Starvation Effects on Larval Development of Beet Armyworm (Lepidoptera: Noctuidae)

2008 ◽  
Vol 43 (2) ◽  
pp. 247-253 ◽  
Author(s):  
Yigen Chen ◽  
John R. Ruberson
Keyword(s):  
Insect Pests ◽  
Head Capsule ◽  
Developmental Time ◽  
Beet Armyworm ◽  
Pupal Weight ◽  
Herbivorous Insect ◽  
The Third ◽  
First Instar ◽  
Starvation Effects ◽  
The Cost

Sporadic starvation of herbivorous insect pests, such as the beet armyworm Spodoptera exigua (Hübner), often occurs due to host plant scarcity and dislodgement from host plants resulting from inclement weather, enemy attack, and other perturbations. We hypothesized that (1) starvation of beet armyworm in earlier instars would increase the possibility of undergoing supernumerary instars greater than would be the case for later instars; and (2) starvation of beet armyworm in earlier instars would prolong developmental time more than starvation in later instars. We tested these hypotheses by starving beet armyworm larvae for 48 h in the first, third, and fifth instars, and monitoring their development. Beet armyworms normally have 5 instars before pupation. Significantly more larvae underwent 6 larval instars (20.22 ± 4.35%) when starved for 2 d in the first instar compared with those starved for 2 d in the third (2.0 ± 2.00) and fifth instars (0.0), and relative to unstarved larvae (0.0). The number of instars that S. exigua larvae will experience can be predicted as early as the third instar-head capsule widths in this instar clearly differentiate for those destined to experience 5 and 6 instars. Developmental times of starved larvae also were prolonged compared with unstarved larvae. Developmental times (mean ± SE in days) of larvae starved in the first instar (20.32 ±0.16) were significantly longer than those starved in the third (17.04 ± 0.20) or fifth instars (16.92 ± 0.10), or than unstarved larvae (14.62 ± 0.25). Timing of starvation significantly affected the pupal weight of larvae undergoing 5 instars. This suggests that (1) starvation of 2 d in very early instars (the first instar) increases the pupal weight at the cost of prolonged developmental time; and (2) starvation of 2 d in later instars (the fifth instar) leads to lower pupal biomass, presumably because of inability to compensate for the loss.

scholarly journals AKTIVITAS EKSTRAK BIJI TANAMAN MINDI MELIA AZEDARACH (L.) TERHADAP SPODOPTERA LITURA (F.) (LEPIDOPTERA: NOCTUIDAE)

2005 ◽  
Vol 5 (1) ◽  
pp. 11-16
Author(s):  
Hamdani Hamdani
Keyword(s):  
Biological Activity ◽  
Insecticidal Activity ◽  
Spodoptera Litura ◽  
Developmental Time ◽  
Seed Extract ◽  
Melia Azedarach ◽  
The Third ◽  
First Instar ◽  
Lepidoptera Noctuidae

Activity of Melia azedarach (L.) seed extract against armyworm Spodoptera litura (F.) (Lepidoptera: Noctuidae). This study was conducted to evaluate the effectivenes and biological activity of Melia azedarach L. (Meliaceae) seed extract against armyworm, Spodoptera litura F. The first instar larvae were fed extract-treated cotton leaves for 2 days, then were maintained on untreated leaves until the third instar stage. Records were kept in regard to the larvae mortality and developmental time of surviving larvae from first instar to third instar. The result showed that Melia azedarach L. seed extract at consentration of 50 g of seeds/l of water (5%) exhibited moderate insecticidal activity against S. litura larvae (43.33 - 68.33% mortality). Addition of detergen at 0.2% to extract did not increase insecticidal activity of the extract. However, boiling seed extract at consentration of 50 g of seeds/l of water (5%) during 10 until 20 minutes increased insecticidal activity of extract (66.67 - 68.33% mortality). Generally, M. azedarach seed extract treatment did not affect  developmental time of  S. litura larvae.

LIFE HISTORY AND HABITS OF THE WILLOW BEAKED GALL MIDGE, MAYETIOLA RIGIDAE (DIPTERA: CECIDOMYIIDAE), IN MICHIGAN

1968 ◽  
Vol 100 (2) ◽  
pp. 202-206 ◽  
Author(s):  
Louis F. Wilson
Keyword(s):  
Life History ◽  
Gall Midge ◽  
Head Capsule ◽  
Instar Larva ◽  
Larval Instars ◽  
The Third ◽  
First Instar ◽  
Salix Discolor

AbstractThe willow beaked gall midge, Mayetiola rigidae (Osten Sacken), is univoltine in Michigan. Adults emerge from bud galls on Salix discolor Mühl. and other willows on mornings of warm days in early April. Eggs are laid singly on or near the buds of the host. Head capsule measurements indicate three larval instars. The last two instars each possess a spatula. The first-instar larva emerges in late April and penetrates the soft bud tissues. The gall begins to develop at the beginning of the second instar in mid-May. The third instar appears in early July and continues to enlarge the gall until fall. Prior to overwintering, the larva lines the inner chamber of the gall with silk and constructs one to seven silken septa across the passageway. Pupation occurs in mid-March. The gall deforms the stem and occasionally a galled branch dies or breaks off.

Growth and development of larvae and adults of Tipula sacra Alexander (Insecta: Diptera) in a series of abandoned beaver ponds

1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Growth And Development ◽  
Adult Emergence ◽  
Head Capsule ◽  
Fourth Instar ◽  
Beaver Ponds ◽  
The Third ◽  
First Instar ◽  
Two Peaks

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.

LIFE HISTORY AND HABITS OF RHABDOPHAGA SP. (DIPTERA: CECIDOMYIIDAE), A GALL MIDGE ATTACKING WILLOW IN MICHIGAN

1968 ◽  
Vol 100 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Louis F. Wilson
Keyword(s):  
Life History ◽  
Gall Midge ◽  
Taxonomic Status ◽  
Head Capsule ◽  
Instar Larva ◽  
Larval Instars ◽  
The Third ◽  
First Instar ◽  
Third Instar Larva ◽  
Salix Discolor

AbstractThe taxonomic status of Rhabdophaga sp. cannot be determined until a complete revision of the genus occurs. Rhabdophaga sp. on Salix discolor Mühl. is univoltine in Michigan. Adults emerge in mid-April, and shortly afterward deposit numerous eggs on the setaceous undersurface of emerging willow leaves; larval eclosion occurs between 1 and 2 weeks later. Head capsule measurements reveal three larval instars. The first-instar larva bores into the stem until it reaches the pith. Gall development begins about mid-June shortly after the second instar appears. The third-instar larva overwinters in the gall and the pupa appears in early April. The prolate gall is found on the proximal ends of young willow shoots; heavily galled shoots usually die.

Stadia, Larval-Pupal Weight, and Width of Head Capsules of Corn Earworm (Lepidoptera: Noctuidae) After Feeding on Varying Resistance Levels of Maize Silks

1991 ◽  
Vol 26 (3) ◽  
pp. 303-309
Author(s):  
B. R. Wiseman ◽  
D. J. Isenhour ◽  
V. R. Bhagwat
Keyword(s):  
Helicoverpa Zea ◽  
Zea Mays L ◽  
Head Capsule ◽  
Developmental Time ◽  
Corn Earworm ◽  
Pupal Weight ◽  
Susceptible Genotype ◽  
Resistant Material ◽  
Maize Silks ◽  
Lepidoptera Noctuidae

Weight of larvae, developmental time to pupation, weight of pupae, length of stadia, and width of head capsule were determined for larvae of the corn earworm, Helicoverpa zea (Boddie), that were fed on meridic diets with silks of ‘Stowell's Evergreen’, a susceptible genotype, or low, intermediate, and high levels of ‘Zapalote Chico’, a corn, Zea mays L., cultivar with antibiotic resistance. As the level of resistance increased, the weight of larvae at 9 days and weight of pupae significantly decreased, and developmental time to pupation significantly increased. Also, as the concentration of resistant material increased in the diet, stadial length also significantly increased. The intermediate and high levels of resistance also resulted in a significant reduction in the width of the head capsule of larvae. Thus, two new characteristics of resistance in maize silks to the corn earworm were identified: increased stadia and decreased width of head capsule.

Efficacy of some insecticide modules against major insect pests and spider population of rice, Oryza sativa L.

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Untreated Control ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Gall Midge ◽  
Stem Borer ◽  
The Other ◽  
The Third ◽  
Treated Plot

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.

scholarly journals Application of UV-C Irradiation to Rosa x hybrida Plants as a Tool to Minimise Macrosiphum rosae Populations

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 702
Author(s):  
Anastasios I. Darras ◽  
Panagiotis J. Skouras ◽  
Panagiotis Assimomitis ◽  
Chara Labropoulou ◽  
George J. Stathas
Keyword(s):  
Host Resistance ◽  
Insect Pests ◽  
Physiological Responses ◽  
Co2 Assimilation ◽  
Aphid Population ◽  
First Instar ◽  
Net Co2 Assimilation ◽  
Macrosiphum Rosae ◽  
Uv C ◽  
Aphid Fecundity

UV-C irradiation is known to enhance plant resistance against insect pests. In the present study, we evaluated the effects of low doses of UV-C on Macrosiphum rosae infesting greenhouse rose (Rosa x hybrida) plants. The application of 2.5-kJ/m2 UV-C irradiation on rose leaves before infestation induced anti-herbivore resistance and negatively affected the aphid fecundity. No eggs and first instar nymphs were recorded on irradiated leaves, whereas an average of 4.3 and 2.7 eggs and 6.7 and 14 first instars were recorded on vars. “Etoile Brilante” and “Arlen Francis” untreated leaves, respectively. UV-C irradiation reduced the aphid population from naturally infested rose plants by up to 58%. In a greenhouse pot trial (GPT) in 2019, UV-C irradiation minimised the initial aphid population six hours after treatment. UV-C elicited host resistance and, also, helped in aphid repulsion without killing the adult individuals. UV-C did not affect the physiological responses of rose plants. The net CO2 assimilation of the UV-C irradiated plants ranged between 10.55 and 15.21 μmol/m2. sec for “Arlen Francis” and between 10.51 and 13.75 μmol/m2. sec for “Etoile Brilante” plants. These values, with only a few exceptions, were similar to those recorded to the untreated plants.

scholarly journals Caterpillar salivary enzymes: "eliciting" a response

2004 ◽  
Vol 85 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Magali Merkx-Jacques ◽  
Jacqueline C. Bede
Keyword(s):  
Artificial Diet ◽  
Spodoptera Exigua ◽  
Induced Defense ◽  
Defense Responses ◽  
Beet Armyworm ◽  
Herbivorous Insect ◽  
Plant Responses ◽  
Plant Defense Responses ◽  
Induced Defense Responses ◽  
Bertha Armyworm

Abstract Plants exhibit remarkable plasticity in their ability to differentiate between herbivorous insect species and subtly adjust their defense responses to target distinct pests. One key mechanism used by plants to recognize herbivorous caterpillars is elicitors present in their oral secretions; however, these elicitors not only cause the induction of plant defenses but recent evidence suggests that they may also suppress plant responses. The absence of “expected changes” in induced defense responses of insect-infested plants has been attributed to hydrogen peroxide produced by caterpillar salivary glucose oxidase (GOX). Activity of this enzyme is variable among caterpillar species; it was detected in two generalist caterpillars, the beet armyworm (Spodoptera exigua) and the bertha armyworm (Mamestra configurata), but not in other generalist or specialist caterpillar species tested. In the beet armyworm, GOX activity fluctuated over larval development with high activity associated with the salivary glands of fourth instars. Larval salivary GOX activity of the beet armyworm and the bertha armyworm was observed to be significantly higher in caterpillars reared on artificial diet as compared with those reared on Medicago truncatula plants. This implies that a factor in the diet is involved in the regulation of caterpillar salivary enzyme activity. Therefore, plant diet may be regulating caterpillar oral elicitors that are involved in the regulation of plant defense responses: our goal is to understand these two processes.

scholarly journals Evaluation of the Susceptibility of Some Eggplant Cultivars to Green Peach Aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae)

Agriculture ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Zienab Raeyat ◽  
Jabraiel Razmjou ◽  
Bahram Naseri ◽  
Asgar Ebadollahi ◽  
Patcharin Krutmuang
Keyword(s):  
Insect Pests ◽  
Growth Parameters ◽  
Green Peach Aphid ◽  
Integrated Management ◽  
Resistance Index ◽  
Dry Weight ◽  
Developmental Time ◽  
Resistance Mechanisms ◽  
Screening Tests ◽  
Population Increase

Due to the detrimental side-effects of synthetic pesticides, the use of nonchemical strategies in the management of insect pests is necessary. In the present study, the susceptibility of fourteen eggplant cultivars to green peach aphid (M. persicae) were investigated. According to preliminary screening tests, ‘Long-Green’, ‘Ravaya’ and ‘Red-Round’ as relatively resistant, and ‘White-Casper’ and ‘Pearl-Round’ as susceptible cultivars were recognized. In the antixenosis tests, the highest hosting preference was documented for ‘White-Casper’. Population growth parameters were used for evaluation of antibiosis. The highest and lowest developmental time (d) was observed on ‘Long-Green’ (4.33 d) and ‘White-Casper’ (3.26 d), respectively. The highest and lowest intrinsic rates of population increase (rm) were on ‘White-Casper’ (0.384 d−1) and ‘Long-Green’ (0.265 d−1), respectively. Significant differences were observed in the height and fresh and dry weight of infested and noninfected plants. Plant resistance index (PRI), as a simplified way to assess all resistance mechanisms, provides a particular value to determine the proper resistant cultivar. The greatest PRI value was observed on ‘Long-Green’. In general, the ‘Long-Green’ showed the least, and the ‘White-Casper’ displayed the most susceptibility among tested cultivars infested by M. persicae, which might be useful in integrated management of this pest.

scholarly journals The costs of functional gastrointestinal disorders and related signs and symptoms in infants: a systematic literature review and cost calculation for England

BMJ Open ◽  
2017 ◽  
Vol 7 (11) ◽  
pp. e015594 ◽  
Author(s):  
James Mahon ◽  
Carlos Lifschitz ◽  
Thomas Ludwig ◽  
Nikhil Thapar ◽  
Julie Glanville ◽  
...  
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Functional Gastrointestinal Disorders ◽  
Signs And Symptoms ◽  
Third Party ◽  
Gastrointestinal Disorders ◽  
Over The Counter ◽  
Party Payer ◽  
The Third ◽  
The Cost

ObjectivesTo estimate the cost of functional gastrointestinal disorders (FGIDs) and related signs and symptoms in infants to the third party payer and to parents.Study designTo estimate the cost of illness (COI) of infant FGIDs, a two-stage process was applied: a systematic literature review and a COI calculation. As no pertinent papers were found in the systematic literature review, a ‘de novo’ analysis was performed. For the latter, the potential costs for the third party payer (the National Health Service (NHS) in England) and for parents/carers for the treatment of FGIDs in infants were calculated, by using publicly available data. In constructing the calculation, estimates and assumptions (where necessary) were chosen to provide a lower bound (minimum) of the potential overall cost. In doing so, the interpretation of the calculation is that the true COI can be no lower than that estimated.ResultsOur calculation estimated that the total costs of treating FGIDs in infants in England were at least £72.3 million per year in 2014/2015 of which £49.1 million was NHS expenditure on prescriptions, community care and hospital treatment. Parents incurred £23.2 million in costs through purchase of over the counter remedies.ConclusionsThe total cost presented here is likely to be a significant underestimate as only lower bound estimates were used where applicable, and for example, costs of alternative therapies, inpatient treatments or diagnostic tests, and time off work by parents could not be adequately estimated and were omitted from the calculation. The number and kind of prescribed products and products sold over the counter to treat FGIDs suggest that there are gaps between treatment guidelines, which emphasise parental reassurance and nutritional advice, and their implementation.

Sign in / Sign up

Export Citation Format

Share Document