The Chemical Sensilla Of Antenna And Mouth Part Of Rodolia Limbata And Chrysopa Formosa

Rodolia limbata Motschlsky which belongs to Coleoptera:Coccinellidae is the primary predator of Drosicha corpulenta (Kuwana) which belongs to Hemiptera:Coccoidea. The later one has a major negative impact on the growth of economical fruit. Chrysopa formosa Brauer which belongs to Neuroptera:Chrysopidae, disperses in most regions of our country, and acts as an important enemy insect to pests like various types of aphid and scale insect as D.corpulenta and mealywing. The identification of behavior of R.limbata toward D.corpulenta and the microstructure and the ultrastructure, on which part this study mainly focus, of sensillum of head part of R.limbata and C.formosa which served as foraging facility, are studied in this research. Insects applied for research were captured on persimmon trees in Jishan county, Yun Cheng city in 2012 and 2013, tests and observation were carried out in laboratory environment, details included:1.The tendency tests of R.limbata toward volatile odor including the odor of D.corpulenta in their habitat are carried out in April to June in 2012, which are also compared to the result of those carried out in the tests for Harmonia axyridis Pallas, the results showed:the adult of R.limbata displayed significant tendency to larva of D.corpulenta and eggs thereof; the larva of R.limbata showed significant tendency toward female adult of D.corpulenta; H.axyridis showed significant tendency to all the pests in the habitat. All the response of tendency tests of the natural enemies mentioned above was highly related to the density of pests odor, only when the density had reached certain level would the natural enemies show significant tendency.2. The male and female adults and fourth stage larvae of R.limbata were captured in June 2012 and October 2013, and then applied to the observation of microstructure and ultrastructure of the sensillum on the head. The results showed:The antenna of male and female adult R.limbata were both clavicorn and consisted of scape, pedicel and 6 subsegments of flagellum. Three types of sensilla were identified, including sensilla trichoid, sensilla chaetica, and sensilla basiconica, the length and distribution of which are significantly different. Sensilla basiconica are clustered on the 4th to 6th subsegment of flagellum, high density appear especially on the end of the 6th subsegment. Only one type of sensilla styloconica was observed on the labial palp of adult R.limbata, whereas two types on the maxillary palp, on which type Ⅱ appeared in large amount. Dotted bumps and pores were found on the distal part of type Ⅱ, and two bundles of; a subtle pore was on the distal part of type Ⅰ, and one bundle of dendrite could be found within; the trichoid-like structure and micro-trichoid were merely extension of cuticle chitin, and no neurons observed.The antenna of fourth stage larva Rodolia limbata were coniform, they were shorter and consisted of three segments, and on which only sensilla tricoid and sensilla basiconica can be observed in small amount, in the TEM, a thick-wall sensilla trichoid was observed at the base of antenna, at the base of which no neurons were exhibited; a thin-wall sensilla basiconica, at the base of which neurons wrapped by sheath cell, was also observed. Two types of sensilla styloconica were on the maxillary palp and labial palp of larva, and both were short, no dendrites extended within, yet neurons were existed at the base.Significant difference was found in the morphology of the maxillary palp and labial palp between adult and larva of Rodolia limbata, typical sensilla styloconica, however, could be found on both of them. Two types of sensilla styloconica were on the maxillary palp and labial palp of larva of Rodolia limbata, whereas only one type on the labial palp of adult and two types on the maxillary palp.3. The female adults of Chrysopa formosa Brauer were captured in October 2013, and then applied to the observation of microstructure and ultrastructure of the sensillum on the head. The results showed:the antenna of adult Chrysopa formosa Brauer was appeared in long flagelliform, and consisted of scape, pedicel and flagellum, the last one which was consisted of 114 subsegments, the consistence and distribution of sensillum of which were appeared in great similarity, could be extremely long. Sensillum were dispersed on the subsegments in 5 circles, two types of sensilla trichoid, sensilla basiconica, sensilla peg and sensilla chaetiform were found on flagellum, and sensilla short trichoid, sensilla short chaetiform and Bohm bristle were observed on scape and pedicel.Sensilla styloconica, sensilla digital, sensilla short peg, sensilla campaniform and sensilla short trichoid were found on the maxillary palp, while an extra type sensilla coeloconica was found on labial palp. Galea and lacinia were found to be highly ossified, and sensilla trichoid and sensilla basiconica were on the labium.