山西农业大学：《普通昆虫学》课程教学资源（专题讲座）Olfactory Systems in Insects Morphology and Function of antennal sensilla

Olfactory Systems in Insects: Morphology and Function of antennal sensilla 闫喜中

Olfactory Systems in Insects: Morphology and Function of antennal sensilla 闫喜中

Olfaction plays a key role in guiding the behavior of most animal species Compared with our knowledge on sensory processing in other sensory systems such as visual and auditory systems,however, olfactory coding and perception is far from being understood

▪ Olfaction plays a key role in guiding the behavior of most animal species. ▪ Compared with our knowledge on sensory processing in other sensory systems such as visual and auditory systems, however, olfactory coding and perception is far from being understood

Insects depend widely on olfactory sense to find food sources,mates,and suitable oviposition sites. Their main olfactory organs are paired antennae Olfactory receptor neurons (ORNs)housed in antennal sensilla detect environmental volatiles,convert external chemical signals into electrical information,and transmit them to the insect'brain

▪ Insects depend widely on olfactory sense to find food sources, mates, and suitable oviposition sites. ▪ Their main olfactory organs are paired antennae ▪ Olfactory receptor neurons (ORNs) housed in antennal sensilla detect environmental volatiles, convert external chemical signals into electrical information, and transmit them to the insect’ brain

General Morphology of the Antenna The antennae have three segments:scape, pedicel,and flagellum S 孕分食66 Coleoptera:Curculionidae anterior view dorsal posterior scape pedicel proximal distal meriston anterior ventral cockroach 5. 10 15202530 flagellum

General Morphology of the Antenna The antennae have three segments: scape, pedicel, and flagellum Coleoptera: Curculionidae cockroach

Table 1.Length,width,and number of segments (Mean SEM)in the antennal flagellum of Z.dixolophella Sex Antennae length(mm) Number of segments Segment length(μm)） Segment width (um) Male (n =32) 7.18±0.04a(6.71-7.57)a 60.87±0.37a(58-65 99.99±0.74a(83.33-116.66) 111.97±1.53a(100-133) Female (n 32) 7.30±0.07a(6.42-8.00 63.62±0.42h(59-68》 89.58±2.56(66.66-100.00) 110.93±1.42a(100.00-116.66) Range in parentheses. Values comparing sexes within the same row followed by the same letter are not significantly different (paired samples t-test,P=0.05). Lepidoptera:Pyralidae Table 1.General characteristies (mean SEM)of the antenna of T.batesi Sex Antennae length No.of Subsegment Subsegment (mm) subsegments length(μm) width(μm) Male 5.38±0.05a 36.25±0.21a 109.52±2.7a 11417±4.2a Female 5.74±0.05l 35.87±0.16a 117.38±2.5b 106.53±3.7a Values comparing sexes within the same row followed by the same letter are not significantly different (P=0.05;t-test).N=32 antennae in each sex. Lepidoptera:Tortricidae

Lepidoptera: Tortricidae Lepidoptera: Pyralidae

the types and distribution of antennal sensilla trichodea Sensilla ( chaetia sensilla(剌) basiconica Sensilla ■ Bohm sensilla ( auriculate sensilla (F) ● coeloconic sensilla(腔锥) campaniformia sensilla ( styloconica Sensilla(栓锥 ■ furcatea Sensilla ( placodea Sensilla(板) ■ Sensilla Cavity(腔) squamiformia Sensilla ( styliform complex sensillum ( Terminal sensory pegs (

the types and distribution of antennal sensilla ▪ trichodea Sensilla (毛) ▪ chaetia sensilla (刺) ▪ basiconica Sensilla (锥 ) ▪ Böhm sensilla () ▪ auriculate sensilla (耳) ▪ coeloconic sensilla (腔锥) ▪ campaniformia sensilla (钟) ▪ styloconica Sensilla (栓锥 ) ▪ furcatea Sensilla (叉) ▪ placodea Sensilla (板) ▪ Sensilla Cavity (腔) ▪ squamiformia Sensilla (鳞 ) ▪ styliform complex sensillum () ▪ Terminal sensory pegs ()

1、trichodea Sensilla The sensilla trichodea were the most numerous sensilla on the antennae,being localized and distributed randomly on all subsegments S.trichodea were hair-shaped,angled about 45'to the antennal surface. They can be divided into two subtypes according to their length:Subtype I(82.19um in length)and Subtype II (39.81um in length),which were present in both males and females (Lepidoptera:Pyralidae) Subtype I is mainly present on male antennae Subtype II is mainly present on female antennae

1、trichodea Sensilla ▪ The sensilla trichodea were the most numerous sensilla on the antennae, being localized and distributed randomly on all subsegments ▪ S. trichodea were hair-shaped，angled about 45′to the antennal surface. ▪ They can be divided into two subtypes according to their length:Subtype I(82.19μm in length) and Subtype II (39.81μm in length),which were present in both males and females (Lepidoptera: Pyralidae). ▪ Subtype I is mainly present on male antennae . Subtype II is mainly present on female antennae

Function: S.trichodea play a major role in sensing mechanical stimuli and in detecting chemical stimuli in insects S.trichodea have been shown to be the olfactory receptors responsible for detecting sex pheromones (host or mate location

Function: ▪ S. trichodea play a major role in sensing mechanical stimuli and in detecting chemical stimuli in insects ▪ S. trichodea have been shown to be the olfactory receptors responsible for detecting sex pheromones （host or mate location）

a trichodea Sensilla ST 5.04 8/2008 Mag Spot WD HV圆P

trichodea Sensilla

2、chaetia sensilla Sensilla chaetica were straight,wide at the base,and blunt (rounded)at the distal end and arose from a distinctive round collar--like socket(自状窝) Sensilla chaetica present on each fagellar segment in both sexes,angle to the antennal surface is larger than S. trichodea about 60'-90

2、chaetia sensilla ▪ Sensilla chaetica were straight, wide at the base, and blunt (rounded) at the distal end and arose from a distinctive round collar-like socket (臼状窝). ▪ Sensilla chaetica present on each fagellar segment in both sexes，angle to the antennal surface is larger than S. trichodea ，about 60′-90′