Persistence of Edovum puttleri (Hymenoptera: Eulophidae) on Potato Plants and Parasitism of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae): Effects of Resource Availability and Weather

1990 ◽  
Vol 19 (6) ◽  
pp. 1732-1737 ◽  
Author(s):  
Kare Idoine ◽  
David N. Ferro
1989 ◽  
Vol 121 (10) ◽  
pp. 841-851 ◽  
Author(s):  
John R. Ruberson ◽  
Maurice J. Tauber ◽  
Catherine A. Tauber ◽  
Ward M. Tingey

AbstractResistant potato plants influenced the parasitoid Edovum puttleri Grissell directly, as well as indirectly through eggs of the parasitoid’s host, the Colorado potato beetle, Leptinotarsa decemlineata (Say). In the field, E. puttleri parasitized more egg masses on plants with no glandular trichomes or with glandular trichomes bearing only enclosed droplets of exudate than on plants with two types of glandular trichomes (one with exposed droplets and the other bearing enclosed droplets). Trichomes with exposed droplets entrapped numerous parasitoids. Although rearing L. decemlineata on resistant plants influenced many of the beetle’s life-history traits, it did not affect the suitability of their eggs for development and survival of preimaginal E. puttleri. However, eggs from L. decemlineata that were reared on resistant potato plants reduced the longevity of the parasitoids and also reduced the number of hosts (eggs) killed by parasitoids.


1987 ◽  
Vol 119 (1) ◽  
pp. 75-82 ◽  
Author(s):  
J. Lashomb ◽  
D. Krainacker ◽  
R.K. Jansson ◽  
Y.S. Ng ◽  
R. Chianese

AbstractParasitism of the Colorado potato beetle, Leptinotarsa decemlineata (Say), by Edovum puttleri Grissell, an exotic egg parasitoid, was studied in relation to the age of host eggs, the age of adult, female parasitoids, and temperature. Parasitism was greater in eggs ≤2 days old than in eggs older than 2 days. Eggs older than 2 days were killed primarily by probing and consequent desiccation. The percentage of eggs killed by probing was positively correlated with host age and negatively correlated with percentage parasitism. Total mortality of eggs from parasitism and probing did not differ among age classes. Following a 3-day preoviposition period, parasitism and probing increased with an increase in the age of females, peaked when adults were ca. 13 days old, and subsequently declined. Parasitism and probing were influenced by temperature: at 15 °C, no parasitism or probing was observed; above 15 °C, mortality from parasitism and probing increased with an increase in temperature up to 30 °C; above 30 °C, the number of eggs that were parasitized and probed decreased with an increase in temperature.


1996 ◽  
Vol 31 (4) ◽  
pp. 432-439 ◽  
Author(s):  
George C. Hamilton ◽  
James H. Lashomb ◽  
Joseph M. Patt

The impact of insecticides currently used in commercial eggplant fields to control the Colorado potato beetle, Leptinotarsa decemlineata (Say), on the egg parasitoid Edovum puttleri Grissell was evaluated. Mortality from contact exposure to leaf residues and ingestion of contaminated honey, and parasitoid emergence from treated egg masses were compared for the following insecticides: esfenvalerate alone and in combination with piperonyl butoxide (PBO), oxamyl, PBO, and rotenone alone and in combination with PBO. Studies were conducted using concentrations of 1.0X, 0.75X, 0.5X, and 0.25X of the maximum labeled rate. Mortality was high and significantly different from controls for all chemicals and rates in both the leaf residue tests and feeding studies. Emergence of E. puttleri from treated egg masses also was significantly impacted by all materials and rates with the exception of PBO. The data suggest that the use of these materials in a pest management program that utilizes E. puttleri may reduce the survival of adults and emergence from eggs, thereby slowing parasitoid establishment.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1030
Author(s):  
Vladimír Půža ◽  
Jiří Nermuť ◽  
Jana Konopická ◽  
Oxana Skoková Habuštová

Colorado potato beetle Leptinotarsa decemlineata is among the most destructive pests of potatoes quickly developing resistance to traditional insecticides. In the present study, we tested the effect of various species and strains of entomopathogenic nematodes on CPB adults, and subsequently, the most effective nematodes were applied alone and in combination with entomopathogenic fungus B. bassiana in pots with potato plants and in the field and their effect on the number of emerging adults was evaluated. In the experimental infections, both the nematode invasion and pathogenicity were variable, and, in several strains, the mortality reached 100%. In pot experiments, soil application of nematodes S. carpocapsae 1343 and S. feltiae Jakub and fungus significantly decreased numbers of emerging CPB adults, while, after the application on leaves, only fungal treatment was effective. The field application of fungus B. bassiana significantly decreased the number of emerging CPB adults in comparison to control sites by ca. 30% while the effect of nematodes and the nematodes–fungus combination was not significant. In conclusion, we demonstrate the necessity of thorough bioassays to select the most effective nematode strains. Entomopathogenic nematodes have the potential to effectively decrease the emergence of CPB adults, but further research is needed to improve the effectiveness in the field.


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 820
Author(s):  
Pierre Bastarache ◽  
Gabriel Wajnberg ◽  
Pascal Dumas ◽  
Simi Chacko ◽  
Jacynthe Lacroix ◽  
...  

The Colorado potato beetle Leptinotarsa decemlineata is an insect pest that threatens potato crops globally. The primary method to control its damage on potato plants is the use of insecticides, including imidacloprid, chlorantraniliprole and spinosad. However, insecticide resistance has been frequently observed in Colorado potato beetles. The molecular targets and the basis of resistance to imidacloprid and chlorantraniliprole have both been previously quantified. This work was undertaken with the overarching goal of better characterizing the molecular changes associated with spinosad exposure in this insect pest. Next-generation sequencing was conducted to identify transcripts that were differentially expressed between Colorado potato beetles exposed to spinosad versus control insects. Results showed several transcripts that exhibit different expression levels between the two conditions, including ones coding for venom carboxylesterase-6, chitinase 10, juvenile hormone esterase and multidrug resistance-associated protein 4. In addition, several microRNAs, such as miR-12-3p and miR-750-3p, were also modulated in the investigated conditions. Overall, this work reveals a molecular footprint underlying spinosad response in Colorado potato beetles and provides novel leads that could be targeted as part of RNAi-based approaches to control this insect pest.


1989 ◽  
Vol 24 (1) ◽  
pp. 62-69 ◽  
Author(s):  
Albert Zitzman ◽  
Michael L. May

Experiments were designed to investigate effects of nitrogen (N) fertilizer supplied to potato plants on growth and food utilization of larval Colorado potato beetles (CPB). Dry mass gain, dry mass consumption, and efficiency of conversion of ingested food (ECI = dry mass gain/dry mass consumption) were determined for the entire larval stage and nitrogen and lipid compositions for larvae just prior to pupation. Dry mass gain and N composition were measured in both laboratory and greenhouse reared larvae, dry mass consumption and ECI in laboratory reared larvae, and lipid composition in greenhouse reared larvae. Significant linear increases with N supply were found for dry mass gain of greenhouse reared larvae, but not laboratory reared larvae, and for N composition of laboratory reared larvae, but not greenhouse reared larvae. No significant effects were demonstrable for consumption and ECI of laboratory reared larvae, or lipid composition of greenhouse reared larvae. These results suggest that N supply can affect performance of CPB larvae but that the effects vary with small differences in rearing conditions.


2021 ◽  
Vol 12 ◽  
Author(s):  
Wei-Nan Kang ◽  
Lin Jin ◽  
Hong-Yu Ma ◽  
Guo-Qing Li

To avoid potential harm during pupation, the Colorado potato beetle Leptinotarsa decemlineata lives in two different habitats throughout its developmental excursion, with the larva and adult settling on potato plants and the pupa in soil. Potato plants and agricultural soil contain a specific subset of aromatics. In the present study, we intended to determine whether the stage-specific bacterial flora plays a role in the catabolism of aromatics in L. decemlineata. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of the operational taxonomic units (OTUs) obtained by sequencing of culture-independent 16S rRNA region enriched a group of bacterial genes involved in the elimination of mono- and polycyclic aromatics at the pupal stage compared with those at the larval and adult periods. Consistently, metabolome analysis revealed that dozens of monoaromatics such as styrene, benzoates, and phenols, polycyclic aromatics, for instance, naphthalene and steroids, were more abundant in the pupal sample. Moreover, a total of seven active pathways were uncovered in the pupal specimen. These ways were associated with the biodegradation of benzoate, 4-methoxybenzoate, fluorobenzoates, styrene, vanillin, benzamide, and naphthalene. In addition, the metabolomic profiles and the catabolism abilities were significantly different in the pupae where their bacteria were removed by a mixture of three antibiotics. Therefore, our data suggested the stage-dependent alterations in bacterial breakdown of aromatics in L. decemlineata.


2000 ◽  
Vol 35 (4) ◽  
pp. 349-359 ◽  
Author(s):  
E. W. Riddick ◽  
G. Dively ◽  
P. Barbosa

We estimated the effect of deploying Cry3A-transgenic potatoes resistant to the Colorado potato beetle, Leptinotarsa decemlineata (Say), on the season-long relative abundance of naturally-occurring generalist predators. Low inputs of foliar insecticides were used in the transgenic fields to suppress nontarget pests and in the nontransgenic fields to prevent total defoliation of potato plants by L. decemlineata. Dominant plant-foraging heteropteran predators and lady beetles were sampled by sweeping foliage, whereas, ground-foraging carnivorous carabids, ants, and spiders were sampled by trapping in pitfalls. Orius insidiosus (Say) was significantly (P ≤ 0.05) more abundant in transgenic treatment fields than in nontransgenic fields in 1994, but not in 1995. None of the coccinellids (3 taxa) were affected by the treatments in either season. The carnivorous carabids (3 taxa) and ants were not affected by either treatment, but spiders were significantly more abundant in the transgenic treatment fields in 1995. We conclude that the deployment of pure stands of Cry3A-transgenic potatoes, with a minimum input of insecticides to suppress non-target pests, will have no deleterious effects on the populations of generalist predators in the potato ecosystem.


2020 ◽  
Vol 367 (6) ◽  
Author(s):  
Carlos Gómez-Gallego ◽  
Miia J Rainio ◽  
M Carmen Collado ◽  
Anastasia Mantziari ◽  
Seppo Salminen ◽  
...  

ABSTRACT Here, we examined whether glyphosate affects the microbiota of herbivores feeding on non-target plants. Colorado potato beetles (Leptinotarsa decemlineata) were reared on potato plants grown in pots containing untreated soil or soil treated with glyphosate-based herbicide (GBH). As per the manufacturer's safety recommendations, the GBH soil treatments were done 2 weeks prior to planting the potatoes. Later, 2-day-old larvae were introduced to the potato plants and then collected in two phases: fourth instar larvae and adults. The larvae's internal microbiota and the adults’ intestinal microbiota were examined by 16S rRNA gene sequencing. The beetles’ microbial composition was affected by the GBH treatment and the differences in microbial composition between the control and insects exposed to GBH were more pronounced in the adults. The GBH treatment increased the relative abundance of Agrobacterium in the larvae and the adults. This effect may be related to the tolerance of some Agrobacterium species to glyphosate or to glyphosate-mediated changes in potato plants. On the other hand, the relative abundances of Enterobacteriaceae, Rhodobacter, Rhizobium and Acidovorax in the adult beetles and Ochrobactrum in the larvae were reduced in GBH treatment. These results demonstrate that glyphosate can impact microbial communities associated with herbivores feeding on non-target crop plants.


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