Scale California red

California red scale pheromone Scheme 9 Vitamin Bi2-mediated Michael addition. 

Other examples include the synthesis of California Red Scale Pheromone [80], prostaglandin PGF2a [81], House Mouse Pheromone [63], and Jasmon-ates [82]. 

Roelofs W Gieselmann M, Cardd A, Tashiro H, Moreno DS, Henrick CA, Identihcation of the California red scale sex pheromone, / Chem Ecol 4 211— 224, 1978. 

Evaluation of Petroleum Fractions against California Red Scale and Citrus Red Mite... 

The insecticidal efficiency under laboratory conditions of various members of two series of narrow boiling petroleum fractions was determined for adult female California red scale, Aonidiella auranfii (Mask.) and eggs of the citrus red mite, Paratetranychus citri (McG.). Correlations between efficiency and various properties of the fractions such as structural character, molecular weight, and viscosity were observed. These correlations Indicate that conventional spray oils used on citrus in California may contain appreciable amounts of hydrocarbons of low insecticidal activity. The evidence indicates that the insecticidal efficiency of spray oils against citrus insect pests may be considerably improved by proper selection with respect to structural character and molecular size. 

Smith (24) conducted intensive studies of the factors involved in the use of oil sprays to control California red scale and other pests of citrus in southern California. He found that insecticidal efficiency and deleterious effect on the trees were closely related to the so-called weight of the spray oil, as indicated by the distillation range, and that this provided a better basis for classification of spray oils than viscosity. The relationship of the unsulfonated residue of petroleum oils to tree injury had been clearly established previ-... 

An initial report is made here on results obtained in laboratory studies of two series of petroleum fractions against adult females of the California red scale, Aonidiella auraniii (Mask.), and against eggs of the citrus red mite, Paratetranychus citri (McG.). 

The two species selected for the laboratory studies—California red scale and citrus red mite—are dominant economic pests of citrus in southern California (5). Constant vigilance against infestations of these species is of primary concern to the growth and production of citrus in the area, and petroleum oil sprays are the most important means of control available. 

California red scales were obtained from a laboratory colony reared and maintained on banana squash. Squash was first used as a host for the mass pr uction of California red scale under laboratory conditions by Rush Bumgardner of the Orange Coimty Insectary, Anaheim, Calif. 12). The suitability of banana squash for this purpose was shown by Flanders IS). Lindgren et al. 15y 17) adapted the rearing methods of the red scale to the requirements of insecticide studies and developed techniques for using this species as a laboratory test insect. 

In the tests with both California red scale and citrus red mite, untreated lots of fruit selected at random from infested fruit prepared for a given day were held with the treated lots and counted for natural mortality. The corrected percentage of kill for each treatment was calculated by means of the Abbott equation (Jf). 

Table I. Efficiency of Petroleum Fractions of Paraffinic (46-M20) and Naphthenic (46-51) Composition against Adult Female California Red Scale...

Mortalities observed in tests of a series of oil dosages against adult female California red scale or eggs of the citrus red mite indicated a positive relation between increased dosage and increased kill. The fit of the points to the line was much better for oil dosages expressed as deposit than for those expressed as spray concentration. However, the variance observed indicated that statistical procedures would be required to arrive at the best fit for a line through the observed points. The method of probit analysis chosen was that proposed by Bliss (2) and modified by Finney (11) for data adjusted for mortality in the controls. 

Series of fractions of paraffinic (P) and naphthenic (N) composition against adult female California red scale... 

The properties and characteristics available for paraffinic fraction 5 appear to be in line with those of the other fractions of the paraffinic series and do not infficate an explanation for a difference in performance against adult California red scale. A similar deviation did not occur in the case of the correlations established for eggs of the citrus red mite. Since the work of Ebeling (7) indicated that contact of oil with the scale insect is generally accomplished by penetration of the oil imder the scale armor, the spreading ability of the oil film appears to be an important factor in the efficiency of an oil against adult California red scale. 

Figures 1 and 2 indicate that the insecticidal efficiency of oils of paraflSnic composition against adult female California red scale is better than that of oils of naphthenic composition. The curves show that the toxicity to red scale of the lighter portions of the two oils tested is low, and that there is an increase to a peak of maximum efficiency with increase in molecular size. These findings agree in general with field experience in California in ths application of spray oils for the control of California red scale. However, the correlations shown in Figures 1 and 2 indicate that an optimum is reached, and that beyond this point efficiency against the scale decreases with further increase in molecular size.

The homochiral f -branched carboxylic acids (13 or enf-13 Table 1) have been used for the synthesis of a variety of natural products21 such as California red scale pheromone,14 a-skytanthine,22 the southern com rootworm pheromone,15 and norpectinatone.16 Pure (5)-3-trichloromethylbutyric acid (a structural subunit of some sponge metabolites) was prepared via conjugate addition of ClaCMgCl to the chiral cro-tonate (16) followed by hydrolysis (Scheme S).23... 

In contrast, the corresponding reactions of RCu/BFa reagents (R = phenyl or alkenyl) with allylic acetals obviously proceed in an anti 5n2 fashion, as shown in (67b). The unsaturated acetals (68), prepared from (R )-butane-1,2-diol, are opened by the PBu3-stabilized reagents to give, after hydrolysis, the (3-substituted aldehydes (69) with high ee (Scheme 27).68,69 The method has been applied to the preparation of a key intermediate (85% ee) for the synthesis of the California red scale pheromone.69... 

Scheffold and colleagues subsequently reported that alkyl iodides 249 add to xfl-unsaturated esters 248 catalyzed by 23 mol% hydroxycobalamine 247 (X=OH) and mediated by light to homolyze 253B [302]. The generation of the active Co(I) species 253A proceeded by electrochemical reduction at a potential of —1.2 V vs SCE. The transformation required a large excess of 248 to promote the addition of the initially generated alkyl radical. The reaction was applied to the total synthesis of the California red scale pheromone. The product... 

California Red Scale is a worldwide citrus pest which can be controlled by means of the pheromone 60. Cohen used reductive lithiation to generate versatile allylic nucleophiles applicable to this type of target.6 The allyl sulfide 61 is lithiated by BuLi and reacts with butenyl bromide a to sulfur to yield 63. Reductive lithiation (Li, DBB) of the product yields allyllithium 64. A regioselective reaction of this nucleophile with formaldehyde at the more substituted terminus is ensured by transmetallation to the allyl titanium 65, which gives 66 after treatment with formaldehyde and bromination. 

The California red scale, Aonidiella aurantii is a worldwide pest of citrus trees and the sex pheromone produced by the females has been identified as a mixture of the norsesquiterpenoid esters, 3-methyl-6-isopropenyl-9-decen-l-yl acetate (XV) and (Z)-3-methyl-6-isopropenyl-3,9-decadien-l-yl acetate (XVI)... 

As in the case of the Comstock and citrus mealybug pheromones, the release data for the California red scale pheomone showed that the laminate formulation made with 16-mil polymeric PVC film gave a long-lasting and suitable dispenser for the monitoring program. The results of these dispenser evaluations are summarized for citrus insect pheromones in Table IV. 

---