Intra- and interspecific predation on four life stage groups by the adult females of Metaseiulus occidentalis, Typhlodromus pyri, Neoseiulus fallacis and Amblyseius andersoni

1996 ◽  
Vol 20 (8) ◽  
pp. 435-444 ◽  
Author(s):  
B. A. Croft ◽  
S. S. Kim ◽  
D. I. Kim
Keyword(s):  
Life Stage ◽  
Typhlodromus Pyri ◽  
Amblyseius Andersoni ◽  
Neoseiulus Fallacis ◽  
Adult Females ◽  
Metaseiulus Occidentalis ◽  
Interspecific Predation

scholarly journals Untersuchungen zum Vorkommen der Phytoseiidae (Acari: Mesostigmata) und Roten Spinne, Panonychus ulmi im Südtiroler Apfelanbau

2021 ◽  
Vol 2 ◽  
Author(s):  
Martin Parth ◽  
Stefanie Fischnaller ◽  
Manuel Messner ◽  
Manfred Wolf
Keyword(s):  
Typhlodromus Pyri ◽  
Panonychus Ulmi ◽  
Neoseiulus Californicus ◽  
Amblyseius Andersoni ◽  
Kampimodromus Aberrans ◽  
Euseius Finlandicus

Von 2014 bis 2017 wurden intensive Untersuchungen zum Raubmilbenvorkommen (Mesostigmata: Phytoseiidae) und Auftreten der Roten Spinne Panonychus ulmi (Prostigmata: Tetranychidae) in ausgewählten Apfelanalgen in Südtirol (Italien) angestellt. Die Populationsdichten der Milben wurden wiederholt an bis zu 50 Standorten im Etschtal und Vinschgau erhoben. In 27 Apfelanlagen wurde im Verlauf der Jahre 2015-2017 die Artenzusammensetzung blattbesiedelnder sowie an Aststrukturen überwinternder Raubmilben eingehend untersucht. Insgesamt wurden 5581 Raubmilben einer morphologischen Artbestimmung unterzogen. Sechs Phytoseiiden-Arten wurden nachgewiesen. Amblyseius andersoni (Chant 1957) konnte an allen Untersuchungstandorten gefunden werden und wies eine Individuendominanz von 80% auf. Ein permanentes Vorkommen von Typhlodromus pyri (Scheuten 1857) und Euseius finlandicus (Oudemans 1915) wurde an 18,5% bzw. 7,4% der Standorte festgestellt. Kampimodromus aberrans (Oudemans 1930), Paraseiulus talbii (Athias-Henriot 1960) und Typhlodromus bakeri (Garman 1948) wurden sporadisch nachgewiesen. Neoseiulus californicus (McGregor 1954) wurde erstmals am Apfel in Südtirol nachgewiesen. Der P. ulmi-Befall im Untersuchungsgebiet erwies sich, sofern gegeben, als äußerst gering. Eine wesentliche Zunahme der Populationsdichten von P. ulmi und eine diesbezügliche Schadwirkung wurden nicht festgestellt.

Developmental Variation in the Dermal Glands and Wax Secretions of the Mealybug, Phenacoccus fraxinus (Hemiptera: Coccoidea: Pseudococcidae)

2009 ◽  
Vol 44 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Yanfeng Zhang ◽  
Yingping Xie ◽  
Jiaoliang Xue ◽  
Weimin Liu
Keyword(s):  
Life Stage ◽  
Ventral Surface ◽  
Early Summer ◽  
The Other ◽  
Scale Insects ◽  
Nymphal Stage ◽  
Developmental Variation ◽  
Dermal Glands ◽  
Adult Females ◽  
Wax Production

A microscopic study of the dermal glands and wax secretions of the mealybug Phenacoccus fraxinus Tang demonstrated that the type, structure, size, quantity and distribution of dermal glands varied with life stage. These variations resulted in different quantities and morphology of waxy secretions with development. The apertures of the trilocular pores were initially small, irregular narrow seams on 1st instars. By the 3rd nymphal stage, these apertures were large and figure-8 shaped. Slender wax filaments were produced in the 1st stage, whereas wax filaments produced in the 3rd stage had an indentation along the middle. These tilocular pores were distributed on the dorsum and the venter of both stages, corresponding to the shape of the aperture. Quinquilocular pores were characterized by a thick rim and were scattered on the ventral surface, but these were not distributed in spiracle furrows as observed with other scale insects. Tubular ducts were composed of 2 layers—outer and inner ductiles—that resulted in the wax secreted from them being long, hollow filaments that served as a framework for the cocoon and ovisac structures. Wax production from these tubular ducts occurred at two distinct times during development. One occurred in late autumn and was produced by the older 2nd -instar nymphs. These waxy filaments were used to construct cocoons for the overwintering mealybugs. The other event occurred in early summer with adult females. These filaments were used to construct the ovisac. During other times of the year, these tubular ducts produced no additional wax.

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