Nondetrimental impact of two concomitant entomopathogenic fungi on life history parameters of a generalist predator, Coccinella septempunctata (Coleoptera: Coccinellidae)

The non-persistent impact of biocontrol agents can be revealed for pest control when associated entomopathogenic fungi (EPFs) negatively affect the natural enemies. In this assay, impacts of Beauvaria bassiana (Balsamo) Vuillemin, and Metarhizium anisopliae (Metschnikoff) Sorokin were studied for their compatibility or side effects on life table parameters of an important generalist predator, Coccinella septempunctata L. The results indicated non-significant impacts of both EPFs on life table parameters of C. septempunctata. The development time (egg-adult) was not significantly different in control (69.79 days) and EPFs treated C. septempunctata (69.35–80.07 days). Both fungi did not induce any significant changes in the fecundity, adult pre-oviposition period (APOP), total preoviposition period (TPOP), and mean generation time (T) as compared to control treatment. Similarly, no difference in fecundity rate of C. septempunctata was observed after EPFs treatment (287.7–288.5) compared to control (290.0). The highest net reproductive rate (R0) occurred in control (87.05 offspring individual−1) and M. anisopliae (86.31 offspring individual−1) as compared to B. bassiana treated beetles (76.97 offspring individual−1). The age-specific fecundity curves indicated that the C. septempunctata had a similar fecundity rate in both EPFs treatments and control. This study demonstrates no significant side effects of B. bassiana and M. anispoliae on the performance and biology of C. septempunctata. Considering the compatibility of both EPFs with C. septempunctata, their combinations can be recommended in various integrated pest management programs.

Sub-Lethal Effects of Lecanicillium lecanii (Zimmermann)-Derived Partially Purified Protein and Its Potential Implication in Cotton (Gossypium hirsutum L.) Defense against Bemisia tabaci Gennadius (Aleyrodidae: Hemiptera)

Whiteflies, Bemisia tabaci Gennadius (Aleyrodidae: Hemiptera), are a polyphagous economically destructive pest of several solanaceous crops around the world. Many secondary metabolites are synthesized by different biotrophic and necrotrophic fungi which are capable of inducing systemic resistance in plants against various phytophagous pests. The present laboratory work demonstrated the anti-insect impact of a protein extracted and purified partially from an entomopathogenic fungus (EPF) Lecanicillium lecanii (Zimmermann) against B. tabaci. Three different concentrations (i.e., 7.43, 11.15, and 22.31 μg mL−1) of this protein were bioassayed to assess its effect on the fecundity rate of B. tabaci on cotton (Gossypium hirsutum L.) plants. Furthermore, the possible implication of this fungal protein in defense pathways of cotton plants was evaluated by determining the expression profiles of salicylic acid (SA) and jasmonic acid (JA) pathways related to major genes through reverse transcription qPCR (RT-qPCR). According to the results, all protein concentrations exerted a significant (F3, 252 = 62.51; p ≤ 0.001) and negative impact on the fecundity rate of B. tabaci females. At the highest protein concentration (22.31 μg mL−1), the minimum rate of fecundity (i.e., 2.46 eggs female−1day−1) of B. tabaci was noted on the seventh day, whereas fecundity rates for the other two protein concentrations (i.e., 11.15 and 7.43 μg mL−1) were, respectively, 3.06 and 3.90 eggs day−1 female−1. The maximum rate of fecundity (6.01 eggs female−1day−1) was recorded in untreated (control) treatments. In addition, the foliar application of L. lecanii derived protein significantly upregulated all SA linked genes (OPR3, PPO1 and COI1) and slightly triggered up the JA linked genes (LOX1, UBQ7 and AOS) in the cotton plants. These findings revealed that this L. lecanii extracted partially purified protein triggered systemic resistance against B. tabaci in the cotton plants, proposing its putative effectiveness as an innovative biological control technique against B. tabaci and other phloem-feeding hemipteran pests. Nevertheless, further investigations such as purification and molecular and functional characterization of this L. lecanii-derived partially purified protein are required.

Do Bio-Insecticides Affect Only Insect Species? Behavior, Regeneration and Sexual Reproduction of A Non-Target Freshwater Planarian

Bio-insecticides have been increasingly used worldwide as ecofriendly alternatives to pesticides, but data on their effects in non-target freshwater organisms is still scarce and limited to insects. The aim of this study was to determine the lethal and sub-lethal effects of the bio-insecticides Bac Control (based on Bacillus thuringiensis kurstaki - Btk) and Boveril (based on Beauveria bassiana - Bb) on regeneration, behavioral and reproductive endpoints of the freshwater planarian Girardia tigrina. The estimated LC50 − 48h were > 800 mg a.i./L for Btk and 60.74 mg a.i./L for Bb. In addition, exposure to Btk significantly decreased locomotion and feeding activities of planarians (lowest observed effect concentration (LOEC) of 12.5 mg a.i./L Btk) and fecundity rate (LOEC = 3.12 mg a.i./L Btk), whereas exposure to Bb significantly delayed regeneration (LOEC = 0.75 mg a.i./L Bb) and decreased fecundity rate (1.5 mg a.i./L Bb) of planarians. Thus, both bio-insecticides induced deleterious sub-lethal effects on a non-insect freshwater invertebrate species. However, only Bb-based formulation affected the survival, fecundity rate and regeneration at concentrations below the maximum predicted environmental concentration (PEC = 247 mg/L). Thus, care should be taken when using such formulations as alternatives to chemical insecticides near aquatic ecosystems.

Effect of elevated temperature on the population dynamics of fall armyworm, Spodoptera frugiperda

Aim: The present study was conducted to determine the growth, survival, fecundity and mortality rate of Spodoptera frugiperda in maize at elevated temperature. Methodology: Biology and life table experiments were carried out in custom made Open Top Chambers (4m x 4m x 4m size) fitted with SCADA under increasing temperature regimes viz., 32˚C, 33˚C, 34˚C, 35˚C and 36˚C. Each stage of the insects was examined daily and the fertility and life-table parameters were calculated by using TWOSEX-MS chart. Results: The overall developmental time for egg, larva, pupa and adult stages (total lifespan) at different elevated temperatures were in the order of 32˚C > 33˚C > 34˚C > 35˚C > 36˚C. The fecundity rate of S. frugiperda at different elevated temperatures were in the order of 34˚C > 33˚C > 32˚C > 35˚C > 36˚C. Interpretation: The current study confirms that the elevated temperature regimes had a positive correlation with fecundity rate upto 34˚C and negative correlation with the survival rate of S. frugiperda.

Dispersal Mechanism Assessment for Panonychus citri (Acari: Tetranychidae) Secondary Outbreaks

Secondary population outbreaks of Panonychus citri (McGregor) (Acari: Tetranychidae) are triggered by synthetic chemical applications (dose and method), which also elicited a change in mites’ behavioral responses. This study aimed to understand the dispersal pattern of P. citri and how changes in dispersal behavior may influence secondary pest outbreaks in the field with or without chemicals. We found positive density and time-dependent dispersal within the inoculated leaflet. Dispersion from inoculated leaflets to the last leaflet depends on initial density and time. A significant difference was observed in the composite dispersal index data and preferred midrib region. The minimum dispersal was observed by P. citri in no direct contact with treated surfaces, whereas attraction was observed on treated surfaces (right). All chemicals gave different dispersal and feed disruption responses depending on the treatment application pattern. The maximum number of mites dispersed and avoid surfaces treated with abamectin and vegetable oil, respectively. Vegetable and EnSpray 99 had a positive impact on toxicity, repellency, and irritancy. The fecundity rate of P. citri boosted with a high dose and direct exposure. Panonychus citri colonization as a single individual or gregarious distribution resulted in a rapid fecundity rate, which may explain why citrus orchards were severely damaged and how suddenly a whole citrus plantation can be highly infested. This study concluded that change in treatment application patterns leads to a change in the behavioral responses in P. citri.

A comparative analysis of the cycle fecundity rates associated with ovarian hyperstimulation along with IUI versus medical management in the treatment of mild to moderate oligozoospermia in males

Background: To compare the pregnancy rate in infertile couples with mild to moderate oligozoospermia receiving ovarian hyperstimulation and IUI, with that of medical management with CC.Methods: A total 120 couples with males having sperm concentration between 5 to 20 million/ml, normal serum gonadotropins and testosterone, and a presumptively fertile partner were enrolled in this prospective clinical study, during the study period of 19 months, 31st January 2019 till 1st September 2020. 120 couples were divided randomly into two groups A (n=60) and B (n=60). In group A, 60 couples were subdivided equally into 3 groups, each having 20 couples. Ovarian hyperstimulation protocols with IUI were used in different subgroups in group A. A total of 216 IUI cycles done for 60 couples. While in group B, 60 males with oligozoospermia were prescribed CC treatment 25mg/day on alternate days for 3 months.Results: Out of 60 patients in group A, 24 achieved pregnancy with a cycle fecundity rate of 4% in CC+IUI, 9.87% in HMG+CC+IUI and 21.67% in HMG+IUI. 5 out of 60 patients in group B achieved pregnancy with cycle fecundity rate of 2.78%.Conclusions: These data suggest that acceptable pregnancy rates can be achieved with IUI combined with ovarian hyperstimulation in males with oligozoospermia. The role of CC treatment in males with oligozoospermia in improving the pregnancy outcome is extremely mearge. Thus, owing to the cost effectiveness and non-invasive modality, IUI is preferred prior to other more invasive and potentially costly reproductive technologies in the treatment of male factor subfertility.

Sub-Lethal Effects of Partially Purified Protein Extracted from Beauveria bassiana (Balsamo) and Its Presumptive Role in Tomato (Lycopersicon esculentum L.) Defense against Whitefly (Bemisia tabaci Genn.)

Plants rely on various physiological and molecular defense mechanisms against biotic stresses such as herbivore insects. Many entomopathogenic fungi synthesize protein molecules that can trigger these plant defenses. This laboratory study characterized the bioactivity of a partially purified protein derived from Beauveria bassiana (ARSEF 2860) against whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), which is an economically important pest of agricultural and horticultural crops worldwide. Different concentrations (i.e., 0.021, 0.042 and 0.063 μM) of fungal protein were bioassayed to determine their sub-lethal effect on the survival percentage and fecundity rate of B. tabaci on tomato (Lycopersicon esculentum) plants. In addition, the putative role of this partially purified B. bassiana protein in the defense mechanisms of plant was assessed through the expression analyses of important genes related to salicylic acid (SA)—and jasmonic acid (JA)—associated pathways using RT-qPCR. Results revealed a significant suppression of the survival percentage and fecundity rate of B. tabaci by the fungal protein. Lowest survival (41%) was recorded for the highest concentration of protein (0.063 μM), whereas mean survival for the other two protein concentrations (0.042 and 0.021 μM) were 62 and 71%, respectively. Likewise, the highest and lowest mean fecundity rates were observed for the control and the highest protein concentration (i.e., 3.3 and 1.8 eggs day−1 female−1, respectively). Furthermore, the exogenous application of B. bassiana-derived protein on tomato plants strongly up-regulated the SA-related genes (PAL, PR1, BGL2 and EDS1) and slightly up-regulated the JA-related genes (AOC, AOS, OPR3 and LOX) as compared to the control plants. These findings demonstrate the putative role of this partially purified B. bassiana protein fraction in inducing systemic resistance in the tomato plants against B. tabaci, suggesting its further purification and characterization to be used as novel biological pest control tool against B. tabaci and other sap-sucking insect pests.

Mancozeb exposure during development and lactation periods results in decreased oocyte maturation, fertilization rates, and implantation in the first-generation mice pups: Protective effect of vitamins E and C

This study aimed to evaluate the mancozeb (MNZ) impact on oocyte maturation of first-generation mice pups as well as their fertilization rate, embryo development, and implantation along with the preventative effect of vitamins E and C. Pregnant mice were randomly divided into six groups: control, vehicle, and MNZ (500 mg/kg body weight (BW)), vitamin E (200 mg/kg BW), MNZ plus vitamin E, MNZ plus vitamin C (100 mg/kg BW), and MNZ plus two vitamins. All treatments were conducted by oral gavage every 2 days from the second day of gestation until the end of lactation. Vitamin treatment was initiated 30 min before receiving MNZ. After birth, first-generation mice pups were kept until adulthood (8–10 W). Adult female mice pups superovulated and then the collected oocytes were examined for nuclear maturity status. After in vitro fertilization of metaphase II oocytes with sperm of the first-generation male mice pups, fertilization rate and embryo development were evaluated over 24 h. Also, the fecundity rate and the number of implanted embryos in vivo were studied on the eighth day of pregnancy. MNZ exposure during embryo development and lactation significantly decreased the total number of collected oocytes, oocyte maturation, fertilization rate, implantation rate, fecundity rate, and embryo development compared with the control group in the first-generation pups. In contrast, vitamin treatments significantly increased these parameters compared to the MNZ group. Reduction in the quality of oocyte, the rate of fertilization, embryo implantation, and development following MNZ exposure could decrease female reproductive success, while coadministration of vitamins E and C could prevent these complications.

Biting rhythm, fecundity and longevity rate of Aedes albopictus (Skuse) females from different urbanized settings in Penang Island, Malaysia under uncontrolled laboratory conditions

Urbanization could potentially modify Aedes albopictus’ ecology by changing the dynamics of the species, and increasing the abundance of their breeding sites due to environmental changes, and thus contribute to dengue outbreaks. An efficient control of the vector requires a deeper understanding on the biological components of this vector. Thus, this study was conducted to evaluate the biting rhythm, fecundity and longevity rate of Ae. albopictus in relation to urbanization strata; urban, suburban and rural areas in Penang Island, Malaysia. The experiments were done in comparison to a laboratory strain. Twenty-four hours biting activity of all the mosquito strains showed a clear bimodal biting activity, with morning and evening twilight peaks. A two-way analysis of variance (ANOVA) found that there was statistically no significant interaction (F(69,192) = 1.337, P > 0.05) between the effects of biting time and mosquito strains. Meanwhile, fecundity rates were shown to be statistically significantly different between mosquito strains (F(3,442) = 10.559, P < 0.05) with urban areas having higher mean number of eggs (mean = 107.69, standard error = 3.98) than suburban (mean = 94.48, standard error = 5.18), and rural areas (mean = 72.52, standard error = 3.87). Longevity rates were significantly higher (F(3,441) = 31.259, P < 0.05) for mosquito strains from urban areas compared to the other strains. These findings would provide crucial and relevant fundamental information to the planning of control program in Malaysia, particularly Penang.Author SummaryAedes mosquito populations associated with human habitation in urban area do not only have the potential to cause biting nuisance, but also cause significant public health risks through the transmission of dengue virus. The socioeconomic effects of urbanization have been comprehensively studied by socio-ecologists, but the ecological effects and their impact on this vector biology was not known. The authors found that in Penang Island, the mean number of eggs laid per female of Aedes albopictus is high in the urban areas than those in suburban and rural areas. The survivorship is high for urban populations parallel to the fecundity rate and apparent biting pattern which is peak at dawn and dusk was noted for all Ae. albopictus strains. The changed environment in the urbanized area where more kinds of breeding containers and more blood sources produced by condensed human population supported by warm climate may facilitate larval development, enhance the vector survivorship and its reproductive fitness. These might be the reasons for quick adaptation and susceptibility of Ae. albopictus in urban areas. As higher fecundity rate and longer adult survival may enhance disease transmission, this species studied is indeed need high attention in terms of vector control.