The antifeedant effect of some new withanolides on three insect species,spodoptera littoralis, epilachna varivestis andtribolium castaneum

1987 ◽  
Vol 15 (1) ◽  
pp. 15-29 ◽  
Author(s):  
K. R. S. Ascher ◽  
Miriam Eliyahu ◽  
E. Glotter ◽  
A. Goldman ◽  
I. Kirson ◽  
...  
2017 ◽  
pp. 135
Author(s):  
Miguel Ángel Villavicencio ◽  
Blanca E. Pérez-Escandón

Insecto feeding activity of a fraction obtained from the leaves of Spigelia longiflora (Loganiaceae) was tested on the larvae of Pseudaletia unipuncta, Spodoptera frugiperda (Lepidoptera) and Epilachna varivestis (Coleoptera). All the three insect species refused to eat diets treated with the obtained fraction


1999 ◽  
Vol 89 (1) ◽  
pp. 65-71 ◽  
Author(s):  
S.S. Martinez ◽  
H.F. van Emden

AbstractSublethal concentrations of azadirachtin incorporated into artificial diet and offered to third-instar larvae of Spodoptera littoralis (Boisduval) prolonged larval instars and reduced food intake. These effects were observed after the treated larvae had been transferred to plain diet; the reduced food intake was therefore a secondary antifeedant effect. Azadirachtin did not influence digestion efficiency but diminished the ability of the larvae to convert both ingested and digested nutrients into growth, particularly immediately after treatment. This effect declined with time once the treatment with azadirachtin had ceased. Growth was more severely reduced than food intake, and the reduction in growth also occurred during periods when food intake was not affected, possibly due to post-ingestive effects.


Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).


Author(s):  
Nguyen Van Hieu ◽  
Nguyen Van Vinh

An intensive field survey on aquatic insects of Me Linh Station for Biodiversity in Vinhphuc province was conducted in December 2015. Specimens were collected at 8 different sites and aquatic insects were collected both quantitatively by Surber net and qualitatively by hand net, pond net. As a result, a total of 110 aquatic insect species belonging to 98 genera, 49 families and 9 orders were recognized. Among these, the order Ephemeroptera had the highest species number with 26 species, followed by Odonata with 25 species, Trichoptera with 18 species, Coleoptera with 15 species, Hemiptera with 11 species, Diptera with 9 species. Lepidoptera, Plecoptera and Megaloptera had the lowest of species number, represented by 3 species of Lepidoptera, 2 species of Plecoptera and 1 species of Megaloptera. Besides, the quantitative analysis results and the functional feeding groups were provided.


2005 ◽  
Vol 58 ◽  
pp. 140-147 ◽  
Author(s):  
M.R. McNeill ◽  
C.J. Fletcher

Nodding thistle receptacle weevil Rhinocyllus conicus and gallfly Urophora solstitialis attack the capitula of nodding thistle Carduus nutans L Between 31 October and 15 December 2003 the phenology of both R conicus and U solstitialis was studied at a dryland site in Canterbury Adult R conicus were more numerous than U solstitialis on capitula throughout the experiment Larvae of R conicus were first found on 11 November (15 of capitula infested) and peaked on 2 December with 53 of capitula infested Only 3 of capitula were infested by U solstitialis Adult R conicus or U solstitialis emerged from 79 of the selected primary and secondary capitula The majority of infested capitula (81) contained only R conicus 2 contained only U solstitialis while 17 contained both insect species Parasitism of R conicus by the braconid parasitoid Microctonus aethiopoides was low and occurred when most weevil eggs had been laid


2020 ◽  
Vol 105 (3) ◽  
pp. 281-299
Author(s):  
Javier Carreño-Barrera ◽  
Luis Alberto Núñez-Avellaneda ◽  
Maria José Sanín ◽  
Artur Campos D. Maia

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.


2019 ◽  
Vol 56 (Special) ◽  
pp. 143-155
Author(s):  
SD Mohapatra ◽  
R Tripathi ◽  
Anjani Kumar ◽  
Suchismita Kar ◽  
Minati Mohapatra ◽  
...  

The insect problem is accentuated in intensive rice cropping where the insects occur throughout the year in overlapping generations. Over 800 insect species damaging rice in one way or another, although the majority of them do very little damage. In India, about a dozen of insect species are of major importance but the economic damage caused by these species varies greatly from field to field and from year to year. Insect pests cause about 10-15 per cent yield losses. Farmers lose an estimated average of 37% of their rice crop to insect pests and diseases every year. This review focuses on precision farming tools being used in rice pest and diseases management viz., forecasting model for real-time pest-advisory services, hyper-spectral remote sensing in pest damage assessment, computer-based decision support system, disruptive technologies (mobile apps).


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