Biologically active some microorganisms have the potential to suppress mosquito larvae (Culex pipiens, Diptera: Culicidae)

AbstractIn six sites in the Košice Basin we collected 17,520 larvae of 15 mosquito species during the seasons (April–August) of 2010 and 2011. They were: Aedes vexans (Meigen, 1830), Ae. cinereus (Meigen, 1818) [or Ae. rossicus (Dolbeskin, Gorickaja & Mitrofanova, 1930], Ochlerotatus geniculatus (Olivier, 1791), Oc. refiki (Medschid, 1928), Oc. rusticus (Rossi, 1790), Oc. sticticus (Meigen, 1838), Oc. punctor (Kirby, 1837), Oc. cataphylla (Dyar, 1916), Oc. cantans (Meigen, 1818)[or Oc. annulipes (Meigen, 1830)], Oc. communis (De Geer, 1776), Oc. flavescens (Müller, 1764), Oc. leucomelas (Meigen, 1804), Culiseta annulata (Schrank, 1776), Culex pipiens (L., 1758) [or Cx. torrentium (Martini, 1925)] and Anopheles maculipennis s.l. The objective of the present research was to identify the mosquito larvae species diversity and compare their distribution and density in urban and suburban localities of the monitored territory.

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The Regulation of Osmotic Pressure and Chloride Concentration in the Haemolymph of Mosquito Larvae

Journal of Experimental Biology ◽

10.1242/jeb.15.2.235 ◽

1938 ◽

Vol 15 (2) ◽

pp. 235-247 ◽

Cited By ~ 2

Author(s):

V. B. WIGGLESWORTH

Keyword(s):

Aedes Aegypti ◽

Osmotic Pressure ◽

Culex Pipiens ◽

Chloride Concentration ◽

Muscular Activity ◽

Chloride Content ◽

Mosquito Larvae ◽

The Difference ◽

High Concentrations ◽

Anal Papillae

The osmotic pressure of the haemolymph in well-fed larvae of Aedes aegypti and Culex pipiens is equivalent to 0.80-0.89% NaCl. During starvation it falls to 0.70% NaCl. The average chloride content of the haemolymph is equivalent to 0.30% NaCl in Aedes, 0.28% in Culex. The non-chloride fraction can be regulated so that the total osmotic pressure remains relatively constant in spite of wide variations in chloride content. The ability of mosquito larvae to take up chloride from dilute solutions (Koch, 1938) is confirmed. In a balanced salt medium both the chloride and osmotic pressure of the blood remain constant until the concentration of the medium reaches o.65-0.75% NaCl. Above this level a variable excess of chloride enters the larva and the total osmotic pressure rises so that it is always a little greater than that of the external medium. At high concentrations (above about 1.6%) the blood chloride rises excessively and all the larvae die. Comparative experiments show that Aedes aegypti is more efficient than Culex pipiens in absorbing and retaining chloride in dilute media, and Culex is perhaps a little better at keeping chloride out in more concentrated media. This difference accords with the difference in their natural breeding places. The anal papillae become greatly enlarged in media almost free from chloride (functional hypertrophy for chloride uptake (Koch, 1938)) and reduced in more concentrated media. The papillae of Culex are more labile in this respect, but the maximum development occurs in Aedes. The ability of larvae to absorb and retain chloride in dilute media is much reduced if they have been reared in more concentrated media. But after transfer to dilute media they soon recover this ability in spite of the reduction in size of the anal papillae. When the larva is deprived of oxygen, muscular activity causes a rise in the osmotic pressure of the blood from about 0.83 to 1.0 or 1.1% NaCl, and this change is associated with extraction of fluid from the tracheoles. But reasons are given for doubting that the level of fluid in the tracheoles is determined by a direct relation between capillarity and osmotic pressure of the blood.

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Evaluation of the efficiency of some predators of aquatic insects as substitutes to disinsect the incomplete of mosquitoes (Culex pipiens molestus ForskalDiptera: Culicidae): تقييم كفاءة بعض المفترسات من الحشرات المائية كبدائل في مكافحة الأطوار غير الكاملة للبعوض (Culex pipiens molestus ForskalDiptera: Culicidae)

Arab Journal of Sciences & Research Publishing - المجلة العربية للعلوم و نشر الأبحاث ◽

10.26389/ajsrp.g08216 ◽

2016 ◽

Vol 2 (2) ◽

Author(s):

Atallah Fahd Mukhlaf , Zwan Thamer Khudair

Keyword(s):

Biological Control ◽

Vector Control ◽

Aquatic Insects ◽

Culex Pipiens ◽

Research Study ◽

Mosquito Larvae ◽

Control Programs ◽

The Third ◽

Culex Pipiens Molestus

All vector control programs emphasize the use of biological control. Anisops sardea (Notonectidae: Hemiptera) and Orthetrum chrysostigma (Libellulidae: Odonata) were common in freshwater communities in Mosul. They were predators of wing-wing larvae. The effectiveness of predisposition, efficacy of research, Study on predators O. chrysostigma, A. sardea using the incomplete stages of mosquitoes Culex pipiens molestus and Chironomus ninevah in the laboratory. Backbones consumed 9.0, 8.0, 6.7 and 6.7 of the four larval ages respectively and 5.3 virgins within 24 hours while the mantis nestled at the same time 8.7 6.7, 6.3 and 5.3 larvae of the four ages respectively and 3.3 virgins. Both predators preferred the third and fourth stages when faced with all the incomplete stages of the prey. The co-existence and synergy between predators O.chrysostigma and A.sardea increased the effectiveness of predation by 17% together. The number of prey consumed per day increased with increasing density in the predators' Search coefficient for both predators. The Orthetrum chrysostigma preferred the Hamoush larvae to the mosquito larvae while the Anisops sardea preferred mosquito larvae to the Hamoush larvae significantly.

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