Artemisia annua extracts, artemisinin and 1,8-cineole, prevent fruit infestation by a major, cosmopolitan pest of apples.

CONTEXT: Extracts of Artemisia annua (L.) (Asteraceae) and artemisinins are used for treatment of malaria, parasitic infections and have potent anticancer properties in cell lines. Eucalyptus oil and 1,8-cineole have antimicrobial, immune-stimulatory, anti-inflammatory, antioxidant, analgesic, and spasmolytic effects. Codling moth, Cydia pomonella, (L.) (Tortricidae), is a major cosmopolitan pest of the apple, potentially causing damage translating to 40 billion US dollars per year, globally. Currently used control measures are either hazardous to agricultural workers and harmful to environment, or ineffective. The potential of plant-derived semiochemicals for codling moth control is heavily understudied. OBJECTIVE: This study evaluated the potential of A. annua extracts, and two chemicals that this plant contains, artemisinin and 1,8-cineole, for preventing apple feeding and infestation by neonate Cydia pomonella larvae. METHODS: We studied effects of A. annua extracts, artemisinin and 1,8-cineole on apple infestation by neonate codling moth larvae using fruit choice assay in laboratory experiments. Preference of fruit treated with test solutions versus fruit treated with solvent was recorded and analyzed. RESULTS: Crude A. annua extracts prevented fruit feeding at 1, 3, and 10 mg/ml. Artemisinin had feeding deterrent effects at 10 and 30 mg/ml, and 1,8-cineole at 100 and 300 mg/ml. DISCUSSION AND CONCLUSIONS: A. annua contains chemicals that prevent apple infestation by codling moth neonates. Artemisinin and 1,8-cineole are among them, but there are other, polar constituents of A. annua, which have similar effects. There is a potential of using our findings in codling moth control and production of codling moth-resistant apples.

Attractants for the green June beetle (Coleoptera: Scarabaeidae).

The purpose of this study was to develop and evaluate lures for adult green June beetles, Cotinis nitida (L.) (Coleoptera: Scarabaeidae), for future use in a mass trapping program. Volatile organic compounds collected from headspace of green June beetles feeding on fermenting ripe apple (Malus spp.), the natural lure that elicits feeding aggregations, were identified and confirmed by gas chromatography and mass spectrometry. Yellow funnel traps baited with 91% isopropanol or the five component blend were equally effective in eliciting aggregation behavior and often more attractive to green June beetles than the natural lure. In 2008, three trap lines adjacent and parallel to the perimeter of two vineyards, each with 12 Xpando yellow funnel traps baited with either 91% isopropanol or the five component blend, differed in catch of green June beetles across sample dates, and sample date by bait interaction but there were no differences among these two baits. A season total of 324,007 green June beetle were captured by these 36 baited traps. A brief review is included of fermentation volatiles attractive to insects. We conclude with the potential cost to use mass trapping against adult green June beetles.

Chilling affects allatal cell proliferation via antennae and protocerebral neurons in the cockroach Diploptera punctata.

The corpora allata (CA) cells in a mated female of the cockroach Diploptera punctata undergo numerous mitotic divisions before an increase in juvenile hormone synthesis. A previous study demonstrated that this mitotic wave could be suppressed by exposure of the mated female to melting ice. Herein, we report that chilling suppresses CA mitosis via antennal perception. Cell proliferation-suppressing stimuli from chilling were acquired in proportion to the length of time of exposure to the low temperature and the physical length of the antennae exposed to chilling. Sixty basal antennal annuli should remain exposed to chilling for at least 1.5 h in order to suppress mitotic divisions in CA. Mitotic divisions in corpus allatum are suppressed by stimuli from contralateral antenna, predominantly via pars intercerebralis neurons. Selective disconnection of pars intercerebralis neurons from CA, prior to chilling, restored the mitotic wave in CA. Cellular divisions did not occur in CA of chilled females if either pars lateralis neurons were severed or left intact.

Protocerebral neurons inhibiting proliferation of corpus allatum cells in the cockroach, Diploptera punctata.

A mitotic wave before an increase in juvenile hormone (JH) synthesis was observed in the corpora allata during each ovarian cycle in the cockroach Diploptera punctata and was shown subsequently to be inhibited by the brain until adult females mated. Each corpus allatum (CA) was innervated by groups of neurons in the contralateral pars intercerebralis (PI) and the ipsilateral pars lateralis (PL). In this article, a third set of neurons is identified that innervates the CA located extralaterally in the contralateral PL. The topography of the brain neurons innervating the CA was reconstructed from confocal optical sections after vital staining with two fluorescent carbocyanine dyes, 1,1'-dihexadecyl-3, 3,3',3'-tetramethylindocarbocyanine perchlorate [DiIC(16) (3)] and 3, 3'-dioctadecyloxacarbocyanine perchlorate [DiOC(18) (3)]. This provided information necessary to disconnect specific pathways within the brain of virgin females and to determine the effect on mitosis in the corpora allata and on the growth of oocytes. Disconnection of the CA from the PI neurons was followed by a prolonged period of moderate mitotic activity in the glands. Disconnection of the CA from PI and contralateral PL neurons was followed by a rapid wave of high mitotic activity in the CA similar to that observed after mating. The ipsilateral PL neurons did not appear to influence CA cell proliferation, because mitotic activity in glands was similar whether or not glands were connected to these neurons. Disconnection of the contralateral PI and/or ipsilateral PL neurons, but not the contralateral PL neurons, from the CA resulted in oocyte growth indicative of increased JH synthesis. The authors conclude that, whereas contralateral PI neurons inhibit both CA cell proliferation and JH synthesis, ipsilateral PL neurons affect only JH synthesis, and contralateral PL neurons modulate cell proliferation slightly only.

Glutamate-induced rise in cytosolic calcium concentration stimulates in vitro rates of juvenile hormone biosynthesis in corpus allatum of Diploptera punctata.

We show that in a cockroach, Diploptera punctata, endocrine function of the corpus allatum may be modulated by L-glutamate, a major fast excitatory neurotransmitter in the central nervous system of vertebrates and invertebrates. The widely accepted concept that synthesis of juvenile hormone (JH) depends upon intracellular calcium concentration, is extended by the finding that 60 and 100 microM L-glutamate induces both an increase in calcium concentration in the cytosol of corpus allatum cells, and stimulates JH synthesis in vitro. We show that L-glutamate stimulates JH synthesis by inducing calcium influx since in calcium-free medium the stimulatory effect is not observed. Furthermore, the non-specific glutamate-receptor antagonist, 100 microM kynurenate, and 1.8 mM magnesium, inhibit the stimulatory effect of L-glutamate on JH synthesis in vitro. These results suggest that functional ionotropic glutamate receptors are present on the surface of the cells in corpus allatum, and that rates of JH are at least in part regulated via these receptors.

In vitro bioassay for the brain allatotropic hormone of Galleria mellonella (Lepidoptera).

An in vitro sensitive bioassay for the Galleria mellonella brain allatotropic hormone (ATTH) was developed. This assay measures the rate of juvenile hormone (JH) synthesis in corpora cardiacacorpora allata complex (CC-CA) stimulated in vitro by ATTH released from the brain during short-term in vitro incubation, or by ATTH extracted from the tissue with methanol. CC-CA of the late VIth instar (VI3) larvae were used for assessment of ATTH. The maximum activation of test CC-CA by ATTH occurred at a concentration of 2 brain equivalents (per 100 ul medium). The highest ATTH activity was exhibited by the brains of chilled VII1 larvae: ATTH extracted from freshly dissected brains, or ATTH released from these brains during 6 h in vitro incubation, activated JH synthesis in the CC-CA nearly five or four times, respectively. The brain of VII1 hydroprenetreated larvae were ATTH inactive.