A winning formula: sustainable control of three stored-product insects through paired combinations of entomopathogenic fungus, diatomaceous earth, and lambda-cyhalothrin.

This research aimed to assess the effectiveness of Metarhizium robertsii, diatomaceous earth (Protect-It), and lambda-cyhalothrin, for the long-term protection of stored wheat against three destructive grain insect pests, Rhyzopertha dominica, Tribolium castaneum, and Trogoderma granarium. Different treatments were applied, both alone and in paired combinations in laboratory and persistence trials. Single treatments exhibited significantly lower mortality rates in comparison to the paired treatments for all tested insect species. Among the single treatments, lambda-cyhalothrin (Lamb) resulted in significantly higher mortality rates in laboratory trials, followed by diatomaceous earth (DE) and M. robertsii (Mr), with insignificant differences between Mr and DE. Evidently, DE exhibited the highest persistence after 120 days of storage for all insect species and initial exposures, although variations in mortality rates among treatments were mostly insignificant. Overall, the most effective treatment in terms of mortality in laboratory, and persistence trials, and progeny production was DE + Lamb, followed by Mr + Lamb, and Mr + DE for all tested insect species. In general, the most susceptible insect species was R. dominica, followed by T. castaneum and T. granarium. This research highlights the effectiveness of M. robertsii, DE, and lambda-cyhalothrin in providing prolonged protection of stored wheat against all the examined grain insect species.

Combinations of Beauveria bassiana and spinetoram for the management of four important stored-product pests: laboratory and field trials.

The current study examines the efficacy of the semi-synthetic insecticide spinetoram and entomopathogenic fungi Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Cordycipitaceae) as wheat protectants against the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), and the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), under laboratory and field trials. One dose of B. bassiana, i.e., 1 × 107 conidia/kg wheat, two doses of spinetoram, i.e., spine1: 0.05 ppm (mg/kg wheat), spine2: 0.1 ppm, and their combinations (Bb + spine1, Bb + spine2) were evaluated at 20, 25, and 30 °C. All treatments provided significantly higher mortality at 30 °C compared with the other two temperatures. Maximum mortality levels were observed in the treatments where B. bassiana was combined with the higher dose of spinetoram (0.1 ppm). All treatments reduced progeny production in comparison with the control groups. Maximum progeny reduction was observed at 30 °C, on wheat treated with the Bb + spine2 combination. The combination Bb + spine2 also provided elevated mortality rates in both laboratory and field persistence trials, but at 180 days caused moderate mortality to all tested insect species. Concerning progeny, at laboratory persistence trials, the combination Bb + spine2 exhibited the lowest offspring emergence to all tested species compared to the other treatments and control. Overall, our study showed that R. dominica was the most susceptible species followed by S. granarius, T. castaneum, and T. granarium. Our findings revealed that the combination of B. bassiana and spinetoram may be a useful tool for efficient and advanced integrated pest management strategies for long storage periods under multiple temperatures.

Compatibility and synergistic interactions of fungi, Metarhizium anisopliae, and insecticide combinations against the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae).

Aphids are major pests affecting cereals, vegetables, fruit, forestry and horticultural produce. A multimodal approach may be an effective route to controlling this prolific pest. We assessed the individual and combined effect of eight insecticides and the entomopathogenic fungi, Metarhizium anisopliae (Metschin.) against the cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae), under laboratory conditions. Six of the insecticides tested were found to be highly compatible (flonicamid, imidacloprid, nitenpyram, dinotefuran, pyriproxyfen and spirotetramat), showing positive integration with the fungus and were selected for bioassays. The combination mixtures (1:1 ratio of M. anisopliae: insecticide) were significantly more toxic to A. gossypii than individual treatments. Maximum mortality (91.68%) of A. gossypii was recorded with combination of flonicamid and M. anisopliae (2.4 × 106 cfu/ml) 72 h after application. While minimum mortality (17.08%) was observed with the individual treatment of M. anisopliae (2.4 × 106 cfu/ml). The insecticides revealed toxicity consistent with their compatibility with M. anisopliae, ranking for efficacy exactly as they did for compatibility. In addition, the synergy factor (SF) and co-toxicity coefficient (CTC) values indicated synergistic interactions at different time intervals. The synergistic efficacy revealed the potential of fungus-insecticide integration against sucking insect pests.

New promising high yielding cotton Bt-Variety RH-647 adapted for specific agro-climatic zone.

The Bt-cotton RH-647 was developed by Cotton Research Institute CRI, Khanpur has been acknowledged for its possesses superior plant characteristics and potential to yield out under harsh agro-climatic conditions of cotton productive district of Rahimyar Khan in Bahawalpur Division and southern Punjab in 2016. RH- 647 for its novel plant structure and improved fiber quality heat and drought tolerant to withstand successfully sustain yield out in harsh, highly variable hot and dry climatic conditions of and harsh seasoned. RH-647 was developed through one-way hybridization of elite parental genotypes accompanied by pedigree selection method through gene pyramiding technique for incorporation of excellent combinations of fiber traits and CLCuV disease tolerance with higher yield potential right from F1 population. The superior plant combinations were selected in F2-F6 generations were entirely based on phenotypic plant traits and progeny yield potential in field, plant shape, number of bolls per plant, average boll weight (g) and fiber quality traits over standard varieties. The single plant progenies were selected 56 sister lines were tested for Bt-gene (Cry1 Ac) were evaluated for high yielding performance for this superior cross and finally RH-647 as superior breeding line was bulked in year 2010. The strain was evaluated in Randomized Complete Block Design in preliminary yield trials (PYT) and two years in Advance Yield Trials (AYT) trials and Zonal Varietal trials for two years. The superior line 647/10 was ensued for performance in variety attestation tests as RH-647. RH-647 performed best in two years varietal trials (NCVT and PCCT and DUS) conducted for two successive growing seasons (2014-2015 and 2015-2016). RH-647 yielded out significantly compared with standard varieties MNH-886, FH-142 and CIM 602. After completion of mandatory trials in year 2016, RH-647 was approved as new Bt. cotton variety "RH-647". RH-647 is early in maturity with high yield potential and best suited for wheat-cotton cropping pattern. It has fluffy opening and is easy to pick, strongly tolerant to CLCuV disease, high Ginning out turn GOT% (40.2%) with improved fiber traits; staple length (28.3 mm), fiber strength (4.2ug/inch) is duly capable to fulfill all industrial requisitions.

Integration of entomopathogenic fungi and eco-friendly insecticides for management of red palm weevil, Rhynchophorus ferrugineus (Olivier).

Red palm weevil (Rhynchophorus ferrugineus) is a voracious pest of date palm worldwide. Pakistan ranks sixth in date palm production globally. Losses to date palm plantations in Pakistan sometimes surpass 10%-20%. Most of the traditional management strategies used by farmers have been found insignificant to combat this voracious pest. The entomopathogenic fungi, Beauveria bassiana [QA-3(L) and QA-3(H)] and insecticides, Nitenpyram (Active 10% SL) [NIT (L) and NIT (H)] were applied to larval (2nd, 4th, and 6th), pupal and adult stages of R. ferrugienus. Integration or alone application of fungi with insecticides at different concentration under laboratory conditions. Combined application was depicted additive and synergistic interactions. Contrarily, highest cumulative mortality (100%) was recorded in 2nd instar larvae as compared to later instar larvae at combined application. The maximum pupal and adult mortality remained 89% and 66% respectively after treatment with [QA-3 (H) + NIT (L)]. The combination of B. bassiana at higher concentration whereas Nitenpyram at lower dose was found more lethal to larvae, pupae and adults of R. ferrugineus. This signifies the need of combining B. bassiana and bio-rational insecticides that can reduce the cost of management with least harm to environment and natural enemies.

Effects of temperature on baseline susceptibility and stability of insecticide resistance against Plutella xylostella (Lepidoptera: Plutellidae) in the absence of selection pressure.

Plutella xylostella L. (Lepidoptera: Plutellidae) is an important pest causing significant losses to vegetables worldwide. Insecticides resistance in P. xylostella is a serious issue for scientists since last 30 years. However, deltamethrin and Bt Cry1Ac are commonly used insecticides against P. xylostella but studies involving development of resistance in P. xylostella against these two insecticides at different temperatures are lacking. The current study was aimed to find out the toxicity of deltamethrin and Bt Cry1Ac, and resistance development in P. xylostella. Results showed that the positive correlation between the temperature and toxicities of deltamethrin and Bt Cry1Ac. The results indicated -0.051, -0.049, -0.047, and -0.046 folds of deltamethrin resistance at 15 °C, 20 °C, 25 °C, and 30 °C temperatures, respectively from 1st to 12th generations. The toxicity of Bt Cry1Ac after 24 h was 2.2 and 4.8 folds on 1st generation at 20 °C and 25 °C temperatures, respectively compared to the toxicity recorded at 15 °C (non-overlapping of 95% confidence limits). Based on the results of this study, it is concluded that the temperature has a positive correlation with the toxicity of deltamethrin and Bt Cry1Ac against the larvae of P. xylostella. This study suggests that deltamethrin and Bt Cry1Ac can be included in the management program of P. xylostella on many vegetable crops. The baseline susceptibility data might be helpful to understand the resistance mechanisms in P. xylostella.

Fitness parameters of Plutella xylostella (L.) (Lepidoptera; Plutellidae) at four constant temperatures by using age-stage, two-sex life tables.

Different temperature zones have significant impact on the population dynamics of Plutella xylostella. Effective management of P. xylostella requires the knowledge of temperature tolerance by different life stages. In the current study, fitness parameters of diamondback moth were reported by using age-stage, two-sex life table traits at four constant temperatures (15, 20, 25 and 30 °C). The life cycle of P. xylostella was significantly longer at 15 °C. The 20 °C level of temperature was found optimal for fecundity, gross reproductive rate (51.74 offspring) and net reproductive rate (44.35 offspring per individual). The adult pre-oviposition period was statistically at par at all four level of temperatures. However, the survival was maximum at 20 °C as compared to other three temperature ranges. Based on the current study, it was concluded that temperature has a great role in population build-up of P. xylostella and effective management tactics should be applied to prevent significant damage to cabbage and other cruciferous crops when the temperature in the field is near 20 °C.

Resistance to commonly used insecticides and phosphine fumigant in red palm weevil, Rhynchophorus ferrugineus (Olivier) in Pakistan.

The red palm weevil Rhynchophorus ferrugineus (Olivier) is an important pest of date palms in many regions of the world. This paper reports the first survey of insecticide resistance in field populations of R. ferrugineus in Pakistan which were collected from seven date palm growing areas across Punjab and Khyber Pakhtunkhwa (KPK) provinces, Pakistan. The resistance was assessed by the diet incorporation method against the formulated commonly used chemical insecticides profenophos, imidacloprid, chlorpyrifos, cypermethrin, deltamethrin, spinosad, lambda-cyhalothrin and a fumigant phosphine. Elevated levels of resistance were recorded for cypermethrin, deltamethrin and phosphine after a long history of insecticide use in Pakistan. Resistance Ratios (RRs) were 63- to 79-fold for phosphine, 16- to 74-fold for cypermethrin, 13- to 58-fold for deltamethrin, 2.6- to 44-fold for profenophos, 3- to 24-fold for chlorpyrifos, 2- to 12-fold for lambda-cyhalothrin and 1- to 10-fold for spinosad compared to a susceptible control line. Resistant R. ferrugineus populations were mainly found in southern Punjab and to some extent in KPK. The populations from Bahawalpur, Vehari, Layyah and Dera Ghazi Khan were most resistant to chemical insecticides, while all populations exhibited high levels of resistance to phosphine. Of the eight agents tested, lower LC50 and LC90 values were recorded for spinosad and lambda-cyhalothrin. These results suggest that spinosad and lambda-cyhalothrin exhibit unique modes of action and given their better environmental profile, these two insecticides could be used in insecticide rotation or assist in phasing out the use of older insecticides. A changed pattern of both insecticides can be used sensibly be recommended without evidence of dose rates and frequencies used.

Multiple Resistances Against Formulated Organophosphates, Pyrethroids, and Newer-Chemistry Insecticides in Populations of Helicoverpa armigera (Lepidoptera: Noctuidae) from Pakistan.

Field populations of Helicoverpa armigera Hübner from 15 localities across the Punjab, Pakistan, were assessed by the leaf dip method for resistance against formulated organophosphates, pyrethroids, and newer insecticide groups. Resistance levels in H. armigera have been incrementally increasing for organophosphate and pyrethroid insecticides after decades of use in Pakistan. Resistance ratios (RRs) documented for organophosphates were 24- to 116-fold for profenofos and 22- to 87-fold for chlorpyrifos. For pyrethroids, RRs were 3- to 69-fold for cypermethrin and 3- to 27-fold for deltamethrin. Resistance levels against newer chemistries were 2- to 24-fold for chlorfenapyr, 1- to 22-fold for spinosad, 1- to 20-fold for indoxacarb, 1- to 18-fold for abamectin, and 1- to 16-fold for emamectin benzoate. Resistant populations of H. armigera were mainly in the southern part of the Punjab, Pakistan. The most resistant populations were collected from Pakpattan, Multan, and Muzzafargarh. Of the nine insecticides tested, LC50 and LC90 values were lower for newer insecticide groups; resistance levels were moderate to very high against organophosphates, very low to high against pyrethroids, and very low to low against the newer-chemistry insecticides. These findings suggest that the newer-chemistry insecticides with different modes of action could be included in insecticide rotations or replace the older insecticides. Supplementing the use of synthetic insecticides with safer alternatives could help to successfully lower the farmer's reliance on insecticides and the incidence of resistance due to repeated use of insecticides against major insect pests.