Insects in general

On account of their small size and frequent aptitude for living under confined conditions, insects constitute an excellent material for microcalorimetric investigations. [85] 

A rather large compilation of respiration rates of insects can be found in an article of Keister and Buck [86]. They observed a typical value of 1 mL 02/(g-h) for the resting metabolism of many insects, which transforms to about 6 mW/g. 

A rough estimate of the hexose metabolism of flying insects which is about 100-fold higher than at rest is given by Sacktor [87]. A 50 mg insect should consume in the average an amount of 30 pmol hexose/(g-min) in flight and have a yield of -1300 kJ/mol O2. 

Comparing the calorimetrically obtained heat output - corrected for the value of evaporation - with that found in respirometry of the mealworm Tenebrio molitor, Peakin registered no significant differences between both methods and observed the familiar U-shaped curve of metabolism during pupation [88], He argued that 

Group effects are rather common among insects, leading to a reduced mass specific heat production rate compared to that of an isolated animal when several individuals of the same species are put together in the calorimeter. Prat [85] showed that the heat dissipation of a female fruit fly Drosophila) of about 1 mg dropped from 0.12 mW to 0.08 mW when together with 4 further fruit flies. This effect is even more pronounced in social insects like honeybees which produce a collective thermogenesis resulting in social homeothermy. 

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The organophosphorons insecticides dimethoate and diazinon are mnch more toxic to insects (e.g., housefly) than they are to the rat or other mammals. A major factor responsible for this is rapid detoxication of the active oxon forms of these insecticides by A-esterases of mammals. Insects in general appear to have no A-esterase activity or, at best, low A-esterase activity (some earlier stndies confnsed A-esterase activity with B-esterase activity) (Walker 1994b). Diazinon also shows marked selectivity between birds and mammals, which has been explained on the gronnds of rapid detoxication by A-esterase in mammals, an activity that is absent from the blood of most species of birds (see Section 23.23). The related OP insecticides pirimiphos methyl and pirimiphos ethyl show similar selectivity between birds and mammals. Pyrethroid insecticides are highly selective between insects and mammals, and this has been attributed to faster metabolic detoxication by mammals and greater sensitivity of target (Na+ channel) in insects. 

Most of the methods that have been used to collect or extract pheromones from true bugs are analogous to methods used with insects in general, and will be summarized here only briefly. The interested reader is referred to several reviews [4,12-14]. First, whole insects or body sections have been soaked in solvent (e.g., N. viridula [15] Campylomma verbasci [16]). However, the value of whole body extracts is questionable because of their complexity, and the bulk of the compounds obtained may be unrelated to the pheromone components, hampering further investigation of the actual pheromone. 

The carbamate and thiocarbamate radicals have toxicity for weeds, fungi, and insects. In general, they are slightly soluble in water and somewhat more volatile than most other herbicides. 

We discuss associative, Pavlovian learning between odours and food reward in Drosophila. We argue that flies (just like insects in general) posses a discrete side... 

For many years, it was believed that phytophagous insects in general were capable of dealkylating and converting dietary C28 and C29 phytosterols to cholesterol to satisfy their need for cholesterol (4). Also, a number of omnivorous species of insects are known to Fe capable of this conversion Thus, cholesterol... 

The Isolation and Identification of free ecdysteroids from Manduca and insects in general has not been too difficult, because we had partition systems that effectively separated free ecdysteroids from their impurities. For example, from processing 130 g of pupae, the ecdysteroids which partition into the butanol phase are now present in only 413 mg of residue (Fig. 3). This material could be further purified by column and thin-layer chromatography and countercurrent distribution. On the other hand, the ecdysteroid conjugates are present in 3.74 g of residue that is water-soluble which presents additional obstacles to further purification. The nature of the conjugation or the impurities present quite often prevented successful column or thin-layer chromatography of the conjugates. More recently, however, a method was described for the separation of... 

Chemical secretions, as we have seen, play an important role in termite foraging, recruitment, caste determination, and nest-building, as they do in social insects in general. However, in termites, we are faced with an excellent opportunity to explain inter-relationships between species in chemical terms because of their frequent reliance on chemical defense, which is linked with other aspects of their biology, such as foraging, feeding habits, nest structure and building behavior. 

Deacetylbaccatin III could be turned into taxol in only four steps (a process called semi-synthesis )- Molecules like this are responsible for the resistance of yew to woodworm and insects in general - yew isn t just poisonous to humans ... 

An immense amount of research on representative 8-endotoxins has been devoted to understanding the mode of action on susceptible insects. In general, following ingestion, the crystalline inclusions are dissolved and then converted to active toxins by insect proteases. The active toxins bind to specific receptor sites and produce pores in the insect gut which results in loss of homeostasis and septicemia, which are lethal to the insect (Broderick et al., 2006). In addition, there may be other less-characterised insect control functions of these toxins such as avoidance of the toxins and feeding paralysis prior to completion of the full lethal pore-formation process (Aronson and Shai, 2001). In many cases, larvae become less susceptible to 8-endotoxins as they age due to fewer binding sites in the older larvae (Gilliland et al., 2002). 

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