Effects of Mild and Low Temperature Incubation on Heat Tolerance in Bombyx mori Embryos
Daisuke Matsuoka,
Katsuhiko Sakamoto
Issue:
Volume 2, Issue 2, June 2018
Pages:
6-9
Received:
28 May 2018
Accepted:
19 June 2018
Published:
12 July 2018
Abstract: Object: For ectothermic insects, thermal tolerance is one of the most essential properties for survival in ambient environments. However, the molecular mechanisms involved in thermal tolerance in the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) have not been fully elucidated. The present study investigated mechanisms that provide heat tolerance in embryos of Bombyx mori. Materials and Methods: Eggs of the bivoltine silkworm strain p50 were exposed to different temperatures, to determine the lethal threshold temperature and to assess the effects of mild and low temperature incubation on tolerance to heat shock and on embryonic protein profiles. Protein levels were measured by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Results: When eggs were exposed to transient heat shock for one hour, the lethal threshold temperature was between 47.0°C and 48.0°C. However, exposure to 40.0°C for four hours, substantially elevated tolerance to the threshold heat shock and simultaneously increased levels of 70 and 27 kDa proteins in eggs, whereas exposure to 35.0°C did not. Exposure to 10.0°C for four hours lowered heat tolerance and did not alter the expression of 70 and 27 kDa proteins. Conclusion: The present findings indicated that hardening silkworm eggs at mild temperatures increases heat tolerance in embryos. To our knowledge this is the first observation of heat hardening in silkworm embryos. These putative heat-shock proteins of 70 and 27 kDa might be involved in the effect of mild temperature hardening on heat tolerance. Cold stress might deprive embryos of energy reserves available for protection against heat damage. Protective mechanisms against heat and cold stress are probably different in this species. Further studies of the molecular mechanisms of heat tolerance should provide insight into the development of novel, high-yield silkworm strains in tropical environments.
Abstract: Object: For ectothermic insects, thermal tolerance is one of the most essential properties for survival in ambient environments. However, the molecular mechanisms involved in thermal tolerance in the silkworm, Bombyx mori L. (Lepidoptera: Bombycidae) have not been fully elucidated. The present study investigated mechanisms that provide heat toleran...
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A Survey of Ectoparasites of Wild Bird Species at Two Gallery Forests Along River Benue at Makurdi Benue State, Nigeria
Stephanie Mdzuami Adelusi,
Isegbe Emmanuel Onah,
Edward Agbo Omudu
Issue:
Volume 2, Issue 2, June 2018
Pages:
10-15
Received:
14 June 2018
Accepted:
28 June 2018
Published:
24 July 2018
Abstract: A survey of ectoparasite species infesting wild birds at two gallery forests in Makurdi was investigated to provide baseline information on the types of ectoparasites infesting wild birds. Birds were trapped from September 2015 to August 2016; a combination of visual examination and dust ruffling technique was used to remove ectoparasites from live birds. Specimens were preserved in labeled vials containing 70% alcohol. The parasites were identified using standard taxonomic keys when viewed under a light microscope. A total of 254 birds were captured out of which, 174 (68.5%) were infested with 1,294 ectoparasites (1,208 lice, 25ticks, 50 mites and 11 flies). The birds had high single infestation 107(42.1%). Ectoparasitic infestation varied significantly between months (F(11, 253)=2.620, P<0.05) and between bird species (F(58, 253)=2.353, P<0.05), with the months of May and June showing higher infestations and at the Mu gallery Forest. The study concludes that there is high prevalence of ectoparasites on wild birds at gallery forests hence making the forests possible reservoir for ectoparasites for domestic birds. The study recommends further studies to determine the effects of parasites on the health of wild birds and possible transmission of parasites from wild to domestic birds.
Abstract: A survey of ectoparasite species infesting wild birds at two gallery forests in Makurdi was investigated to provide baseline information on the types of ectoparasites infesting wild birds. Birds were trapped from September 2015 to August 2016; a combination of visual examination and dust ruffling technique was used to remove ectoparasites from live...
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Predator Ants of the Date Palm Termite Microcerotermes diversus Silvestri and Effects of ant Morphometric Characteristics on ant Functional Response
Masoud Latifian,
Behzad Habibpour,
Brad Kard
Issue:
Volume 2, Issue 2, June 2018
Pages:
16-22
Received:
25 August 2018
Accepted:
5 September 2018
Published:
4 October 2018
Abstract: Scouting for formicidae presence in Microcerotermes diversus galleries was conducted from March to September 2014 in 10 date palm trees located in the Omaltomire region of Khuzestan Province, Iran. Measurements and morphological observations were made of 20 ant workers. For the in vitro predation test, M. diversus nymphs (n = 10 per replicate) were placed in a petri dish. Then, live freshly field-collected worker of ants were added. After 24 h, the number termite nymphs that were fully or partially devoured was determined. Five ants, including Plagiolepis pallescens, Polyrhachis lacteipennis, Pheidole teneriffana, Crematogaster antaris, and Monomorium destructor were predators of termites in date palm orchards. P. lacteipennis and P. teneriffana, and P. pallescens, C. antaris, and M. destructor, showed Type II and Type III functional responses, respectively. The highest predation efficiency, and the lowest handing time coupled with the highest attack rate by predators was recorded for P. lacteipennis and P. teneriffana, and C. antaris and M. destructor, respectively. Predator ant characteristics measured include: HL-Head length; HW-head width; SL-scape length; EL-eye length; PW-pronotal width; WL-thorax length; GL-gaster length; TL-total length; FL-femur length. HL, HW, SL, EL and FL showed positive effects on the functional response parameters. Results showed that termite defense capabilities declined with increasing of ant predation efficiency.
Abstract: Scouting for formicidae presence in Microcerotermes diversus galleries was conducted from March to September 2014 in 10 date palm trees located in the Omaltomire region of Khuzestan Province, Iran. Measurements and morphological observations were made of 20 ant workers. For the in vitro predation test, M. diversus nymphs (n = 10 per replicate) were...
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