scholarly journals Effect of Insecticides on Natural-Enemies

2021 ◽  
Author(s):  
Mohamed Abdel-Raheem

Pesticides management options for control of invertebrate pests in many parts of the world. Despite an increase in the use of pesticides, crop losses due to pests have remained largely unchanged for 30–40 years. Beyond the target pests, broad-spectrum pesticides may affect non-target invertebrate species, including causing reductions in natural enemy population abundance and activity, and competition between pest species. Assays of invertebrates against weathered residues have shown the persistence of pesticides might play an important part in their negative impacts on natural enemies in the field. A potential outcome of frequent broad-spectrum pesticide use is the emergence of pests not controlled by the pesticides but benefiting from reduced mortality from natural enemies and competitive release, commonly known as secondary pests.

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 239
Author(s):  
Davide Scaccini ◽  
Enrico Ruzzier ◽  
Kent M. Daane

Grape cultivation is a billion-dollar agricultural sector in California, where invasive or novel pest species can disrupt management practices. We report herein on a new pest associated with California vineyards, the carpentermoth Givira ethela (Neumoegen and Dyar, 1893). Rather than an invasive species, G. ethela appears to be a newly recognized wood-boring pest of Vitis vinifera (L.) in regions of California’s Central Valley, where its initial occurrence has been dated back to, at least, the beginning of the 2000s. The habitus of adult, genitalia and pupa is illustrated. Givira ethela distribution in California is updated including published records and new data. Carpentermoth galleries seem to facilitate the access of Planococcus ficus Signoret, 1875 to vine sap and protection from natural enemies, environmental stresses, and pesticide treatments. Notes on pest status, life history, monitoring practices, natural enemies, and management options on grapes are also discussed. Tools for the Integrated Pest Management of G. ethela should include the correct identification of the insect and its damage, a full understanding of its biology and ecology, the application of monitoring methods, and the identification of economic thresholds and injury levels.


2008 ◽  
Vol 48 (12) ◽  
pp. 1481 ◽  
Author(s):  
Ary A. Hoffmann ◽  
Andrew R. Weeks ◽  
Michael A. Nash ◽  
G. Peter Mangano ◽  
Paul A. Umina

The Australian grains industry is dealing with a shifting complex of invertebrate pests due to evolving management practices and climate change as indicated by an assessment of pest reports over the last 20–30 years. A comparison of pest outbreak reports from the early 1980s to 2006–07 from south-eastern Australia highlights a decrease in the importance of pea weevils and armyworms, while the lucerne flea, Balaustium mites, blue oat mites and Bryobia mites have increased in prominence. In Western Australia, where detailed outbreak records are available from the mid 1990s, the relative incidence of armyworms, aphids and vegetable weevils has recently decreased, while the incidence of pasture cockchafers, Balaustium mites, blue oat mites, redlegged earth mites, the lucerne flea and snails has increased. These changes are the result of several possible drivers. Patterns of pesticide use, farm management responses and changing cropping patterns are likely to have contributed to these shifts. Drier conditions, exacerbated by climate change, have potentially reduced the build-up of migratory species from inland Australia and increased the adoption rate of minimum and no-tillage systems in order to retain soil moisture. The latter has been accompanied by increased pesticide use, accelerating selection pressures for resistance. Other control options will become available once there is an understanding of interactions between pests and beneficial species within a landscape context and a wider choice of ‘softer’ chemicals. Future climate change will directly and indirectly influence pest distributions and outbreaks as well as the potential effectiveness of endemic natural enemies. Genetically modified crops provide new options for control but also present challenges as new pest species are likely to emerge.


2020 ◽  
Vol 71 (4) ◽  
pp. 257-272
Author(s):  
Onat Başbay ◽  
Mudar Salimeh ◽  
Eddie John

We review the continuing and extensive spread of Papilio demoleus in south-eastern Turkey and in regions of Turkey and Syria adjacent to the north-eastern Mediterranean. Since the authors documented the arrival of this attractive but potentially destructive papilionid species at coastal areas of Syria in 2019, regular monitoring has confirmed successful overwintering there, as well as in Turkey. As previously indicated, P. demoleus is widely recognized as an invasive pest species in Citrus-growing areas of the world and hence its arrival is of potential economic importance to a region in which citrus is widely grown.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Hosam M. K. H. El-Gepaly

AbstractSorghum panicles offer a very rich microenvironment for many insect pest species and their natural enemies. Thirty arthropod species belonging to 28 families, pertaining to 9 orders were obtained from sorghum panicles planted in Sohag Governorate, Egypt, during the 3 successive seasons of 2016–2018. Out of these species were 14 pests, 16 predators, and 3 parasitoids. Lepidopteran and hemipteran pests were the most dominant species-infested sorghum-panicles during the mature stages of the panicles. Three microlepidopteran pests, the noctuid, Eublemma (Autoba) gayneri (Roth.); the pyralid, Cryptoblabes gnidiella Millière, and the cosmopterigid, Pyroderces simplex Walsingham, were recorded as major pest species infesting sorghum panicles in Sohag Governorate. The dipteran parasitoid species, Nemorilla floralis (Fallen) (Tachinidae) emerged from the pupae of the E. gayneri and C. gnidiella, while the hymenopteran parasitoid, Brachymeria aegyptiaca (Chalcididae) was obtained from the pupae of all the studied microlepidopteran pests. Spiders, coccinellids, and Orius spp. were the dominant predators collected form panicles. Post-harvest, larvae, and pupae of lepidopteran pests, especially P. simplex recorded (147, 96, and 79 larvae) and (47, 30, and 73 pupae)/10 panicles in 2016, 2017, and 2018 seasons, respectively.


Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 545
Author(s):  
Sara Straffon Díaz ◽  
Luca Carisio ◽  
Aulo Manino ◽  
Paolo Biella ◽  
Marco Porporato

Megachile sculpturalis (Smith, 1853) is the first exotic bee species in Europe. Its remarkably fast expansion across this continent is leading to a growing concern on the extent of negative impacts to the native fauna. To evaluate the interactions of exotic bees with local wild bees, we set up trap nests for above-ground nesting bees on a semi-urban area of north-western Italy. We aimed to investigate the interaction in artificial traps between the exotic and native wild bees and to assess offspring traits accounting for exotic bee fitness: progeny sex ratio and incidence of natural enemies. We found that the tunnels occupied by exotic bees were already cohabited by O. cornuta, and thus the cells of later nesting alien bees may block the native bee emergence for the next year. The progeny sex ratio of M. sculpturalis was strongly unbalanced toward males, indicating a temporary adverse population trend in the local invaded area. In addition, we documented the presence of three native natural enemies affecting the brood of the exotic bee. Our results bring out new insights on how the M. sculpturalis indirectly competes with native species and on its performance in new locations.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Quentin Struelens ◽  
Diego Mina ◽  
Olivier Dangles

Abstract Background Landscape composition has the potential to foster regulating ecosystem services such as pollination and biocontrol in temperate regions. However, most landscape studies do not take pesticide use into account even though it is the main control strategy worldwide and has negative impacts on beneficial insects. Moreover, few studies have explored these combined effects in smallholder cropping system with diverse landscapes and small cultivated fields. Methods We assessed the effect of semi-natural cover and pesticide use on pollinator and herbivore abundances and functions in 9 fields in the Ecuadorian Andes through participatory experiments with smallholder farmers. We performed a path analysis to quantify the effects of landscape and pesticide use on herbivory, pollination and ultimately yield. Results Pesticide use significantly reduced pollinator abundance but had no significant effect on pest abundance. Similarly, we found non-significant effects of landscape composition on either herbivory and pollination. The study also provides new information on understudied Andean lupine’s pests and pollinators, whose application for small farmers is discussed. Finally, we hypothesize that peculiarities of tropical smallholder cropping systems and landscapes could explain the non-significant landscape effects on insect-based processes, which calls for more research in places outside the well-studied temperate region. Conclusions Landscape composition did not show any significant effect on pest and pollinator while pesticide use decreased the abundance pollinators, but with no significant effect on yield. This study also provides information about Andean lupine reproduction and overcompensation mechanisms that could be of interest for local farmers and researchers of this understudied crop.


1999 ◽  
Vol 26 (3) ◽  
pp. 212-217 ◽  
Author(s):  
B.R. TERSHY ◽  
L. BOURILLÓN ◽  
L. METZLER ◽  
J. BARNES

The >150 islands in north-western México are relatively pristine, but may easily be damaged by unregulated human use. Tourists visit many of these islands, but their numbers and impact are unknown. To examine some of the costs and benefits of ecotourism we sent a questionnaire to 42 ecotourism companies that visit islands in north-western México; 29 respondents reported that tourist days on these islands had increased at >7% yr-1, from <15 000 in 1986 to about 47 000 in 1993. Neither government regulation nor cost of trips were reported to be important impediments to tourism growth. In 1993, ecotourist organizations visiting islands reported spending US$3.7 million, none of which went directly to the protection and management of the islands. We provide several management options to increase the conservation benefits of ecotourism and minimize the negative impacts.


Zootaxa ◽  
2021 ◽  
Vol 5039 (4) ◽  
pp. 561-570
Author(s):  
SUNIL JOSHI ◽  
HASEENA BHASKAR ◽  
V.S. AASHIQ POON ◽  
B.R. JAYANTHI MALA ◽  
P.D. KAMALA JAYANTHI ◽  
...  

The notoriously destructive and invasive soft scale, Ceroplastes cirripediformis Comstock (Hemiptera: Coccomorpha: Coccidae), is recorded for the first time from India. The scale is redescribed to facilitate its identification and information on its host range, natural enemies and distribution is provided. An identification key to the Indian species in this genus is given. Management options in the event of an outbreak are discussed briefly. The establishment of this scale insect warrants special attention in India as it is a potentially damaging plant pest and has a broad host range across many plant families.  


2021 ◽  
Vol 25 (1) ◽  
pp. 1-22
Author(s):  
MP Ali ◽  
B Nessa ◽  
MT Khatun ◽  
MU Salam ◽  
MS Kabir

The damage caused by insect pest is the continual factor for the reduction of rice production. To date, 232 rice insect pest species are identified in Bangladesh and more than 100 species of insects are considered pests in rice production systems globally, but only about 20 - 33 species can cause significant economic loss. The major goal of this study is to explore all the possible ways of developed and proposed technologies for rice insect pests management and minimize economic losses. Insect pests cause 20% average yield loss in Asia where more than 90% of the world's rice is produced. In Bangladesh, outbreak of several insects such as rice hispa, leafroller, gallmidge, stem borers and brown planthopper (BPH) occurs as severe forms. Based on previous reports, yield loss can reach upto 62% in an outbreak situation due to hispa infestation. However, BPH can cause 44% yield loss in severe infestested field. To overcome the outbreaks in odd years and to keep the loss upto 5%, it is necessary to take some preventive measures such as planting of resistant or tolerant variety, stop insecticide spraying at early establishment of rice, establish early warning and forecasting system, avoid cultivation of susceptible variety and following crop rotation. Subsequent quick management options such as insecticidal treatment for specific insect pest should also be broadcasted through variety of information systems. Advanced genomic tool can be used to develop genetically modified insect and plants for sustainable pest management. In addition, to stipulate farmers not use insecticides at early crop stgae and minimize general annualized loss, some interventions including training rice farmers, regular field monitoring, digitalization in correct insect pests identification and their management (example; BRRI rice doctor mobile app), and demonstration in farmers field. Each technology itself solely or combination of two or more or all the packages can combat the insect pests, save natural enemies, harvest expected yield and contribute to safe food production in Bangladesh. Bangladesh Rice J. 25 (1) : 1-22, 2021


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