Detection of food in immature and adult stages of water scavenger beetle, Hydrophilus acuminatus (Coleoptera: Hydrophilidae)

2021 ◽  
pp. 1-15
Author(s):  
Toshio Inoda

Abstract The water scavenger beetle, Hydrophilus acuminatus (Motschulsky) (Coleoptera: Hydrophilidae), has two types of feeding modes: carnivorous during the larval stage and omnivorous during the adult stage. To investigate how the beetles detect food, larvae were provided with pond snails and snail visceral mass and adults were provided with algae and thawed blood worms. Larvae found snails and visceral mass hidden in the filter paper (only “smell” could be used); however, visceral mass was found 22–27 minutes sooner than snails, 40–53 minutes. Time to find the visceral mass that was exposed (all senses could be used) or hidden (only “smell” could be used) showed similar values, 5.4–8.0 or 7.6–8.5 minutes, respectively. Adults found algae exposed on the filter paper in 54 ± 73 minutes (mean ± standard deviation), whereas no adults found the algae hidden in the filter paper. In contrast, all adults found the thawed blood worms in the exposed (10.3 ± 13 minutes) and hidden conditions (11.0 ± 12.7 minutes). Adults did not show feeding behaviour towards the algae or thawed blood worms in the transparent microtube (only “sight” could be used). These suggest that larvae use smell, whereas adults use smell and touch and/or taste to detect their food.

1991 ◽  
Vol 11 (4) ◽  
pp. 2149-2153 ◽  
Author(s):  
Y Feng ◽  
L E Gunter ◽  
E L Organ ◽  
D R Cavener

The importance to in vivo translation of sequences immediately upstream of the Drosophila alcohol dehydrogenase (Adh) start codon was examined at two developmental stages. Mutations were introduced into the Adh gene in vitro, and the mutant gene was inserted into the genome via germ line transformation. An A-to-T substitution at the -3 position did not affect relative translation rates of the ADH protein at the second-instar larval stage but resulted in a 2.4-fold drop in translation of ADH at the adult stage. A second mutant gene, containing five mutations in the region -1 to -9, was designed to completely block translation initiation. However, transformant lines bearing these mutations still exhibit detectable ADH, albeit at substantially reduced levels. The average fold reduction at the second-instar larval stage was 5.9, while at the adult stage a 12.5-fold reduction was observed.


2020 ◽  
Vol 80 (4) ◽  
pp. 769-776
Author(s):  
T. M. Sileem ◽  
A. L. Mehany ◽  
R. S. Hassan

Abstract Fumigant activities for three essential oils; Garlic oil (Allium sativum L); Chili pepper (Capsicum annuum L.) and Nigella (Nigella sativa L.) were assessed at different concentrations against the adult and 20-days old larval stages of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) in the laboratory. The accumulative mortality was observed at different exposure periods (3, 5 and 7 days). The residual effect of garlic oil that was the effective oil, on the treated wheat grains was evaluated with respect to histological changes in the liver, kidney, and stomach of rat fed on this treated wheat. The results showed that the mortality rates of treated stages increased with increasing the time of fumigation treatment. Moreover the highest essential oils toxicity at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (126, 53, and 47 mg/L air) for adult stage and were (79, 62, and 41 mg/L air) for larval stage, respectively in the case of Garlic oil treatment. While, the lowest essential oils effective was Nigella oil at the Median lethal concentration (LC50) values for exposure periods (3, 5 and 7 days) to fumigation were (3594, 629, and 335 mg/L air) for adult stage and were (1040, 416, and 227 mg/L air) for larval stage, respectively. The toxicity effect of various essential oils against adults and larvae of T. castaneum at the LC50at 7 days fumigation could be arranged in descending order as follows: Garlic oil, Chili pepper oil, and Nigella oil. The histological changes showed that the organs slightly affected at the fumigation for 3 days. It may be concluded that the garlic essential oil is the good effective fumigant to control T. castaneum in the stored products and it recommended that the fumigation period does not exceed 3 days. The garlic essential oil has the potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity and its safety.


2021 ◽  
Author(s):  
Zerguine Karima

The family of Chironomidae is a group of Diptera insects belonging to the suborder of Nematocera, commonly called “non-biting midges” in the adult stage and “bloodworms” in the larval stage. The Chironomidae are often the most abundant group of macroinvertebrates, in number of species and individuals, encountered in all aquatic environments of freshwater, brackish, terrestrial and even the sea. Likewise, Chironomidae occur in all the continents. The Chironomidae family is divided into 11 sub-families that have diffrent ecological statues. Despite the wealth of data on Chironomidae in the Holarctic region, other parts of the world are poorly studied and few guides to identifying Chironomidae have been produced. This chapter includes a theoretical synthesis on the Chironomidae, it deals with the Biology (life cycle and description of different stages), description of all subfamilies and the ecology of this important family of Diptera.


2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .


1981 ◽  
Vol 23 (1) ◽  
pp. 151-154 ◽  
Author(s):  
V. R. Rausch ◽  
R. L. Rausch

The chromosomes of Echinococcus multilocularis Leuckart, 1863 have been described, based on components of cells from the adult stage and the larval stage of the cestode. Chromosomal complements of 2n = 18, n = 9 were confirmed. The fundamental number of chromosomal arms was 24. Karyograms are presented, in which the 18 elements are grouped according to arm-ratios and size. An idiogram of G-bands is included.


1969 ◽  
Vol 101 (3) ◽  
pp. 306-313 ◽  
Author(s):  
Charles O. Rexrode

AbstractDuring 1965–67, the seasonal history and habits of two oak bark beetles, Pseudopityophthorus minutissimus (Zimm.) and P. pruinosus (Eichhoff), were studied in 47 oaks, Quercus spp., in southern Ohio.All study trees were attacked and the male beetles made initial entry into the trees. The attack period per tree was usually 1–3 days, and the density of attack varied from 5 to 120 galleries 1 ft2 of surface area. Oviposition began as soon as egg gallery construction began, and the incubation period was about 5 days in the summer. The rate of egg gallery construction was about 0.2 in./day in mid-summer. The average length of the egg galleries was 1.9 cm and the average number of eggs per gallery was 41.5. Over 50% of the parent adults of both species re-emerged after egg gallery construction and oviposition. The re-emerging parent adults can attack, lay eggs, and re-emerge three times. The larval stage can last 25–247 days, the pupal stage 15–139 days, and the adult stage 7–198 days. The beetles can overwinter in every stage but the pupal stage. Spring emergence occurred 29 April in 1966 and 14 April in 1967, and in southern Ohio, two generations and a partial one occur each year.Trap trees were attacked 7–205 days and brood emergence lasted 58–329 days. The beetles can attack one tree three times.


Danaus chrysippus is a danaid butterfly commonly found throughout Africa. It feeds, in its larval stage, on species of milkweed (fam. Asclepiadacae). If the milkweed species has a high cardenolide content, then the larva as well as its pupa and the subsequent adult will be toxic to birds. If, however, the larva has fed on a species of milkweed with little or no cardenolide content, then it will be palatable to birds and so will the pupa and the adult. All the three stages (larval, pupa and adult), whether palatable or not, are subject to attack by birds. The larvae, on the other hand, also act as hosts to a large number of parasitoids. In this paper a theoretical model is described which incorporates the following three assumptions that have been verified experimentally: (i) female butterflies prefer to oviposition the species of plants on which they had developed; (ii) birds are able to distinguish between externally identical larvae from the shape of the plant on which the larvae are feeding; (iii) female parasitoids select, for oviposition, D. chrysippus larvae feeding on plants toxic to vertebrate predators. The simulations using the theoretical model predicts that parasitoids will prefer to lay their eggs in toxic larvae that are less likely to be predated by birds. This predation makes it advantageous for larvae to feed on non-toxic plants. This larval advantage is countered at the adult stage by bird predation. As one type of butterfly becomes too common, the other type will be at an advantage. The polymorphism for palatability is maintained primarily through selection at the larval stage and not by bird predation on the adult butterflies. The experimental data supporting the above assumptions are discussed. Computer simulation predicts the behaviour of birds and parasitoids as it affects the relative frequency of toxic and non-toxic butterflies.


1941 ◽  
Vol 19 (3-4) ◽  
pp. 75-84 ◽  
Author(s):  
P. A. Clapham ◽  
B. G. Peters

Hook dimensions of Multiceps glomeratus show that the hooks are capable of reaching full adult size in the coenurus stage.The available material showed that M. serialis hooks were slightly larger than those of M. glomeratus in the adult stage; in the coenurus stage the differences were not significant.Statistically, the dimensions measuring the length of the blade of the hook are the most satisfactory.There are significantly large variances in most cystic hook dimensions from one cyst to another, and from one scolex to another within a single cyst, but not from one group of scolices to another. It follows that in biometric work it is important to sample several scolices from each cyst, and several cysts of any one species, but that groups can be disregarded.The variability of most hook measurements is in the region of 5%; i.e. the standard deviation is about 5% of the mean dimension.The danger of extensive generalisation from limited data should be guarded against. Thus, while the species variance was significantly larger than the cyst variance in the case of adult hooks in the material available, it is quite possible that this would no longer have been the case if material from other sources had been available.


2017 ◽  
Author(s):  
Jonathon A. Siva-Jothy ◽  
Katy M. Monteith ◽  
Pedro F. Vale

AbstractDeciding where to eat and raise offspring carries important fitness consequences for all animals, especially if foraging, feeding and reproduction increase the risk of exposure to pathogens. In insects with complete metamorphosis, foraging occurs mainly during the larval stage, while oviposition decisions are taken by adult-stage females. Selection for infection avoidance behaviours may therefore be developmentally uncoupled. Using a combination of experimental infections and behavioural choice assays, here we tested if Drosophila melanogaster fruit flies avoid potentially infectious environments at distinct developmental stages. When given conspecific fly carcasses as a food source, larval-stage flies did not discriminate between carcasses that were clean or infected with the pathogenic Drosophila C Virus (DCV), even though scavenging was a viable route of DCV transmission. Adult females however, discriminated between different oviposition sites, laying more eggs near a clean rather than an infectious carcass if they were healthy; DCV-infected females did not discriminate between the two environments. While potentially risky, laying eggs near potentially infectious carcasses was always preferred to sites containing only fly medium. Our findings suggest that infection avoidance can play an important role in how mothers provision their offspring, and underline the need to consider infection avoidance behaviours at multiple life-stages.


2020 ◽  
Vol 12 (3) ◽  
pp. 272-276
Author(s):  
C.S. Oaya

Abstract. Study on the biology of groundnut bruchid, Caryedon serratus Olivier was carried out in the Laboratory of the Department of Agricultural Technology, Adamawa State College of Agriculture, Ganye, Adamawa State from June to September, 2015. The sex of the bruchid (male and female) was assigned the sub-treatment while the period of development was the main treatment and was replicated three times. The work considered the pre-oviposition stage, incubation stage, larval stage, pupal stage, adult stage and the total life cycle of the bruchid (male and female). The experiment was carried out under Laboratory conditions at 30-35°C temperature and 70-90% relative humidity. After the experiment was established, weekly counting of the total number of eggs laid was carried out at intervals. The results showed that, the mean developmental stages in both female and male bruchids were: 6.50 and 6.00 days; 17.00 and 18.00 days; 13.50 and 13.50 days; 12.00 and 13.50 days; 48.00 and 50.00 days for incubation stage, larval stage, pupal stage, adult stage and total life cycle of the bruchids, respectively. Moreover, the mean pre-oviposition and oviposition stages in female adult bruchid were 1.50 and 5.50 days, respectively.


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