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The Chemical Mechanism in Discrimination of Previously Parasitized Hosts by the Egg Parasitoid Aprostocetus Prolixus

Author: WenYanJu
Tutor: LiJiQuan
School: Agricultural University of Hebei
Course: Ecology
Keywords: The mulberry longicorn eggs Tetrastichus Parasitic mulberry longicorn groove Mark pheromone Host recognition Chemical mechanism
CLC: S476.3
Type: Master's thesis
Year: 2011
Downloads: 17
Quote: 0
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Abstract

The mulberry germari (Apriona germari Hope) is our important Boring Beetle the Sang germari eggs Tetrastichus (Aprostocetus prolixus) mulberry longicorn important parasitoid in the egg stage. This article the parasitoid identify the parasitic the mulberry longicorn groove chemical mechanism, which is important for to reveal the mulberry longicorn the eggs Tetrastichus the parasitic mechanism, and the parasitic wasp control Apriona germari harm. In the normal groove with some parasitic groove (parasitized or their parasitic groove) exist at the same time under the conditions, the female wasps first come into contact with the number of times of the normal groove was significantly higher than the parasitic groove (normal - it bee parasitic: P lt; 0.01, normal - own parasitic: P lt; 0.001), time to find a normal groove significantly less than the parasitic groove (normal - it is parasitism: P lt; 0.001, normal - own parasitic: P = 0.008) Table of of Mingsang longicorn eggs Tetrastichus parasitic process one (or some) link on the groove mark this marker at close range Sang germari eggs Tetrastichus perception the parasitic wasps produce aversion to Select normal groove; parasitic wasps in the the normal groove on the search time, the spying on time and parasitism rate is also significantly higher than the parasitic groove (search time: normal - it parasitized P = 0.002, the normal - own parasitic P = 0.006; spying Time: normal - it parasitized (P = 0.006), normal - own parasitic P = 0.008; parasitic rate: normal - it parasitized P lt; 0.01, normal - their own the parasitic P lt; 0.001). Exist in the normal groove and certain parasitic groove, Sang germari eggs Tetrastichus priority parasitic normal groove, to avoid excessive parasitic. When it parasitized and own parasitic groove exist when, the mulberry longicorn eggs Tetrastichus these two have parasitic behavior parameters of the groove was no significant difference between the (exposed to two the number of groove: P gt; 0.05 ; find the groove to the desired time: P = 0.499; Search Time: P = 0.612; spying time: P = 0.310; the parasitic rate: P gt; 0.05) Table Mingsang longicorn eggs Tetrastichus, does not have to distinguish it parasitized groove and their parasitic groove. Non-selective experiments with parasitic groove (it bee or own parasitic groove) compared with the eggs Tetrastichus easier (normal spawning parasitic on the normal groove - Bee: P = 0.024; normal - their own : P = 0.010), which once again proved that the the mulberry longicorn eggs Tetrastichus parasitic process marked groove. Only the face of some kind of parasitic groove when the female wasps through parasitic rate of 56%; in the case of the normal groove alternative has been the parasitic groove parasitic was 14.3%, which indicates that in the presence of normal groove the eggs Tetrastichus also parasitic groove. Select Experiment discovered, egg engages small bee normal engraved groove and there crawling traces groove of the behavior parameters No significant significant difference (normal engraved grooves - there it bee crawling traces groove: groove first is the contact to the number of times, P GT ; 0.05; each groove to find the time required, P = 0.476; searching time, P = 0.931; spying on time, P = 0.420; the parasitism rate P gt; 0.05; the normal grooved - own crawling traces groove: engraved The groove is first come into contact with the number of times, P GT; 0.05; find each groove to the time required, P = 0.931; search time, P = 0.678; spying time, P = 0.859; parasitism rate P GT; 0.05). This indicates that the the eggs Tetrastichus not distinguish between normal groove and groove Description the eggs Tetrastichus during the search (including the tentacles search and ovipositor spying behavior) not marked groove searching by yourself or other individuals. When the mulberry germari eggs Tetrastichus deal with both normal groove and the groove has been parasitic parasitic wasps lay their eggs but not smear each groove first parasitic bees come into contact with the number of times there is no significant difference (P gt ; 0.05), parasitoids time to come into contact with each groove is also no significant difference (P = 0.638), the search time, spying on the two groove and parasitism rate was no significant difference (search time spying on time, P = 0.433, P = 0.538;; parasitism rate, P gt; 0.05), Description the eggs Tetrastichus not recognize normal groove and parasitic but unparasitized the ovipositor smear the groove. Also shows that the parasitic process, parasitic wasps in the groove surface search, spying, the ovipositor Against Apriona egg detection, spawning neither the mulberry longicorn eggs on the surface of the groove and engraved tank marked. Based on the above experimental results can easily find the spawning mark the only smear the mulberry germari eggs Tetrastichus ovipositor groove, this smear physical behavior will not be on the surface of the groove mark, only the chemical marker , i.e. tag pheromone. By non-selective experiments found the the mulberry longicorn eggs Tetrastichus in the normal groove on parasitism rate was significantly higher than were parasitized once, or parasitic twice groove (normal - it is parasitism: P = 0.028; normal - it bee the parasitic twice: P = 0.000), was significantly higher than in a groove is parasitic parasitic parasitic twice the groove (P = 0.013). This indicates that the cumulative surface of the groove, with the increase in the number of groove parasitic labeled pheromone also increased. The number of groove of the for bioassay experiments extract the Sang germari eggs Tetrastichus female bees head, chest, abdomen, come into contact for the first time dropping dichloromethane extract small bee abdomen was significantly less than that of the control groove ( only dropping dichloromethane solvent normal groove) (P lt; 0.05), dropping small bee abdomen dichloromethane extract a groove on the matter of search time was significantly less than that of the control engraved groove (P lt; 0.05) groove, while dropping other solvent extract was no significant difference compared with the control, indicating that the the parasitic wasps mark pheromone comes from the parasitic bee abdomen, and dichloromethane best solvent for the extraction of the parasitic wasps mark prime. GC-MS (gas chromatography - mass spectrometry), the mulberry longicorn eggs Tetrastichus abdomen dichloromethane extract compounds including hydrocarbons, aldehydes, fatty acids, esters and terpenes. 20 hydrocarbons content of 40.55%, and there are three kinds; aldehydes content was 0.32%; containing seven kinds of fatty acid content of 54.96%; ester compound is 2, the content was 3.7%, terpenoids two, the content was 0.18%. Poison sac of the mulberry germari eggs Nie wasp Duchenne gland, venom, ovarian dichloromethane extract biometric experiment, parasitic wasps to find the control groove time was significantly less than the dropping Duchenne groove gland extracts ( P = 0.048), the groove in the the control groove on the search time significantly more than dropping Duchenne gland extracts (P = 0.039), the rate is also higher than in the the control groove on the parasitic dropping Duchenne gland extracts engraved grooves (P lt; 0.001). Parasitic wasps dropping poison sac of venom gland or ovarian extract the the physical groove on the behavior of parameters compared with the control groove no significant differences, suggesting that the Duchenne gland extract eggs Tetrastichus aversion and inhibit spawning, said Ming Sang longicorn the eggs Tetrastichus the mark pheromone from Duchenne gland. Choice experiment found that, the the Sang germari eggs Tetrastichus dropping dichloromethane solvent) in the control groove (parasitic dropping to 10μg tetracosane the groove (P lt; 0.05) was significantly higher than the first time, The number of times of access to the control groove significantly more than the groove dropwise added 10μg of palmitic acid (P-LT; 0.05), and 1μg of palmitic acid and 1μg tetracosane, hexadecane (1μg and 10μg) and heptacosane (1μg and 10μg) of the eggs Tetrastichus host recognition behavior, palmitic acid and tetracosanoic important component for the eggs Tetrastichus mark pheromone.

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