scholarly journals MICROTUBULES IN RELATION TO THE MOTILITY OF A SPERM SYNCYTIUM IN AN ARMORED SCALE INSECT

1966 ◽  
Vol 29 (2) ◽  
pp. 251-265 ◽  
Author(s):  
W. Gerald Robison

Male scale insects of the species Parlatoria oleae Colvée (Homoptera: Coccoidea) produce motile sperm bundles. The bundle is a syncytium consisting of 10 to 20 closely packed, filamentous spermatozoa, which share a common cytoplasm and are enclosed in a common membrane. The individual spermatozoon is not surrounded by a plasma membrane, but is delimited by a scroll-like sheath composed of 45 to 50 microtubules. The microtubules run parallel to the long axis of the spermatozoon and are arranged in a spiral pattern as seen in transection. The outside diameter measures approximately 140 to 220 A and the inside diameter, 70 to 100 A. The spermatozoon is about 300 µ long and tapers gradually from a diameter of approximately 0.3 µ anteriorly to 0.1 µ posteriorly. The anterior half (150 µ) has a threadlike core of chromatin about 0.07 µ in diameter. A homogeneous cytoplasm surrounds the nuclear core and fills the posterior half of the spermatozoon. Neither osmium tetroxide nor glutaraldehyde fixation revealed the presence of a nuclear envelope, acrosomal membranes, mitochondria, flagellum, or centrioles. In spite of the apparent lack of orthodox cell organelles, the spermatozoon is actively motile upon release from the bundle. It exhibits capactiy for motility throughout its entire length. Since the sheath of microtubules is the only structure which extends the full length of the spermatozoon, it probably plays a significant role in spermatozoan motility.

2011 ◽  
Vol 101 (4) ◽  
pp. 429-434 ◽  
Author(s):  
D.-S. Park ◽  
S.-J. Suh ◽  
P.D.N. Hebert ◽  
H.-W. Oh ◽  
K.-J. Hong

AbstractAlthough DNA barcode coverage has grown rapidly for many insect orders, there are some groups, such as scale insects, where sequence recovery has been difficult. However, using a recently developed primer set, we recovered barcode records from 373 specimens, providing coverage for 75 species from 31 genera in two families. Overall success was >90% for mealybugs and >80% for armored scale species. The G·C content was very low in most species, averaging just 16.3%. Sequence divergences (K2P) between congeneric species averaged 10.7%, while intra-specific divergences averaged 0.97%. However, the latter value was inflated by high intra-specific divergence in nine taxa, cases that may indicate species overlooked by current taxonomic treatments. Our study establishes the feasibility of developing a comprehensive barcode library for scale insects and indicates that its construction will both create an effective system for identifying scale insects and reveal taxonomic situations worthy of deeper analysis.


1898 ◽  
Vol 30 (4) ◽  
pp. 78-81
Author(s):  
F. M. Webster

In the year 1889, Mr. Henry Tryon, Assistant Curator of the Queensland, Australia, Museum, in a report on the insect and fungus pests, published as report No. 1, by the Department of Agriculture of Queensland, pp. 89-91 describes a species of scale insect found on the peach, as the White Scale, Diaspis amygdali (fig 7). and reported its occurrence both at Brisbane, Queesland, and Sydney, New South Wales. Although described as the White Scale, the author continually refers to it as the peach scale, in his paper, and the latter name has been adopted in America for the species. Of its habits Mr. Tryon states that: “At first its presence is betrayed by small white spots or patches on the bark of the smaller branches; but as the insect increases these soon become in many places confluent, and the individual scales overlap one another, or are contorted by being squeezed together closely, or even appear to lie one over the other, and where the male scale insects crowd together these spots present a more finely chaffy appearance. As it will occur quite up to the tips of the branches, the complete destruction of any tree subjected to the attack of the peach scale, and owing to it, is only a matter of time. When already in patches on the branchlets prior to the formation of the leaves and fruit, in early spring, it does not hinder their formation; the leaves are green as usual, the fruit sets, but is soon retarted in its growth and shrivels up”. Writing me under date of November 7th 1897, however, Mr. Tryon has this to say of its present condition in Queensland: “This Coccid is far from being generally distributed in Queensland, and nowhere have I observed it to act very prejudicially to the trees that it attacks.


EDIS ◽  
1969 ◽  
Vol 2004 (18) ◽  
Author(s):  
Anthony Camerino

Ground pearls are a primitive subterrestrial relative of the widely recognized above ground armored scale insect (family Diaspididae). While retaining well-developed fossorial legs with numerous setae (which scale insects do not have), ground pearls do not possess the ability to secrete scales similar to their scale relatives (Beardsley and Gonzalez). Instead, the ground pearls excrete a waxy covering that totally surrounds their body with the exception of their piercing- sucking mouthparts. The voided waxy spherical covering of the insect is the most likely structure to be encountered. The sphere is pink to yellowish-brown in color and measures from 1/6 of an inch in diameter to as small as a grain of sand (Short). The exposed mouthparts are used to feed and attach to the roots of plants. This document is EENY-277, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: November 2002.  EENY277/IN554: Ground Pearls, Margarodes spp. (Insecta: Hemiptera: Margarodidae) (ufl.edu)


2014 ◽  
Vol 105 (1) ◽  
pp. 110-120 ◽  
Author(s):  
J.C. Andersen ◽  
R.A. Gwiazdowski ◽  
K. Gdanetz ◽  
M.E. Gruwell

AbstractArmored scale insects and their primary bacterial endosymbionts show nearly identical patterns of co-diversification when viewed at the family level, though the persistence of these patterns at the species level has not been explored in this group. Therefore we investigated genealogical patterns of co-diversification near the species level between the primary endosymbiont Uzinura diaspidicola and its hosts in the Chionaspis pinifoliae–Chionaspis heterophyllae species complex. To do this we generated DNA sequence data from three endosymbiont loci (rspB, GroEL, and 16S) and analyzed each locus independently using statistical parsimony network analyses and as a concatenated dataset using Bayesian phylogenetic reconstructions. We found that for two endosymbiont loci, 16S and GroEL, sequences from U. diaspidicola were broadly associated with host species designations, while for rspB this pattern was less clear as C. heterophyllae (species S1) shared haplotypes with several other Chionaspis species. We then compared the topological congruence of the phylogenetic reconstructions generated from a concatenated dataset of endosymbiont loci (including all three loci, above) to that from a concatenated dataset of armored scale hosts, using published data from two nuclear loci (28S and EF1α) and one mitochondrial locus (COI–COII) from the armored scale hosts. We calculated whether the two topologies were congruent using the Shimodaira–Hasegawa test. We found no significant differences (P = 0.4892) between the topologies suggesting that, at least at this level of resolution, co-diversification of U. diaspidicola with its armored scale hosts also occurs near the species level. This is the first such study of co-speciation at the species level between U. diaspidicola and a group of armored scale insects.


1968 ◽  
Vol 61 (4) ◽  
pp. 1086-1088 ◽  
Author(s):  
H. L. Maltby ◽  
Eteazar Jimenez-Jimenez ◽  
Paul DeBach

Zootaxa ◽  
2021 ◽  
Vol 5052 (2) ◽  
pp. 1-40
Author(s):  
GILLIAN W. WATSON ◽  
DAVID OUVRARD

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are obligate plant parasites feeding on plant sap; some are damaging pests in agriculture, horticulture and forestry. Despite their economic importance, the scale insects found in continental Africa have not been extensively studied and the keys for identifying them are incomplete and scattered through the literature in several languages. The aim of this study is to improve our understanding of the African scale insect fauna. As a first step towards their identification, we provide a key to the 23 families currently known from continental Africa, based on slide-mounted adult females, covering Aclerdidae, Asterolecaniidae, Cerococcidae, Coccidae, Conchaspididae, Dactylopiidae, Diaspididae, Eriococcidae, Halimococcidae, Kermesidae, Kerriidae, Kuwaniidae, Lecanodiaspididae, Margarodidae, Matsucoccidae, Micrococcidae, Monophlebidae, Ortheziidae, Phoenicococcidae, Pseudococcidae, Putoidae, Rhizoecidae and Stictococcidae.  


2021 ◽  
Author(s):  
Angela Whittaker

Abstract Magnolia scale, Neolecanium cornuparvum, is a scale insect that is native to the eastern USA, where it is a widely distributed pest of wild and ornamental Magnolia in landscapes and nurseries. In general, non-native species of Magnolia tend to be more susceptible to attack than native US species. N. cornuparvum has also been reported on Wisteria in Connecticut. The genus and species were first reported from Canada from a specimen of N. cornuparvum collected in 1998 in southern Ontario, where the insect is now an established pest of Magnolia, having probably been spread via the plant trade. An infestation of scale insects believed to be N. cornuparvum was first observed in Hawaii on Sesbania tomentosa on Kauai in August 2004; it had significant adverse effects on this endangered species.


1995 ◽  
Vol 43 (10) ◽  
pp. 1079-1084 ◽  
Author(s):  
G Thiéry ◽  
J Bernier ◽  
M Bergeron

We describe a simple new technique based on the affinity of imidazole and osmium tetroxide for unsaturated lipids. Organs (e.g., kidney, liver, intestine) were perfused in vivo with a glutaraldehyde solution. Tissue fragments were then immersed in a solution containing imidazole and OsO4 and are further stained with a double lead and copper citrate solution. Ultra-thin (0.06 microns) or thick (0.1-0.3 microns) sections were observed with transmission electron microscopy (80-100 kV). The method presented permits excellent visualization of cell membranes (e.g., endoplasmic reticulum, endocytotic apparatus) because it favors good resin penetration and the alkaline pH preserves cell volume. A better stereomicroscopic analysis of the relationship between cell organelles can be carried out with thick sections. The imidazole/osmium can be used routinely because the technical steps are easy and simple to follow. Furthermore, it can complement other cytochemical methods.


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