DELAYED DEVELOPMENT OF MICROCTONUS VITTATAE (HYMENOPTERA: BRACONIDAE) IN SUPERPARASITIZED ADULTS OF PHYLLOTRETA CRUCIFERAE (COLEOPTERA: CHRYSOMELIDAE)

1983 ◽  
Vol 115 (4) ◽  
pp. 441-442 ◽  
Author(s):  
H. G. Wylie

The length of the developmental period from oviposition to adult emergence for nondiapausing individuals of a solitary endophagous braconid, Microctonus vittatae Mues., was usually about 4 wk at 20°C, 70–80% R.H., and a 16h:8h L:D cycle. However, living second and subsequent instar parasite larvae were occasionally found in adults of Phyllotreta cruciferae (Goeze) and Phyllotreta striolata (F.) (Coleoptera: Chrysomelidae) dissected 25–30 days after parasitization. Most of these beetles also contained one or more dead parasite eggs or first-instar larvae, suggesting that superparasitism prolonged development of the single surviving parasite in each host. Therefore, the effect of superparasitism on the parasite's development was investigated by recording the length of the developmental period of M. vittatae in two groups of adult P. cruciferae, one consisting of a majority of superparasitized individuals and the other mostly of hosts with only one immature parasite each.

1985 ◽  
Vol 117 (5) ◽  
pp. 541-545 ◽  
Author(s):  
H.G. Wylie

AbstractMicroctonus vittatae Mues. oviposit in the hemolymph of flea beetles, Phyllotreta striolata (F.) and Phyllotreta cruciferae (Goeze), by inserting the ovipositor into the host's mouth and occasionally, membranous areas between body segments. Some of the eggs are transported in the hemolymph posteriorly from the head to the thorax or abdomen, and some laid in the thorax are carried into the abdomen, but eggs hatch in all 3 body regions of the hosts. First-instar larvae that eclose in the head and thorax disperse into the abdomen where they develop. Egg and larval dispersal into the abdomen increase the probability that the parasite has adequate space for development.


2019 ◽  
Vol 47 (2) ◽  
pp. 253-262
Author(s):  
Umme Habiba ◽  
W Islam ◽  
Selina Parween

The present study was planned to evaluate the effect of spinosad on the survivability and development of Sitophilus oryzae on four wheat varieties viz., BARI-26, BARI-28, Shatabdi-21 and Prodip-24. Three doses in three replications for spinosad were applied to four wheat varieties. Spinosad concentrations significantly increased the total developmental period compared to the control in a dose-dependent manner on four wheat varieties. The highest developmental period took 41.67 ± 0.33 days to become adult was recorded in S-21 at 0.0003 μl/g of spinosad in F1. All adults of F1 did not reach in F2 because surprisingly all adults died after emergence. So, no developmental period was found in S-21 (0.00±0.00) and B-28 (0.00 ± 0.00) days at 0.0003 μl/g spinosad in F2. On the other hand, five mated females were released on the treated wheat with different concentrations of spinosad for 10 - 15 days; then they were removed. Treated wheat was checked for up to 30 to 60 days and observed the progeny for two successive generations (1st and 2nd). Each combination of insect species, insecticide rate, and exposure duration were replicated three times. Among four wheat varieties, the lowest adult emergence was recorded as 08.00 ± 0.58 in F1 and totally controlled in F2 generation in S-21 variety at 0.0003 μl/g. Spinosad concentrations significantly increased the total developmental period compared to the control in a dosedependent manner on four wheat varieties. Bangladesh J. Zool. 47(2): 253-262, 2019


Author(s):  
Carmen García-Alba

This study is part of a larger research study (doctoral dissertation), in which a comparative study with adolescent samples is done: 50 anorexic restricting patients (ANP), 50 patients diagnosed with depression (DP) and 50 non patients (NP). The proposed objective is two-fold: 1) To try to clarify the existing relationship between Anorexia (AN) and Depression (D), investigated from diverse disciplines but without conclusive results. 2) To detect in the ANP personality different traits from those of other groups, which should, if possible, allow to detect them at an early stage for an adequate prognosis. The current article presents the Rorschach findings in relation to the cognitive functioning of the ANP. In them, the following has been detected: (1) An information processing similar to that of the other groups, even with a more complete (L ≤ .99), more complex (DQ+↑) and better discriminated (Zd↑) grasp of the stimulus; (2) Mediating processes very similar to those of the other groups, sharing with them the perceptive maladjustments (X–%↑) and an excessive individualism (Xu%↑); (3) A clearly differentiating ideation disorder. Definitely, the ANP use predominantly ideation (M↑), but their thought, usually well-adjusted (MQo↑), presents eventual operations of delusional type (MQnone↑). Above that, their thinking is marked by a great passivity (Mp↑), which makes them more vulnerable to accept ideas without criticizing them and it results in a very inefficient thinking, which spins around these concepts without finding solutions, entering into a sort of ruminating which is completely unproductive. The differences toward the obsessive pathology are established. The discriminant analysis conducted with all the Rorschach variables that resulted as significant throughout the research, provides quite a consistent function which discriminates the ANP: MQnone↑, Mp↑, FD↓, Ma↑, MQo↑, AdjD↑, Sum H↑, (H)↑. Based on this we can understand that these adolescents, being in a developmental period of big changes and disorientations in relation with their own image, confronted with life events, and possibly starting off with some biologic vulnerability: (1) Due to the alterations of their ideation, accept without criticism (Mp) irrational ideas dominating in our culture, in which slimness appears as the only model, synthesis of intelligence, beauty and success; remaining captured in this type of mental activity (MQnone), which they cannot escape nor criticize (Mp), despite they reason adequately on other topics (MQo); (2) Their alterations of self-perception [(H)] make them hide themselves in a fantasized image, which is the axis of their interests and the only thing that really matters to them; (3) The resources they have to decide on behaviors and to finish these deliberately (AdjD), and their scarce tendency to the introspection (FD) lead to their decision of not eating, based on distorted and passively accepted thinking, which has great power and thus, so difficult to modify. Finally, based on the Rorschach data obtained, the hypothesis of a personality disorder as underlying pathology is pointed out.


Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.


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.


2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
N. Mbahin ◽  
S. K. Raina ◽  
E. N. Kioko ◽  
J. M. Mueke

A study on the life cycle of the silkmothAnaphe panda(Boisduval) was conducted in two different habitats of the Kakamega Forest in western Kenya: Ikuywa, an indigenous forest, and Isecheno, a mixed indigenous forest. Eggs were laid in clusters, and the incubation period ranged from 40 to 45 days. Larvae fed onBridelia micrantha(Hochst) and passed through seven instars. The developmental period took between 83 to 86 days in the dry season and 112 to118 days in the rainy season. The pupal period ranged between 158 and 178 days in the rainy season and, on the other hand, between 107 and 138 days in the dry season. But the later caught up in development with those that formed earlier. Moths emerged from mid-October until mid-May. Longevity of adultAnaphe pandamoths took between 4 and 6 days, but generally females seemed to live longer than males. The moth also seems to have higher lifespan in the indigenous forest compared to the mixed indigenous forest.


2021 ◽  
Vol 5 (2) ◽  
pp. 29-33
Author(s):  
Sabera Yasmin ◽  
Mohammed Ali ◽  
Md. Mizanur Rahman ◽  
Mst. Salma Akter ◽  
Md. Abdul Latif

The bean flower thrips, Megalurothrips usitatus is a major pest of mung bean that causes flower dropping and significant yield loss of the crop. M. usitatus demonstrated to have variable lifespan when reared on different leguminous hosts but on mung bean, an important pulse crop in Bangladesh, is unknown. The experiment was conducted to determine the biological attributes of M. usitatus on mung bean in a climate control chamber at 26 ± 1°C, 75 ± 3% RH, and 16:8 hours L:D in the laboratory. The results revealed that the incubation period, first instar larva, second instar larva, prepupa, and pupal period of M. usitatus were 3.13 ± 0.06, 1.48 ± 0.05, 2.30 ± 0.08, 1.30 ± 0.07, and 2.26 ± 0.13 days, respectively. The combined developmental period from egg to adult was 10.54 ± 0.15 (mean ± SE) days. The larvae of M. usitatus were similar in appearance to the adults, but they lacked wings and were smaller and different in color. The first instar was pale yellow, while the second instar was darker and larger, ranging from deep yellow to orange-red. The wing pads of the prepupae were shorter than that of the pupae. The antennae of the prepupa were straight, but they were bent in the pupa. In the case of pre-adult mortality of M. usitatus, the mortality of the first instar larva was 14.41%, second instar larva 22.77%, prepupa 14.10%, and pupa 65.67%. The pre-adult mortality was 80.51% overall. Adult males had lower longevity (6.42 ± 0.44 days) than females (12.07± 1.56 days). The developmental period of M. usitatus on mung bean indicated the suitability of the leguminous crop as a potential host, as well as the need for information on the pest’s various growth stages in order to design effective management strategies.


1938 ◽  
Vol 29 (4) ◽  
pp. 425-456 ◽  
Author(s):  
A. J. Duarte

General Growth.Generally, females have higher rates of growth than males. The phases, however, do not show appreciable differences in the rate. The pronotum has for increase in length the highest values which decrease throughout the instars (whereas the constants for the other parts remain fairly stable up to the fifth instar).Dyar's rule was applied for the growth in length of the middle femur and the width of the head, and it was found that the rule holds good for these parts.Przibram's rule, as modified by Bodenheimer, holds true for the growth in length of the different parts and shows the occurrence of latent cell-divisions varying from one (width of head and of pronotum) to four (length of pronotum). The number of latent cell-divisions keeps fairly constant in both phases.For wet weight Przibram's principle is inapplicable, owing to the large percentage of differences between the actual and calculated values.Gregarious males are heavier than solitary males up to the third stadium ; gregarious females are heavier than solitary females up to the third stadium ; fourth, fifth and adult stadia being characterized by higher values in wet weight for solitary females than for gregarious females. Females have higher rates of increase in wet weight than males. No significant differences exist in the rates of increase between gregarious and solitary individuals. In the fifth-adult stadium all the rates decrease except in gregarious females, which show a rise.Gregarious insects have higher values in dry weight than solitary insects, except solitary females in the adult stadium. The coefficients are higher for females than for males.The rates of increase reach the highest values in the second-third stadium of gregarious insects and solitary females, whereas solitary males have their highest value in the fourth-fifth stadium.With the exception of solitary females, all the rates of growth in dry weight decline in the fifth-adult stadium.The rates of growth of the hind legs obtained from the cube-roots of their wet weights are compared with the rates of linear growth of the hind femora. Their variation throughout the instars seems to be in opposite directions. Therefore it is suggested that the rates of growth in wet weight of the hind legs and the rates of growth in length of the respective hind femora are independent of each other.Growth of the parts.The application of the exponential allometry formula y=bxα to the data on dimensions of the parts of Locusta shows the existence of negative, positive and almost isometric growth.The pronotum has the highest value for the growth in length relatively to the growth in length of the middle femur ; the lowest value pertains to the growth in width of the head.Males have higher values than females ; phase gregaria exhibits higher growth-ratios than phase solitaria.With the exception of the hind femur the growth-ratios decline throughout the instars. The greatest decline pertains to the growth in length of the pronotum.A growth-gradient exists in Locusta with the highest value in the pronotum. The middle femur divides the growth-gradient into two parts : an anterior part with values decreasing with the growth of the insect, and a posterior part whose values increase with its growth.Effects of the amputation of the hind tibiae on crowded locusts.The effects obtained by mutilating both hind tibiae of three hundred first instar hoppers of Locusta migratoria migratorioides and placing them in a crowded condition are compared with the effects obtained by crowding a batch of the same number of first instar unoperated insects.The insects with their hind tibiae cut off did not develop as far as those of the control batch ; the differences in dimensions are greater for the hind femur than for the other parts of the body.In the experimental batch the hind femur, as a consequence of its useless condition, became extremely short as compared with the elytra, bringing the ratio E/F to a high value (over 1·950), thus leading to a false interpretation.The occurrence of the black-orange coloration in both batches suggested that both developed towards phase gregaria. This coloration was stronger and more uniform in the control batch than it was in the experimental batch. Thus the control animals developed into a better gregarious type.


1985 ◽  
Vol 6 (2) ◽  
pp. 177-181 ◽  
Author(s):  
D. A. Enobakhare

AbstractThe biology of the aphid, Cerataphis variabilis H.R.L., on Raphia hookeri Mann & Wendl., was studied in the laboratory and the field using a ‘clip-on’ cage and a sleeve cage. The first instar lasted 5.1 days. The second and third instars each lasted 2.45 days, while the fourth instar lasted 2.4 days. The total developmental period of the nymphs was 11.3 days at 26.4 ± 1.43°C and r.h. 83 ± 1.46%; 11.6 days at 26.4 ± 1.63°C and r.h. 85 ± 1.19%; 12.9 days at 27.9 ± 1.04°C and r.h. 75.5 ± 1.64%; 12.95 days at 27.8 ± 0.33°C and r.h. 69 ± 1.23%; 15 days at 21.4 ± 0.58°C and r.h. 45 ± 1.77%. These periods were significantly different at 5% level (LSD = 0.59 days). The higher the temperature and relative humidity the shorter the developmental period (with temperature: r = −0.69, 20.8–28.9°C; r.h.: r = −0.97, 43.2–86.2%). The number of progeny per adult ranged from 54 to 60 in a period of 28–31 days. The longevity ranged from 31 to 34 days.


2019 ◽  
Vol 35 (2) ◽  
pp. 214-224 ◽  
Author(s):  
Cristina Alonso ◽  
Estrella Romero

La relación entre el sexting y la personalidad en los adolescentes ha sido escasamente investigada. Además, es notoria la escasez de estudios longitudinales que aborden los predictores y consecuencias del sexting. Este estudio analiza los datos de 624 adolescentes que fueron evaluados en dos ocasiones (T1 y T2) distanciadas por un período de un año, y a los que se administraron cuestionarios para medir el sexting, los rasgos de personalidad del modelo de cinco factores (MCF), y posibles consecuencias psicosociales del sexting (acoso/ciberacoso, bienestar emocional). Los resultados indican que mayor extraversión y menor amabilidad y responsabilidad (T1) se relacionan con sexting (T2). El estudio permite también identificar qué facetas específicas de personalidad (T1) se asocian con el sexting registrado en T2. Además, los análisis de regresión muestran que la extraversión predice aumentos en sexting entre T1 y T2. En cuanto a las consecuencias, una alta implicación en sexting T1 predice descensos en la victimización y en las emociones positivas experimentadas entre T1 y T2. Por tanto, este estudio muestra que la personalidad permite predecir los cambios en sexting a lo largo de la adolescencia; el sexting, a su vez, parece asociarse a consecuencias psicosociales relevantes en este período del desarrollo. The relationships between personality and sexting have been scarcely studied. In addition, the scarcity of longitudinal studies about predictors and consequences of sexting is notorious. This study analyzed the longitudinal data from 624 adolescents who were evaluated on two occasions (T1 and T2) separated by a period of one year, and to whom questionnaires were administered to measure sexting, the personality traits of the five factor model (FFM), as well as possible psychosocial consequences of sexting. The results indicate that high extraversion and low agreeableness and conscientiousness (T1) are related to sexting (T2). In addition, the study also allows us to identify which specific facets of personality (T1) are associated with sexting registered in T2. On the other hand, regression analyses indicate that extraversion predicts increases in sexting between T1 and T2. As for the outcomes of sexting, a high involvement in sexting T1 predicts decreases in victimization and in the positive emotions experienced between T1 and T2. Therefore, this study shows that personality allows for prediction of changes in sexting throughout adolescence; sexting, in turn, seems to be associated with relevant psychosocial consequences in this developmental period.


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