scholarly journals Effects of Dehumidification on the Survivorship of Four Psocid Species

2021 ◽  
Author(s):  
Abena F Ocran ◽  
George P Opit ◽  
Bruce H Noden ◽  
Frank H Arthur ◽  
Bradford M Kard
Keyword(s):  
Relative Humidity ◽  
Life Stages ◽  
Survival Times ◽  
Stored Product Pests ◽  
Early Instar ◽  
D 12 ◽  
Liposcelis Entomophila

Abstract Psocids are damaging stored-product pests. In this study, eggs and early-instar nymphs, adults, and all life stages of Liposcelis entomophila, L. decolor, L. bostrychophila, and L. paeta were subjected to 43, 50, or 75% (Control) relative humidity (RH) for 2, 4, 6, 8, 10, 12, 14, or 16 d at 30.0°C. All adults of these species died within 8 d at both 43 and 50% RH, except for L. bostrychophila, which required 12 d at 50% RH for 100% mortality to occur. For all life stages and eggs and early-instar nymphs, maximum survival times (times to 100% mortality) at 43 or 50% RH for L. entomophila, L. decolor, L. bostrychophila, and L. paeta, were 8 and 10 d, 8 and 12 d, 12 and 14 d, and 12 and 16 d, respectively. During this study, numbers of nymphs and adults of all species 14 d after the RH treatments increased within the 75% RH Control arenas. Different species and life stages responded differently to 43 and 50% RH, as time to kill all stages of the four psocid species was 8–12 and 10–16 d, respectively. Results indicate that using a specific RH environment may be effective in psocid management.

The survival of desiccation by the free-living stages of Trichostrongylus colubriformis (Nematoda: Trichostrongylidae)

Parasitology ◽  
1982 ◽  
Vol 84 (3) ◽  
pp. 455-462 ◽  
Author(s):  
D. A. Wharton
Keyword(s):  
Relative Humidity ◽  
Prolonged Exposure ◽  
Infective Larva ◽  
Survival Times ◽  
Free Living ◽  
Trichostrongylus Colubriformis ◽  
Second Stage ◽  
Infective Larvae

SummaryThe survival of the free-living stages of Trichostrongylus colubriformis under defined conditions of temperature and relative humidity was investigated. The survival of embryonated eggs was poor at 0, 33 and 54·5 % relative humidity (rel. hum.) at 20 °C but hatching occurred from a proportion of eggs even after exposure for 104 days to 76 and 98% rel. hum. at 20 °C. Second-stage larvae were desiccation-susceptible and were killed within 6 h even at 98% rel. hum. and 20 °C. Infective larvae, dried separately or in clumps, survived prolonged exposure to desiccation at 33–98% rel. hum. and 20 °C with 50% survival times of 58–164 days. Clump formation did not enhance survival in this range. Infective larvae also survived exposure to vacuum desiccation with 50% survival times of 8·8 h in clumps and 4·5 h when dried separately. The infective larva thus readily survives desiccation and may prove a useful model for the study of anhydrobiosis.

scholarly journals Soil drenching with entomopathogenic fungi for control of the soil-dwelling life stages and adults of the same generation of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

2019 ◽  
Vol 110 (2) ◽  
pp. 242-248 ◽  
Author(s):  
I. Garrido-Jurado ◽  
G. Resquín-Romero ◽  
M. Yousef-Naef ◽  
A. Ríos-Moreno ◽  
E. Quesada-Moraga
Keyword(s):  
Entomopathogenic Fungi ◽  
Spodoptera Littoralis ◽  
Reproductive Potential ◽  
Total Mortality ◽  
Life Stages ◽  
Egg Viability ◽  
Survival Times ◽  
Average Survival ◽  
Lepidoptera Noctuidae ◽  
Overall Mortality

AbstractFour Beauveria bassiana and three Metarhizium brunneum isolates were evaluated, as soil drenches, against Spodoptera littoralis prepupae. Treatment efficacy was determined by assessing total mortality during development from prepupae through to pupae and adults; mortality and sub-lethal effects on reproduction were also quantified for adults emerging from surviving prepupae/pupae. All isolates were pathogenic but overall mortality varied between 31.7 and 83.3% (0% for control); average survival time was 7.5–10.5 days (14.0 days for control). From 1.7–15.0% of adults emerging from surviving prepupae/pupae were deformed (0% in control). Contact with fungal suspensions as prepupae/pupae caused a significant reduction in fecundity of emerging adult females (15–58.9%), and a significant reduction in egg viability (6.8–28.4%) compared with controls. Two isolates were selected for virulence evaluation against S. littoralis prepupae. The LC50s were 1.7 × 107 and 1.8 × 107 conidia ml−1 and the median survival times were 7 and 6 days for isolates EAMa 01/58-Su and EAMb 09/01-Su, respectively. Destruxin A was present in pupae developing from prepupae treated with isolates EAMa 01/58-Su (0.010 ± 0.002 µg pupae−1) and EAMb 09/01-Su (0.015 ± 0.003 µg pupae−1). The use of entomopathogenic fungi as soil drenches could be a key component of S. littoralis IPM strategies due to direct reductions in the number of soil-dwelling life stages and, also, the significant reduction in reproductive potential of surviving adults.

Laboratory studies of Blattisocius keegani (Fox) (Acari: Ascidae) reared on eggs of navel orangeworm: potential for biological control

2010 ◽  
Vol 101 (5) ◽  
pp. 499-504 ◽  
Author(s):  
H.Q. Thomas ◽  
F.G. Zalom ◽  
N.L. Nicola
Keyword(s):  
Biological Control ◽  
Relative Humidity ◽  
Egg Laying ◽  
Laboratory Studies ◽  
Amyelois Transitella ◽  
Navel Orangeworm ◽  
Stored Product Pests ◽  
The Family ◽  
Lepidoptera Pyralidae ◽  
C 30

AbstractBlattisocius keegani (Fox) is a predatory mite in the family Ascidae (Acari), noted for potential biological control of Coleopteran stored product pests. Performance of B. keegani on eggs of navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae), was investigated. Mites completed development from egg to adult in 9.2±0.22 days at 25°C and 50–60% relative humidity, and in 6.33±0.29 days at 32.2°C, 30% relative humidity. Mites provisioned with three or five eggs consumed a median of 1.25 to 1.5 eggs, with a maximum of three eggs consumed over 24 h. Regression analyses indicated egg-laying by B. keegani was significantly correlated with the number of A. transitella eggs consumed, and female mites laid an average of 5.82±0.44 eggs over 72 h. Blattisocius keegani, developed on fresh and frozen eggs, laid significantly more eggs when provided with fresh eggs (F3,26=6.16, P=0.0026) and were able to develop on frozen Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs as an alternative host. Mites were equally fecund when fed eggs stored at 0° or −20°C. Provisioning of adult moth bodies in addition to egg prey items increased mite fecundity, although it was demonstrated that B. keegani are phoretic on adult moths as well. The results are the first experimental evidence of B. keegani as a predator of Lepidopteran eggs, as a phoretic species, and of their potential for biological control of navel orangeworm.

How long do eriophyoid mites live?

Zoosymposia ◽  
2021 ◽  
Vol 20 ◽  
Author(s):  
SEBAHAT K. OZMAN-SULLIVAN ◽  
GREGORY T. SULLIVAN
Keyword(s):  
Relative Humidity ◽  
Development Time ◽  
Ornamental Plants ◽  
Mite Species ◽  
Major Influence ◽  
Adult Longevity ◽  
Life Stages ◽  
Biological Studies ◽  
Eriophyoid Mites ◽  
Almost All

The eriophyoid mites (Acari: Eriophyoidea) are extremely small, highly specialized and obligately phytophagous, and ~ 80% of the ~ 5,000 known species are monophagous. They include pests of more than 50 important food and industrial crops and ornamental plants. Conversely, other species have been investigated for their potential role in the biological control of weeds. In this literature review, the data on the development time, adult longevity and lifespan of eriophyoid species generated in 74 studies from 1930 to 2021 was compiled. The eriophyoids were from three families, Eriophyidae, Diptilomiopidae and Phytoptidae, 24 genera and 47 species that included 43 eriophyids, two phytoptids and two diptilomiopids. The most studied genus was Aceria (13 species), followed by Aculus (4) and Calacarus (3). The host plants were in a range of vegetative forms, including grasses, a climber, shrubs and trees, in different families that included Poaceae, Rosaceae and Rutaceae. Almost all the investigations were carried out in laboratory settings under numerous combinations of species, gender, diet/host plant, temperature, relative humidity and photoperiod. These variables all affected the development time, adult longevity and lifespan of eriophyoid mites, with temperature consistently a major influence and relative humidity consistently important. Male life stages were always shorter than female life stages. Phyllocoptruta oleivora (Ashmead) males had the shortest lifespan of 7.1 d at 32 °C on green orange fruit and Aculops lycopersici (Massee) females had the longest lifespan of 46.4 d at 11 °C on young tomato leaves. Biological studies on the duration of their life stages are required to develop models that predict the dynamics of eriophyoid populations in the field to support IPM programs and organic farming. Moreover, these studies are becoming increasingly valuable as globalization and climate change facilitate the spread of invasive eriophyoid mite species.

Life history of Amblyseius fustis (Pritchard and Baker), an indigenous predator of the cassava red mite, Oligonychus gossypii (zacher) in south western Nigeria

1985 ◽  
Vol 6 (2) ◽  
pp. 193-197 ◽  
Author(s):  
T. O. Ezulike ◽  
J. A. Odebiyi
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Relative Humidity ◽  
Developmental Stages ◽  
Developmental Period ◽  
Life Stages ◽  
Male And Female ◽  
Significant Difference ◽  
History Of ◽  
Male To Female

AbstractThe life history of Amblyseius fustis (Pritchard and Baker) was studied in the laboratory at a fluctuating temperature and relative humidity ranging from 24.4 to 28.0°C and 55.5 to 75.6%, respectively. The developmental stages consist of egg, larva, protonymph, deutonymph and adult. The life cycle, from egg to adult of both male and female was about 8 days, while longevity was about 19.2 days. Mated female laid an average of 18.8 eggs. There was no significant difference in the longevity and fecundity of predators fed on different life stages of the host. The proportion of male to female in the progeny of mated females was 1:4.A. fustis has a shorter developmental period and lives longer than its prey, but the latter is more fecund (26.9 eggs/♀) and has a higher proportion of females in its progeny (1:4.8). The shorter developmental period and the longer life span of the predator are likely to offset the higher fecundity of the prey.

Susceptibility of Halyomorpha halys (Hemiptera: Pentatomidae) eggs to different life stages of three generalist predators

2014 ◽  
Vol 147 (2) ◽  
pp. 222-226 ◽  
Author(s):  
P.K. Abram ◽  
J. Doyon ◽  
J. Brodeur ◽  
T. D. Gariépy ◽  
G. Boivin
Keyword(s):  
Invasive Pest ◽  
Generalist Predators ◽  
Halyomorpha Halys ◽  
Life Stages ◽  
Stink Bug ◽  
Predator Species ◽  
Predator Attack ◽  
Late Instar ◽  
Early Instar ◽  
Differential Ability

AbstractThe invasive stink bug Halyomorpha halys Stål (Hemiptera: Pentatomidae) has recently become established in Canada, but little information is available regarding the ability of natural enemies to attack this pest in its invaded range. We tested the capacity of several life stages of three generalist predators, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), Coleomegilla maculata De Geer (Coleoptera: Coccinellidae), and Podisus maculiventris (Say) (Hemiptera: Pentatomidae), to attack H. halys eggs. The relative susceptibility of H. halys eggs to predator attack was compared to P. maculiventris eggs. We found evidence for differential ability to consume H. halys and P. maculiventris eggs both among predator species and within species among life stages. The most H. halys eggs were consumed by late-instar C. carnea, while fewest were consumed by second-instar and adult C. maculata, and second-instar C. carnea. The susceptibility of H. halys eggs to predators was similar to that of P. maculiventris eggs, with only early-instar P. maculiventris nymphs consuming significantly less H. halys eggs than P. maculiventris eggs. Our results provide a baseline for further testing of generalist predators against H. halys and illustrate the potential importance of considering the breadth of ontogeny across which candidates are able to attack the invasive pest.

scholarly journals The oxygen consumption rates of different life stages of the endoparasitic nematode

2010 ◽  
Vol 29 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Willie Van Aardt ◽  
Don Loots ◽  
Sonia Steenkamp
Keyword(s):  
Oxygen Consumption ◽  
Relative Humidity ◽  
Oxygen Consumption Rate ◽  
Consumption Rate ◽  
Secondary Infection ◽  
Life Stage ◽  
Life Stages ◽  
Adult Nematode ◽  
Respiration Physiology ◽  
Consumption Rates

The oxygen consumption rates of different life stages of the endoparasitic nematode, Pratylenchus zeae (Nematoda: Tylenchida) during non- and post-anhydrobiosisPratylenchus zeae, widely distributed in tropical and subtropical regions, is an endoparasite in roots of maize and other crop plants. The nematode is attracted to plant roots by CO2 and root exudates and feeds primarily on cells of the root cortex, making channels and openings where the eggs are deposited, with the result that secondary infection occurs due to bacteria and fungi. Nothing is known about the respiration physiology of this nematode and how it manages to survive during dry seasons. To measure the oxygen consumption rate (VO2 ) of individual P. zeae (less than half a millimeter long), a special measuring technique namely Cartesian diver micro-respirometry was applied. The Cartesian divers were machined from Perspex, and proved to be more accurate to measure VO2 compared with heavier glass divers used in similar experiments on free living nematodes. An accuracy of better than one nanoliter of oxygen consumed per hour was achieved with a single P. zeae inside the diver. Cartesian diver micro-respirometry measurements are based in principle on the manometric changes that occur in a fl otation tube in a manometer set-up when oxygen is consumed by P. zeae and CO2 from the animal is chemically absorbed. VO2 was measured for eggs (length: < 0.05 mm), larvae (length: 0.36 mm) and adults (length: 0.47 mm) before induction to anhydrobiosis. P. zeae from infected maize roots were extracted and exposed aseptically to in vitro maize root cultures in a grow cabinet at 50 % to 60% relative humidity at 28 ºC using eggs, larvae and adults. VO2 was also measured for post-anhydrobiotic eggs, larvae and adults by taking 50 individuals, eggs and larvae from the culture and placing them in Petri-dishes with 1% agar/water to dry out for 11 days at 28 ºC and 50% relative humidity. The VO2 was measured after the anhydrobiotic eggs, larvae and adults were re-hydrated for 12 hours in a high humidity atmosphere. The average VO2 value found for ten consecutive measurements during a 50 minute period of one adult using the diver technique was 32.8 nanoliter per hour. The differences between the ten VO2 values were less than 3.5 %, an indication of the accuracy of the diver measurements. The average VO2 values from ten measurements per life stage, expressed in nanolitres per hour per life stage of the pre-anhydro-biotes (eggs: 7.96; larva: 6.13; adult: 26.04) were compared with those of post-anhydrobiotes 12 hours after anhydrobiosis. The average VO2 values of the post-anhydrobiotes for the three life stages (egg: 19.34; larva: 14.17; adult: 32.86) were statistically signifi cantly higher in comparison with the pre-anhydrobiotes. The reasons for the difference are that high concentrations of metabolites, probably in the form of trehalose, accumulate during the anhydrobiosis stage to be utilized during the post-anhydrobiotic revival period. The oxygen consumption rate was also expressed in nanolitres per hour per microgram adult nematode after applying the following equation taken from the literature: M = a2 x b/16 x 1000 where M = mass (µg) of adult nematode; a = largest body width (µm); b = body length (µm). Using this equation it was found that one gram P. zeae uses 503 times more oxygen compared with one gram mammal the size of a cow. This high specifi c oxygen consumption rate (MO2 ) is a direct indication of the large metabolic damage this endoparasitic nematode can have on the metabolic substrates provided by the roots of the various plant crops it parasitize. 

scholarly journals Divergence in Gut Bacterial Community Among Life Stages of the Rainbow Stag Beetle Phalacrognathus muelleri (Coleptera: Lucanidae)

Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 719
Author(s):  
Miaomiao Wang ◽  
Xingjia Xiang ◽  
Xia Wan
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Community Composition ◽  
Bacterial Community Structure ◽  
High Throughput Sequencing ◽  
Bacterial Community Composition ◽  
Alpha Diversity ◽  
Illumina Miseq ◽  
Life Stages ◽  
Early Instar

Although stag beetles are popular saprophytic insects, there are few studies about their gut bacterial community. This study focused on the gut bacterial community structure of the rainbow stag beetle (i.e., Phalacrognathus muelleri) in its larvae (three instars) and adult stages, using high throughput sequencing (Illumina Miseq). Our aim was to compare the gut bacterial community structure among different life stages. The results revealed that bacterial alpha diversity increased from the 1st instar to the 3rd instar larvae. Adults showed the lowest gut bacterial alpha diversity. Bacterial community composition was significantly different between larvae and adults (p = 0.001), and 1st instar larvae (early instar) had significant differences with the 2nd (p= 0.007) and 3rd (p = 0.001) instar larvae (final instar). However, there was little difference in the bacterial community composition between the 2nd and 3rd instar larvae (p = 0.059). Our study demonstrated dramatic shifts in gut bacterial community structure between larvae and adults. Larvae fed on decaying wood and adults fed on beetle jelly, suggesting that diet is a crucial factor shaping the gut bacterial community structure. There were significant differences in bacterial community structure between early instar and final instars larvae, suggesting that certain life stages are associated with a defined gut bacterial community.

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