Planotortrix Excessana Research Articles

Sex pheromone biosynthesis in the leafroller moth Planotortix excessana by Δ10 desaturation

AbstractWith the use of deuterium‐labeled saturated fatty acids coupled with gas chromatography‐mass spectrometric analysis, biosynthesis of the sex pheromone component (Z)‐8‐tetradecenyl acetate in the greenheaded leafroller moth Planotortrix excessana was shown to proceed via Δ10 desaturation of palmitate. The resultant (Z)‐10‐hexadecenoate is two carbon chain‐shortened to the precursor (Z)‐8‐tetradecenoate. The minor component (Z)‐10‐tetradecenyl acetate is biosynthesized by Δ10 desaturation of myristate. This is the first confirmation of Δ10 desaturation in an eukaryotic system.

Sex pheromone ofPlanotortrix species found on mangrove

(Z)-5-Tetradecenyl acetate and tetradecyl acetate were identified as sex pheromone components of an unnamedPlanotortrix leafroller moth species found onAvicennia resinifera (mangrove). An equal mixture of the two compounds used as bait gave field trap catches at least as good as those baited with caged virgin females. Traps baited with the two chemicals caught malePlanotortrix moths in a mangrove swamp not previously found to host the unnamedPlanotortrix species. Adults of the unnamedPlanotortrix species and of the greenheaded leafroller,Planotortrix excessana are morphologically indistinguishable. The sex pheromone ofP. excessana has been found previously to be a mixture of (Z)-S-tetradecenyl acetate and tetradecyl acetate, and this means that the two species may now be distinguished by sex pheromone differences.

Identity of a microsporidium from three New Zealand pasture insects: Costelytra zealandica (Coleoptera, scarabeidae), Wiseana spp. (Lepidoptera, Hepialidae), and Listronotus bonariensis (Coleoptera, Curculionidae)

The life cycles of multisporous microsporidia isolated from grass grubs ( Costelytra zealandica), porina ( Wiseana spp.), and Argentine stem weevils ( Listronotus bonariensis) are investigated by light and electron microscopic examination of laboratory-reared and -infected specimens. Each microsporidian isolate is cross-infectious to each host insect, as well as to laboratory-reared larvae of Planotortrix excessana (Lepidoptera, Tortricidae). Comparison with live material of Pleistophora oncoperae (Microsporida, Pleistophoridae), collected from Oncopera alboguttata (Lepidoptera, Hepialidae) in Australia, indicates that these isolates are synonymous with P. oncoperae. Ultrastructural features suggest that this species should be transferred to the genus Vavraia.

Use of traps for monitoring adult leafrollers in apple orchards

Abstract Port wine bait traps placed in Canterbury apple orchards caught leafrollers, trapping more female than male moths (with the extent of this difference varying with species). Most of the trapped females had mated, as shown by the presence of spermatophores in their bursa copulatrix. Mating frequency was related to moth population density and species. At lower population densities, mating was reduced. Greenheaded leafroller (Planotortrix excessana (Walker)) females mated more frequently than either brownheaded leafroller (Ctenopseustis obliquana (Walker)) or lightbrown apple moth (Epiphyas postvittana (Walker)) (LBAM) females. By comparison, an increase in pheromone trap catches of LBAM coincided with the beginning of oviposition by each flight. Bait trap catches were low during the second flight in January and February, whereas pheromone trap catches of the third LBAM flight were reduced (possibly by competition from the greater numbers of female moths present). A significant relationship between t...

Laboratory colonisation ofPlanotortrix excessanaon artificial diet

Abstract Greenheaded leafrollers, Planotortrix excessana (Lepidoptera: Tortricidae) were reared for eight consecutive generations (total of 74 000 insects) on an artificial diet containing raspberry leaf powder. At 18± 1°C, 60 ± 5% RH and 18: 6 h L: D cycle (for eggs, larva, and pupa; 24 h dark for adults), the average life cycle parameters were as follows. Egg development, 11 days; larval period, ♂ 48, ♀ 54 days; pupal period, ♂ ♀ 18 days; adult life span, ♂ 20, ♀ 18 days; 90% eggs laid in 10 days; pupal wt, ♂ 40, ♀ 48 mg; survival from established neonate larva to adult 84%. This species is now in continuous culture and is currently in the sixteenth generation.

Toxicity of insecticides toEpiphyas postvittana(Walker) andPlanotortrix excessana(Walker) (Lepidoptera: Tortricidae)

Abstract The responses of Epiphyas postvittana and Planotortrix excessana (Lepidoptera: Tortricidae) larvae to insecticides were compared using three laboratory methods: topical application, direct application, and exposure to residues. The order of toxicity was fenvalerate > chlorpyrifos > azinphos-methyl > phosmet for topically applied insecticides on E. postvittana, and fenvalerate > azinphos-methyl for P. excessana. For technical grade insecticides applied to first instar E. postvittana larvae in a Potter tower, the order of toxicity was deltamethrin > cypermethrin > fenvalerate > permethrin > azinphos-methyl > triazophos > chlorpyrifos > azinphos-ethyl > phosmet > carbaryl > etrimphos > DDD. Against first-instar P. excessana larvae, with the same method, the order of toxicity was cypermethrin > fenvalerate > azinphos-methyl > chlorpyrifos > phosmet > carbaryl. After exposure of first-instar E. postvittana and P. excessana to residues, the order of toxicity was deltamethrin > chlorpyrifos > cypermethr...

Sex pheromone precursors in two primitive New Zealand tortricid moth species

Female pheromone gland extracts of two primitive New Zealand tortricid species that use (Z)-8- tetradecenyl acetate as a pheromone component were analyzed for pheromone precursors. Both Planotortrix excessana and Ctenopseustis obliquana contained (Z)-8- tetradecenoate as well as large amounts of (Z)-10- hexadecenoate . We propose that (Z)-8- tetradecenyl acetate is synthesized from hexadecanoate (palmitic acid) by an unusual Δ10 desaturation, chain shortening and subsequent reduction and acetylation. A Δ11 enzyme is used for sex pheromone biosynthesis in most of the Tortricinae species for which pheromone identifications have been reported.

Leafrollers (Lepidoptera: Tortricidae) in a strawberry crop in Horowhenua: abundance and control

Abstract Three species of leafrollers (Ctenopseustis obliquana, Epiphyas postvittana, and Planotortrix excessana) were found to be common on strawberries in Levin. During 1979–80 P. excessana was the most abundant species except for a short period in mid-summer when E. postvittana predominated. Larvae were active throughout the year, peak numbers being obtained in the March-May and July-September periods. A chemical control trial showed that early application of endosulfan, followed by regular treatments with dichlorvos throughout the growing season, reduced leafroller larval numbers to low levels. A spray programme which included two early season endosulfan applications and also the acaricide, cyhexatin, throughout the growing season, gave the best results.