Age-Dependent Fecundity and Fertility Life Tables of the Predator Brontocoris tabidus (Heteroptera: Pentatomidae) Under Field Conditions

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) was exposed to gammacyhalothrin to study the stimulatory effect of low concentrations of this pyrethroid. The doses studied were 23.4375, 11.7188, 5.8594, 2.9297, 1.4648, 0.7324 mg.litre-1 and water, as control. The third, fourth, and fifth instars of P. nigrispinus were shorter with all the doses of this insecticide. The survival and longevity of this predator was highest with the lowest doses. The oviposition period of P. nigrispinus decreased as the doses increased. The lowest pre-and postoviposition periods were found with 11.7188 mg.litre-1 of gammacyhalothrin. The dose 0.7324 mg.litre-1 increased the clutch interval. The egg viability was similar between the treatments. The number of eggs per clutch, clutches per female, incubation period, and female body weight were not affected. The hormesis response could be used as a tool for IPM programs, allowing the manipulating parameters of this predator in synergism with this insecticide.

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Thermal requirements and age-specific life tables of cowpea aphids in cowpea under natural field conditions

Arquivos do Instituto Biológico ◽

10.1590/1808-1657000502018 ◽

2019 ◽

Vol 86 ◽

Author(s):

José Edmir Girão Filho ◽

Luiz Evaldo de Moura Pádua ◽

Gilson Lages Fortes Portela ◽

Francinalva de Morais Sousa

Keyword(s):

Maximum Error ◽

Life Tables ◽

Field Conditions ◽

Reproduction Rate ◽

Daily Production ◽

Thermal Requirements ◽

Degree Day ◽

Proposed Model ◽

Time Of Year ◽

Net Reproduction

ABSTRACT: Thermal requirements and life tables of insects are important tools in the ecological management of pests. Thus, this study aimed to construct age-specific life tables for Aphis craccivora at different times of the year and, based on their thermal requirements, predict the occurrence of adults under field conditions. To that end, aphids of known age were kept in cages over cowpea plants at different times of the year - November 2016 and March, April, and June 2017 - at the Agricultural Sciences Center of the Federal University of Piauí. Parameters of development, fertility, and mortality were observed daily, allowing us to construct age-specific life tables, as well as an accumulated degree-day model to predict adult occurrence. The time of year affected the first and second stages of development of the cowpea aphid, the nymphal and reproductive periods, longevity, the biological cycle, the number of nymphs produced per female, the daily production of nymphs per female, life expectancy (ex), and survival (Lx). However, the fertility life tables showed significant differences only in the net reproduction rate (R0). The proposed degree-day model reached an accuracy of one day or more than the observed value, with a maximum error of 12.9%. We concluded that the proposed model is adequate to predict the occurrence of adults in the field and that the population parameters of A. craccivora in cowpea are negatively affected during November and positively affected in June.

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Effects of Hyperoxia on Lung Utrastructure

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067121 ◽

1970 ◽

Vol 28 ◽

pp. 26-27

Author(s):

Gladys Harrison

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Light Microscopy ◽

Oxygen Effects ◽

Age Dependent ◽

The Central Nervous System ◽

The Subject ◽

Space Age ◽

Alveolar Septa ◽

Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

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