Field-Aged Insecticide Residues on Chrysoperla johnsoni (Neuroptera: Chrysopidae)

2019 ◽  
Vol 112 (5) ◽  
pp. 2109-2115 ◽  
Author(s):  
Kaushalya G Amarasekare ◽  
Preston H Brown ◽  
Peter W Shearer

Abstract We studied the direct (lethal) and indirect (sublethal) effects of field-aged insecticide residues of spinetoram, chlorantraniliprole and lambda-cyhalothrin on adults and larvae of the green lacewing, Chrysoperla johnsoni Henry, Wells and Pupedis an important generalist predator in western United States pear orchards. We applied formulated pesticides using their high label rates mixed with 935 liters/ha of water on pear trees utilizing an airblast sprayer. We collected leaves from the experiment trees at 1, 7, 14, 21 days after treatment (DAT) and exposed C. johnsoni adults and second instars to insecticide residues or untreated control for 72 h. We monitored larvae that survived the treatments until adult emergence (for larvae) or adults until death (for paired adults). We assessed the adults for acute and chronic mortality, longevity, fecundity, and fertility, and larvae for acute mortality, sex ratio, developmental time, and survival of adults emerged from treated second instars, to determine lethal and sublethal effects. The field-exposed insecticide residues of chlorantraniliprole exhibited higher lethal and sublethal toxicities on C. johnsoni during the 21-d leaf collection period when compared with the field-exposed residue toxicities of lambda-cyhalothrin and spinetoram. The field-exposed residue of lambda-cyhalothrin and spinetoram exhibited moderate toxicities on C. johnsoni during the 21-d leaf collection period. Results from this study show similar trends with previous studies using multiple routes of exposure laboratory assays and field experiments on Chrysoperla sp. The direct and indirect effects of field-aged residues of spinetoram, chlorantraniliprole, and lambda-cyhalothrin on C. johnsoni are discussed.

2019 ◽  
Vol 113 (2) ◽  
pp. 770-778
Author(s):  
Kaushalya G Amarasekare ◽  
Peter W Shearer

Abstract Deraeocoris brevis (Uhler) is a key predatory natural enemy of insects and mites in pear orchards in the United States. Insecticides used for crop protection in pear orchards and their residues can negatively affect populations of D. brevis. The focus of this study was to investigate the field-aged residual effects of lambda-cyhalothrin, spinetoram, and chlorantraniliprole insecticides on D. brevis through contact exposure. An airblast sprayer was used to apply the high label rate of insecticides on pear trees. Leaves were collected from the experimental trees at 1 d after treatment (DAT) and then at 7-d intervals up to 21 DAT. Adults and nymphs were exposed to leaves with insecticide residues or untreated control for 72 h in the laboratory. The nymphs that survived the treatments were reared until they emerged as adults. The surviving paired adults were reared until death. The treated nymphs were assessed for acute mortality, survival, developmental time, and the sex ratio if they emerged as adults. The treated adults were assessed for acute and chronic mortality, fecundity, fertility, and longevity. Both nymphs and adults exposed to leaf residues of lambda-cyhalothrin had significantly higher acute mortality compared with the insects exposed to the control. When compared with the control treatment, the toxicity of field-aged residues of lambda-cyhalothrin, chlorantraniliprole, and spinetoram can persist over a longer period of time. Similar patterns were observed in previous laboratory and field experiments on D. brevis. We discuss the residual effects of three insecticides through contact exposure of D. brevis.


2021 ◽  
Author(s):  
Dyrson O. A. Neto ◽  
Pablo C. Gontijo ◽  
Geraldo Andrade CARVALHO

Abstract The agriculture industry seeks to reconcile control tactics for pest management, necessitating studies of lethal and sublethal effects of insecticides on natural enemies. The effect of six insecticides with diverse modes of action—ethiprole, etofenprox, lambda-cyhalothrin, lambda-cyhalothrin + chlorantraniliprole, pymetrozine, and thiamethoxam + chlorantraniliprole—were evaluated after spraying on eggs, third-instar larvae, pupae, and adults of Harmonia axyridis , a generalist predator in cotton crops. Ethiprole was the only one that had no lethal effect on the predator at any stage of its development; however, it caused sublethal effects when applied to eggs (shortening of the larval phase and lower reproduction). Lambda-cyhalothrin caused high predator mortality after exposure at all stages. Due to the high compatibility between the ladybug H. axyridis and ethiprole, this compound is recommended for use in cotton integrated pest management programs. The other insecticides were harmful in lethal or sublethal tests, and further work in semifield and field conditions is required to confirm if they reduce H. axyridis populations.


1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.


Author(s):  
S. Ragul ◽  
N. Manivannan ◽  
K. Iyanar ◽  
N. Ganapathy ◽  
G. Karthikeyan

Background: Blackgram [Vigna mungo (L.) Hepper] is a rich source of protein. It is one of the major crops essentially involved in daily human diets. However, storage pest bruchine [Callosobruchus maculatus (F.)] is a major production constraint for legumes. A research was formulated to assess the bruchine resistance in 20 blackgram genotypes along with the biochemical analysis to find out the active biochemical components responsible for the resistance activity.Methods: The experiment was carried out during August- October, 2019 at Entomology Laboratory, National Pulses Research Center, Vamban, India. The experimental material comprised of 20 blackgram genotypes which were screened for bruchine resistance. Further, confirmatory trial was conducted with selected resistant entries and highly susceptible entries during October- December, 2019. Both experiments were carried out in completely randomized design and replicated three times. GC-MS analysis on the resistant and susceptible entries were performed to ascertain the active biochemical components conferring resistance.Result: Among the genotypes, TU 68 had comparatively late developmental time (days), less number of adult emergence, higher mean developmental period (days), less susceptibility index, less seed damage (%) and less seed weight loss (%). Genotype TU 68 was found to be resistant in the confirmatory trial also. Less number of adult emergence and higher mean developmental period indicated the delayed developmental period which is a mechanism of bruchine resistance. GC-MS analysis on resistant (TU 68) and susceptible (MDU 1) genotypes indicated the presence of active biochemical compounds with insectifuge activity in TU 68. Hence, TU 68 could be utilized in the hybridization programmeas donor for bruchine resistance.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Aurélie Babin ◽  
Marie-Paule Nawrot-Esposito ◽  
Armel Gallet ◽  
Jean-Luc Gatti ◽  
Marylène Poirié

Abstract Bioinsecticides based on Bacillus thuringiensis (Bt) spores and toxins are increasingly popular alternative solutions to control insect pests, with potential impact of their accumulation in the environment on non-target organisms. Here, we tested the effects of chronic exposure to commercial Bt formulations (Bt var. kurstaki and israelensis) on eight non-target Drosophila species present in Bt-treated areas, including D. melanogaster (four strains). Doses up to those recommended for field application (~ 106 Colony Forming Unit (CFU)/g fly medium) did not impact fly development, while no fly emerged at ≥ 1000-fold this dose. Doses between 10- to 100-fold the recommended one increased developmental time and decreased adult emergence rates in a dose-dependent manner, with species-and strain-specific effect amplitudes. Focusing on D. melanogaster, development alterations were due to instar-dependent larval mortality, and the longevity and offspring number of adult flies exposed to bioinsecticide throughout their development were moderately influenced. Our data also suggest a synergy between the formulation compounds (spores, cleaved toxins, additives) might induce the bioinsecticide effects on larval development. Although recommended doses had no impact on non-target Drosophila species, misuse or local environmental accumulation of Bt bioinsecticides could have side-effects on fly populations with potential implications for their associated communities.


1981 ◽  
Vol 71 (2) ◽  
pp. 289-297 ◽  
Author(s):  
B. Persson

AbstractSpodoptera exempta (Wlk.) was reared for one year at three locations in Kenya: Msabaha on the coast, Nairobi, and Mbita Point on Lake Victoria. The potential yearly number of generations was 15·8 at Msabaha, 6·6 at Nairobi and 13·1 at Mbita Point. Average developmental time from egg deposition to adult emergence was 23·1, 54·9 and 27·8 days, respectively. The longest, 77·3 days, was recorded in Nairobi and the shortest, 19·4 days, at Msabaha. The survival rate varied little seasonally at the coast but was erratic inland, with some generations failing and others very successful. Larvae offered a choice of maize and stargrass (Cynodon dactylon) showed a preference for stargrass. Survival was higher on stargrass than on maize but the developmental time was longer. Mortality was highest in the larval stage. In all generations and at all locations, death was usually caused by a nuclear polyhedrosis virus. There was a positive relationship between larval mortality and rainfall, and a negative one between larval mortality and sunshine. Mating was restricted to after midnight. Females oviposited and then mated during the same night. Peak egg-laying took place before midnight, with a smaller peak at about 02·00–04·00 h.


2017 ◽  
Vol 149 (2) ◽  
pp. 251-264 ◽  
Author(s):  
T.P.N. Hariprasad ◽  
N.J. Shetty

AbstractAnopheles stephensi Liston (Diptera: Culicidae), an urban malaria vector in India, is controlled by insecticides. Sublethal concentrations can be effective in reducing mosquito populations and disease transmission by reducing its reproductive fitness. In this study, sublethal effects of alphamethrin, a synthetic pyrethroid, were assessed on selected fitness parameters. Late third instars of the Goraguntepalya strain, Bangalore, were exposed to three sublethal doses, LC10 – 0.00006, LC30 – 0.0004, and LC50 – 0.0014 mg/L and their effects on fecundity, egg hatchability, sex ratio, and longevity in parental, F1 and F2 generations. The morphology of gonads, pattern of pupation, and adult emergence were also assessed. We found a significant reduction in fecundity and hatchability among the sublethal concentrations as well as across generations. Survival analysis showed significant reduction in lifespan of exposed groups. Delay in pupation, eclosion, and no distortion in sex ratio was observed. The results suggest that sublethal concentrations of alphamethrin may have negative effects on exposed individuals and subsequent generations.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 622c-622
Author(s):  
Daniel F. Warnock ◽  
David W. Davis ◽  
William D. Hutchison

European corn borer (ECB), Ostrinia nubilalis Hübner, can severely affect sweet corn quality. Selection techniques in field experiments have improved ear feeding resistance associated with morphological features and/or allelochemicals. A laboratory bioassay was used to detect chemical resistance factors in silk and kernel tissues of 10 variously resistant sweet corn genotypes. When added to a nutritively complete diet, kernel tissue from W182E, MN275, and MN272 decreased (P ≤ 0.05) 10-day larval weight (66.3, 61.7, and 54.5 mg, respectively) while kernel tissue from MG15, MN270, and MN3053 increased (P ≤ 0.05) 10-day larval weight (88.3, 81.5, and 80.8 mg, respectively) compared to a cellulose control (71.0 mg). These weight differences, however, were not significant developmentally as 10-day larval maturation (fourth to fifth instar) and pupation time (13.9 to 16.3 days) were similar to the cellulose control (fifth instar and 14.8 days). Silk tissue additions to the diet decreased (P ≤ 0.05) 10-day larval weight compared to the cellulose control (71.0 mg). Larvae exposed to diet containing silk tissue from MN3053, W182E, and `Apache' were lightest (9.1, 8.3, and 7.8 mg, respectively). The heaviest larvae exposed to silk tissue were from diet including `Jubilee' tissue (54.1 mg). Contrary to the instar levels found on the cellulose control, larvae feeding for 10 days on a diet containing silk tissue mainly were at third or early fourth instar excluding larvae exposed to `Jubilee' silk (fourth to fifth instar). For all genotypes, silk additions to diet increased the pupation time compared to kernel additions. Kernel, and especially silk tissue, may contain chemical resistance factors which decrease larval weight and increase developmental time. Identifying sweet corn genotypes with chemical resistance factors may enhance ECB resistance breeding efficiency.


1998 ◽  
Vol 27 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Antônio R. Panizzi ◽  
Ana P. M. Mourão ◽  
Émerson D. M. Oliveira

Laboratory and field studies indicated that privet, Ligustrum lucidum (Oleaceae), is an important host plant of the neotropical stink bug, Loxa deducta (Walker) (Hemiptera: Pentatomidae) in northern Paraná state. Survivorship of nymphs was high (82.9%) when fed immature fruits of privet. Nymph developmental time (from the 2nd stadium to adult) lasted <FONT FACE=Symbol>»</FONT> 49 d. At adult emergence, females attained greater (199.5 mg) fresh body weight than males (180.0 mg). Survivorship of adult L. deducta decreased gradually with time. Mean total longevity was <FONT FACE=Symbol>»</FONT> 62 d for females and <FONT FACE=Symbol>»</FONT> 55 d for males. Of 30 females observed, 25 (83.3%) oviposited when fed fruits of privet. The preoviposition period was 13.9 (± 0.51) d; fecundity was 17.8 (± 1.60) egg masses/female, and 236.0 (± 21.98) eggs/female; egg hatchability was 65.0 (± 6.48)%. Considering the total period of 4-wks, the percentage increase in fresh body weight was <FONT FACE=Symbol>»</FONT> 70% for females, and <FONT FACE=Symbol>»</FONT> 45% for males. During summer months (December to February), relatively low numbers of insects were collected on privet. During March, nymph and adult populations increased reaching a peak during April, and decreasing in May at the end of autumn. This tendency continued throughout winter (June-July-August), reaching almost zero in September at the beginning of spring, and increasing somewhat again in October-November.


2019 ◽  
Vol 76 (7) ◽  
pp. 2033-2044 ◽  
Author(s):  
David M Fields ◽  
Nils Olav Handegard ◽  
John Dalen ◽  
Christiane Eichner ◽  
Ketil Malde ◽  
...  

Abstract Seismic surveys use airguns that emit low frequency high magnitude sound to detect subsea resources and to map seabed geology. The effect of seismic blasts on Calanus spp., a key food source for commercially important fish, was assessed in field experiments. Immediate mortality of copepods was significantly different from controls at distances of 5 m or less from the airguns. Mortality 1 week after the airgun blast was significantly higher—by 9% relative to controls—in the copepods placed 10 m from the airgun blast but was not significantly different from the controls at a distance of 20 m from the airgun blast. The increase in mortality—relative to controls—did not exceed 30% at any distance from the airgun blast. Only two genes changed in response to the airgun blast; however, their function is unknown. There were no sublethal effects of the seismic blasts on the escape performance or the sensory threshold needed to initiate an escape response at any of the distances from the airgun blast that were tested. Results from these experiments suggest that seismic blasts have limited effects on the mortality or escape response of Calanus sp. within 10 m of the blast and no measurable impact at greater distances.


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