Light- induced electron transfer and ATP synthesis in a carotene synthesizing insect

Light- induced electron transfer and ATP synthesis in a carotene synthesizing insect
Jean Christophe Valmalette, Aviv Dombrovsky, Pierre Brat, Christian Mertz3, Maria Capovilla & Alain Robichon

A singular adaptive phenotype of a parthenogenetic insect species (Acyrthosiphon pisum) was selected in cold conditions and is characterized by a remarkable apparition of a greenish colour. The aphid pigments involve carotenoid genes well defined in chloroplasts and cyanobacteria and amazingly present in the aphid genome, likely by lateral transfer during evolution. The abundant carotenoid synthesis in aphids suggests strongly that a major and unknown physiological role is related to these compounds beyond their canonical anti-oxidant properties. We report here that the capture of light energy in living aphids results in the photo induced electron transfer from excited chromophores to acceptor molecules. The redox potentials of molecules involved in this process would be compatible with the reduction of the NAD1 coenzyme. This appears as an archaic photosynthetic system consisting of photo-emitted electrons that are in fine funnelled into the mitochondrial reducing power in order to synthesize ATP molecules.

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A new species of Atheroides Haliday (Hemiptera, Aphididae) native to North America

A new species of Atheroides Haliday (Hemiptera, Aphididae) native to North America
Gary L. Miller, Andrew S. Jensen, Mark A. Metz, Robert R. Parmenter

Abstract
We report and describe the first species of Atheroides Haliday presumed to be native to North America,
collected at the Valles Caldera National Preserve, New Mexico, USA. We hypothesize its placement
among the Siphini based on morphological, phylogenetic analysis and extend the distribution of the genus
to the Holoarctic. We expand the key of the known Atheroides to include the new species and discuss the
current hypotheses of the geographic distribution of the type species, Atheroides serrulatus Haliday.


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Stylet Penetration Activities by Aphis craccivora (Homoptera: Aphididae) on Plants and Excised Plant Parts of Resistant and Susceptible Cultivars of Cowpea (Leguminosae)

Stylet Penetration Activities by Aphis craccivora (Homoptera: Aphididae) on Plants and Excised Plant Parts of Resistant and Susceptible Cultivars of Cowpea (Leguminosae)
BILLY ANNAN, WARD M. TINGEY, GEORGE A. SCHAEFERS, W. F. TJALLINGII, ELAINE A. BACKUS, AND K. N. SAXENA

ABSTRACT
Direct current electrical penetration graphs (DC-EPGs) were used to analyze the stylet penetration activities of cowpea aphid, Aphis craccivora Koch, on plants of aphid-resistant (ICV-12) and aphid-susceptible (ICV-1) cultivars of cowpea, Vigna unguiculata (L.) Walpers. Aphid stylet penetration on whole plants at seedling, ßowering, and podding stages were studied in one experiment, and in another experiment excised leaves from seedling plants, excised ßowers, and excised pods were tested. Electrical signals depicting the aphid stylet penetration activities on their host plants were ampliÞed, recorded onto a paper chart recorder, and scored for speciÞc waveform patterns. Compared with similar tissues of ICV-1, intact leaves and excised seedling foliage of ICV-12 plants caused severe disruption of aphid stylet penetration activities. This was manifested in frequent penetration attempts that were abruptly terminated or unsustained, and in shorter penetration times, signifying antixenosis resistance in ICV-12. There was reduced occurrence of E waveforms, which represent stylet activity in plant vascular tissues. Also, prior exposure of test aphids to plants of one cultivar did not signiÞcantly inßuence the expected stylet penetration activities on plants of the other cultivar. Overall, ICV-12 exhibited high levels of resistance against A. craccivora.

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Genetic Variation in the Myzus persicae Complex (Homoptera: Aphididae): Evidence for a Single Species

Genetic Variation in the Myzus persicae Complex (Homoptera: Aphididae): Evidence for a Single Species
KIERAN M. CLEMENTS, BRIAN M. WIEGMANN, CLYDE E. SORENSON, CLYDE F. SMITH,
PAUL A. NEESE, AND R. MICHAEL ROE1


ABSTRACT
Genetic variation was assessed for the closely related aphids Myzus nicotianae Blackman and Myzus persicae (Sulzer), previously classiÞed as a single species. Populations of both red and green color morphs, collected from tobacco and nontobacco hosts from 3 continents, were analyzed via random ampliÞed polymorphic DNA (RAPD)-polymerase chain reaction (PCR) and mitochondrial cytochrome oxidase II (COII) and elongation factor- 1 alpha (EF-1a) gene sequencing. Three other Myzus speciesÑM. cerasi (F.), M. hemerocallis Takahashi, and M. varians Davidson) Ñwere used as outgroups in our analyses. RAPD-PCR analysis revealed many, easily detectable genetic polymorphisms between the Myzus persicae complex and the outgroup species. The small number of polymorphisms detected within the complex were not correlated with host plant or the geographic origin of populations. The sequences of both COII and EF-1a for all populations within the M. persicae complex were identical, although signiÞcant variation was evident between the M. persicae complex and outgroup taxa. These results strongly suggest the synonymy of M. persicae and M. nicotianae.


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