Semiochemicals from Domestic Cat Urine and Feces Reduce Use of Scratching Surfaces.

Scratching is a natural behavior in cats but can cause damage to household furnishings. In this work, we sought to identify potential semiochemicals in the urine and feces of domestic cats that may modify cat scratching behavior. Sex differences among adult, intact cats were examined for volatile molecules in their urine (n = 7 females, 7 males) and feces (n = 8 females, 10 males) using gas chromatography-mass spectrometry (GC-MS). Males had seven times more 3-Mercapto-3-Methyl Butanol (MMB, p < 0.001) in the urine and 98% more butanoic acid (p = 0.02) in the feces than females. One mL of mineral oil without (i.e., control) or with MMB (0.1 µg/mL) and butanoic acid (100 µg/mL; i.e., treatment), which corresponds to the estimated biological amount in a single elimination from a male cat, were evaluated for their effectiveness in modifying the use of scratching devices by cats. Two identical cardboard standing scratchers, treated with either the control or the solution containing both semiochemicals delivered through a hanging cotton sock were placed side by side in a home/shelter environment. The preference test consisted of exposing individual cats (n = 28) to both scratchers for 20 min and recording the duration and frequency they interacted or scratched each scratcher. The semiochemical solution significantly decreased scratching time (21.19 ± 3.8 vs. 6.08 ± 3.8 s; p < 0.001) and interaction time (31.54 ± 5.9 vs. 12.90 ± 5.9 s; p = 0.0001) and tended to reduce scratching frequency (1.49 ± 0.3 vs. 0.82 ± 0.3 times; p = 0.07) compared with the control solution. The male-representative solution of MMB and butanoic acid was aversive to cats and might have future applications in protecting furniture from the destructive scratching or in modifying behavior of domestic cats.

Nectar Source and Pollinator Cross Contamination and Persistence of Pyriproxyfen Associated with the Use of Autodissemination Techniques for Mosquito Control.

Controlling container inhabiting mosquitoes such as Aedes aegypti and Ae. albopictus is often difficult because of the requirement to treat small and inaccessible cryptic sources of water where larvae are located. Autodissemination approaches based on the dissemination of insect growth regulators (IGRs) have been demonstrated as an effective means to treat these cryptic larval habitats and provide population control. Autodissemination approaches are attractive because they are based on the mosquitoes disseminating small amounts of IGRs compared to more traditional insecticide applications. While dissemination of small amounts of IGRs seems like an advantage, these approaches could lead to unintended transfer and effects on nontarget insect pollinators by delivering highly potent IGRs to nectar sources. Here we looked for the indirect and direct transfer of pyriproxyfen (PPF) to natural and artificial nectar sources and painted lady butterflies, Vanessa cardui, in semifield cages using the release of treated Ae. albopictus males or an autodissemination station. We also performed persistence tests of PPF in oviposition containers and natural and artificial nectar sources when exposed to laboratory and natural conditions. The data suggest that there is direct and indirect transfer to nectar sources and V. cardui associated with the use of autodissemination approaches. We discuss the results in the context of using autodissemination approaches for mosquito control and the potential risks these approaches may pose to nontarget insect pollinators.

Indirect transfer of pyriproxyfen to European honeybees via an autodissemination approach.

The frequency of arboviral disease epidemics is increasing and vector control remains the primary mechanism to limit arboviral transmission. Container inhabiting mosquitoes such as Aedes albopictus and Aedes aegypti are the primary vectors of dengue, chikungunya, and Zika viruses. Current vector control methods for these species are often ineffective, suggesting the need for novel control approaches. A proposed novel approach is autodissemination of insect growth regulators (IGRs). The advantage of autodissemination approaches is small amounts of active ingredients compared to traditional insecticide applications are used to impact mosquito populations. While the direct targeting of cryptic locations via autodissemination seems like a significant advantage over large scale applications of insecticides, this approach could actually affect nontarget organisms by delivering these highly potent long lasting growth inhibitors such as pyriproxyfen (PPF) to the exact locations that other beneficial insects visit, such as a nectar source. Here we tested the hypothesis that PPF treated male Ae. albopictus will contaminate nectar sources, which results in the indirect transfer of PPF to European honey bees (Apis mellifera). We performed bioassays, fluorescent imaging, and mass spectrometry on insect and artificial nectar source materials to examine for intra- and interspecific transfer of PPF. Data suggests there is direct transfer of PPF from Ae. albopictus PPF treated males and indirect transfer of PPF to A. mellifera from artificial nectar sources. In addition, we show a reduction in fecundity in Ae. albopictus and Drosophila melanogaster when exposed to sublethal doses of PPF. The observed transfer of PPF to A. mellifera suggests the need for further investigation of autodissemination approaches in a more field like setting to examine for risks to insect pollinators.

Identification of Faecal Maternal Semiochemicals in Swine (Sus scrofa) and their Effects on Weaned Piglets.

Piglets are attracted to maternal faeces early in life. Thus, the aim of this study was to identify faecal maternal semiochemicals that attract piglets and evaluate their effects on piglets at weaning. Faecal samples were collected from eight sows during gestation and lactation. Faecal semiochemicals were extracted and identified using solid phase extraction and GC/MS. A total of 26 volatiles were present in lactating and gestating sow faeces. Sows secreted no unique semiochemical after farrowing. However, the concentration of skatole and myristic acid were 2.68 and 1.13 times higher after farrowing. A free-choice preference assessment showed that piglets had a preference for a feeder sprayed with a solution containing skatole and myristic acid. No preference was found when feeders were sprayed with skatole and myristic acid individually. The application of skatole and myristic acid to the feeders of weaned pigs significantly reduced piglet aggression by 30% and tended to increase feeding behaviour by 35% the first 24 h post-weaning. These results suggest that skatole and myristic acid might be acting as a multicomponent maternal signal that attracts piglets and has a calming effect at weaning.