Plant Acceptance for Oviposition of Tetranychus urticae on Strawberry Leaves Is Influenced by Aromatic Plants in Laboratory and Greenhouse Intercropping Experiments

The objective was to evaluate aromatic plants’ effects on the acceptance, preference, egg load, and life span of females of the twospotted spider mite (TSSM) in laboratory experiments and TSSM population under aromatic plants’ intercropping in greenhouse experiments. The pseudofruits production was also evaluated. For the laboratory, basil’s, Chinese chives’, chives’, and garlic’s influence on TSSM were tested on strawberry leaves. Four laboratory experiments were conducted: (1) Multiple choice test; (2) T-shaped arena test; (3) host–plant acceptance on aromatic plant or strawberry leaves; and (4) performance of TSSMs on strawberry leaves under aromatic plant influence. For the greenhouse experiments, assessments of the TSSM populations were realized by observing TSSM with a 10× magnifying glass on strawberry leaves in a monocrop or intercropped with Chinese chives, chives, garlic, or onion. Pseudofruit production was evaluated. Our results show that strawberry leaves were strongly preferred by TSSM. The T-shaped arena test revealed that all aromatic plants repel the TSSM. The test with the performance of TSSM females revealed that aromatic plants affected the mite’s biological parameters. Chinese chives reduced the number of eggs laid per day by 33.22%, whereas garlic reduced the number by 17.30% and chives reduced it by 12.46%. The total number of eggs was reduced by 34.79% with Chinese chives and 25.65% with garlic. Greenhouse experiments showed that chives reduced TSSM populations on two cycles and Chinese chives and garlic reduced TSSM populations on the first cycle only. With our findings, we suggest that Chinese chives, chives, and garlic are the primary candidates for intercropping use against TSSM. Chinese chives and garlic reduced the total number of eggs, but only garlic reduced female mite longevity. However, none of the intercropping plants improved strawberry pseudofruit production.

The impact of pesticides used in greenhouses, on the predatory mite neoseiulus californicus (parasitiformes, phytoseiidae)

Nine commercial pesticides currently used in Russian greenhouses against pests (aphids, thrips, whiteflies) were selected to determine their toxicity to predatory mite Neoseiulus californicus McGregor in order to find out the potential use him affected by chemical treatments Vertimec (abamectin), Fitoverm (aversectin C), Clipper (bifenthrin), Novaction (malation), Oberon (spiromesifen), Bitoxibacillin (Bacillus thuringiensis var. thuringiensis), Actara (tiametoxam), Admiral (piriproxifen), Confidor (imidacloprid), Mospilan (acetamiprid). The recommended concentration of the preparation (T), half the concentration (1/2T), and a double concentration (2T) were used on the female mite in the experiments. The side effects of the pesticides applied to the predator mite were determined one, three, and five days after the application. The recommended concentration of the preparation of Vertimec, Fitoverm and Clipper showed a higher toxic effect on N. californicus femails (mortality rate 100%). The obtained data reveals the impossibility of their joint application with the release of N. californicus. The toxic effects of Mospilan, Confidor, Admiral, Actara, Bitoxibacillin and Novaktion on N. californicus females were a low level (mortality of females 0-16,6%). The present study confirms that the use of predatory mite N. californicus in combination with these pesticides prospectively in Integrated Pest Management in Russian greenhouse conditions.

Scabies and other mite infections

Acariasis in humans and animals is caused by a diversity of parasitic mites taxonomically grouped into the class Arachnida, subclass Acari. The zoonotic species that can transfer from birds and animals to man (e.g. Cheyletiella spp; Dermanyssus spp and Ornithonyssus spp) are important in that they often cause major skin irritation or a hypersensitivity reactions or alternatively act as vectors of diseases such as scrub typhus. Like ticks the lifecycle of mites involves four life stages of development. The female mite lays eggs on the host or in the environment; the eggs hatch into larvae and pass through two nymphal stages. All stages have eight legs except the six-legged larva. Transmission is predominantly via direct contact between hosts; however fomites have been recognised as a potential source of infestation although the importance of this is variable and dependent on the ability of the mite to survive in the environment. The geographic range of most zoonotic species is worldwide although some varieties may be rare or non-existent in some countries. No developmental change or propagation of the organism occurs during the transmission.

PALPAL TARSAL SENSILLA OF THE FEMALE MITE, VARROA JACOBSONI OUDEMANS (ACARI: VARROIDAE)

The structure, distribution, and type of sensory hairs on the palptarsus of female Varroa jacobsoni Oudemans were examined by scanning electron and phase contrast microscopy. The two large, peg-like setae with apical pores are chemoreceptor sensilla chaetica. The seven slender, round tipped setae, stained with crystal violet at the hair cuticle, are considered to be the chemoreceptor sensilla trichodea. A number of long hairs that did not stain with crystal violet are trichoid tactile setae. The possible functions of these sensilla were discussed.

Scabies in Childhood

Scabies is an extremely contagious disorder caused by an itch mite, Sarcoptes scabiei, which attacks infants and children as well as adults. Infestation begins with a newly fertilized female mite. She tunnels into the stratum corneum and lives in cutaneous burrows which may measure several millimeters to a few centimeters in length. The parasite favors areas with a low concentration of pilosebaceous follicles and a thin stratum corneum. This seems to account for a difference in the distribution of lesions in infants and young children compared to older children and adults.1 INCIDENCE Epidemics of scabies occur in 30-year cycles, each one lasting about 15 years. We presently are near the end of a world-wide pandemic which began in 1964 and, if estimates are correct, should last until or beyond 1979 or 1980.2 CASE HISTOR A 3-month-old white female infant started with a pruritic eruption at 2 months of age. She had a scaly erythematous papular eruption on the trunk, the postauricular areas, and extremities (Fig 1) and was otherwise healthy.3 Microscopic examinations of skin scrapings and fungal cultures were performed, and the eruption was treated as a seborrheic dermatitis with frequent shampoos and topical fluocinolone acetonide cream. Two weeks later the rash had spread to the back of the head and neck, the entire trunk, and all extremities including the palms and soles.

ST. LOUIS ENCEPHALITIS

A colony of chicken mites (Dermanyssus gallinae) was established from a single adult female mite and her offspring. This colony of mites was shown to be free of the virus of St. Louis encephalitis. Infection of mites from this homogeneous colony with the virus of St. Louis encephalitis was accomplished by feeding on chickens having viremia. The virus was recovered as readily from mites which had not been allowed to feed for 8 days as from mites freshly engorged, showing that the demonstration of virus in the mites does not depend on the presence of fresh infective chicken blood. Transovarian passage of the St. Louis virus into the second generation has been demonstrated in mites infected experimentally. The female mite infected as an adult can pass the St. Louis virus through eggs laid after additional feeding on normal blood. Persistence of the virus for a period of 6 months has been shown in a colony of mites infected experimentally in the laboratory.