scholarly journals Abundance, seasonality and parasitism of Diaspididae (Hemiptera) on olive trees

2019 ◽  
Vol 25 (1/2) ◽  
pp. 85-93
Author(s):  
Gabriela Chesim De Souza ◽  
Luiza Rodrigues Redaelli ◽  
Vera Regina dos Santos Wolff
Keyword(s):  
Outer Part ◽  
Scale Insects ◽  
Rio Grande Do Sul ◽  
Parasitism Rate ◽  
Temperature Variations ◽  
Armored Scale ◽  
Aspidiotus Nerii ◽  
Recent Activity ◽  
Olive Trees ◽  
Total Parasitism

Olive culture is a recent activity in Rio Grande do Sul, Brazil with little information on its scale insects. Abundance and seasonality of armored scale insects (Hemiptera, Diaspididae) and their parasitism was evaluated in olive orchard, Olea europaea L., cultivar Arbequina, in Caçapava do Sul (30°30′43″ S, 53°29′27″ W), RS, Brazil. Samples were monthly collected from April 2012 to March 2013. At each occasion 20 trees were drawn and, from each quadrant of their canopies (northern, southern, eastern and western) two branches (20 - 30 cm - length and contained at least 20 leaves) were randomly removed, respectively from the inner part and the outer part of the canopy. We found five species of Diaspididae, Aonidiella aurantii (Maskell), Hemiberlesia cyanophylli (Signoret), Acutaspis paulista (Hempel), Aspidiotus nerii Bouché and Melanaspis obscura (Comstock). It was not found an unique pattern of abundance, indicating that these species respond differently to temperature variations between seasons. The armored scale insects were evenly distributed among quadrants. Only H. cyanophylli showed differences in abundance between the inner and outer branches. We registered parasitism in all Diaspididae species; the total parasitism rate was 9.78%.

scholarly journals Suitability of Five Horticulturally Important Armored Scale Insects as Hosts for an Exotic Predaceous Lady Beetle1

1993 ◽  
Vol 11 (1) ◽  
pp. 28-30 ◽  
Author(s):  
Brenda C. Bull ◽  
Michael J. Raupp ◽  
Mark R. Hardin ◽  
Clifford S. Sadof
Keyword(s):  
Pupal Stage ◽  
The United States ◽  
Scale Insects ◽  
Armored Scale ◽  
Aspidiotus Nerii ◽  
Pseudaulacaspis Pentagona ◽  
Chilocorus Kuwanae ◽  
San Jose Scale ◽  
White Peach Scale ◽  
Euonymus Scale

Abstract Chilocorus kuwanae (Sylvestri) was imported from Korea to the United States for release against the euonymus scale (Unaspis euonymi (Comstock)). Field observations suggest that C. kuwanae feeds on a number of other armored scale insects, including white peach scale (Pseudaulacaspis pentagona (Targionni-Tozzeti)) and obscure scale (Melanaspis obscura (Comstock)). However, such observations have not been rigorously examined under controlled conditions. Our laboratory investigations indicate that C. kuwanae survives and reproduces well on San Jose scale (Quadraspidiotus perniciosus (Comstock)), in addition to euonymus scale. Fecundity was reduced in adults fed white peach scale. Few larvae survived to adulthood when fed oleander scale (Aspidiotus nerii (Bouche)). Adults failed to reproduce on obscure scale; none of the larvae fed this host survived to the pupal stage.

scholarly journals Efficacy of Horticultural Oil and Insecticidal Soap against Selected Armored and Soft Scales

2017 ◽  
Vol 27 (5) ◽  
pp. 618-624 ◽  
Author(s):  
Carlos R. Quesada ◽  
Clifford S. Sadof
Keyword(s):  
Insect Pests ◽  
Chemical Properties ◽  
Scale Insects ◽  
Effective Management ◽  
Pine Needle ◽  
Soft Scale ◽  
Armored Scale ◽  
Aspidiotus Nerii ◽  
High Control ◽  
Calico Scale

Insecticidal soap and horticultural oil have the potential to kill individuals within populations of soft-bodied insect pests by suffocation. However, scientific literature is inconsistent about the efficacy of insecticidal soaps and petroleum-based oils against armored scale (Hemiptera: Diaspidae) and soft scale (Hemiptera: Coccidae). We examined the efficacy of horticultural oil and insecticidal soap against armored and soft scales at different developmental life stages. Studies were conducted in the laboratory and field with two species of armored scale [pine needle scale (Chionaspis pinifoliae) and oleander scale (Aspidiotus nerii)] and two species of soft scale [calico scale (Eulecanium cerasorium) and striped pine scale (Toumeylla pini)]. All insecticide applications were made at a rate of 2 gal per 100 gal water. Our laboratory results suggested that horticultural oil and insecticidal soap killed both calico scale (73% and 93%, respectively) and oleander scale (67% and 78%, respectively) when insecticides targeted 1-day-old scales. Scale insects built up tolerance to both materials over time after they settled. However, our field data indicated that horticultural oil had high control of settled armored scale [oleander scale (90%) and pine needle scale (83%)], but failed to control settled soft scale [stripe pine scale (5%)]. Insecticidal soap reduced armored scale [oleander scale (54%)]. Neither horticultural oil nor insecticidal soap significantly reduced populations of adult armored or soft scales compared with a control. Overall, horticultural oil killed a greater percentage of armored scales than soft scales, whereas insecticidal soap gave greater control against soft scales. We suggest that differences were driven by chemical properties of both insect integuments and insecticides. The waxy cover of an armored scale might reduce penetration of polar insecticidal soap whereas polar integument of a soft scale might impede infiltration of the lipophilic horticultural oil. Consequently, timing application to crawler stage is important for effective management of armored or soft scale with horticultural oils and insecticidal soaps.

scholarly journals Biological Control of Armored Scale Insects in Mexico

1968 ◽  
Vol 61 (4) ◽  
pp. 1086-1088 ◽  
Author(s):  
H. L. Maltby ◽  
Eteazar Jimenez-Jimenez ◽  
Paul DeBach
Keyword(s):  
Biological Control ◽  
Scale Insects ◽  
Armored Scale

scholarly journals A mutualism without honeydew: what benefits forMelissotarsus emeryiants and armored scale insects (Diaspididae)?

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3599 ◽  
Author(s):  
Christian Peeters ◽  
Imre Foldi ◽  
Danièle Matile-Ferrero ◽  
Brian L. Fisher
Keyword(s):  
Building Material ◽  
Malpighian Tubules ◽  
Host Tree ◽  
Scale Insects ◽  
Suitable Host ◽  
Free Living ◽  
Armored Scale ◽  
Plant Hosts ◽  
Armoured Scale Insects ◽  
Harmful Effects

Mutualisms between ants and sap-sucking insects generally involve clear benefits for both partners: the ants provide protection in exchange for honeydew. However, a single ant genus associates with armoured scale insects (Diaspididae) that do not excrete honeydew. We studied three colonies ofMelissotarsus emeryiants from two localities in Mozambique. Vast numbers of the diaspididMorganella conspicuaoccupied galleries dug by the ants under the bark of living trees. Unlike free-livingM. conspicuaand other diaspidids,M. conspicualiving with ants are known to lack shields, likely because they gain protection against enemies and desiccation. Nevertheless, we documented the occurrence of rare individuals with shields inside ant galleries, indicating that their glands continue to secrete wax and proteins as building material. This is likely to constitute a significant portion of the ants’ diet, in addition to diaspidid exuviae and excretions from the Malpighian tubules. Indeed,Melissotarsusworkers cannot walk outside the galleries due to modified middle legs, forcing them to obtain all nourishment within the tree.Melissotarsusfounding queens, however, must locate a suitable host tree while flying, and acquire diaspidid crawlers. This mutualism involves ants that are highly specialised to chew through living wood, and diaspidids that can also live freely outside the bark. It is extremely widespread in Africa and Madagascar, recorded from 20 tree families, and harmful effects on plant hosts require rapid study.

Nectria flammea. [Descriptions of Fungi and Bacteria].

1981 ◽  
Author(s):  
C. Booth
Keyword(s):  
South Africa ◽  
New Zealand ◽  
Geographical Distribution ◽  
New Guinea ◽  
Scale Insects ◽  
Wide Range ◽  
Aspidiotus Nerii ◽  
Pseudaulacaspis Pentagona

Abstract A description is provided for Nectria flammea. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: The fungus occurs on a variety of scale insects, Aspidiotus nerii, Hemiberlesia rapax (53, 1-694), Pseudaulacaspis pentagona (55, 2093) etc. on a wide range of hosts, Acacia, Brachyglottis, Camellia, Citrus, Coffea, Morus, Ribes, Salix, Thea, Weinmannia, etc. GEOGRAPHICAL DISTRIBUTION: Australia, Belize, Fiji, India, Japan, New Zealand, Papua and New Guinea, Tanzania, Tonga, Uganda, South Africa, Sarawak, Zambia. TRANSMISSION: Airborne by ascospores or by moisture droplets as conidia.

Heterochromatization and euchromatization of whole genomes in scale insects (Coccoidea: Homoptera)

Development ◽  
1990 ◽  
Vol 108 (Supplement) ◽  
pp. 29-34 ◽  
Author(s):  
Uzi Nur
Keyword(s):  
Scale Insects ◽  
Congeneric Species ◽  
Maternal Origin ◽  
Paternal Origin ◽  
Whole Genomes ◽  
Armored Scale ◽  
Males And Females

In several families of scale insects (coccids), the sex of an embryo is determined by the number of genetically active genomes present (one=males, two=females). In mealybugs (Pseudococcidae), both males and females develop from fertilized eggs but, in the embryos that develop into males, the set of chromosomes (genome) of paternal origin (PG) becomes heterochromatic (H) and genetically inactive and is not transmitted to the offspring. The mechanism that reduces the number of active genomes in male embryos may vary between families and even between congeneric species. Thus, in male embryos of most armored scale species (Diaspididae), the PG is eliminated, while in a few species it becomes H. In two genera of soft scales (Coccidae), males develop from unfertilized eggs when one of two identical genomes of maternal origin becomes H. In most male tissues, one genome remains H. However, in several tissues that become polyploid by endoreduplication, the PG becomes E and genetically active. The tissues in which the PG becomes E often vary between species and the analysis of hybrid males demonstrated that whether the PG becomes H or remains E is determined by the genome of maternal origin. The euchromatization of the PG in the haploid sector of mosaic male embryos and the presence of spermatocytes with two E genomes (instead of one E and one H), following the irradiation of young mealybug males, strongly suggest that the maintenance of the H state requires the presence of a genetically active genome.

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