Biological activity of natural phytoecdysteroids from Ajuga iva against the sweetpotato whitefly Bemisia tabaci and the persea mite Oligonychus perseae

BACKGROUND: Ecdysteroids are steroid hormones that control moulting and govern several changes during metamorphoses in arthropods. The discovery of the same molecules (phytoecdysteroids) in several plant species displayed a wide array of rather beneficial agricultural impact. Many representatives of the genus Ajuga plants contain phytoecdysteroids with a 5β‐7‐ene‐6‐one system exhibiting physiological activities in insects. RESULTS: By means of chromatographic (silica gel column, TLC) and LC‐MS, two major ecdysteroids (20‐hydroxyecdysone and cyasterone) have been isolated and identified from Israeli carpet bugle Ajuga iva (L.) Schreber (Lamiales: Lamiaceae) plants. Ajuga iva extract fractionated on the silica gel column yielded two fractions that showed high activity against the sweetpotato whitefly Bemisis tabaci and the persea mite Oligonychus perseae. A dose of 5 mg AI L^?1 of the purely identified A. iva ecdysterone significantly reduced fecundity, fertility and survival of these pests, while commercial 20‐hydroxyecdysone at the same dose had lesser effects. CONCLUSION: The results demonstrate considerable efficacy of natural phytoecdysteroids against major agricultural pests, and suggests that these materials should be considered for potential development of friendly control agents. Copyright © 2011 Society of Chemical Industry     

Outbreak of rabbit hemorrhagic disease virus 2 in the southwestern United States: first detections in southern California

An outbreak of rabbit hemorrhagic disease virus 2 (RHDV2)-associated disease occurred in the southwestern United States following its first detection in New Mexico in March 2020. The disease spread throughout several states and was diagnosed for the first time in California on May 11, 2020, in a black-tailed jackrabbit (Lepus californicus). The following day, the California Department of Food and Agriculture (CDFA) issued an order banning the entrance into California of several lagomorph species and their products from any state in which the disease had been detected in the last 12 mo. RHDV2 is a threat to wild lagomorph species in California, including the endangered riparian brush rabbit (Sylvilagus bachmani riparius). Therefore, the California Department of Fish and Wildlife (CDFW) started tracking any mortality event in wild lagomorph populations. As of August 9, 2020, RHDV2 had been detected in wild and domestic lagomorphs of several counties in southern California that were submitted to the California Animal Health and Food Safety laboratory system by the CDFA or the CDFW. These positive cases included 2 additional black-tailed jackrabbits and 3 desert cottontail rabbits (Sylvilagus audubonii). In addition, the infection spilled over to domestic populations, whereby it was confirmed on July 10, 2020, in a domestic rabbit (Oryctolagus cuniculus).     

Relationships between native tree species and soil properties in the indigenous forest fragments of the Eastern Arc Mountains of the Taita Hills,Kenya

The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the world due to their high biodiversity of both plant and animal species. This relationship was assessed by using Spearman correlation and principal component analyses (PCA). The results of these analyses should be useful in instituting forest restoration programs that are crucial for the forests. Both the soil and vegetation studied were sampled from 17 subplots in the natural forest fragments of Ngangao (120 ha), Chawia (86 ha) and Mbololo (185 ha). The soil variables measured were: pH, texture, soil nutrients of C, N, Ca, P, K, Mg and Na. In total 36 native tree species from 13 families were identified from the three forest fragments. Ordination results show that axis 1 accounted for 35% and axis 2 for 25% of the total variation in species composition, indicating that the structure of vegetation is related to two major environmental gradients. The correlation analyses of species and soil properties showed that Na and clay particles were the most important determinants of species distribution; pH and soil variables such as C, N, Ca and P also played minor roles. Unexpectedly, some species (e.g. Psychotria petitii) showed positive relationships with Na attributed to possible substitution for K. Relationships with P were both positive (e.g. Craibia zimmermannii) and negative (e.g. Albizia gummifera) with some species, attributable to pH levels. An ANOVA for soil variables showed that there were differences in the Ca content in Mbololo (due to the parent material) and P in Ngangao where a special relationship was observed between some of the species. The presence of gaps accounted for the distribution of seedlings but not for the saplings, whose distribution responded more to factors similar to those to which mature trees respond. Soil-species relationships that were established may be utilized along with soil analyses when choosing native species for restoration.     

Systemic mycosis in a California sea lion (Zalophus californianus) with detection of cystofilobasidiales DNA

A 6-yr-old, intact male California sea lion (Zalophus californianus) with a systemic mycosis died after 5 wk of antifungal drug therapy. Antemortem clinical findings included hind flipper swelling, ring-lesions on skin of the flippers, and dermal nodules that increased in size and number spreading from the hind flippers and ventral abdomen to the foreflippers and muzzle. Lesions were accompanied by severe lymphadenopathy and development of systemic clinical signs despite therapy using itraconazole and later voriconazole. Histopathologic evaluation of biopsies revealed granulomatous dermatitis due to infection by fungus-producing yeast cells in tissue. Isolation attempts, using biopsied skin and tissue samples collected at necropsy, failed to yield growth of a fungus producing yeast cells like those in histologic section. Consensus polymerase chain reaction (PCR) tests of biopsied skin for fungal DNA produced an amplicon having significant sequence identity with a Cystofilobasidiales, a fungus belonging to a subclade that includes several Cryptococcus spp. Histopathologic evaluation of necropsy tissues revealed a systemic mycosis with yeast cells disseminated throughout subcutis, lymph nodes, and viscera. Hepatic necrosis was identified associated with acute liver failure, possibly from the voriconazole administration. This is the first report documenting the clinical presentation, treatment, and pathologic findings of infection associated with Cystofilobasidiales in a marine mammal and serves to expand the understanding of mycoses in pinnipeds.     

Effects of maternal streptozotocin-diabetes on fetal growth, energy reserves and body composition of newborn pigs

Two doses of Streptozotocin (50 and 100 mg/kg body weight) were administered to two groups of pregnant gilts at d 80 of gestation to determine the influence of two levels of maternal diabetes on the gilts, their developing progenies and the body composition of the pigs. All the experimental animals received 1.82 kg of gestation diet/day throughout gestation. Serum glucose concentration increased to hyperglycemic levels in low-dose and high-dose groups; insulin concentrations decreased (P less than .01) in the high-dose, but not in the low-dose group (P greater than .05). Maternal free fatty acids (FFA) increased (P less than .05) in both treatment groups when compared with the control. However, birth weight of the litter and litter size were not affected. The liver weight increased (P less than .01) in the progeny of high-dose but not the low-dose group. Total liver DNA and RNA were not altered by the treatments, however; total liver protein and protein:DNA ratio increased (P less than .01) in the progeny of high-dose gilts. Pigs from high-dose and low-dose groups showed increases (P less than .01) in liver glycogen concentrations and percentage liver lipid. Body chemical composition data showed increases in percentage dry matter and percentage lipid (P less than .05 and P less than .01, respectively) in the progeny of high-dose but not in the low-dose group. It was concluded that streptozotocin administered to gestating gilts increased the maternal nutrient supply to the developing pigs, which resulted in higher energy status of the pigs at birth.