H. virescens

Cypermethrin H. virescens Field strains Altered NaCh Little metabolic... 

The role of the nervous system in pheromone biosynthesis in moths is not clearly understood. Christensen and co-workers [208-211] proposed that the neurotransmitter octopamine may be involved as an intermediate messenger during the stimulation of sex pheromone production in H. virescens. These workers suggested that octopamine was involved in the regulation of pheromone production and that PBAN s role lies in the stimulation of octopamine release at nerve endings. However, contradicting results concerning octopa-mine-stimulated pheromone production were reported in the same species as well as other moth species [163,172,212-214]. 

In the general spectrum of host-parasite relationships, there is considerable parasite-induced host variability resulting in perturbed host physiology, biochemistry, and developmental behavior (8, 21, 22). There is a wide range of speculation that the parasite has the capacity to modulate or regulate host systems (8, 10, 23). It is clear that the C. sonorensis polydnavirus induces developmental arrest in H. virescens larva (18, 24,... 

Northern blot analyses indicate that sequences of the four repeated elements are present on transcripts expressed in H. virescens by 2 hpp (25). Steady-state RNA levels peak at 2-6 hpp and then decline over the next 8 days. These transcripts are not as abundant as the cysteine-rich transcripts but are still major viral expression products. 

Another limonoid isolated from neem seeds and determined to be as potent as azadirachtin as an ecdysis inhibitor has been identified as 3-deacetylazadirachtinol (Figure 15) (57). Both compounds were lethal to 50% of the treated H. virescens larvae (EI5Q) at 0.8 ppm in artificial diet (Table VII). Structurally, there are two differences between the compounds. In 3-deacetylazadirachtinol, the C-ll-O-C-13 ether linkage of azadirachtin is reductively cleaved at the 11 position and the acetoxyl group at C-3 is hydrolyzed to a hydroxyl group. 

C. nigriceps could distinguish between the odor of plants that have been damaged by its specihc host H. virescens and the odor of plants damaged by a closely related non-host. In a natural, non-agricultural environment, Kessler and Baldwin (2001) supplemented the odor of wild tobacco plants with synthetic volatiles and found that (Z)-3-hexenol, linalool and (Z)-a-bergamotene all increased the predation rate... 

The role of the nervous system in pheromone biosynthesis in moths is not clearly understood. In several moths, including L. dispar (Tang et al., 1987 Thyagaraja and Raina, 1994), H. virescens (Christensen et al., 1991), S. littoralis (Marco et al., 1996), and M. brassicae (Iglesias et al., 1998), an intact VNC was reported as necessary for pheromone biosynthesis by intact moths. On the other hand, in many species (even in some of those mentioned above) isolated pheromone glands responded to applied synthetic PBAN in an in vitro culture. 

Aubrey J. G., Boudreaux H. B., GrodnerM. L. and Hammond A. M. (1983) Sex pheromone-producing cells and their associated cuticle in female Heliothis zea and H. virescens (Lepidoptera Noctuidae). Ann. Entomol. Soc. Am. 76, 343-348. 

What do SNMPs do The identification of Apo/SNMPl followed photoaffinity labeling studies that tentatively identified a 69 kDa protein as a pheromone receptor (Vogt et al., 1987) however, a role as pheromone receptor seems highly unlikely because SNMPs appear to associate with most olfactory neurons, and are neither 7-transmembrane domain receptors nor show the diversity expected for ORs. SNMPs certainly show no similarity to the presumed ORs identified in D. melangaster, A. gambiaea and H. virescens (Clyne et al., 1999 Vosshall et al., 1999 Hill et al., 2002 Krieger et al., 2002). If SNMPs are not ORs, what are they ... 

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