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A new species of Canon Solovyev, 2014 (Lepidoptera: Limacodidae) from Thailand

Pellinen MJ, Solovyev AV

Zootaxa, 2015 Jun 02;3964(2):294-7.
PMID: 26249438 DOI: 10.11646/zootaxa.3964.2.9

Canon Solovyev is a small genus belonging to the Parasa-complex of Limacacodidae. It is distributed from northern India to the Malayan Peninsula. The genus previously included two species: C. punica (Herrich-Schäffer) from the Indian region and C. eos Solovyev from Nepal. Canon punica is recorded from China (Yunnan), northern Thailand and Malaysia, but specimens from northern Thailand and probably those from China (Yunnan) represent a new species that is described herein: C. sripanae Pellinen and Solovyev, new species. Externally, C. sripanae is similar to other Canon species, but it differs from punica and eos in hindwing color and male genitalia. The moths studied were collected at UV and mixed lights. Genitalia of the male holotype and a male and female paratypes are figured. Nomenclature of this study is based on Solovyev (2014).

Matched MeSH terms: Moths/growth & development
Spray coverage and pest management efficacy of a solid set canopy delivery system in high density apples

Owen-Smith P, Perry R, Wise J, Jamil RZR, Gut L, Sundin G, et al.

Pest Manag Sci, 2019 Nov;75(11):3050-3059.
PMID: 30895726 DOI: 10.1002/ps.5421

BACKGROUND: Air blast sprayers are not optimized for spraying the short statured trees in modern apple orchards, resulting in off target drift and variable coverage. A solid set canopy delivery system (SSCDS) consisting of a microsprayer array distributed throughout the orchard was investigated as a replacement agrochemical application method in this study. SSCDS's have the potential to optimize coverage, rapidly spray applications, and remove the operator and tractor from the orchard.
RESULTS: Air blast and SSCDS applications were compared using water sensitive paper, bioassays, and pest damage assessments. Pest management and coverage were compared using application volumes of 700 and 795 L ha-1 , respectively. In 2013, adaxial coverage measurements showed no difference between the treatments, but air blast sprayers had higher coverage levels on the abaxial surfaces. There were no significant differences in coverage in 2014. Bioassays using Choristoneura rosaceana fed on leaf discs treated by the SSCDS displayed 95.8% mortality in 2013 and 94.2% mortality in 2014, and air blast treated larval mortality was 95% in 2013 and 100% in 2014. Damage evaluations in both years generally showed no significant differences between the air blast plots and the SSCDS plots, but significant differences between the treated plots and untreated control.
CONCLUSIONS: The prototype SSCDS was an effective pest management tool in high density apples, and offered a number of advantages over an air blast. Further engineering and research into coverage optimization would offer producers a novel tool for foliar agrochemical applications. © 2019 Society of Chemical Industry.

Matched MeSH terms: Moths/growth & development
Skin-piercing blood-sucking moths II: Studies on a further 3 adult Calyptra [Calpe] sp. (Lepid., Noctuidae)

Bänziger H

Acta Trop, 1979 Mar;36(1):23-37.
PMID: 35931

1. Of the scarce Calyptra minuticornis, C. orthograpta and C. labilis, 51, 24, and 7 adults, respectively, were observed during some 600 night inspections at over 100 sites in 1965--1967 and 1971--1977. 2. Hitherto biologically completely unknown, and not recorded before in S.E. Asia, the latter two species flew in or near tropical monsoon forests in hilly regions (300--600 m) of N. Thailand (C. orthograpta also N. Laos). C. minuticornis was found in these and in tropical evergreen and semi-evergreen rain forests of S. Thailand and N.W. Malaysia. 3. In N. Thailand the three species were more common at the end of the cool season/start of the hot season and at the start of the rainy season. They were active mainly during the first half of the night 4. Flight and piercing behaviour, alighting, resting, enemies, and the lack of females, were similar to virtually identical with the "classical" skin-piercing blood-sucking C. eustrigata. 5. C. labilis was seen attacking elephant, C. orthograpta also water buffalo and sambar, C. minuticornis also zebu and tapir but not sambar. C. minuticornis settled on man also but did not pierce. 6. Through no piercing of hosts' skin has actually been seen in nature, indirect evidence suggests that the 3 moths are likely to be occasional blood-suckers. They pierced and sucked blood from the author's skin in experiments. 7. Reasons for lack of direct evidence may be: less developed hematophagy, less favoured hosts, lack of easy-to-pierce injured skin (which also trigger the piercing response), different climatic and phytoecological environment, fewer specimens than in the case of C. eustrigata. 8. Field observations and experiments indicate that the closely related, fruit-piercing Oraesia emarginata is not skin-piercing blood-sucking--a habit likely to be exhibited mainly in humid equatorial regions by a few Calyptra only.

Matched MeSH terms: Moths/growth & development
Fulltext Pathogenicity of Nosema sp. (Microsporidia) in the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

Kermani N, Abu-Hassan ZA, Dieng H, Ismail NF, Attia M, Abd Ghani I

PLoS One, 2013;8(5):e62884.
PMID: 23675435 DOI: 10.1371/journal.pone.0062884

Biological control using pathogenic microsporidia could be an alternative to chemical control of the diamondback moth (DBM) Plutella xylostella (Lepidoptera: Plutellidae). The microsporidium Nosema bombycis (NB) is one of the numerous pathogens that can be used in the Integrated Pest Management (IPM) of DBM. However, its pathogenicity or effectiveness can be influenced by various factors, particularly temperature. This study was therefore conducted to investigate the effect of temperature on NB infection of DBM larvae. Second-instar larvae at different doses (spore concentration: 0, 1×10²,1×10³,1×10⁴, and 1×10⁵) at 15°, 20°, 25°, 30° and 35°C and a relative humidity(RH) of 65% and light dark cycle (L:D) of 12∶12. Larval mortality was recorded at 24 h intervals until the larvae had either died or pupated. The results showed that the spore concentration had a significant negative effect on larval survival at all temperatures, although this effect was more pronounced (92%) at 35°C compared with that at 20 and 30°C (≃50%) and 25°C (26%). Histological observations showed that Nosema preferentially infected the adipose tissue and epithelial cells of the midgut, resulting in marked vacuolization of the cytoplasm. These findings suggest that Nosema damaged the midgut epithelial cells. Our results suggest that Nosema had a direct adverse effect on DBM, and could be utilized as an important biopesticide alternative to chemical insecticides in IPM.

Matched MeSH terms: Moths/growth & development
Genetic and biochemical approach for characterization of resistance to Bacillus thuringiensis toxin Cry1Ac in a field population of the diamondback moth, Plutella xylostella

Sayyed AH, Haward R, Herrero S, Ferré J, Wright DJ

Appl Environ Microbiol, 2000 Apr;66(4):1509-16.
PMID: 10742234

Four subpopulations of a Plutella xylostella (L.) strain from Malaysia (F(4) to F(8)) were selected with Bacillus thuringiensis subsp. kurstaki HD-1, Bacillus thuringiensis subsp. aizawai, Cry1Ab, and Cry1Ac, respectively, while a fifth subpopulation was left as unselected (UNSEL-MEL). Bioassays at F(9) found that selection with Cry1Ac, Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai gave resistance ratios of >95, 10, 7, and 3, respectively, compared with UNSEL-MEL (>10,500, 500, >100, and 26, respectively, compared with a susceptible population, ROTH). Resistance to Cry1Ac, Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai in UNSEL-MEL declined significantly by F(9). The Cry1Ac-selected population showed very little cross-resistance to Cry1Ab, B. thuringiensis subsp. kurstaki, and B. thuringiensis subsp. aizawai (5-, 1-, and 4-fold compared with UNSEL-MEL), whereas the Cry1Ab-, B. thuringiensis subsp. kurstaki-, and B. thuringiensis subsp. aizawai-selected populations showed high cross-resistance to Cry1Ac (60-, 100-, and 70-fold). The Cry1Ac-selected population was reselected (F(9) to F(13)) to give a resistance ratio of >2,400 compared with UNSEL-MEL. Binding studies with (125)I-labeled Cry1Ab and Cry1Ac revealed complete lack of binding to brush border membrane vesicles prepared from Cry1Ac-selected larvae (F(15)). Binding was also reduced, although less drastically, in the revertant population, which indicates that a modification in the common binding site of these two toxins was involved in the resistance mechanism in the original population. Reciprocal genetic crosses between Cry1Ac-reselected and ROTH insects indicated that resistance was autosomal and showed incomplete dominance. At the highest dose of Cry1Ac tested, resistance was recessive while at the lowest dose it was almost completely dominant. The F(2) progeny from a backcross of F(1) progeny with ROTH was tested with a concentration of Cry1Ac which would kill 100% of ROTH moths. Eight of the 12 families tested had 60 to 90% mortality, which indicated that more than one allele on separate loci was responsible for resistance to Cry1Ac.

Matched MeSH terms: Moths/growth & development
Genetic and biochemical characterization of field-evolved resistance to Bacillus thuringiensis toxin Cry1Ac in the diamondback moth, Plutella xylostella

Sayyed AH, Raymond B, Ibiza-Palacios MS, Escriche B, Wright DJ

Appl Environ Microbiol, 2004 Dec;70(12):7010-7.
PMID: 15574894

The long-term usefulness of Bacillus thuringiensis Cry toxins, either in sprays or in transgenic crops, may be compromised by the evolution of resistance in target insects. Managing the evolution of resistance to B. thuringiensis toxins requires extensive knowledge about the mechanisms, genetics, and ecology of resistance genes. To date, laboratory-selected populations have provided information on the diverse genetics and mechanisms of resistance to B. thuringiensis, highly resistant field populations being rare. However, the selection pressures on field and laboratory populations are very different and may produce resistance genes with distinct characteristics. In order to better understand the genetics, biochemical mechanisms, and ecology of field-evolved resistance, a diamondback moth (Plutella xylostella) field population (Karak) which had been exposed to intensive spraying with B. thuringiensis subsp. kurstaki was collected from Malaysia. We detected a very high level of resistance to Cry1Ac; high levels of resistance to B. thuringiensis subsp. kurstaki Cry1Aa, Cry1Ab, and Cry1Fa; and a moderate level of resistance to Cry1Ca. The toxicity of Cry1Ja to the Karak population was not significantly different from that to a standard laboratory population (LAB-UK). Notable features of the Karak population were that field-selected resistance to B. thuringiensis subsp. kurstaki did not decline at all in unselected populations over 11 generations in laboratory microcosm experiments and that resistance to Cry1Ac declined only threefold over the same period. This finding may be due to a lack of fitness costs expressed by resistance strains, since such costs can be environmentally dependent and may not occur under ordinary laboratory culture conditions. Alternatively, resistance in the Karak population may have been near fixation, leading to a very slow increase in heterozygosity. Reciprocal genetic crosses between Karak and LAB-UK populations indicated that resistance was autosomal and recessive. At the highest dose of Cry1Ac tested, resistance was completely recessive, while at the lowest dose, it was incompletely dominant. A direct test of monogenic inheritance based on a backcross of F1 progeny with the Karak population suggested that resistance to Cry1Ac was controlled by a single locus. Binding studies with 125I-labeled Cry1Ab and Cry1Ac revealed greatly reduced binding to brush border membrane vesicles prepared from this field population.

Matched MeSH terms: Moths/growth & development