The population of spider feeding on insect pests of cotton was observed throughout the growth period of the crop, being maximum in the month of July. Chrysoperla was observed from second fortnight of June to harvesting of the crop being maximum in November. The incidence of coccinellids was recorded from the middle of August to middle of September and remained till harvesting of the crop being maximum in the first fortnight of November. A positive significant effect of maximum and minimum temperature on spider and negative significant effect on population of chrysoperla and coccinellids was recorded. Evening RH exerted positive significant effect on spider and negative significant effect on coccinellids.

The whitefly, Bemisia tabaci, an insect of the order Hemiptera which attacks more than 600 species of plants, is one of the most important agricultural pests around the world. The insecticidal Cry proteins from Bacillus thuringiensis (Bt) are useful biological pesticides, and some are toxic to Hemipteran insects. In this study, Colombian native isolates of Bt were functionally characterized at molecular and biological levels. The strains contained between one and five different crystal shapes: round, triangular, amorphous, bipyramidal and squared. The strains presented between three to seven bands of proteins in their electrophoretic pattern that were organized into six groups according to their possible biological activity on insect pests. Cry1Aa, cry1Ab, cry1Ac, cry1B and cry1C genes were identified for PCR in the different Bt isolates. Bioassays were performed on tomato leaves whose surface was spread with 3 μg · ml−1 crude extract of Bt toxins. Second instar larvae of whitefly, which were placed on top of leaves and exposed to the toxins for 7 days, exhibited mortalities from 18 to 69%. The lethal concentration 50 (LC50) of ZBUJTL39, Bt kurstaki HD1 and ZCUJTL9 strains were 1.83, 1.85 and 2.16 μg · ml−1, respectively (p < 0.05). These results show that the native Bt strain ZBUJTL39, which contained the genes cry1Aa, cry1Ab, cryCa and cryBa could eventually be used for the development of an integrated management program together with other tools for the control of B. tabaci.

Rachiplusia nu (Lepidoptera: Noctuidae) is the main soybean plague in Argentina. The main strategy employed to control this pest is chemical control, applying different chemical groups regardless of their harmful effects on the environment and human health. Different biological products using entomopathogenic fungi have been developed and are commercially available to control different insect pests worldwide. The objective of this work was to develop and apply, under field conditions, different fungal formulations using entomopathogenic fungi to control R. nu larvae. The mortality percentages in bioassays of R. nu larvae treated with different colonies of fungal entomopathogens ranged between 86.6 ± 8.4% for Beauveria bassiana (LPSc 1098) and 56.6 ± 4.2% for Metarhizium anisopliae (LPSc 907). Under laboratory conditions using fungal formulations of B. bassiana, the formulation 4 (LPSc 1086) exhibited the highest mortality percentage (100%), followed by formulation 5 (LPSc 1098), 97 ± 1.3%. Under field conditions, larval mortalities were 82.4 ± 5.56% for formulation F4 and 61.8 ± 7.5% for formulation F5. The results obtained in this work indicate that although a greater number of tests under field conditions with the fungal formulation F4 are necessary, the results obtained in this work allow speculating that it is possible to use this fungal formulation under field conditions to control R. nu.

Annual losses of cocoa in Ghana to insect pests are significant. The use of integrated pest management (IPM) tools is critical for effective pest management. Previous studies on the subject have considered how farmers perceive the economic impact of insect pests on cocoa. These studies however did not investigate farmers’ ability to identify pests, associated damage symptoms and their implications for pest management. The current study, therefore, assessed farmers’ ability to correctly associate insect damage with the pest species that caused it. A total of 600 farmers were interviewed in the Eastern, Ashanti, Western, Brong Ahafo and Central Regions of Ghana with a structured open and closedended questionnaire. Most farmers (>85%) were unable to correctly identify and associate pests to their damage. The majority (>80%) of farmers also could not link the immature stages of insect pests to their adult stages. Wrong identification of the major pests (>85%) led to a wide variation in the timing of insecticide application amongst farmers. The majority of the farmers (60%) interviewed had not received training in insect pest identification. The study shows that 90% of the farmers, who had received some training, got it from the Cocoa Health and Extension Division (CHED) of the Ghana Cocoa Board (COCOBOD). Almost all respondents (98%) agreed that correct pest identification is critical for effective pest control. The importance of pest identification and monitoring as a component of IPM is discussed.

Global warming and climate change are some of the most widely discussed topics in today's society, and they are of considerable importance to agriculture globally. Climate change directly affects agricultural production. On the other hand, the agricultural sector is inherently sensitive to climate conditions, and this has made the agricultural sector one of the most vulnerable sectors to the effects of global climate change. Rising CO2 levels in the atmosphere, increased temperature, and altering precipitation patterns all substantially influence agricultural insect pests and agricultural productivity. Climate change has a number of implications for insect pests. They can lead to a decreased biological control effectiveness, particularly natural enemies, increased incidence of insect-transmitted plant diseases, increased risk of migratory pest invasion, altered interspecific interaction, altered synchrony between plants and pests, increase in the number of generations, increased overwintering survival, and increase in geographic distribution. As a consequence, agricultural economic losses are a real possibility, as is a threat to human food and nutrition security. Global warming will necessitate sustainable management techniques to cope with the altering state of pests, as it is a primary driver of pest population dynamics. Future studies on the impacts of climate change on agricultural insect pests might be prioritized in several ways. Enhanced integrated pest control strategies, the use of modelling prediction tools, and climate and pest population monitoring are only a few examples.

In this short communication describing experiments carried out on the larvae of two insects, Unaspis euonymi Comstock (feeding on Euonymus japonicus Thunb.) and Dynaspidiotus britannicus Newstead (feeding on Laurus nobilis L.), we evaluate for the first time the efficiency of using DNA insecticides in the control of sap-sucking insects, including armored scale insects. Over a period of 10 days, high insect mortality was detected in both U. euonymi and D. britannicus, accompanied by a significant decrease in the concentration of target RNAs. At the same time, no visible changes were observed when the leaves of the host plants were subjected to treatment with DNA insecticides for one month. The results show the high efficiency of DNA insecticides used against hemipteran insect pests. It is noteworthy that the high efficiency of DNA insecticides and their low cost in comparison with RNA preparations provides a safe and extremely promising potential vehicle for the control of sap-sucking insects.

5.8S ribosomal RNA plays an important role in protein synthesis and eukaryotic ribosome translocation. Contact DNA insecticides based on antisense fragments of 5.8S ribosomal RNA gene of gypsy moth Lymantria dispar L. showed prospective insecticidal activity on its larvae. The most pronounced insecticidal effect was found for antisense fragments 10 and 11 nucleotides long (oligoRIBO-10 and oligoRIBO-11), whereas 12 nucleotides long fragment (oligoRIBO-12) caused the lowest level of insect mortality. This data corresponds to results obtained earlier using rabbit reticulocyte and wheat germ extracts, where maximum inhibition of protein synthesis was observed when a relevant oligomer 10-11 nucleotides long was used, whilst longer chain lengths resulted in reduced inhibition. Using oligoRIBO-11 fragment we have shown penetration of antisense oligonucleotides to insect cells through insects’ exoskeletons. MALDI technique registered the penetration of the oligoRIBO-11 fragment into insect cells after 30 min and a significant response of insect cells to the applied oligonucleotide after 60 min, which indicates not only that the oligonucleotide enters the insect cells, but also the synthesis of new substances in response to the applied DNA fragment. Contact DNA insecticides developed from the L. dispar 5.8S ribosomal RNA gene provide a novel biotechnology for plant protection using unmodified antisense oligonucleotides.

Obviously, the moment has come in agriculture and forestry when we must decide to gradually abandon (where possible) non-selectively acting chemical insecticides, taking into consideration the overall decrease in the total biomass of insects, especially pollinators, and the increased number of diseases and human deaths directly or indirectly associated with chemical insecticides. Yet with the world facing the rapid growth of human populations, the annual reduction of cultivated areas, and substantial losses from insect pests, most experts believe that no serious alternative to chemical insecticides exists. However, there is definitely room to create more well-tailored chemical insecticides. And there is hope, in the form of effective DNA insecticides able to provide an adequate level of safety for non-target organisms. In this short communication describing experiments carried out on the larvae of Ceroplastes japonicus Green (feeding on Ilex aquifolium Linnaeus), we show for the first time the enormous potential for the use of DNA insecticides in the control of soft scale insects and how they could replace non-selective organophosphate insecticides.