scholarly journals Effect of Larval Topical Application of Juvenile Hormone on Cuticular Chemical Composition of Mischocyttarus consimilis (Vespidae: Polistinae) Females

Sociobiology ◽  
2020 ◽  
Vol 67 (3) ◽  
pp. 433
Author(s):  
Erika Fernandes Neves ◽  
Thiago Santos Montagna ◽  
Luiz Carlos Santos Junior ◽  
Kamylla Balbuena Michelutti ◽  
Claudia Andrea Lima Cardoso ◽  
...  

Juvenile  Hormone  (JH)  is  considered  the  main  determinant  of  caste  in  social insects, though little is known about how this hormone acts in social wasps, especially the independent-founding species. The known relationship between JH titer and caste in the colony and we suggest a relationship among the effects of JH and the cuticular chemical profile. Therefore, this study aimed to test the hypothesis that topical application of JH to larvae of different instars alters the cuticular chemical composition of newly emerged females of Mischocyttarus consimilis (Zikán), influencing the dynamics of colony. Two techniques were used to evaluate the variation in cuticular chemical composition: Fourier transform infrared photoacoustic spectroscopy and gas chromatography coupled to mass spectrometry (GC-MS). Indeed, the application of JH did significantly alter the cuticular chemical composition of adult females that received treatment at the larval stage in comparison to control. The effects of JH were instar-dependent in that the results of topical application were significant when performed at third larval instar. Overall, these results add evidence that caste determination may, at least in part may be pre-imaginal in species of independent-founding social wasps.

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 251
Author(s):  
Maria Fraga-Corral ◽  
Paz Otero ◽  
Lucia Cassani ◽  
Javier Echave ◽  
Paula Garcia-Oliveira ◽  
...  

Tannins are polyphenolic compounds historically utilized in textile and adhesive industries, but also in traditional human and animal medicines or foodstuffs. Since 20th-century, advances in analytical chemistry have allowed disclosure of the chemical nature of these molecules. The chemical profile of extracts obtained from previously selected species was investigated to try to establish a bridge between traditional background and scientific data. The study of the chemical composition of these extracts has permitted us to correlate the presence of tannins and other related molecules with the effectiveness of their apparent uses. The revision of traditional knowledge paired with scientific evidence may provide a supporting background on their use and the basis for developing innovative pharmacology and food applications based on formulations using natural sources of tannins. This traditional-scientific approach can result useful due to the raising consumers’ demand for natural products in markets, to which tannin-rich extracts may pose an attractive alternative. Therefore, it is of interest to back traditional applications with accurate data while meeting consumer’s acceptance. In this review, several species known to contain high amounts of tannins have been selected as a starting point to establish a correlation between their alleged traditional use, tannins content and composition and potential bioaccessibility.


2002 ◽  
Vol 59 (3) ◽  
pp. 585-588 ◽  
Author(s):  
José Ednilson Miranda ◽  
Sérgio Antonio de Bortoli ◽  
Roque Takahashi

Juvenile hormone analogues have been tested as insect growth regulators in silkworm (Bombyx mori), seeking an increment of silk production. These chemical products, when applied in small or moderate rates, promote the extension of the last larval instar. To understand the physiologic consequences on silk production by the silkworm strain C115 x N108, the application of methoprene, a juvenile hormone analogue, was performed to evaluate its effects on larval development and silk production. Methoprene was topically applied 48h after the fourth larval ecdysis, on the dorsal integument of the 2nd thoracic segment of the insects, at seven rates between 0 and 20 ng a.i. Methoprene influenced positively the duration of the fifth instar and the weight gain of the insects. The application of 1ng methoprene resulted in the heaviest silkglands, cocoons, shell cocoons and pupae weights. Comparatively to the control, the increment on silk production (approximately 24%) by the use of 1ng methoprene was more accentuated than the corresponding negative effects on the cocooning rate (approximately 12%).


2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900
Author(s):  
Mikel González ◽  
Sergio López ◽  
Gloria Rosell ◽  
Arturo Goldarazena ◽  
Angel Guerrero

The chemical profile of the cuticle and internal tissues of four species of Culicoides have been studied for the first time by gas chromatography-mass spectrometry. The chemical composition of females of C. obsoletus s.l. and C. lupicaris, vectors of diverse viral diseases, have been compared with that of other biting midges, such as C. kibunensis and C. fascipennis, and the non-biting midge Forcipomyia bipunctata. A total of 61 compounds belonging to 8 major chemical classes were identified in cuticular and internal tissues in n-hexane extracts. The compounds include carboxylic acids (CAs) (C6-C20), with C16:0, C16:1 and C18:1 being dominant, branched hydrocarbons (C29 to C38 mono/di/trimethylalkanes), linear hydrocarbons (C15 to C33, mainly odd chain carbons), terpenes (geranylacetone, geranylgeraniol acetate, squalene, terpenic alcohol), steroids (cholesterol), aldehydes (C9-C10 and even chain C20 to C30), and esters. The chemical profile depends on the species and whether the extracts are external (cuticle) or internal. The contents of linear and branched hydrocarbons and aldehydes was high in cuticular extracts but practically absent in internal tissues, which were, in contrast, rich in CAs, terpenes and steroids. The results are discussed and compared with other Culicoides midges and mosquito-related species.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1824
Author(s):  
Luís R. O. Cruz ◽  
Nikolaos Polyzos ◽  
Ângela Fernandes ◽  
Spyridon A. Petropoulos ◽  
Francesco Di Gioia ◽  
...  

The present study investigated the effect of salinity (Control: 1.8 dS/m, S1: 3.0 dS/m and S2: 4.5 dS/m) on the chemical composition and bioactive properties of three basil cultivars (Red Basil, Dark Opal Red and Basilico Rosso). Crop performance was not affected by increasing salinity in DoR and BaR. Fat, ash and carbohydrates content increased by salinity in DoR, whereas energetic value was negatively affected. Free sugars (total and individual compounds) increased under saline conditions (S2) in BaR, whereas reducing trends were observed for the main organic acids and tocopherols in all the cultivars. The major fatty acids were α-linolenic, linoleic and palmitic acids with no consistent salinity effects, while the richest polyphenols were sagerinic acid and eriodictyol-O-malonylhexoside. Finally, basil extracts showed moderate antioxidant and strong antifungal activity. In conclusion, salinity showed a genotype dependent effect on the chemical profile and bioactivities of the tested cultivars.


Parasitology ◽  
1990 ◽  
Vol 100 (3) ◽  
pp. 445-452 ◽  
Author(s):  
H. Hurd ◽  
C. Strambi ◽  
N. E. Beckage

SUMMARYMetacestodes of Hymenolepis diminuta cause a perturbance of vitellogenesis in the intermediate host Tenebrio molitor. The reduction in host reproductive output associated with infection may be due to this pathophysiology. Many of these events are regulated by host juvenile hormone (JH). A comparison of the titre of JH and its rate of degradation in female control and parasitized 15-day-old insects has been made. Haemolymph from female beetles contained 1·27 pMol JH equivalents/100 µl. No significant difference was associated with infection. However, topical application of a JH analogue, methoprene, at the time of infecion or 8 days post-infection reduced the significant accumulation of vitellogenin usually found in the haemolymph of females 12 days or more post-infection. These findings indicate that parasite-induced alteration of host vitellogenesis is not mediated via alteration in JH titres, although observations made after hormone supplementation suggest some form of interaction between the parasite and the host endocrine system.


1984 ◽  
Vol 39 (11-12) ◽  
pp. 1150-1154 ◽  
Author(s):  
U. Bührlen ◽  
H. Emmerich ◽  
H. Rembold

Abstract The titer of juvenile hormone III (JH-III) has been determined by the use of combined gas chromatography-mass spectroscopy (GC-MS) in whole body extracts of the larvae, prepupae, pupae and adults of Drosophila hydei. A characteristic JH-III titer curve was established by use of the hormone derivatives. No other juvenile hormone homologs were detected. JH-III shows a broad peak maximum of about 30 pmol/g fresh weight during the last larval instar, whereas only traces of the hormone are detectable at pupariation. Prepupae and pupae exhibit about the same JH-III level. In older pupae and in the pharate adults there was no JH-III detectable but it reappeared soon after emergence. Low values of JH-III are found in young male and female flies. The JH contents rise to distinct peaks in older and reproductive adults, both in male and female animals.


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