Histopathological Investigations on Rickettsiella-like sp. and Nonoccluded Viruses Infecting the Pecan Weevil Curculio caryae, the Squash Beetle Epilachna borealis, and the Mexican Bean Beetle Epilachna varivestis.

Electron microscopic observations of abnormal specimens of pecan weevils, Curculio caryae, squash beetles, Epilachna borealis, and Mexican bean beetles, Epilachna varivestis, obtained from insect-rearing facilities and from field collections revealed that rickettsia-like organisms (RLOs) and viruses caused disease in these species. Several pleomorphic forms of the RLOs which were similar to those of Rickettsiella sp. were found in tissues of the fat body, hypodermis, tracheal matrix, muscle, and midgut of each insect species.

Evaluation of plant constituents associated with pecan phylloxera gall formation.

The weights of pecanCarya illinoensis Koch galls caused by several species ofPhylloxera (Homoptera: Phylloxeridae) were negatively correlated with leaf and nut weights and nut production. Several allelochemicals (isoquercitrin, juglone, and 2 proanthocyanidins) were isolated from galls, and their antibiotic potentials were estimated, based on their toxicity to the bacteriaPseudomones maltophilia (Hugh et Ryschenkow). Pecan proanthocyanidins (condensed tannins) were characterized for the first time, and their stereochemistry was elucidated.

Hydrocarbons from males, females, and larvae of pecan weevil: Curculio caryae (Horn).

As part of a program to identify as many as possible of the components of the pecan weevil, Curculio caryae (Horn), the hydrocarbons from males, females, and larvae were isolated by solvent extraction and column chromatography and subjected to gas lipuid chromatography-mass spectrometry analysis. n-Alkanes from C14-C32 in the larvae and unsaturated and branched chain hydrocarbons from C20-C32 in males and females were found. There are no significant differences between the hydrocarbons of the male and female pecan weevils.

Lipid composition of the pecan weevil,Curculio caryae (Horn).

The lipids of larvae, male adults, and female adults of the pecan weevil,Curculio caryae (Horn), were studied, and special attention was given the fatty acid composition. The larvae contained an unusually high amount of lipid material (40.6%), most of it concentrated in the neutral lipid fraction.