Effect of prey density on functional and numerical responses of the predatory mite Typhlodromus negevi (Acari: Phytoseiidae)

Author(s):  
Aly H. Rasmy ◽  
G. M. Abou-Elella
Keyword(s):  
2020 ◽  
Vol 25 (6) ◽  
pp. 1147-1157
Author(s):  
Rosenya Michely Cintra Filgueiras ◽  
Jairo De Almeida Mendes ◽  
Francisco Wesller Batista Da Silva ◽  
Eduardo Pereira De Sousa Neto ◽  
José Wagner Da Silva Melo

Raoiella indica Hirst (Acari: Tenuipalpidae) is a polyphagous pest widely dispersed worldwide and a particular threat to crops from the Arecaceae family. Control measures are still being evaluated in recently invaded countries. A possible control strategy for this pest is the use of predatory mites. A recent study has suggested Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a potential biological control agent of R. indica. In the present study we determined the prey stage preference of N. barkeri when offered different stages of R. indica besides its functional response and numerical over its prey stage preferred. The predatory mite N. barkeri showed a marked preference for eggs over other stages of the prey. The regression analysis indicated that the predatory mite N. barkeri exhibited a Type II functional response. The prey density needed to start the oviposition was 10 R. indica eggs. The number of eggs laid by N. barkeri females increased with an increase in the prey density and tended to stabilize when prey availability was greater than 80 R. indica eggs, with average oviposition of 2 eggs/female. Our study suggests that N. barkeri shows potential to reduce populations of R. indica, especially at low prey densities. However, further studies are needed to investigate whether R. indica supports the development of immature stages of N. barkeri.


Author(s):  
İsmail Döker ◽  
Kemal Yalcin ◽  
Kamil Karut ◽  
Cengiz Kazak

Functional and numerical responses of the predatory mite, Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) to four different biological stages (egg, larva, protonymph and adult male) of the citrus brown mite, Eutetranychus orientalis (Klein) (Acari: Tetranychidae) were determined under laboratory conditions. In the experiments, six different prey densities (5, 10, 20, 40, 60 and 80) for each biological stage of the prey were provided to the predatory mite for 24 hours. Results showed that the proportion of prey consumption of I. degenerans decelerated with increasing prey densities of all biological stages of the prey. Logistic regression analysis indicated that I. degenerans showed a Type II functional response regardless of prey stage. The attack rate (α) and the handling time (Th) varied based on the biological stages. The highest α (1.596) and the lowest Th (0.014) values were determined when the predator fed on adult males and larvae of E. orientalis, respectively. The numerical response curves were similar to those of Type II functional response. The efficiency of conversion of ingested food (ECI) of female I. degenerans decreased on all biological stages when prey density increased. The highest and the lowest average daily mean number of eggs laid by I. degenerans were found as 0.45 and 1.90 when it fed on eggs and larvae of its prey, respectively. According to the results, I. degenerans has a potential to be used as a predator in biological control of E. orientalis.


Author(s):  
Maria Edvânia Neves Barros ◽  
Francisco Wesller Batista Da Silva ◽  
Eduardo Pereira De Sousa Neto ◽  
Manoel Carlos Da Rocha Bisneto ◽  
Débora Barbosa De Lima ◽  
...  

The suppression of pest populations by a predator depends on two basic components of the predator-prey interaction: the functional and the numerical responses of the predator. Such responses can be affected by exposure to acaricides. In the present study, the effects of acaricides (abamectin, azadirachtin, fenpyroximate, and chlorfenapyr) on the functional and numerical responses of the predatory mite, Amblyseius largoensis (Acari: Phytoseiidae) an important natural enemy of the pest mite, Raoiella indica (Acari: Tenuipalpidae), were investigated. The exposure of A. largoensis to acaricides occurred through contact with a surface contaminated with dried acaricide residue. Subsequently, A. largoensis exhibited a type II functional response, which was not altered by exposure of any acaricides. However, exposure to abamectin resulted in a decrease in the average mean numbers of prey consumed by a predator. Exposure to acaricides increased prey handling time by 67%, 25%, 38%, and 35% for abamectin, azadirachtin, fenpyroximate, and chlorfenapyr, respectively. Exposure to abamectin reduced the attack rate of A. largoensis by 52%. The numerical response of A. largoensis was only affected by exposure to abamectin, where just 60% of the females oviposited, and regardless of the prey density, the average mean numbers of eggs/female/day was always less than 0.4. The food conversion efficiency into biomass of A. largoensis eggs decreased with increasing prey density, and this trend was not altered by exposure to any acaricides. However, exposure to abamectin drastically compromised the oviposition of A. largoensis, showing no increase in egg production with increasing prey density.


2015 ◽  
Vol 68 ◽  
pp. 446-446
Author(s):  
D.J. Wilson ◽  
P.J. Gerard

Spiny snout mite (Neomolgus capillatus) is a potential biocontrol agent for clover flea (Sminthurus viridis) a white clover pest on dairy farms in warmer and wetter parts of New Zealand In the 1990s this mite was introduced from Brittany France into Tasmania for clover flea control Results during the release programme were highly promising and subsequent anecdotal farmer reports indicate widespread decreases in damage As N capillatus is a predatory mite and already known to attack nontarget organisms habitat specificity will determine whether it could be introduced into New Zealand without risk to native insects To assess this pastures on nine of the original Tasmanian release farms and adjacent nontarget habitats ranging from bush wetlands eucalypt stands to sand dune country were sampled in April 2014 Litter samples were collected heat extracted and mite species identified Neomolgus capillatus was found at effective densities in pastures that had good clover cover Where present it displaced Bdellodes spp mites that are ineffective against clover flea No N capillatus were found in the nontarget habitats all of which lacked clover and contained other predatory mites including Bdellodes spp Therefore the preference by N capillatus for lush pastures makes it an excellent prospect for introduction as a biocontrol agent into clover flea prone regions of New Zealand


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuki Togashi ◽  
Mifumi Goto ◽  
Hojun Rim ◽  
Sayaka Hattori ◽  
Rika Ozawa ◽  
...  

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