Suitability of monotypic and mixed diets for development, population growth and predation capacity of Typhlodromus bagdasarjani (Acari: Phytoseiidae).

We quantified the life table parameters and predation capacity of a generalist predatory mite, Typhlodromus bagdasarjani Wainstein and Arutunjan on five monotypic diets, including Tetranychus urticae Koch (TSSM) eggs in the presence (SW) and absence (SN) of webs, Trialeurodes vaporariorum Westwood (GHWF) eggs (G), honeydew (H), and maize pollen (M) as well as three mixed diets, including SN + M, SN + G, and G + M. Our results showed that the individuals fed on the mixed diets had a considerably shorter developmental time and pre-oviposition period (APOP), higher oviposition days, higher fecundity and population growth rate than those raised on the monotypic diets. Furthermore, we found that the mixed diet of TSSM and GHWF eggs was the most favorable diet, resulted in the highest fecundity and population growth rate, shortest developmental time and APOP. While TSSM eggs alone in the presence of webs and honeydew were the worst diets resulted in the longest developmental time, lower oviposition day, higher fecundity and population growth rate. Our data determined that TSSM has more nutritional benefits than GHWF for T. bagdasarjani. We observed the positive effects of pollen addition to prey on the predatory mite's immature and adult life-history characters; however, it reduced the predation rate. Overall, maize pollen could enhance ecosystem services provided against spider mites and whiteflies by positively impacting the increase of T. bagdasarjani population. This predator may be more effective when two prey species are available than when only one species is present.

Pollen Alone or a Mixture of Pollen Types? Assessing Their Suitability for Mass Rearing of Neoseiulus cucumeris (Acari: Phytoseiidae) Over 20 Generations.

The generalist predatory mite, Neoseiulus cucumeris (Oudemans) is known as one of the most effective natural enemies on many pests. This economically important biocontrol agent was reared for 20 generations on date palm and castor bean pollen as well as a mixture of pollen types, including date palm, castor bean, and almond. The performance of this predator was evaluated by comparing its life table parameters after different generations (G1-G20) fed on each diet in a laboratory at 25 ± 1°C, 60 ± 5% RH, and a photoperiod of 16:8 (L: D) h. The development time of the predator reared on all tested diets had no significant difference in G20. The intrinsic rate of increase (r) of N. cucumeris by feeding on the mixed pollen (0.197 day-1) was significantly higher than that on castor bean, or date palm pollen (0.146 or 0.152 day-1 in G1, respectively). Our results indicated that the predator's performance was not affected by long-term feeding on the pollen diets, as well as there was no considerable difference between pollen alone and pollen mixture diets. Furthermore, mites reared on pollen diets had higher quality than those reared on natural prey, Tetranychus urticae Koch.

Does feeding on pollen grains affect the performance of Amblyseius swirskii (Acari: Phytoseiidae) during subsequent generations?

Diet is a critical component of the mass-rearing of biological control agents, but the impacts of diet are not always immediately obvious and can take several generations to manifest, resulting in poor survival, reproduction, and ability to kill prey under natural conditions. Our present study aimed to investigate the performance of a commercially-reared phytoseiid mite, Amblyseius swirskii, after four (G4) and six (G6) consecutive generations on pollen grains of two plant species, as well as its ability to find and kill its natural prey, Tetranychus urticae, after long-term rearing on each diet. We found no significant difference between the two diets in intrinsic and finite rates in G4. However, both diet and generation exerted a significant influence on the fecundity of A. swirskii. By G6, females reared on almond pollen had greater net reproductive and intrinsic rate compared to those reared on maize pollen. Conversely, A. swirskii fed on maize pollen consumed fewer prey than those reared on other diets, especially at higher prey densities. The findings have important implications for developing the mass-rearing program of A. swirskii on non-prey diets. Further research must explore the suitability of almond pollen in the large-scale culture of A. swirskii.

Modeling Temperature-Dependent Development Rate of Neoseiulus cucumeris (Acari: Phytoseiidae) Fed on Two Alternative Diets.

Developmental time of the predatory mite Neoseiulus cucumeris (Oudemans) fed on cattail and almond pollen was determined under laboratory conditions at nine constant temperatures: 10, 15, 20, 25, 27, 30, 32, 35 and 38°C. No development was observed at 10°C. The lower temperature threshold (T0) was estimated to be 10. 97 and 10. 29°C for the almond and cattail pollen, respectively, using the Ikemoto linear model. Thermal constant (K) for pre-adult development of N. cucumeris was 112.8 and 123.5 DD fed on almond and cattail pollen, respectively, using the Ikemoto linear model. The interaction between diet and temperature had a significant effect on the developmental rate of N. cucumeris. The nonlinear Pradhan-Taylor, Janisch/Kontodimas, Briere-1, and Janisch/Rochat models best described the developmental rate of pre-adult stages of N. cucumeris. The estimated Tfast by Pradhan-Taylor model was 31.9 and 33.9°C when fed on almond and cattail pollen, respectively, which was similar to the observed shortest developmental time at 32°C. Our results revealed that N. cucumeris could develop over a wide temperature range (15-35°C), which is a desirable characteristic for a biocontrol agent in biological control programs.

Mass Production of Neoseiulus cucumeris (Acari: Phytoseiidae): An Assessment of 50 Generations Reared on Almond Pollen.

Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae), an economically important biocontrol agent, was reared on almond pollen for 50 generations. We evaluated the effect of rearing predators on this pollen by comparing biological parameters at different generations (G1-G50). The shortest and longest development time occurred in G5 and G10, respectively. Females at the fifth and 50th generations laid eggs earlier than those of other generations. Females at G50 laid eggs over a longer period and produced more eggs than females of other generations, although females in the earlier generations had a higher gross reproductive rate and net reproductive rate than later generations. The intrinsic rate of increase, as well as the finite rate of increase of N. cucumeris in the fifth and 50th generations was significantly greater than those in other generations, while the first generation had the lowest values of these parameters. The dorsal shield length of both females and males and the width of females were found to be unaffected by their constant feeding on almond pollen. However, the number of rearing generations significantly affected the width of males. Long-term rearing of N. cucumeris for at least 50 generation on almond pollen did not substantially affect the predator's quality and this food source could be used for the mass production of this predator. Almond pollen should be assessed in rearing other phytoseiid mites that are important in biocontrol strategies.

Attempt to Develop Cost-Effective Rearing of Amblyseius swirskii (Acari: Phytoseiidae): Assessment of Different Artificial Diets.

Commercial production of Amblyseius swirskii Athias-Henriot based on storage mites needs both space and labor to maintain large cultures of these prey, and also may lead to health problems for workers. Therefore, the accessibility of a suitable artificial diet could eliminate the mentioned problems; however, the artificial diets must support the persistent production of high quality progeny. This study endeavored to find a more easily available and cheaper nutrient that may further reduce the cost of diet production for A. swirskii. The predator's performance was determined when it was fed on a basic artificial diet (AD1) composed of honey, sucrose, tryptone, yeast extract, and hen egg yolk, and on eight other artificial diets consisting of 80% AD1 enriched with different nutrients including maize pollen (AD2), hemolymph of Plusia gamma L. (AD3), Ephestia eggs (AD4), Artemis cysts (AD5), Ephestia last-instar larvae (AD6), multivitamin syrup (AD7), bovine serum albumin (AD8), and bull sperm (AD9). The lowest development time was on AD2. The highest value of fecundity and oviposition period were observed on AD5, followed by AD2 and AD4. The intrinsic rate of increase (r) and the finite rate of increase (λ) reached the maximal value on AD5. Feeding on AD2 and AD5 resulted in highest value of R0 (net reproductive rate). Our results indicated that Artemia cysts and maize pollen had better potential to be used as nutrient in artificial diet for mass production of A. swirskii. Overall, it seems that AD2 is the most cost effective than others.

Description of a new species of Julolaelaps (Acari, Mesostigmata, Laelapidae) from Iran.

Julolaelaps hallidayi sp. n., was collected from soil of river verge in Brujen, Chaharmahal va Bakhtiari province, Iran. Description and illustrations of this new species based on adult females are presented. Some entries are added to the key of Moraza and Kazemi (2012) to include the new species.