scholarly journals Trophic eggs compensate for poor offspring feeding capacity in a subsocial burrower bug

2010 ◽  
Vol 7 (2) ◽  
pp. 194-196 ◽  
Author(s):  
Narumi Baba ◽  
Mantaro Hironaka ◽  
Takahiro Hosokawa ◽  
Hiromi Mukai ◽  
Shintaro Nomakuchi ◽  
...  
Keyword(s):  
Maternal Investment ◽  
Evolutionary Origin ◽  
Intact Seed ◽  
Physiological Constraints ◽  
First Instar ◽  
Important Constraint ◽  
Trophic Eggs ◽  
Almost All

Various animals produce inviable eggs or egg-like structures called trophic eggs, which are presumed to be an extended maternal investment for the offspring. However, there is little knowledge about the ecological or physiological constraints associated with their evolutionary origin. Trophic eggs of the seminivorous subsocial burrower bug ( Canthophorus niveimarginatus ) have some unique characteristics. Trophic eggs are obligate for nymphal survival, and first-instar nymphs die without them. To identify the cause of nymphal death, we hypothesized that first-instar nymphs starve to death because they cannot feed on anything but trophic eggs. Although first-instar nymphs fed on artificially exposed endosperm did survive, nymphs that were provided with intact seed were not able to penetrate the seed vessel and starved to death. Another hypothesis that trophic eggs play a role in transferring the midgut symbiont, essential for survival in heteropteran bugs, from mother to offspring was rejected because almost all nymphs had retained the symbiont without feeding on trophic eggs. These results suggest that poor feeding capacity of the offspring is the cause of nymphal death, and the important constraint that promotes the evolution of the curious trophic egg system in C. niveimarginatus .

Egg size and taxon: their influence on survival and development of chrysopid hatchlings after food and water deprivation

1991 ◽  
Vol 69 (10) ◽  
pp. 2644-2650 ◽  
Author(s):  
Catherine A. Tauber ◽  
Maurice J. Tauber ◽  
Michael J. Tauber
Keyword(s):  
Life History ◽  
Water Deprivation ◽  
Egg Size ◽  
Maternal Investment ◽  
Developmental Rate ◽  
Life History Variation ◽  
Larval Size ◽  
First Instar ◽  
Survival And Development ◽  
Phylogenetic Lineages

Genus- and species-level differences characterize the pattern of life-history variation in two distinct phylogenetic lineages of chrysopids, Chrysopa and Chrysoperla. Species in the genus Chrysopa exhibit significant variation in egg size, and this variation is positively correlated with the ability of hatchlings to withstand periods of food and water deprivation prior to their initial feeding. The variation is also significantly correlated with larval size, as measured by the tibial length of first-instar larvae. Although the six Chrysopa species differ in several other life-history traits (i.e, the incubation period and rate of first-instar larval development), the variation is unrelated to egg size. It appears that maternal allocation of resources to eggs largely serves to enhance embryonic growth and the survival of hatchlings during searching. That is, within the Chrysopa lineage egg size varies; larger eggs yield larger, more robust hatchlings. These hatchlings may or may not develop faster than congeners from small eggs. In comparison with Chrysopa, the genus Chrysoperla has less variability in egg size and developmental rate. Furthermore, although Chrysoperla eggs are relatively small, the ability of hatchlings to endure periods of food or water deprivation is at least as great as it is in the Chrysopa species with large eggs. We conclude that maternal investment in larval fitness has different ontogenetic pathways, ecological roles, and phylogenetic histories in the two genera.

Impact of parasitism by larval Limnochares aquatica (Acari: Hydrachnidia; Limnocharidae) on juvenile Gerris comatus, Gerris alacris, and Gerris buenoi (Insecta: Hemiptera; Gerridae)

1989 ◽  
Vol 67 (9) ◽  
pp. 2238-2243 ◽  
Author(s):  
Bruce P. Smith
Keyword(s):  
Age Structure ◽  
Natural Populations ◽  
Fourth Instar ◽  
The Other ◽  
Water Striders ◽  
First Instar ◽  
Almost All ◽  
Host Parasite

Laboratory-reared first-instar juvenile Gerris comatus Drake &Hottes, Gerris alacris Hussey, and Gerris buenoi Kirkaldy were exposed to larval Limnochares aquatica (L.). Development and mortality of parasitized juvenile water striders were monitored and compared with those of unparasitized insects. Duration of infestation was from 6 to 13 days during which surviving hosts moulted several times, with engorging larvae transferring to the teneral host during the moulting process. Most mites dropped off the host during the host's second instar, and all mites were off the host by the host's fourth instar. Parasitism by larval mites significantly increased mortality, duration of instars, and variance in age at first moult for parasitized water striders. Mortality and duration of first instars were directly correlated with number of mites per host. Parasite-induced mortality was not evident until 2 days after attachment of mites, and almost all mortality occurred within the host's first instar. Gerris comatus and G. alacris apparently did not differ in response to parasitism; however, G. buenoi showed greater mortality than the other gerrid species when carrying comparable numbers of mites. The effects of parasitism on juvenile water striders within natural populations are predicted to be severe, and would reduce recruitment while also increasing variation in age structure.

PHOSPHOMONOESTERASE ACTIVITY IN THE LIFE-CYCLE STAGES OF SCHISTOCERCA GREGARIA

1968 ◽  
Vol 100 (6) ◽  
pp. 649-655 ◽  
Author(s):  
S. N. H. Naqvi ◽  
Shahid H. Ashrafi ◽  
M. A. H. Qadri
Keyword(s):  
Alkaline Phosphatase ◽  
Acid Phosphatase ◽  
Embryonic Development ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
Schistocerca Gregaria ◽  
Adult Males ◽  
First Instar ◽  
Almost All

AbstractThe acid and alkaline phosphatase activity was measured in the developing egg and in the alimentary canal of aging nymphs as well as adult males and females of different ages. Para-nitrophenol was used as colorimetric standard and disodium p-nitrophenyl phosphate as substrate. Activity was measured in terms of micromoles of p-nitrophenol liberated from the substrate as a result of enzyme action.Acid phosphatase activity was noticed to increase with the embryonic development and was higher than in the case of alkaline phosphatase. The alkaline phosphatase activity was lowest in the freshly laid egg, but increased more sharply than acid phosphatase during embryonic development.The activity of both the acid and alkaline phosphatases was highest in the first instar and declined gradually to the fifth instar. The activity of acid phosphatase was higher than alkaline phosphatase in all stages except the first instar where it was almost equal. The activity of both the enzymes was higher during the intermoulting period and declined at each moult indicating a hormone–enzyme relationship.In adults, activity of both the enzymes increased up to the maturation period after which the activity gradually decreased. Acid phosphatase activity was generally higher in males whereas alkaline phosphatase activity was generally higher in females. In almost all cases, the acid phosphatase activity was found to be higher than the alkaline phosphatase.

scholarly journals Direct Silk Applications of Corn Oil and Bacillus thuringiensis as a Barrier to Corn Earworm Larvae in Sweet Corn

2003 ◽  
Vol 13 (3) ◽  
pp. 509-514 ◽  
Author(s):  
Rosalind Cook ◽  
Anne Carter ◽  
Pam Westgate ◽  
Ruth Hazzard
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Sweet Corn ◽  
Corn Oil ◽  
Field Studies ◽  
Corn Earworm ◽  
Untreated Plot ◽  
Promising Alternative ◽  
First Instar ◽  
Almost All

Field studies were conducted in 2000 and 2001 to rate the efficacy and longevity of four pesticide treatments against corn earworm (Helicoverpa zea) larvae (CEW) in sweet corn (Zea mays). The four treatments used were 1) corn oil, 2) Bacillus thuringiensis ssp. kurstaki (Bt), 3) oil + Bt, and 4) an untreated plot. All treatments were applied on silk day 5. Silk day 1 was the first day that more than 50% of the ears had 2.5 cm (1 inch) or more silks emerging from the husk using a hand-held pump applicator. Two first-instar CEW larvae were placed directly into silk channel of selected ears on 6 different days (days 3, 6, 9, 12, 15, and 18 after first silk). The same six ears were then harvested 4 days later. Untreated ears had more live CEW and higher levels of feeding damage than the other three treatments ears for all harvest days in both years. The number of CEW found per ear was lower when Bt was included in the treatment. The use of corn oil gave the lowest damage ratings on almost all harvest days in both years. Treatments which contained oil had the highest number of marketable ears in both years, but also the highest percentage of underdeveloped kernels at the tip of the ear (6% to 9%). The oil and Bt treatments appeared to control CEW for at least 17 days, from silking through maturity. This treatment regime appears to be a promising alternative for growers to conventional pest management methods.

scholarly journals Checklist of the Myriapoda in Cretaceous Burmese amber and a correction of the Myriapoda identified by Zhang (2017)

Check List ◽  
2018 ◽  
Vol 14 (6) ◽  
pp. 1131-1140 ◽  
Author(s):  
Thomas Wesener ◽  
Leif Moritz
Keyword(s):  
Fossil Record ◽  
Burmese Amber ◽  
First Instar ◽  
Almost All

An inventory of the Myriapoda (Diplopoda, Chilopoda, Symphyla) from Cretaceous Burmese amber, Myanmar, is presented, including the oldest and/or first fossil record for numerous orders. For millipedes (Diplopoda) 527 records, including 460 new specimens determined by us, belonging to 13 of 16 recent orders are listed: Polyxenida, Glomeri­desmida, Glomerida, Siphonophorida, Polyzoniida, Platydesmida, Siphoniulida, Chordeumatida, Polydesmida, Stemmiulida, Callipodida, Spirostreptida and Spirobolida. For centipedes, 33 records for 4 of the 5 recent orders are listed: Scutigero­morpha, Lithobiomorpha, Scolopendromorpha and Geophilomorpha. For Symphyla, three records for both families, Scutigerellidae and Scolopendrellidae, are listed. The majority of Diplopoda records (30.5%) are Polydesmida. The record of the Polyzoniida includes first instar octopod juveniles. The checklist includes the first fossil representatives known of the Platydesmida, as well as the oldest known fossils of the Polyxenida, Glomeridesmida, Glomerida, Siphono­phorida, Polyzoniida, Siphoniulida, Spirostreptida, as well as both Symphyla families. Misidentifications by Zhang (2017) are corrected; while most Chilopoda in that list are correct, almost all Diplopoda are misidentified.

Desiccation resistance in pre-diapause, diapause and post-diapause larvae of Choristoneura fumiferana (Lepidoptera: Tortricidae)

2001 ◽  
Vol 91 (5) ◽  
pp. 321-326 ◽  
Author(s):  
É Bauce ◽  
E. Han
Keyword(s):  
Water Content ◽  
Freeze Drying ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Water Evaporation ◽  
Desiccation Resistance ◽  
First Instar ◽  
Access To Water ◽  
Almost All

AbstractDesiccation resistance was examined in pre-diapause, diapause and post-diapause larvae of the spruce budworm, Choristoneura fumiferana (Clemens), in terms of passive water evaporation under three desiccation conditions: freeze-drying, desiccant-drying at 2°C and desiccant-drying 18°C. Diapausing second instar larvae and post-diapause non-feeding second instar larvae showed strongest desiccation resistance: a significant amount of water was retained after repeated drying under desiccating conditions, while pre-diapause first instar larvae and post-diapause feeding instar larvae lost almost all their water content after one or two drying cycles. A hibernaculum covering had no effect on water evaporation. While dead larvae tended to lose significantly more water than their living counterparts, particularly among first instar larvae, such an impact much weaker among diapausing second instar larvae. Desiccation resistance was lost when post-diapause second instar larvae were allowed access to water while the level of desiccation resistance was maintained or enhanced when the larvae did not have access to water. These results are discussed the context of overwintering ecology of the species and possible mechanisms for the desiccation resistance are also discussed.

scholarly journals How bean weevil (Acanthoscelides obtectus, Coleoptera, Bruchinae) larvae die on legume seeds

2020 ◽  
Author(s):  
Árpád Szentesi
Keyword(s):  
Larval Development ◽  
Seed Coat ◽  
Oviposition Preference ◽  
Larval Performance ◽  
Bean Weevil ◽  
Acanthoscelides Obtectus ◽  
Intact Seed ◽  
First Instar ◽  
Choice Tests ◽  
Seed Coats

Abstract BackgroundThe host specificity and the range of possible wild and cultivated hosts of the dry bean weevil, Acanthoscelides obtectus (Coleoptera, Chrysomelidae, Bruchinae), a seed predator of beans, is poorly known. In addition, female oviposition preference and larval performance relationship is complicated by the respective importance of seed coat and cotyledon, because, on the one hand, paradoxically, females lay eggs on the basis of stimuli of the seed coat alone, without directly being able to assess the quality of cotyledon’s suitability for larval development. On the other, the thickness of seed coat may prevent first instar larvae from entering the seeds, even if cotyledons were suitable for development.ResultsThe seeds of 62 leguminous species and 82 accessions occurring in Hungary were tested in no-choice tests for egg-laying. The ability of first instar larvae to overcome seed coat, as a physical barrier, was measured with intact seed coat, whereas drilled seed coats allowed assessing the suitability of cotyledon for development. Seeds of 18 species (35% of them Lathyrus) supported larval development to adults, if the seed coat was drilled, however, only nine produced adults, if the seed coat was intact. Seed coats thicker than 0.1 mm could be an obstacle for first instar larvae. There was no overall positive correlation between oviposition preference and larval performance, with the exception of 16 so-called acceptable non-hosts (Kendall’s τ = 0.3088). Bean weevil females also demonstrated an ovipositional hierarchy of legume species even in no-choice tests.ConclusionsResults demonstrate that whereas the use of some acceptable non-host species by the bean weevil is possible in seed stores, the same is unlikely under outdoor conditions, because it requires the recognition of basically different oviposition substrates (pods).

Habitat Association of Klebsiella Species

1985 ◽  
Vol 6 (2) ◽  
pp. 52-58 ◽  
Author(s):  
Susan T. Bagley
Keyword(s):  
Drinking Water ◽  
Gastrointestinal Tract ◽  
Surface Waters ◽  
Industrial Effluents ◽  
Opportunistic Pathogen ◽  
Habitat Associations ◽  
Habitat Association ◽  
Klebsiella Species ◽  
Almost All ◽  
Polluted Waters

AbstractThe genus Klebsiella is seemingly ubiquitous in terms of its habitat associations. Klebsiella is a common opportunistic pathogen for humans and other animals, as well as being resident or transient flora (particularly in the gastrointestinal tract). Other habitats include sewage, drinking water, soils, surface waters, industrial effluents, and vegetation. Until recently, almost all these Klebsiella have been identified as one species, ie, K. pneumoniae. However, phenotypic and genotypic studies have shown that “K. pneumoniae” actually consists of at least four species, all with distinct characteristics and habitats. General habitat associations of Klebsiella species are as follows: K. pneumoniae—humans, animals, sewage, and polluted waters and soils; K. oxytoca—frequent association with most habitats; K. terrigena— unpolluted surface waters and soils, drinking water, and vegetation; K. planticola—sewage, polluted surface waters, soils, and vegetation; and K. ozaenae/K. rhinoscleromatis—infrequently detected (primarily with humans).

SEM Cold Stage Techniques for the Observation of Vegetative and Floral Apices of Oat (Avena sativa L.) Plants

1977 ◽  
Vol 35 ◽  
pp. 590-591
Author(s):  
B. K. Kirchoff ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Critical Point ◽  
Avena Sativa ◽  
Substantial Improvement ◽  
Fresh Tissue ◽  
Cold Stage ◽  
Critical Point Drying ◽  
Almost All ◽  
Cell Collapse ◽  
Conductive Paint ◽  
Carbon Based

In attempting to use the SEM to investigate the transition from the vegetative to the floral state in oat (Avena sativa L.) it was discovered that the procedures of fixation and critical point drying (CPD), and fresh tissue examination of the specimens gave unsatisfactory results. In most cases, by using these techniques, cells of the tissue were collapsed or otherwise visibly distorted. Figure 1 shows the results of fixation with 4.5% formaldehyde-gluteraldehyde followed by CPD. Almost all cellular detail has been obscured by the resulting shrinkage distortions. The larger cracks seen on the left of the picture may be due to dissection damage, rather than CPD. The results of observation of fresh tissue are seen in Fig. 2. Although there is a substantial improvement over CPD, some cell collapse still occurs.Due to these difficulties, it was decided to experiment with cold stage techniques. The specimens to be observed were dissected out and attached to the sample stub using a carbon based conductive paint in acetone.

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