Rond.) (Hymenoptera: Pteromalidae) is determined to evaluate its potential as a biological control agent. Four female wasps in the presence of males parasitoids, were allowed to oviposit during their life span or hosts at different densities. The data were fit by Rogers? (1972) parasitoid model. The rate of parasitoid search was a?= 0.123 ±0.005 life span-1, and handling time Th = 0.056 ± 0.002 life span-1. Volume of grain had no significant (P>0.001) effect on number of parasitoids emerging. Key words: Functional response; Dinarmus basalis; Callosobruchus maculatus J. bio-sci. 14: 11-16, 2006


2013 ◽  
Vol 53 (4) ◽  
pp. 399-403 ◽  
Author(s):  
Vahid Mahdavi ◽  
Moosa Saber

Abstract The functional response is a behavioral phenomena defined as the relation between the parasitized host per each parasitoid and host density. This phenomenon can be useful in assessing parasitoid efficiency for the biological control of the host. Parasitoid wasps are most important insects and they play a significant role in the natural control of pests via their parasitism activities. In this study, the effects of diazinon and malathion were evaluated on the functional response of Habrobracon hebetor Say to different densities of last instar larvae of Anagasta kuehniella Zeller. Young adult females (< 24 h old) of the parasitoid were exposed to LC30 values of pesticides. Host densities of 2, 4, 8, 16, 32, and 64 were offered, to treated young females for 24 h in 10 cm Petri dishes. At this point, the parasitism data were recorded. The experiments were conducted in eight replications. The functional response was type Ш in the control and insecticide treatments. Searching efficiency in the control, diazinon and malathion-treated wasps were 0.008±0.002, 0.003±0.002, and 0.004±0.002 h-1, handling times were 1.38±0.1, 7.95±0.91, and 6.4±0.81 h, respectively. Diazinon and malathion had the highest and the lowest effect on searching efficiency of H. hebetor, respectively. After conducting advanced field studies, it was found that malathion may be used as a compatible chemical material with biological control agent in IPM programs.


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